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Sample records for advance precipitation measurements

  1. Recent Advances in Spaceborne Precipitation Radar Measurement Techniques and Technology

    NASA Technical Reports Server (NTRS)

    Im, Eastwood; Durden, Stephen L.; Tanelli, Simone

    2006-01-01

    NASA is currently developing advanced instrument concepts and technologies for future spaceborne atmospheric radars, with an over-arching objective of making such instruments more capable in supporting future science needs and more cost effective. Two such examples are the Second-Generation Precipitation Radar (PR-2) and the Nexrad-In-Space (NIS). PR-2 is a 14/35-GHz dual-frequency rain radar with a deployable 5-meter, wide-swath scanned membrane antenna, a dual-polarized/dual-frequency receiver, and a realtime digital signal processor. It is intended for Low Earth Orbit (LEO) operations to provide greatly enhanced rainfall profile retrieval accuracy while consuming only a fraction of the mass of the current TRMM Precipitation Radar (PR). NIS is designed to be a 35-GHz Geostationary Earth Orbiting (GEO) radar for providing hourly monitoring of the life cycle of hurricanes and tropical storms. It uses a 35-m, spherical, lightweight membrane antenna and Doppler processing to acquire 3-dimensional information on the intensity and vertical motion of hurricane rainfall.

  2. Advanced Precipitation Radar Antenna to Measure Rainfall From Space

    NASA Technical Reports Server (NTRS)

    Rahmat-Samii, Yahya; Lin, John; Huang, John; Im, Eastwood; Lou, Michael; Lopez, Bernardo; Durden, Stephen

    2008-01-01

    To support NASA s planned 20-year mission to provide sustained global precipitation measurement (EOS-9 Global Precipitation Measurement (GPM)), a deployable antenna has been explored with an inflatable thin-membrane structure. This design uses a 5.3 5.3-m inflatable parabolic reflector with the electronically scanned, dual-frequency phased array feeds to provide improved rainfall measurements at 2.0-km horizontal resolution over a cross-track scan range of up to 37 , necessary for resolving intense, isolated storm cells and for reducing the beam-filling and spatial sampling errors. The two matched radar beams at the two frequencies (Ku and Ka bands) will allow unambiguous retrieval of the parameters in raindrop size distribution. The antenna is inflatable, using rigidizable booms, deployable chain-link supports with prescribed curvatures, a smooth, thin-membrane reflecting surface, and an offset feed technique to achieve the precision surface tolerance (0.2 mm RMS) for meeting the low-sidelobe requirement. The cylindrical parabolic offset-feed reflector augmented with two linear phased array feeds achieves dual-frequency shared-aperture with wide-angle beam scanning and very low sidelobe level of -30 dB. Very long Ku and Ka band microstrip feed arrays incorporating a combination of parallel and series power divider lines with cosine-over-pedestal distribution also augment the sidelobe level and beam scan. This design reduces antenna mass and launch vehicle stowage volume. The Ku and Ka band feed arrays are needed to achieve the required cross-track beam scanning. To demonstrate the inflatable cylindrical reflector with two linear polarizations (V and H), and two beam directions (0deg and 30deg), each frequency band has four individual microstrip array designs. The Ku-band array has a total of 166x2 elements and the Ka-band has 166x4 elements with both bands having element spacing about 0.65 lambda(sub 0). The cylindrical reflector with offset linear array feeds

  3. Global Precipitation Measurement

    NASA Technical Reports Server (NTRS)

    Hou, Arthur Y.; Skofronick-Jackson, Gail; Kummerow, Christian D.; Shepherd, James Marshall

    2008-01-01

    This chapter begins with a brief history and background of microwave precipitation sensors, with a discussion of the sensitivity of both passive and active instruments, to trace the evolution of satellite-based rainfall techniques from an era of inference to an era of physical measurement. Next, the highly successful Tropical Rainfall Measuring Mission will be described, followed by the goals and plans for the Global Precipitation Measurement (GPM) Mission and the status of precipitation retrieval algorithm development. The chapter concludes with a summary of the need for space-based precipitation measurement, current technological capabilities, near-term algorithm advancements and anticipated new sciences and societal benefits in the GPM era.

  4. Global precipitation measurement (GPM)

    NASA Astrophysics Data System (ADS)

    Neeck, Steven P.; Flaming, Gilbert M.; Adams, W. James; Smith, Eric A.

    2001-12-01

    The National Aeronautics and Space Administration (NASA) is studying options for future space-based missions for the EOS Follow-on Era (post 2003), building upon the measurements made by Pre-EOS and EOS First Series Missions. One mission under consideration is the Global Precipitation Measurement (GPM), a cooperative venture of NASA, Japan, and other international partners. GPM will capitalize on the experience of the highly successful Tropical Rainfall Measurement Mission (TRMM). Its goal is to extend the measurement of rainfall to high latitudes with high temporal frequency, providing a global data set every three hours. A reference concept has been developed consisting of an improved TRMM-like primary satellite with precipitation radar and microwave radiometer to make detailed and accurate estimates of the precipitation structure and a constellation of small satellites flying compact microwave radiometers to provide the required temporal sampling of highly variable precipitation systems. Considering that DMSP spacecraft equipped with SSMIS microwave radiometers, successor NPOESS spacecraft equipped with CMIS microwave radiometers, and other relevant international systems are expected to be in operation during the timeframe of the reference concept, the total number of small satellites required to complete the constellation will be reduced. A nominal plan is to begin implementation in FY'03 with launches in 2007. NASA is presently engaged in advanced mission studies and advanced instrument technology development related to the mission.

  5. Advances in Understanding Global Water Cycle with Advent of Global Precipitation Measurement (GPM) Mission

    NASA Technical Reports Server (NTRS)

    Smith, Eric A.; Starr, David (Technical Monitor)

    2002-01-01

    Within this decade the internationally organized Global Precipitation Measurement (GPM) Mission will take an important step in creating a global precipitation observing system from space. One perspective for understanding the nature of GPM is that it will be a hierarchical system of datastreams beginning with very high caliber combined dual frequency radar/passive microwave (PMW) rain-radiometer retrievals, to high caliber PMW rain-radiometer only retrievals, and then on to blends of the former datastreams with additional lower-caliber PMW-based and IR-based rain retrievals. Within the context of the now emerging global water & energy cycle (GWEC) programs of a number of research agencies throughout the world, GPM serves as a centerpiece space mission for improving our understanding of the global water cycle from a global measurement perspective. One of the salient problems within our current understanding of the global water and energy cycle is determining whether a change in the rate of the water cycle is accompanying changes in climate, e.g., climate warming. As there are a number of ways in which to define a rate-change of the global water cycle, it is not entirely clear as to what constitutes such a determination. This paper presents an overview of the GPM Mission and how its observations can be used within the framework of the oceanic and continental water budget equations to determine whether a given perturbation in precipitation is indicative of an actual rate change in the global water cycle, consistent with required responses in water storage and/or water flux transport processes, or whether it is the natural variability of a fixed rate cycle.

  6. Precipitation Measurements from Space: The Global Precipitation Measurement Mission

    NASA Technical Reports Server (NTRS)

    Hou, Arthur Y.

    2007-01-01

    Water is fundamental to the life on Earth and its phase transition between the gaseous, liquid, and solid states dominates the behavior of the weather/climate/ecological system. Precipitation, which converts atmospheric water vapor into rain and snow, is central to the global water cycle. It regulates the global energy balance through interactions with clouds and water vapor (the primary greenhouse gas), and also shapes global winds and dynamic transport through latent heat release. Surface precipitation affects soil moisture, ocean salinity, and land hydrology, thus linking fast atmospheric processes to the slower components of the climate system. Precipitation is also the primary source of freshwater in the world, which is facing an emerging freshwater crisis in many regions. Accurate and timely knowledge of global precipitation is essential for understanding the behavior of the global water cycle, improving freshwater management, and advancing predictive capabilities of high-impact weather events such as hurricanes, floods, droughts, and landslides. With limited rainfall networks on land and the impracticality of making extensive rainfall measurements over oceans, a comprehensive description of the space and time variability of global precipitation can only be achieved from the vantage point of space. This presentation will examine current capabilities in space-borne rainfall measurements, highlight scientific and practical benefits derived from these observations to date, and provide an overview of the multi-national Global Precipitation Measurement (GPM) Mission scheduled to bc launched in the early next decade.

  7. Global Precipitation Measurement (GPM) implementation

    NASA Astrophysics Data System (ADS)

    Neeck, Steven P.; Kakar, Ramesh K.; Azarbarzin, Ardeshir A.; Hou, Arthur Y.

    2010-10-01

    The Global Precipitation Measurement (GPM) mission will provide enhanced space-based precipitation measurements with sufficient coverage, spatial resolution, temporal sampling, retrieval accuracy, and microphysical information to advance the understanding of Earth's water and energy cycle and to improve predictions of its climate, weather, and hydrometeorological processes. Such improvements will in turn improve decision support systems in broad societal applications (e.g. water resource management, agriculture, transportation, etc). GPM is a partnership between NASA and the Japan Aerospace Exploration Agency (JAXA), building upon their highly successful partnership on the Tropical Rainfall Measuring Mission (TRMM). The GPM architecture consists of NASA satellites operating in partnership with other earth-observing satellites and instruments to produce global precipitation science data. The current generation of multi-satellite global precipitation products based on microwave/infrared sensors from uncoordinated satellite missions has for its anchor the TRMM precipitation radar and the TRMM Microwave Imager measurements over the tropics and subtropics (+/- 35 degrees latitude), with a mean sampling time of approximately 17 hours. The GPM mission will deploy a spaceborne Core Observatory as a reference standard to unify a space constellation of research and operational microwave sensors aimed at providing uniformly calibrated precipitation measurements globally every 2-4 hours. The Core Observatory measurements will provide, for the first time, quantitative information on precipitation particle size distribution needed for improving the accuracy of precipitation estimates by microwave radiometers and radars. In addition, the GPM will also include a second microwave radiometer and a Tracking and Data Relay Satellite (TDRS) communications subsystem for near real time data relay for a future partner-provided constellation satellite. This second GPM Microwave Imager (GMI

  8. The Global Precipitation Measurement Mission

    NASA Astrophysics Data System (ADS)

    Jackson, Gail

    2014-05-01

    The Global Precipitation Measurement (GPM) mission's Core satellite, scheduled for launch at the end of February 2014, is well designed estimate precipitation from 0.2 to 110 mm/hr and to detect falling snow. Knowing where and how much rain and snow falls globally is vital to understanding how weather and climate impact both our environment and Earth's water and energy cycles, including effects on agriculture, fresh water availability, and responses to natural disasters. The design of the GPM Core Observatory is an advancement of the Tropical Rainfall Measuring Mission (TRMM)'s highly successful rain-sensing package [3]. The cornerstone of the GPM mission is the deployment of a Core Observatory in a unique 65o non-Sun-synchronous orbit to serve as a physics observatory and a calibration reference to improve precipitation measurements by a constellation of 8 or more dedicated and operational, U.S. and international passive microwave sensors. The Core Observatory will carry a Ku/Ka-band Dual-frequency Precipitation Radar (DPR) and a multi-channel (10-183 GHz) GPM Microwave Radiometer (GMI). The DPR will provide measurements of 3-D precipitation structures and microphysical properties, which are key to achieving a better understanding of precipitation processes and improving retrieval algorithms for passive microwave radiometers. The combined use of DPR and GMI measurements will place greater constraints on possible solutions to radiometer retrievals to improve the accuracy and consistency of precipitation retrievals from all constellation radiometers. Furthermore, since light rain and falling snow account for a significant fraction of precipitation occurrence in middle and high latitudes, the GPM instruments extend the capabilities of the TRMM sensors to detect falling snow, measure light rain, and provide, for the first time, quantitative estimates of microphysical properties of precipitation particles. The GPM Core Observatory was developed and tested at NASA

  9. Measurement of size-dependent composition variations for gamma prime (γ') precipitates in an advanced nickel-based superalloy.

    PubMed

    Chen, Y Q; Slater, T J A; Lewis, E A; Francis, E M; Burke, M G; Preuss, M; Haigh, S J

    2014-09-01

    Energy-dispersive X-ray (EDX) spectroscopy in the scanning transmission electron microscope (STEM) has been used to demonstrate the presence of size-dependent compositional variation for L12-structured Ni3Al-type gamma-prime (γ') precipitates within a commercial RR1000 Ni-based superalloy. This semi-quantitative elemental analysis has been achieved using electrochemical extraction of the γ' precipitates from the γ matrix. The applicability of this approach to size-dependent compositional analysis of precipitates was confirmed by a comparison of the size distribution for the extracted precipitates with those present in traditional electropolished foil specimens in the size range 20-250nm. By applying suitable thickness-dependent absorption-corrections we have demonstrated that the composition of γ' precipitates in our material depends on the size of the precipitate in the range of 5nm to 3μm. In particular, the Al content was observed to increase in smaller γ' precipitates while Ti and Ta contents are constant for all sizes of precipitate. Hf was observed to be present only in the largest precipitates. This type of local compositional information provides invaluable input to assess the accuracy of microstructural modelling for these complex alloys and provides new evidence supporting the importance of anti-site diffusion. PMID:24814008

  10. Measurement of size-dependent composition variations for gamma prime (γ') precipitates in an advanced nickel-based superalloy.

    PubMed

    Chen, Y Q; Slater, T J A; Lewis, E A; Francis, E M; Burke, M G; Preuss, M; Haigh, S J

    2014-09-01

    Energy-dispersive X-ray (EDX) spectroscopy in the scanning transmission electron microscope (STEM) has been used to demonstrate the presence of size-dependent compositional variation for L12-structured Ni3Al-type gamma-prime (γ') precipitates within a commercial RR1000 Ni-based superalloy. This semi-quantitative elemental analysis has been achieved using electrochemical extraction of the γ' precipitates from the γ matrix. The applicability of this approach to size-dependent compositional analysis of precipitates was confirmed by a comparison of the size distribution for the extracted precipitates with those present in traditional electropolished foil specimens in the size range 20-250nm. By applying suitable thickness-dependent absorption-corrections we have demonstrated that the composition of γ' precipitates in our material depends on the size of the precipitate in the range of 5nm to 3μm. In particular, the Al content was observed to increase in smaller γ' precipitates while Ti and Ta contents are constant for all sizes of precipitate. Hf was observed to be present only in the largest precipitates. This type of local compositional information provides invaluable input to assess the accuracy of microstructural modelling for these complex alloys and provides new evidence supporting the importance of anti-site diffusion.

  11. Advanced Microwave Precipitation Radiometer (AMPR) for remote observation of precipitation

    NASA Technical Reports Server (NTRS)

    Galliano, J. A.; Platt, R. H.

    1990-01-01

    The design, development, and tests of the Advanced Microwave Precipitation Radiometer (AMPR) operating in the 10 to 85 GHz range specifically for precipitation retrieval and mesoscale storm system studies from a high altitude aircraft platform (i.e., ER-2) are described. The primary goals of AMPR are the exploitation of the scattering signal of precipitation at frequencies near 10, 19, 37, and 85 GHz together to unambiguously retrieve precipitation and storm structure and intensity information in support of proposed and planned space sensors in geostationary and low earth orbit, as well as storm-related field experiments. The development of AMPR will have an important impact on the interpretation of microwave radiances for rain retrievals over both land and ocean for the following reasons: (1) A scanning instrument, such as AMPR, will allow the unambiguous detection and analysis of features in two dimensional space, allowing an improved interpretation of signals in terms of cloud features, and microphysical and radiative processes; (2) AMPR will offer more accurate comparisons with ground-based radar data by feature matching since the navigation of the ER-2 platform can be expected to drift 3 to 4 km per hour of flight time; and (3) AMPR will allow underflights of the SSM/I satellite instrument with enough spatial coverage at the same frequencies to make meaningful comparisons of the data for precipitation studies.

  12. The Global Precipitation Measurement (GPM) Project

    NASA Technical Reports Server (NTRS)

    Azarbarzin, Ardeshir; Carlisle, Candace

    2010-01-01

    The Global Precipitation Measurement (GP!v1) mission is an international cooperative effort to advance the understanding of the physics of the Earth's water and energy cycle. Accurate and timely knowledge of global precipitation is essential for understanding the weather/climate/ecological system, for improving our ability to manage freshwater resources, and for predicting high-impact natural hazard events including floods, droughts, extreme weather events, and landslides. The GPM Core Observatory will be a reference standard to uniformly calibrate data from a constellation of spacecraft with passive microwave sensors. GPM is being developed under a partnership between the United States (US) National Aeronautics and Space Administration (NASA) and the Japanese Aerospace and Exploration Agency (JAXA). NASA's Goddard Space Flight Center (GSFC), in Greenbelt, MD is developing the Core Observatory, two GPM Microwave Imager (GMI) instruments, Ground Validation System and Precipitation Processing System for the GPM mission. JAXA will provide a Dual-frequency Precipitation Radar (DPR) for installation on the Core satellite and launch services for the Core Observatory. The second GMI instrument will be flown on a partner-provided spacecraft. Other US agencies and international partners contribute to the GPM mission by providing precipitation measurements obtained from their own spacecraft and/or providing ground-based precipitation measurements to support ground validation activities. The Precipitation Processing System will provide standard data products for the mission.

  13. The Global Precipitation Measurement (GPM) Project

    NASA Technical Reports Server (NTRS)

    Azarbarazin, Ardeshir Art; Carlisle, Candace C.

    2008-01-01

    The GIobd Precipitation hleasurement (GPM) mission is an international cooperatiee ffort to advance weather, climate, and hydrological predictions through space-based precipitation measurements. The Core Observatory will be a reference standard to uniform11 calibrate data from a constellatism of spacecraft with passive microuave sensors. GP3l mission data will be used for scientific research as well as societal applications. GPM is being developed under a partnership between the United States (US) National .Aeronautics and Space Administration (XASA) and the Japanese Aerospace and Exploration Agency (JAYA). NASA is developing the Core Observatory, a Low-Inclination Constellation Observatory, two GPM Rlicrowave Imager (GXII) instruments. Ground Validation System and Precipitation Processing System for the GPRl mission. JAXA will provide a Dual-frequency Precipitation Radar (DPR) for installation on the Core satellite and launch services for the Core Observatory. Other US agencies and international partners contribute to the GPkf mission by providing precipitation measurements obtained from their own spacecraft and,'or providing ground-based precipitation measurements to support ground validation activities. The GPM Core Observatory will be placed in a low earth orbit (-400 krn) with 65-degree inclination, in order to calibrate partner instruments in a variety of orbits. The Core Observatory accommodates 3 instruments. The GkfI instrument provides measurements of precipitation intensity and distribution. The DPR consists of Ka and Ku band instruments, and provides threedimensional measurements of cloud structure, precipitation particle size distribution and precipitation intensitj and distribution. The instruments are key drivers for GPM Core Observatory overall size (1 1.6m x 6.5m x 5.0m) and mass (3500kg), as well as the significant (-1 950U.3 power requirement. The Core Spacecraft is being built in-house at Goddard Space Flight Center. The spacecraft structure

  14. Precipitation from Space: Advancing Earth System Science

    NASA Technical Reports Server (NTRS)

    Kucera, Paul A.; Ebert, Elizabeth E.; Turk, F. Joseph; Levizzani, Vicenzo; Kirschbaum, Dalia; Tapiador, Francisco J.; Loew, Alexander; Borsche, M.

    2012-01-01

    Of the three primary sources of spatially contiguous precipitation observations (surface networks, ground-based radar, and satellite-based radar/radiometers), only the last is a viable source over ocean and much of the Earth's land. As recently as 15 years ago, users needing quantitative detail of precipitation on anything under a monthly time scale relied upon products derived from geostationary satellite thermal infrared (IR) indices. The Special Sensor Microwave Imager (SSMI) passive microwave (PMW) imagers originated in 1987 and continue today with the SSMI sounder (SSMIS) sensor. The fortunate longevity of the joint National Aeronautics and Space Administration (NASA) and Japan Aerospace Exploration Agency (JAXA) Tropical Rainfall Measuring Mission (TRMM) is providing the environmental science community a nearly unbroken data record (as of April 2012, over 14 years) of tropical and sub-tropical precipitation processes. TRMM was originally conceived in the mid-1980s as a climate mission with relatively modest goals, including monthly averaged precipitation. TRMM data were quickly exploited for model data assimilation and, beginning in 1999 with the availability of near real time data, for tropical cyclone warnings. To overcome the intermittently spaced revisit from these and other low Earth-orbiting satellites, many methods to merge PMW-based precipitation data and geostationary satellite observations have been developed, such as the TRMM Multisatellite Precipitation Product and the Climate Prediction Center (CPC) morphing method (CMORPH. The purpose of this article is not to provide a survey or assessment of these and other satellite-based precipitation datasets, which are well summarized in several recent articles. Rather, the intent is to demonstrate how the availability and continuity of satellite-based precipitation data records is transforming the ways that scientific and societal issues related to precipitation are addressed, in ways that would not be

  15. NASA's Global Precipitation Measurement (GPM) Mission for Science and Society

    NASA Astrophysics Data System (ADS)

    Jackson, Gail

    2016-04-01

    Water is fundamental to life on Earth. Knowing where and how much rain and snow falls globally is vital to understanding how weather and climate impact both our environment and Earth's water and energy cycles, including effects on agriculture, fresh water availability, and responses to natural disasters. The Global Precipitation Measurement (GPM) Mission, launched February 27, 2014, is an international satellite mission to unify and advance precipitation measurements from a constellation of research and operational sensors to provide "next-generation" precipitation products. The joint NASA-JAXA GPM Core Observatory serves as the cornerstone and anchor to unite the constellation radiometers. The GPM Core Observatory carries a Ku/Ka-band Dual-frequency Precipitation Radar (DPR) and a multi-channel (10-183 GHz) GPM Microwave Radiometer (GMI). Furthermore, since light rain and falling snow account for a significant fraction of precipitation occurrence in middle and high latitudes, the GPM instruments extend the capabilities of the TRMM sensors to detect falling snow, measure light rain, and provide, for the first time, quantitative estimates of microphysical properties of precipitation particles. As a science mission with integrated application goals, GPM is designed to (1) advance precipitation measurement capability from space through combined use of active and passive microwave sensors, (2) advance the knowledge of the global water/energy cycle and freshwater availability through better description of the space-time variability of global precipitation, and (3) improve weather, climate, and hydrological prediction capabilities through more accurate and frequent measurements of instantaneous precipitation rates and time-integrated rainfall accumulation. Since launch, the instruments have been collecting outstanding precipitation data. New scientific insights resulting from GPM data, an overview of the GPM mission concept and science activities in the United States

  16. Advances in Satellite Microwave Precipitation Retrieval Algorithms Over Land

    NASA Astrophysics Data System (ADS)

    Wang, N. Y.; You, Y.; Ferraro, R. R.

    2015-12-01

    Precipitation plays a key role in the earth's climate system, particularly in the aspect of its water and energy balance. Satellite microwave (MW) observations of precipitation provide a viable mean to achieve global measurement of precipitation with sufficient sampling density and accuracy. However, accurate precipitation information over land from satellite MW is a challenging problem. The Goddard Profiling Algorithm (GPROF) algorithm for the Global Precipitation Measurement (GPM) is built around the Bayesian formulation (Evans et al., 1995; Kummerow et al., 1996). GPROF uses the likelihood function and the prior probability distribution function to calculate the expected value of precipitation rate, given the observed brightness temperatures. It is particularly convenient to draw samples from a prior PDF from a predefined database of observations or models. GPROF algorithm does not search all database entries but only the subset thought to correspond to the actual observation. The GPM GPROF V1 database focuses on stratification by surface emissivity class, land surface temperature and total precipitable water. However, there is much uncertainty as to what is the optimal information needed to subset the database for different conditions. To this end, we conduct a database stratification study of using National Mosaic and Multi-Sensor Quantitative Precipitation Estimation, Special Sensor Microwave Imager/Sounder (SSMIS) and Advanced Technology Microwave Sounder (ATMS) and reanalysis data from Modern-Era Retrospective Analysis for Research and Applications (MERRA). Our database study (You et al., 2015) shows that environmental factors such as surface elevation, relative humidity, and storm vertical structure and height, and ice thickness can help in stratifying a single large database to smaller and more homogeneous subsets, in which the surface condition and precipitation vertical profiles are similar. It is found that the probability of detection (POD) increases

  17. Successes with the Global Precipitation Measurement (GPM) Mission

    NASA Technical Reports Server (NTRS)

    Skofronick-Jackson, Gail; Huffman, George; Stocker, Erich; Petersen, Walter

    2016-01-01

    Water is essential to our planet Earth. Knowing when, where and how precipitation falls is crucial for understanding the linkages between the Earth's water and energy cycles and is extraordinarily important for sustaining life on our planet during climate change. The Global Precipitation Measurement (GPM) Core Observatory spacecraft launched February 27, 2014, is the anchor to the GPM international satellite mission to unify and advance precipitation measurements from a constellation of research and operational sensors to provide "next-generation" precipitation products. GPM is currently a partnership between NASA and the Japan Aerospace Exploration Agency (JAXA). Status and successes in terms of spacecraft, instruments, retrieval products, validation, and impacts for science and society will be presented. Precipitation, microwave, satellite

  18. Global Precipitation Measurement (GPM) Mission Development Status

    NASA Technical Reports Server (NTRS)

    Azarbarzin, Ardeshir Art

    2011-01-01

    Mission Objective: (1) Improve scientific understanding of the global water cycle and fresh water availability (2) Improve the accuracy of precipitation forecasts (3) Provide frequent and complete sampling of the Earth s precipitation Mission Description (Class B, Category I): (1) Constellation of spacecraft provide global precipitation measurement coverage (2) NASA/JAXA Core spacecraft: Provides a microwave radiometer (GMI) and dual-frequency precipitation radar (DPR) to cross-calibrate entire constellation (3) 65 deg inclination, 400 km altitude (4) Launch July 2013 on HII-A (5) 3 year mission (5 year propellant) (6) Partner constellation spacecraft.

  19. The advanced microwave precipitation radiometer: A new aircraft radiometer for passive precipitation remote sensing

    NASA Technical Reports Server (NTRS)

    Hood, Robbie E.; Spencer, Roy W.; James, Mark W.

    1991-01-01

    Past studies of passive microwave measurements of precipitating systems have yielded broad empirical relationships between hydrometeors and microwave transmission. In general, these relationships fall into two categories of passive microwave precipitation retrievals rely upon the observed effect of liquid precipitation to increase the brightness temperature of a radiometrically cold background such as an ocean surface. A scattering-based method is based upon the effect that frozen hydrometeors tend to decrease the brightness temperature of a radiometrically warm background such as land. One step toward developing quantitative brightness temperature-rain rate relationships is the recent construction of a new aircraft instrument sponsored by National Aeronautics and Space Administration/Marshall Space Flight Center (NASA/MSFC). This instrument is the Advanced Microwave Precipitation Radiometer (AMPR) designed and built by Georgia Tech Research Institute to fly aboard high altitude research aircraft such as the NASA ER-2. The AMPR and its accompanying data acquisition system are mounted in the Q-bay compartment of the NASA ER-2.

  20. Global Precipitation Measurement: Methods, Datasets and Applications

    NASA Technical Reports Server (NTRS)

    Tapiador, Francisco; Turk, Francis J.; Petersen, Walt; Hou, Arthur Y.; Garcia-Ortega, Eduardo; Machado, Luiz, A. T.; Angelis, Carlos F.; Salio, Paola; Kidd, Chris; Huffman, George J.; De Castro, Manuel

    2011-01-01

    This paper reviews the many aspects of precipitation measurement that are relevant to providing an accurate global assessment of this important environmental parameter. Methods discussed include ground data, satellite estimates and numerical models. First, the methods for measuring, estimating, and modeling precipitation are discussed. Then, the most relevant datasets gathering precipitation information from those three sources are presented. The third part of the paper illustrates a number of the many applications of those measurements and databases. The aim of the paper is to organize the many links and feedbacks between precipitation measurement, estimation and modeling, indicating the uncertainties and limitations of each technique in order to identify areas requiring further attention, and to show the limits within which datasets can be used.

  1. Global Precipitation Measurement (GPM) Mission Applications: Activities, Challenges, and Vision

    NASA Technical Reports Server (NTRS)

    Kirschbaum, Dalia; Hou, Arthur

    2012-01-01

    Global Precipitation Measurement (GPM) is an international satellite mission to provide nextgeneration observations of rain and snow worldwide every three hours. NASA and the Japan Aerospace Exploration Agency (JAXA) will launch a "Core" satellite carrying advanced instruments that will set a new standard for precipitation measurements from space. The data they provide will be used to unify precipitation measurements made by an international network of partner satellites to quantify when, where, and how much it rains or snows around the world. The GPM mission will help advance our understanding of Earth's water and energy cycles, improve the forecasting of extreme events that cause natural disasters, and extend current capabilities of using satellite precipitation information to directly benefit society. Building upon the successful legacy of the Tropical Rainfall Measuring Mission (TRMM), GPM's next-generation global precipitation data will lead to scientific advances and societal benefits within a range of hydrologic fields including natural hazards, ecology, public health and water resources. This talk will highlight some examples from TRMM's IS-year history within these applications areas as well as discuss some existing challenges and present a look forward for GPM's contribution to applications in hydrology.

  2. Global Precipitation Measurement (GPM) Mission Applications: Activities, challenges, and vision

    NASA Astrophysics Data System (ADS)

    Kirschbaum, D. B.; Hou, A. Y.

    2012-12-01

    Global Precipitation Measurement (GPM) is an international satellite mission to provide next-generation observations of rain and snow worldwide every three hours. NASA and the Japan Aerospace Exploration Agency (JAXA) will launch a "Core" satellite carrying advanced instruments that will set a new standard for precipitation measurements from space. The data they provide will be used to unify precipitation measurements made by an international network of partner satellites to quantify when, where, and how much it rains or snows around the world. The GPM mission will help advance our understanding of Earth's water and energy cycles, improve the forecasting of extreme events that cause natural disasters, and extend current capabilities of using satellite precipitation information to directly benefit society. Building upon the successful legacy of the Tropical Rainfall Measuring Mission (TRMM), GPM's next-generation global precipitation data will lead to scientific advances and societal benefits within a range of hydrologic fields including natural hazards, ecology, public health and water resources. This talk will highlight some examples from TRMM's 15-year history within these applications areas as well as discuss some existing challenges and present a look forward for GPM's contribution to applications in hydrology.

  3. New Approaches For Validating Satellite Global Precipitation Measurements

    NASA Technical Reports Server (NTRS)

    Smith, Eric A.; Einaudi, Franco (Technical Monitor)

    2001-01-01

    The scientific successes of the Tropical Rainfall Measuring Mission (TRMM) and additional recent satellite-focused precipitation retrieval projects, particularly those based on use of passive microwave radiometer measurements, have paved the way for a more advanced mission currently under development as the Global Precipitation Measurement (GPM) mission. This new mission is motivated by a number of scientific questions that TRMM research has posed over a range of space-time scales and within a variety of scientific disciplines that are becoming more integrated into earth system science modeling.

  4. Precipitation Measurements from Space: Why Do We Need Them?

    NASA Technical Reports Server (NTRS)

    Hou, Arthur Y.

    2006-01-01

    Water is fundamental to the life on Earth and its phase transition between the gaseous, liquid, and solid states dominates the behavior of the weather/climate/ecological system. Precipitation, which converts atmospheric water vapor into rain and snow, is central to the global water cycle. It regulates the global energy balance through interactions with clouds and water vapor (the primary greenhouse gas), and also shapes global winds and dynamic transport through latent heat release. Surface precipitation affects soil moisture, ocean salinity, and land hydrology, thus linking fast atmospheric processes to the slower components of the climate system. Precipitation is also the primary source of freshwater in the world, which is facing an emerging freshwater crisis in many regions. Accurate and timely knowledge of global precipitation is essential for understanding the behavior of the global water cycle, improving freshwater management, and advancing predictive capabilities of high-impact weather events such as hurricanes, floods, droughts, and landslides. With limited rainfall networks on land and the impracticality of making extensive rainfall measurements over oceans, a comprehensive description of the space and time variability of global precipitation can only be achieved from the vantage point of space. This presentation will examine current capabilities in space-borne rainfall measurements, highlight scientific and practical benefits derived from these observations to date, and provide an overview of the multi-national Global Precipitation Measurement (GPM) Mission scheduled to be launched in the early next decade.

  5. Global Precipitation Measurement (GPM) Mission: Overview and Status

    NASA Technical Reports Server (NTRS)

    Hou, Arthur Y.

    2012-01-01

    The Global Precipitation Measurement (GPM) Mission is an international satellite mission specifically designed to unify and advance precipitation measurements from a constellation of research and operational microwave sensors. NASA and JAXA will deploy a Core Observatory in 2014 to serve as a reference satellite to unify precipitation measurements from the constellation of sensors. The GPM Core Observatory will carry a Ku/Ka-band Dual-frequency Precipitation Radar (DPR) and a conical-scanning multi-channel (10-183 GHz) GPM Microwave Radiometer (GMI). The DPR will be the first dual-frequency radar in space to provide not only measurements of 3-D precipitation structures but also quantitative information on microphysical properties of precipitating particles. The DPR and GMI measurements will together provide a database that relates vertical hydrometeor profiles to multi-frequency microwave radiances over a variety of environmental conditions across the globe. This combined database will be used as a common transfer standard for improving the accuracy and consistency of precipitation retrievals from all constellation radiometers. For global coverage, GPM relies on existing satellite programs and new mission opportunities from a consortium of partners through bilateral agreements with either NASA or JAXA. Each constellation member may have its unique scientific or operational objectives but contributes microwave observations to GPM for the generation and dissemination of unified global precipitation data products. In addition to the DPR and GMI on the Core Observatory, the baseline GPM constellation consists of the following sensors: (1) Special Sensor Microwave Imager/Sounder (SSMIS) instruments on the U.S. Defense Meteorological Satellite Program (DMSP) satellites, (2) the Advanced Microwave Scanning Radiometer-2 (AMSR-2) on the GCOM-W1 satellite of JAXA, (3) the Multi-Frequency Microwave Scanning Radiometer (MADRAS) and the multi-channel microwave humidity sounder

  6. Diurnal variability of precipitation from TRMM measurements

    NASA Astrophysics Data System (ADS)

    Yang, Song; Smith, Eric A.; Kuo, Kwo-Sen

    2006-12-01

    This investigation focuses on developing a better understanding of the assorted mechanisms controlling the global distribution of diurnal rainfall variability. The horizontal distributions of precipitation's diurnal cycle, based on eight years of TRMM Microwave Imager (TMI) and TRMM Precipitation Radar (PR) measurements involving three TRMM standard algorithms, are analyzed in detail at various spatiotemporal scales. Results demonstrate the prominence of the late-evening to early-morning precipitation maxima over oceans and the mid- to late-afternoon maxima over continents, but also reveal a widespread distribution of secondary maxima occurring over both oceans and continents, maxima which generally mirror their counterpart regime's behavior. That is, many ocean regions exhibit clear-cut secondary afternoon precipitation maxima while many continental areas exhibit just as evident secondary morning maxima. Notably, this investigation represents the first comprehensive study of these secondary maxima and their widespread nature when analyzed using a global precipitation dataset. The characteristics of the secondary maxima are thoroughly mapped and described on a global grid. In addition, a Fourier harmonic decomposition scheme is used to examine detailed amplitude and phase properties of the primary and secondary maxima -- as well as tertiary and quartern modes. Accordingly, the advantages, ambiguities, and pitfalls resulting from using harmonic analysis are also examined.

  7. Global Precipitation Measurement Cold Season Precipitation Experiment (GCPEx): For Measurement Sake Let it Snow

    NASA Technical Reports Server (NTRS)

    Skofronick-Jackson, Gail; Hudak, David; Petersen, Walter; Nesbitt, Stephen W.; Chandrasekar, V.; Durden, Stephen; Gleicher, Kirstin J.; Huang, Gwo-Jong; Joe, Paul; Kollias, Pavlos; Reed, Kimberly A.; Schwaller, Mathew R.; Stewart, Ronald; Tanelli, Simone; Tokay, Ali; Wang, James R.; Wolde, Mengistu

    2014-01-01

    As a component of the Earth's hydrologic cycle, and especially at higher latitudes,falling snow creates snow pack accumulation that in turn provides a large proportion of the fresh water resources required by many communities throughout the world. To assess the relationships between remotely sensed snow measurements with in situ measurements, a winter field project, termed the Global Precipitation Measurement (GPM) mission Cold Season Precipitation Experiment (GCPEx), was carried out in the winter of 2011-2012 in Ontario, Canada. Its goal was to provide information on the precipitation microphysics and processes associated with cold season precipitation to support GPM snowfall retrieval algorithms that make use of a dual-frequency precipitation radar and a passive microwave imager on board the GPM core satellite,and radiometers on constellation member satellites. Multi-parameter methods are required to be able to relate changes in the microphysical character of the snow to measureable parameters from which precipitation detection and estimation can be based. The data collection strategy was coordinated, stacked, high-altitude and in-situ cloud aircraft missions with three research aircraft sampling within a broader surface network of five ground sites taking in-situ and volumetric observations. During the field campaign 25 events were identified and classified according to their varied precipitation type, synoptic context, and precipitation amount. Herein, the GCPEx fieldcampaign is described and three illustrative cases detailed.

  8. The Global Precipitation Measurement (GPM) Mission: Overview and Status

    NASA Technical Reports Server (NTRS)

    Hou, Arthur

    2008-01-01

    The Global Precipitation Measurement (GPM) Mission is an international satellite mission to unify and advance global precipitation measurements from a constellation of dedicated and operational microwave sensors. The GPM concept centers on the deployment of a Core Spacecraft in a non-Sun-synchronous orbit at 65 degrees inclination carrying a dual-frequency precipitation radar (DPR) and a multi-frequency passive microwave radiometer (GMI) with high-frequency capabilities to serve as a precipitation physics observatory and calibration standard for the constellation radiometers. The baseline GPM constellation is envisioned to comprise conical-scanning microwave imagers (e.g., GMI, SSMIS, AMSR, MIS, MADRAS, GPM-Brazil) augmented with cross-track microwave temperature/humidity sounders (e.g., MHS, ATMS) over land. In addition to the Core Satellite, the GPM Mission will contribute a second GMI to be flown in a low-inclination (approximately 40 deg.) non-Sun-synchronous orbit to improve near real-time monitoring of hurricanes. GPM is a science mission with integrated applications goals aimed at (1) advancing the knowledge of the global water/energy cycle variability and freshwater availability and (2) improving weather, climate, and hydrological prediction capabilities through more accurate and frequent measurements of global precipitation. The GPM Mission is currently a partnership between NASA and the Japan Aerospace Exploration Agency (JAXA), with opportunities for additional partners in satellite constellation and ground validation activities. Within the framework of the inter-governmental Group ob Earth Observations (GEO) and Global Earth Observation System of Systems (GEOSS), GPM has been identified as a cornerstone for the Precipitation Constellation (PC) being developed under the auspices of Committee of Earth Observation Satellites (CEOS). The GPM Core Observatory is scheduled for launch in 2013, followed by the launch of the GPM Low-Inclination Observatory in

  9. Global Precipitation Measurement (GPM) launch, commissioning, and early operations

    NASA Astrophysics Data System (ADS)

    Neeck, Steven P.; Kakar, Ramesh K.; Azarbarzin, Ardeshir A.; Hou, Arthur Y.

    2014-10-01

    The Global Precipitation Measurement (GPM) mission is an international partnership co-led by NASA and the Japan Aerospace Exploration Agency (JAXA). The mission centers on the GPM Core Observatory and consists of an international network, or constellation, of additional satellites that together will provide next-generation global observations of precipitation from space. The GPM constellation will provide measurements of the intensity and variability of precipitation, three-dimensional structure of cloud and storm systems, the microphysics of ice and liquid particles within clouds, and the amount of water falling to Earth's surface. Observations from the GPM constellation, combined with land surface data, will improve weather forecast models; climate models; integrated hydrologic models of watersheds; and forecasts of hurricanes/typhoons/cylcones, landslides, floods and droughts. The GPM Core Observatory carries an advanced radar/radiometer system and serves as a reference standard to unify precipitation measurements from all satellites that fly within the constellation. The GPM Core Observatory improves upon the capabilities of its predecessor, the NASA-JAXA Tropical Rainfall Measuring Mission (TRMM), with advanced science instruments and expanded coverage of Earth's surface. The GPM Core Observatory carries two instruments, the NASA-supplied GPM Microwave Imager (GMI) and the JAXA-supplied Dual-frequency Precipitation Radar (DPR). The GMI measures the amount, size, intensity and type of precipitation, from heavy-tomoderate rain to light rain and snowfall. The DPR provides three-dimensional profiles and intensities of liquid and solid precipitation. The French Centre National d'Études Spatiales (CNES), the Indian Space Research Organisation (ISRO), the U.S. National Oceanic and Atmospheric Administration (NOAA), the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), and the U.S. Department of Defense are partners with NASA and

  10. Global Precipitation Measurement Mission Launch and Commissioning

    NASA Technical Reports Server (NTRS)

    Davis, Nikesha; Deweese, Keith; Vess, Missie; Welter, Gary; O'Donnell, James R., Jr.

    2015-01-01

    During launch and early operation of the Global Precipitation Measurement (GPM) Mission, the Guidance, Navigation and Control (GNC) analysis team encountered four main on orbit anomalies. These include: (1) unexpected shock from Solar Array deployment, (2) momentum buildup from the Magnetic Torquer Bars (MTBs) phasing errors, (3) transition into Safehold due to albedo-induced Course Sun Sensor (CSS) anomaly, and (4) a flight software error that could cause a Safehold transition due to a Star Tracker occultation. This paper will discuss ways GNC engineers identified and tracked down the root causes. Flight data and GNC on board models will be shown to illustrate how each of these anomalies were investigated and mitigated before causing any harm to the spacecraft. On May 29, 2014, GPM was handed over to the Mission Flight Operations Team after a successful commissioning period. Currently, GPM is operating nominally on orbit, collecting meaningful scientific data that will significantly improve our understanding of the Earth's climate and water cycle.

  11. Deducing high-altitude precipitation from glacier mass balance measurements

    NASA Astrophysics Data System (ADS)

    Giesen, Rianne H.; Immerzeel, Walter W.; Wanders, Niko

    2016-04-01

    The spatial distribution of precipitation in mountainous terrain is generally not well known due to underrepresentation of gauge observations at higher elevations. Precipitation tends to increase with elevation, but since observations are mainly performed in the valleys, the vertical precipitation gradient cannot be deduced from these measurements. Furthermore, the spatial resolution of gridded meteorological data is often too coarse to resolve individual mountain chains. Still, a reliable estimate of high-elevation precipitation is required for many hydrological applications. We present a method to determine the vertical precipitation gradient in mountainous terrain, making use of glacier mass balance observations. These measurements have the advantage that they provide a basin-wide precipitation estimate at high elevations. The precipitation gradient is adjusted until the solid precipitation over the glacier area combined with the calculated melt gives the measured annual glacier mass balance. Results for the glacierized regions in Central Europe and Scandinavia reveal spatially coherent patterns, with predominantly positive precipitation gradients ranging from -4 to +28 % (100 m)‑1. In some regions, precipitation amounts at high elevations are up to four times as large as in the valleys. A comparison of the modelled winter precipitation with observed snow accumulation on glaciers shows a good agreement. Precipitation measured at the few high-altitude meteorological stations is generally lower than our estimate, which may result from precipitation undercatch. Our findings will improve the precipitation forcing for glacier modelling and hydrological studies in mountainous terrain.

  12. A Plan for Measuring Climatic Scale Global Precipitation Variability: The Global Precipitation Mission

    NASA Technical Reports Server (NTRS)

    Smith, Eric A.; Einaudi, Franco (Technical Monitor)

    2000-01-01

    The outstanding success of the Tropical Rainfall Measuring Mission (TRMM) stemmed from a near flawless launch and deployment, a highly successful measurement campaign, achievement of all original scientific objectives before the mission life had ended, and the accomplishment of a number of unanticipated but important additional scientific advances. This success and the realization that satellite rainfall datasets are now a foremost tool in the understanding of decadal climate variability has helped motivate a comprehensive global rainfall measuring mission, called 'The Global Precipitation Mission' (GPM). The intent of this mission is to address looming scientific questions arising in the context of global climate-water cycle interactions, hydrometeorology, weather prediction, the global carbon budget, and atmosphere-biosphere-cryosphere chemistry. This paper addresses the status of that mission currently planed for launch in the early 2007 time frame. The GPM design involves a nine-member satellite constellation, one of which will be an advanced TRMM-like 'core' satellite carrying a dual-frequency Ku-Ka band radar (df-PR) and a TMI-like radiometer. The other eight members of the constellation can be considered drones to the core satellite, each carrying some type of passive microwave radiometer measuring across the 10.7-85 GHz frequency range, likely based on both real and synthetic aperture antenna technology and to include a combination of new lightweight dedicated GPM drones and both co-existing operational and experimental satellites carrying passive microwave radiometers (i.e., SSM/l, AMSR, etc.). The constellation is designed to provide a minimum of three-hour sampling at any spot on the globe using sun-synchronous orbit architecture, with the core satellite providing relevant measurements on internal cloud precipitation microphysical processes. The core satellite also enables 'training' and 'calibration' of the drone retrieval process. Additional

  13. Advanced Ceramics Property Measurements

    NASA Technical Reports Server (NTRS)

    Salem, Jonathan; Helfinstine, John; Quinn, George; Gonczy, Stephen

    2013-01-01

    Mechanical and physical properties of ceramic bodies can be difficult to measure correctly unless the proper techniques are used. The Advanced Ceramics Committee of ASTM, C-28, has developed dozens of consensus test standards and practices to measure various properties of a ceramic monolith, composite, or coating. The standards give the "what, how, how not, and why" for measurement of many mechanical, physical, thermal, and performance properties. Using these standards will provide accurate, reliable, and complete data for rigorous comparisons with other test results from your test lab, or another. The C-28 Committee has involved academics, producers, and users of ceramics to write and continually update more than 45 standards since the committee's inception in 1986. Included in this poster is a pictogram of the C-28 standards and information on how to obtain individual copies with full details or the complete collection of standards in one volume.

  14. Precipitation measurements by using of a disdrometer at Syowa station

    NASA Astrophysics Data System (ADS)

    Hirasawa, Naohiko; Yamanouchi, Takashi; Konishi, Hiroyuki

    2016-04-01

    The Laser Precipitation Monitor (LPM, manufactured by Thies) has been installed as a disdrometer at Syowa station, East Antarctica, since February 2015. We firstly explore the character of the data because, basically, our experiences in precipitation measurement in the Antarctic region have been very few and also because disdrometer is in a test phase toward the operational use in the world. Indeed, SPICE (Solid Precipitation InterComparison Experiment) project conducted by WMO at various sites around the world (including two sites in Japan) has tested several disdrometers, including LPM. LPM measures precipitation particle size and fall velocity for an individual particle, and compiles the precipitation microphysical parameters together with estimated precipitation intensity per minute. From our domestic experiences related to SPICE, we have confirmed that LPM measurements are affected by wind such as the higher intensity of precipitation under the higher wind speed. At the poster, we will discuss the precipitation intensity obtained at Syowa station, being compared with other meteorological parameters.

  15. Global Precipitation Measurement. Report 7; Bridging from TRMM to GPM to 3-Hourly Precipitation Estimates

    NASA Technical Reports Server (NTRS)

    Shepherd, J. Marshall; Smith, Eric A.; Adams, W. James (Editor)

    2002-01-01

    Historically, multi-decadal measurements of precipitation from surface-based rain gauges have been available over continents. However oceans remained largely unobserved prior to the beginning of the satellite era. Only after the launch of the first Defense Meteorological Satellite Program (DMSP) satellite in 1987 carrying a well-calibrated and multi-frequency passive microwave radiometer called Special Sensor Microwave/Imager (SSM/I) have systematic and accurate precipitation measurements over oceans become available on a regular basis; see Smith et al. (1994, 1998). Recognizing that satellite-based data are a foremost tool for measuring precipitation, NASA initiated a new research program to measure precipitation from space under its Mission to Planet Earth program in the 1990s. As a result, the Tropical Rainfall Measuring Mission (TRMM), a collaborative mission between NASA and NASDA, was launched in 1997 to measure tropical and subtropical rain. See Simpson et al. (1996) and Kummerow et al. (2000). Motivated by the success of TRMM, and recognizing the need for more comprehensive global precipitation measurements, NASA and NASDA have now planned a new mission, i.e., the Global Precipitation Measurement (GPM) mission. The primary goal of GPM is to extend TRMM's rainfall time series while making substantial improvements in precipitation observations, specifically in terms of measurement accuracy, sampling frequency, Earth coverage, and spatial resolution. This report addresses four fundamental questions related to the transition from current to future global precipitation observations as denoted by the TRMM and GPM eras, respectively.

  16. Global Precipitation Measurement Mission Launch and Commissioning

    NASA Technical Reports Server (NTRS)

    Davis, Nikesha; DeWeese, Keith; Vess, Melissa; O'Donnell, James R., Jr.; Welter, Gary

    2015-01-01

    During launch and early operation of the Global Precipitation Measurement (GPM) Mission, the Guidance, Navigation, and Control (GN&C) analysis team encountered four main on-orbit anomalies. These include: (1) unexpected shock from Solar Array deployment, (2) momentum buildup from the Magnetic Torquer Bars (MTBs) phasing errors, (3) transition into Safehold due to albedo induced Course Sun Sensor (CSS) anomaly, and (4) a flight software error that could cause a Safehold transition due to a Star Tracker occultation. This paper will discuss ways GN&C engineers identified the anomalies and tracked down the root causes. Flight data and GN&C on-board models will be shown to illustrate how each of these anomalies were investigated and mitigated before causing any harm to the spacecraft. On May 29, 2014, GPM was handed over to the Mission Flight Operations Team after a successful commissioning period. Currently, GPM is operating nominally on orbit, collecting meaningful scientific data that will significantly improve our understanding of the Earth's climate and water cycle.

  17. Uncertainty Estimation of Global Precipitation Measurement through Objective Validation Strategy

    NASA Astrophysics Data System (ADS)

    KIM, H.; Utsumi, N.; Seto, S.; Oki, T.

    2014-12-01

    Since Tropical Rainfall Measuring Mission (TRMM) has been launched in 1997 as the first satellite mission dedicated to measuring precipitation, the spatiotemporal gaps of precipitation observation have been filled significantly. On February 27th, 2014, Dual-frequency Precipitation Radar (DPR) satellite has been launched as a core observatory of Global Precipitation Measurement (GPM), an international multi-satellite mission aiming to provide the global three hourly map of rainfall and snowfall. In addition to Ku-band, Ka-band radar is newly equipped, and their combination is expected to introduce higher precision than the precipitation measurement of TRMM/PR. In this study, the GPM level-2 orbit products are evaluated comparing to various precipitation observations which include TRMM/PR, in-situ data, and ground radar. In the preliminary validation over intercross orbits of DPR and TRMM, Ku-band measurements in both satellites shows very close spatial pattern and intensity, and the DPR is capable to capture broader range of precipitation intensity than of the TRMM. Furthermore, we suggest a validation strategy based on 'objective classification' of background atmospheric mechanisms. The Japanese 55-year Reanalysis (JRA-55) and auxiliary datasets (e.g., tropical cyclone best track) is used to objectively determine the types of precipitation. Uncertainty of abovementioned precipitation products is quantified as their relative differences and characterized for different precipitation mechanism. Also, it is discussed how the uncertainty affects the synthesis of TRMM and GPM for a long-term satellite precipitation observation records which is internally consistent.

  18. NASA Measures Extreme Precipitation From Space

    NASA Video Gallery

    From Jan. 25 through Feb. 3, IMERG data estimated that the most extreme precipitation over the United States during this period was over 200mm (7.9 inches) in an area where stormy weather frequentl...

  19. Current Status of Japanese Global Precipitation Measurement (GPM) Research Project

    NASA Astrophysics Data System (ADS)

    Kachi, Misako; Oki, Riko; Kubota, Takuji; Masaki, Takeshi; Kida, Satoshi; Iguchi, Toshio; Nakamura, Kenji; Takayabu, Yukari N.

    2013-04-01

    The Global Precipitation Measurement (GPM) mission is a mission led by the Japan Aerospace Exploration Agency (JAXA) and the National Aeronautics and Space Administration (NASA) under collaboration with many international partners, who will provide constellation of satellites carrying microwave radiometer instruments. The GPM Core Observatory, which carries the Dual-frequency Precipitation Radar (DPR) developed by JAXA and the National Institute of Information and Communications Technology (NICT), and the GPM Microwave Imager (GMI) developed by NASA. The GPM Core Observatory is scheduled to be launched in early 2014. JAXA also provides the Global Change Observation Mission (GCOM) 1st - Water (GCOM-W1) named "SHIZUKU," as one of constellation satellites. The SHIZUKU satellite was launched in 18 May, 2012 from JAXA's Tanegashima Space Center, and public data release of the Advanced Microwave Scanning Radiometer 2 (AMSR2) on board the SHIZUKU satellite was planned that Level 1 products in January 2013, and Level 2 products including precipitation in May 2013. The Japanese GPM research project conducts scientific activities on algorithm development, ground validation, application research including production of research products. In addition, we promote collaboration studies in Japan and Asian countries, and public relations activities to extend potential users of satellite precipitation products. In pre-launch phase, most of our activities are focused on the algorithm development and the ground validation related to the algorithm development. As the GPM standard products, JAXA develops the DPR Level 1 algorithm, and the NASA-JAXA Joint Algorithm Team develops the DPR Level 2 and the DPR-GMI combined Level2 algorithms. JAXA also develops the Global Rainfall Map product as national product to distribute hourly and 0.1-degree horizontal resolution rainfall map. All standard algorithms including Japan-US joint algorithm will be reviewed by the Japan-US Joint

  20. An Update on Oceanic Precipitation Rate and its Zonal Distribution in Light of Advanced Observations from Space

    NASA Technical Reports Server (NTRS)

    Behrangi, Ali; Stephens, Graeme; Adler, Robert F.; Huffman, George J.; Lambrigsten, Bjorn; Lebstock, Matthew

    2014-01-01

    This study contributes to the estimation of the global mean and zonal distribution of oceanic precipitation rate using complementary information from advanced precipitation measuring sensors and provides an independent reference to assess current precipitation products. Precipitation estimates from the Tropical Rainfall Measuring Mission (TRMM) precipitation radar (PR) and CloudSat cloud profiling radar (CPR) were merged, as the two complementary sensors yield an unprecedented range of sensitivity to quantify rainfall from drizzle through the most intense rates. At higher latitudes, where TRMM PR does not exist, precipitation estimates from Aqua's Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E) complemented CloudSat CPR to capture intense precipitation rates. The high sensitivity of CPR allows estimation of snow rate, an important type of precipitation at high latitudes, not directly observed in current merged precipitation products. Using the merged precipitation estimate from the CloudSat, TRMM, and Aqua platforms (this estimate is abbreviated to MCTA), the authors' estimate for 3-yr (2007-09) nearglobal (80degS-80degN) oceanic mean precipitation rate is approx. 2.94mm/day. This new estimate of mean global ocean precipitation is about 9% higher than that of the corresponding Climate Prediction Center (CPC) Merged Analysis of Precipitation (CMAP) value (2.68mm/day) and about 4% higher than that of the Global Precipitation Climatology Project (GPCP; 2.82mm/day). Furthermore, MCTA suggests distinct differences in the zonal distribution of precipitation rate from that depicted in GPCPand CMAP, especially in the Southern Hemisphere.

  1. Measurement of solid precipitation with an optical disdrometer

    NASA Astrophysics Data System (ADS)

    Lempio, G. E.; Bumke, K.; Macke, A.

    2007-04-01

    A study about measurements of solid precipitation using an optical disdrometer is presented. The optical disdrometer is an improved version of the ODM 470 disdrometer. It allows to measure hydrometeors within a size range of 0.4 to 22 mm in diameter. The main advantage of this instrument is its ability to estimate accurately precipitation even under strong wind conditions (Großklaus, 1996). To measure solid precipitation a geometrical model was developed to determine the mean cross-sectional area of snow crystals for different predefined shapes and sizes. It serves to develop an algorithm, which relates the mean cross sectional area of snow crystals to their maximum dimension, liquid water content, and terminal velocity. The algorithm was applied to disdrometer measurements during winter 1999/2000 in Uppsala/Sweden. Resulting precipitation was compared to independent measurements of a Geonor gauge and to manual measurements. In terms of daily precipitation the disdrometer shows a reliable performance.

  2. Measuring auroral precipitation parameters without in situ microchannel plate instrumentation

    NASA Astrophysics Data System (ADS)

    Lynch, K. A.; Hampton, D. L.; Zettergren, M. D.; Conde, M.; Lessard, M.; Michell, R.; Samara, M.

    2013-12-01

    Recent advances in groundbased detector technology have resulted in accurate, high-sensitivity, emission-line filtered images of aurora with sub- to a few- km resolution over a few 100 km region collected at a few second to a few Hz cadence. By combining these images with information from other groundbased instrumentation (ISR, remote photometers, and FPIs) and using well-documented empirical relationships between intensity and precipitating electron characteristics, these images hold the potential for providing an accurate, mesoscale, 2-D time history of the key parameters (characteristic energy and energy flux) of the precipitating electrons that caused the optical aurora within the imager's field of view. In situ measurements can be more accurate, but they are limited to highly localized 1-D line trajectories and are of limited use for meso-scale modeling. However, a limitation of the groundbased technique is that subvisual (low energy) precipitation is not captured. Onboard measurements of total number flux provide low resource measurements capturing specific boundary crossings and gradients as well as net precipitation including the portion not observed optically. The combination of minimal onboard instrumentation supplementing rigorous groundbased inversions can provide an optimal set of inputs for ionospheric modelling tools. Thus we are investigating the capabilities and limitations of using inversions of groundbased observations in the place of in situ precipitation monitors. While several inversion techniques are possible we will discuss two methods used in the analysis of recent rocket experiments. The first, used for the Cascades2 rocket, compares measured altitude profiles of auroral emissions to those from a 1-D electron transport code to confirm optically that two arcs transited by the rocket were produced by significantly different electron spectra. The second method, for the MICA rocket, uses the 2-D temperature maps from the Scanning Doppler

  3. The Global Precipitation Measurement (GPM) Mission contributions to terrestrial hydrology and societal applications

    NASA Astrophysics Data System (ADS)

    Kirschbaum, D.; Skofronick Jackson, G.; Huffman, G. J.

    2015-12-01

    Too much or too little rain can serve as a tipping point for triggering catastrophic flooding and landslides or widespread drought. Knowing when, where and how much rain is falling globally is vital to understanding how vulnerable areas may be more or less impacted by these disasters. The Global Precipitation Measurement (GPM) mission is an international constellation of satellites coordinated through a partnership with NASA and the Japan Aerospace Exploration Agency (JAXA) to provide next-generation global observations of rain and snow. The GPM mission centers on the deployment of a Core Observatory satellite that serves as a reference standard to unify precipitation measurements from a constellation of research and operational satellites. This satellite launched from Tanegashima Space Complex in Japan on January 28th, 2014 and carries advanced instruments setting a new standard for precipitation measurements from space. The GPM Core Observatory satellite measures rain and snow using two science instruments: the GPM Microwave Imager (GMI) and the Dual-frequency Precipitation Radar (DPR). The GMI captures precipitation intensities and horizontal patterns, while the DPR provides insights into the three dimensional structure of precipitating particles. Together these two instruments provide a database of measurements against which other partner satellites' microwave observations can be meaningfully compared and combined to make a global precipitation dataset. GPM has already provided unprecedented views of typhoons, extratropical systems, light rain, snow storms and extreme precipitation. Through improved measurements of precipitation globally, the GPM mission provides new insights into measuring the fluxes of Earth's water cycle. This presentation will outline new findings and advancements of GPM in understanding and modeling of Earth's water and energy cycles, improving forecasting of extreme events that cause natural hazards and disasters, and extending current

  4. Global Precipitation Measurement: GPM Microwave Imager (GMI) Algorithm Development Approach

    NASA Technical Reports Server (NTRS)

    Stocker, Erich Franz

    2009-01-01

    This slide presentation reviews the approach to the development of the Global Precipitation Measurement algorithm. This presentation includes information about the responsibilities for the development of the algorithm, and the calibration. Also included is information about the orbit, and the sun angle. The test of the algorithm code will be done with synthetic data generated from the Precipitation Processing System (PPS).

  5. Inconsistency in precipitation measurements across the Alaska-Yukon border

    NASA Astrophysics Data System (ADS)

    Scaff, L.; Yang, D.; Li, Y.; Mekis, E.

    2015-12-01

    This study quantifies the inconsistency in gauge precipitation observations across the border of Alaska and Yukon. It analyses the precipitation measurements by the national standard gauges (National Weather Service (NWS) 8 in. gauge and Nipher gauge) and the bias-corrected data to account for wind effect on the gauge catch, wetting loss and trace events. The bias corrections show a significant amount of errors in the gauge records due to the windy and cold environment in the northern areas of Alaska and Yukon. Monthly corrections increase solid precipitation by 136 % in January and 20 % for July at the Barter Island in Alaska, and about 31 % for January and 4 % for July at the Yukon stations. Regression analyses of the monthly precipitation data show a stronger correlation for the warm months (mainly rainfall) than for cold month (mainly snowfall) between the station pairs, and small changes in the precipitation relationship due to the bias corrections. Double mass curves also indicate changes in the cumulative precipitation over the study periods. This change leads to a smaller and inverted precipitation gradient across the border, representing a significant modification in the precipitation pattern over the northern region. Overall, this study discovers significant inconsistency in the precipitation measurements across the USA-Canada border. This discontinuity is greater for snowfall than for rainfall, as gauge snowfall observations have large errors in windy and cold conditions. This result will certainly impact regional, particularly cross-border, climate and hydrology investigations.

  6. Use of Dual Polarization Radar in Validation of Satellite Precipitation Measurements: Rationale and Opportunities

    NASA Technical Reports Server (NTRS)

    Chandrasekar, V.; Hou, Arthur; Smith, Eric; Bringi, V. N.; Rutledge, S. A.; Gorgucci, E.; Petersen, W. A.; SkofronickJackson, Gail

    2008-01-01

    Dual-polarization weather radars have evolved significantly in the last three decades culminating in the operational deployment by the National Weather Service. In addition to operational applications in the weather service, dual-polarization radars have shown significant potential in contributing to the research fields of ground based remote sensing of rainfall microphysics, study of precipitation evolution and hydrometeor classification. Furthermore the dual-polarization radars have also raised the awareness of radar system aspects such as calibration. Microphysical characterization of precipitation and quantitative precipitation estimation are important applications that are critical in the validation of satellite borne precipitation measurements and also serves as a valuable tool in algorithm development. This paper presents the important role played by dual-polarization radar in validating space borne precipitation measurements. Starting from a historical evolution, the various configurations of dual-polarization radar are presented. Examples of raindrop size distribution retrievals and hydrometeor type classification are discussed. The quantitative precipitation estimation is a product of direct relevance to space borne observations. During the TRMM program substantial advancement was made with ground based polarization radars specially collecting unique observations in the tropics which are noted. The scientific accomplishments of relevance to space borne measurements of precipitation are summarized. The potential of dual-polarization radars and opportunities in the era of global precipitation measurement mission is also discussed.

  7. Global Precipitation Measurement (GPM) Mission: Precipitation Processing System (PPS) GPM Mission Gridded Text Products Provide Surface Precipitation Retrievals

    NASA Technical Reports Server (NTRS)

    Stocker, Erich Franz; Kelley, O.; Kummerow, C.; Huffman, G.; Olson, W.; Kwiatkowski, J.

    2015-01-01

    In February 2015, the Global Precipitation Measurement (GPM) mission core satellite will complete its first year in space. The core satellite carries a conically scanning microwave imager called the GPM Microwave Imager (GMI), which also has 166 GHz and 183 GHz frequency channels. The GPM core satellite also carries a dual frequency radar (DPR) which operates at Ku frequency, similar to the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar, and a new Ka frequency. The precipitation processing system (PPS) is producing swath-based instantaneous precipitation retrievals from GMI, both radars including a dual-frequency product, and a combined GMIDPR precipitation retrieval. These level 2 products are written in the HDF5 format and have many additional parameters beyond surface precipitation that are organized into appropriate groups. While these retrieval algorithms were developed prior to launch and are not optimal, these algorithms are producing very creditable retrievals. It is appropriate for a wide group of users to have access to the GPM retrievals. However, for researchers requiring only surface precipitation, these L2 swath products can appear to be very intimidating and they certainly do contain many more variables than the average researcher needs. Some researchers desire only surface retrievals stored in a simple easily accessible format. In response, PPS has begun to produce gridded text based products that contain just the most widely used variables for each instrument (surface rainfall rate, fraction liquid, fraction convective) in a single line for each grid box that contains one or more observations.This paper will describe the gridded data products that are being produced and provide an overview of their content. Currently two types of gridded products are being produced: (1) surface precipitation retrievals from the core satellite instruments GMI, DPR, and combined GMIDPR (2) surface precipitation retrievals for the partner constellation

  8. Current status of the dual-frequency precipitation radar on the global precipitation measurement core spacecraft

    NASA Astrophysics Data System (ADS)

    Furukawa, K.; Nio, T.; Konishi, T.; Oki, R.; Masaki, T.; Kubota, T.; Iguchi, T.; Hanado, H.

    2015-10-01

    The Dual-frequency Precipitation Radar (DPR) on the Global Precipitation Measurement (GPM) core satellite was developed by Japan Aerospace Exploration Agency (JAXA) and National Institute of Information and Communications Technology (NICT). The GPM is a follow-on mission of the Tropical Rainfall Measuring Mission (TRMM). The objectives of the GPM mission are to observe global precipitation more frequently and accurately than TRMM. The frequent precipitation measurement about every three hours will be achieved by some constellation satellites with microwave radiometers (MWRs) or microwave sounders (MWSs), which will be developed by various countries. The accurate measurement of precipitation in mid-high latitudes will be achieved by the DPR. The GPM core satellite is a joint product of National Aeronautics and Space Administration (NASA), JAXA and NICT. NASA developed the satellite bus and the GPM Microwave Imager (GMI), and JAXA and NICT developed the DPR. JAXA and NICT developed the DPR through procurement. The configuration of precipitation measurement using active radar and a passive radiometer is similar to TRMM. The major difference is that DPR is used in GPM instead of the precipitation radar (PR) in TRMM. The inclination of the core satellite is 65 degrees, and the nominal flight altitude is 407 km. The non-sun-synchronous circular orbit is necessary for measuring the diurnal change of rainfall similarly to TRMM. The DPR consists of two radars, which are Ku-band (13.6 GHz) precipitation radar (KuPR) and Ka-band (35.5 GHz) precipitation radar (KaPR). Both KuPR and KaPR have almost the same design as TRMM PR. The DPR system design and performance were verified through the ground test. GPM core observatory was launched at 18:37:00 (UT) on February 27, 2014 successfully. DPR orbital check out was completed in May 2014. The results of orbital checkout show that DPR meets its specification on orbit. After completion of initial checkout, DPR started Normal

  9. An Enhanced Global Precipitation Measurement (GPM) Validation Network Prototype

    NASA Technical Reports Server (NTRS)

    Schwaller, Matthew R.; Morris, K. Robert

    2009-01-01

    A Validation Network (VN) prototype is currently underway that compares data from the Precipitation Radar (PR) instrument on NASA's Tropical Rainfall Measuring Mission (TRMM) satellite to similar measurements from the U.S. national network of operational weather radars. This prototype is being conducted as part of the ground validation activities of NASA's Global Precipitation Measurement (GPM) mission. GPM will carry a Dual-frequency Precipitation Radar instrument (DPR) with similar characteristics to the TRMM PR. The purpose of the VN is to identify and resolve significant discrepancies between the U.S. national network of ground radar (GR) observations and satellite observations. The ultimate goal of such comparisons is to understand and resolve the first order variability and bias of precipitation retrievals in different meteorological/hydrological regimes at large scales. This paper presents a description of, and results from, an improved algorithm for volume matching and comparison of PR and ground radar observations.

  10. Inter-comparison of precipitation retrievals from the Global Precipitation Measurement mission constellation.

    NASA Astrophysics Data System (ADS)

    Kidd, Chris; Matsui, Toshihisa; Randel, Dave; Stocker, Erich; Kummerow, Chris

    2015-04-01

    The Global Precipitation Measurement mission (GPM) is an international satellite mission that brings together a number of different component satellites and sensors, each contributing observations capable of providing information on precipitation. The joint US-Japan core observatory, launched on 27 February 2014, carries the GPM Microwave Imager (GMI) and the Dual-frequency Precipitation Radar (DPR). The core observatory serves as a standard against which other sensors in the constellation are calibrated, providing a consistent observational dataset to ensure the highest quality precipitation retrievals to be made. Precipitation retrievals from the constellation of partner satellites are generated through the common framework of the Goddard-PROFiling (GPROF) scheme, and is applied to both the conically-scanning sensors and the cross-track sensors; the provision of precipitation estimates from all the constellation sensors contributing to the better-than 3-hour average temporal sampling. This study focuses upon the inter-comparison of the products from the different sensors during the first year of GPM operations; March 2014-February 2015. The two regions chosen for the inter-comparison, are the United States and Western Europe, and utilize the extensive radar networks of these regions. Statistical results were generated for instantaneous precipitation retrievals for each of the constellation sensors. Results show that overall the retrievals from the cross-track observations produce higher correlations with the surface radar data sets than the retrievals from the conically-scanning observations, although they tend to have higher root-mean squared errors. Some variation in performance between the individual types of sensors is also noted, which may be attributed to assumptions within the retrieval scheme (e.g. resolution, background fields, etc); other differences require further investigation.

  11. Prototype of NASA's Global Precipitation Measurement Mission Ground Validation System

    NASA Technical Reports Server (NTRS)

    Schwaller, M. R.; Morris, K. R.; Petersen, W. A.

    2007-01-01

    NASA is developing a Ground Validation System (GVS) as one of its contributions to the Global Precipitation Mission (GPM). The GPM GVS provides an independent means for evaluation, diagnosis, and ultimately improvement of GPM spaceborne measurements and precipitation products. NASA's GPM GVS consists of three elements: field campaigns/physical validation, direct network validation, and modeling and simulation. The GVS prototype of direct network validation compares Tropical Rainfall Measuring Mission (TRMM) satellite-borne radar data to similar measurements from the U.S. national network of operational weather radars. A prototype field campaign has also been conducted; modeling and simulation prototypes are under consideration.

  12. Mars heavy ion precipitating flux as measured by MAVEN

    NASA Astrophysics Data System (ADS)

    Leblanc, F.

    2015-12-01

    Mars' atmospheric escape induced by heavy planetary ions accelerated by the solar wind and reimpacting Mars' atmosphere has been suggested to occur. The sputtering of Mars' atmosphere has been even suggested to lead to a significant cumulated loss along Mars' history. Up to now, only a limited number of observations have been possible. ASPERA-3/Mars Express observed such precipitation only during extreme solar conditions events suggesting that sputtering might be not as intense as theoretically predicted. Based on MAVEN first six months of observations, we here show that precipitation of heavy ions also occur during quiet solar conditions and that the average precipitating flux during this period is significant and globally in good agreement with predictions. From these measured precipitating flux, we propose a first estimate of the atmospheric escape induced by sputtering. Up to 8.8×105 O/cm2/s was lost by Mars' atmosphere between November 2014 and April 2015.

  13. Using NDVI to measure precipitation in semi-arid landscapes

    USGS Publications Warehouse

    Birtwhistle, Amy N.; Laituri, Melinda; Bledsoe, Brian; Friedman, Jonathan M.

    2016-01-01

    Measuring precipitation in semi-arid landscapes is important for understanding the processes related to rainfall and run-off; however, measuring precipitation accurately can often be challenging especially within remote regions where precipitation instruments are scarce. Typically, rain-gauges are sparsely distributed and research comparing rain-gauge and RADAR precipitation estimates reveal that RADAR data are often misleading, especially for monsoon season convective storms. This study investigates an alternative way to map the spatial and temporal variation of precipitation inputs along ephemeral stream channels using Normalized Difference Vegetation Index (NDVI) derived from Landsat Thematic Mapper imagery. NDVI values from 26 years of pre- and post-monsoon season Landsat imagery were derived across Yuma Proving Ground (YPG), a region covering 3,367 km2 of semiarid landscapes in southwestern Arizona, USA. The change in NDVI from a pre-to post-monsoon season image along ephemeral stream channels explained 73% of the variance in annual monsoonal precipitation totals from a nearby rain-gauge. In addition, large seasonal changes in NDVI along channels were useful in determining when and where flow events have occurred.

  14. Classification of Tropical Oceanic Precipitation Using High Altitude Aircraft Microwave and Electric Field Measurements

    NASA Technical Reports Server (NTRS)

    Cecil, Daniel J.; LaFontaine, Frank J.; Hood, Robbie E.; Blakeslee, Richard; Mach, Douglas; Heymsfield, Gerald

    2004-01-01

    A physically intuitive and computationally simple precipitation mapping algorithm has been developed for use with the airborne Advanced Microwave Precipitation Radiometer (AMPR). The algorithm is based on microwave emission and scattering properties of precipitation. Specifically, emission by liquid water allows increasing brightness temperatures at low frequencies to be interpreted as increasing rain rates. Scattering by large hydrometeors (particularly graupel and hail) causes relative minima in the brightness temperatures, with progressively larger hydrometeors scattering progressively longer wavelengths. The vigor of convection is therefore ascertained according to which wavelengths are being significantly scattered. The combination of emission and scattering information from four microwave channels is used to assign a precipitation category, which is related to the liquid rain rate, the vertical extent of precipitation, and the vigor of convection. The qualitative precipitation categories output by the passive microwave algorithm have been verified using coincident radar (ER-2 Doppler Radar - EDOP) and electric field measurements (Lightning Instrument Package - LIP). These coincident measurements can subsequently be used to quantify rain rates, hydrometeor contents, and vertical profiles that are typical for each precipitation category. This algorithm has been developed using an airborne platform. Comparisons are being made with other airborne, satellite, and ground-based radar and radiometer data. This technique shows promise both as a research tool and potentially as a real-time analysis tool, which could be applied to either traditional or uninhabited aerial vehicles.

  15. Advanced microscopy techniques resolving complex precipitates in steels

    NASA Astrophysics Data System (ADS)

    Saikaly, W.; Soto, R.; Bano, X.; Issartel, C.; Rigaut, G.; Charaï, A.

    1999-06-01

    Scanning electron microscopy as well as analytical transmission electron microscopy techniques such as high resolution, electron diffraction, energy dispersive X-ray spectrometry (EDX), parallel electron energy loss spectroscopy (PEELS) and elemental mapping via a Gatan Imaging Filter (GIF) have been used to study complex precipitation in commercial dual phase steels microalloyed with titanium. Titanium nitrides, titanium carbosulfides, titanium carbonitrides and titanium carbides were characterized in this study. Both carbon extraction replicas and thin foils were used as sample preparation techniques. On both the microscopic and nanometric scales, it was found that a large amount of precipitation occurred heterogeneously on already existing inclusions/precipitates. CaS inclusions (1 to 2 μm), already present in liquid steel, acted as nucleation sites for TiN precipitating upon the steel's solidification. In addition, TiC nucleated on existing smaller TiN (around 30 to 50 nm). Despite the complexity of such alloys, the statistical analysis conducted on the non-equilibrium samples were found to be in rather good agreement with the theoretical equilibrium calculations. Heterogeneous precipitation must have played a role in bringing these results closer together.

  16. Electron Precipitation at Mars: Advancing Our Understanding with MAVEN

    NASA Astrophysics Data System (ADS)

    Al Noori, H.; Lillis, R. J.; Fillingim, M. O.

    2015-12-01

    Electrons from the solar wind enter the Martian upper atmosphere from space in a process known as electron precipitation. These electrons are confined to move along magnetic field lines and, when those field lines intersect the atmosphere, the electrons collide with atmospheric neutral particles, resulting in heating, dissociation, ionization and excitation of those neutrals. Electron precipitation is an important source of energy input to the Mars upper atmosphere, and is typically the dominant source on the nightside. Past observations from Mars Global Surveyor have characterized patterns of electron precipitation, but only at ~400 km and ~2 AM local time. The MAVEN mission and in particular the SWEA instrument, provides an opportunity to study the distribution of suprathermal electrons in near-Mars space, over a range of altitudes from 120-6000 km and at a range of local times. We will present preliminary observations of flux patterns of these electrons.

  17. Analysis of precipitation teleconnections in CMIP models as a measure of model fidelity in simulating precipitation

    NASA Astrophysics Data System (ADS)

    Langenbrunner, B.; Neelin, J.; Meyerson, J.

    2011-12-01

    The accurate representation of precipitation is a recurring issue in global climate models, especially in the tropics. Poor skill in modeling the variability and climate teleconnections associated with El Niño/Southern Oscillation (ENSO) also persisted in the latest Climate Model Intercomparison Project (CMIP) campaigns. Observed ENSO precipitation teleconnections provide a standard by which we can judge a given model's ability to reproduce precipitation and dynamic feedback processes originating in the tropical Pacific. Using CMIP3 Atmospheric Model Intercomparison Project (AMIP) runs as a baseline, we compare precipitation teleconnections between models and observations, and we evaluate these results against available CMIP5 historical and AMIP runs. Using AMIP simulations restricts evaluation to the atmospheric response, as sea surface temperatures (SSTs) in AMIP are prescribed by observations. We use a rank correlation between ENSO SST indices and precipitation to define teleconnections, since this method is robust to outliers and appropriate for non-Gaussian data. Spatial correlations of the modeled and observed teleconnections are then evaluated. We look at these correlations in regions of strong precipitation teleconnections, including equatorial S. America, the "horseshoe" region in the western tropical Pacific, and southern N. America. For each region and season, we create a "normalized projection" of a given model's teleconnection pattern onto that of the observations, a metric that assesses the quality of regional pattern simulations while rewarding signals of correct sign over the region. Comparing this to an area-averaged (i.e., more generous) metric suggests models do better when restrictions on exact spatial dependence are loosened and conservation constraints apply. Model fidelity in regional measures remains far from perfect, suggesting intrinsic issues with the models' regional sensitivities in moist processes.

  18. Global Precipitation Measurement Mission: Architecture and Mission Concept

    NASA Technical Reports Server (NTRS)

    Bundas, David

    2005-01-01

    The Global Precipitation Measurement (GPM) Mission is a collaboration between the National Aeronautics and Space Administration (NASA) and the Japanese Aerospace Exploration Agency (JAXA), and other partners, with the goal of monitoring the diurnal and seasonal variations in precipitation over the surface of the earth. These measurements will be used to improve current climate models and weather forecasting, and enable improved storm and flood warnings. This paper gives an overview of the mission architecture and addresses some of the key trades that have been completed, including the selection of the Core Observatory s orbit, orbit maintenance trades, and design issues related to meeting orbital debris requirements.

  19. Study of accuracy of precipitation measurements using simulation method

    NASA Astrophysics Data System (ADS)

    Nagy, Zoltán; Lajos, Tamás; Morvai, Krisztián

    2013-04-01

    Hungarian Meteorological Service1 Budapest University of Technology and Economics2 Precipitation is one of the the most important meteorological parameters describing the state of the climate and to get correct information from trends, accurate measurements of precipitation is very important. The problem is that the precipitation measurements are affected by systematic errors leading to an underestimation of actual precipitation which errors vary by type of precipitaion and gauge type. It is well known that the wind speed is the most important enviromental factor that contributes to the underestimation of actual precipitation, especially for solid precipitation. To study and correct the errors of precipitation measurements there are two basic possibilities: · Use of results and conclusion of International Precipitation Measurements Intercomparisons; · To build standard reference gauges (DFIR, pit gauge) and make own investigation; In 1999 at the HMS we tried to achieve own investigation and built standard reference gauges But the cost-benefit ratio in case of snow (use of DFIR) was very bad (we had several winters without significant amount of snow, while the state of DFIR was continously falling) Due to the problem mentioned above there was need for new approximation that was the modelling made by Budapest University of Technology and Economics, Department of Fluid Mechanics using the FLUENT 6.2 model. The ANSYS Fluent package is featured fluid dynamics solution for modelling flow and other related physical phenomena. It provides the tools needed to describe atmospheric processes, design and optimize new equipment. The CFD package includes solvers that accurately simulate behaviour of the broad range of flows that from single-phase to multi-phase. The questions we wanted to get answer to are as follows: · How do the different types of gauges deform the airflow around themselves? · Try to give quantitative estimation of wind induced error. · How does the use

  20. The Global Precipitation Measurement (GPM) Mission: Overview and U.S. Science Status

    NASA Astrophysics Data System (ADS)

    Hou, Arthur Y.; Skofronick-Jackson, Gail; Stocker, Erich F.

    2013-04-01

    The Global Precipitation Measurement (GPM) Mission is a satellite mission specifically designed to unify and advance precipitation measurements from a constellation of research and operational microwave sensors provided by a consortium of international partners. NASA and JAXA will deploy a Core Observatory in 2014 to serve as a reference satellite for precipitation measurements by the constellation sensors. The GPM Core Observatory will carry a Ku/Ka-band Dual-frequency Precipitation Radar (DPR) and a conical-scanning multi-channel (10-183 GHz) GPM Microwave Radiometer (GMI). The DPR, the first dual-frequency radar in space, will provide not only measurements of 3-D precipitation structures but also quantitative information on microphysical properties of precipitating particles. The DPR and GMI measurements will together provide a database that relates vertical hydrometeor profiles to multi-frequency microwave radiances over a variety of environmental conditions across the globe. This combined database will serve as a common transfer standard for improving the accuracy and consistency of precipitation retrievals from all constellation radiometers. In addition to the Core Observatory, the GPM constellation consists of (1) Special Sensor Microwave Imager/Sounder (SSMIS) instruments on the U.S. Defense Meteorological Satellite Program (DMSP) satellites, (2) the Advanced Microwave Scanning Radiometer-2 (AMSR-2) on the GCOM-W1 satellite of JAXA, (3) the Multi-Frequency Microwave Scanning Radiometer (MADRAS) and the multi-channel microwave humidity sounder (SAPHIR) on the French-Indian Megha-Tropiques satellite, (4) the Microwave Humidity Sounder (MHS) on the National Oceanic and Atmospheric Administration (NOAA) Polar Orbiting Environmental Satellites (POES), (5) MHS instruments on MetOp satellites launched by the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), (6) the Advanced Technology Microwave Sounder (ATMS) on the National Polar

  1. Precipitation Measurements From Space: Workshop report. An element of the climate observing system study

    NASA Technical Reports Server (NTRS)

    Atlas, D. (Editor); Thiele, O. W. (Editor)

    1981-01-01

    Global climate, agricultural uses for precipitation information, hydrological uses for precipitation, severe thunderstorms and local weather, global weather are addressed. Ground truth measurement, visible and infrared techniques, microwave radiometry and hybrid precipitation measurements, and spaceborne radar are discussed.

  2. The Global Precipitation Measurement (GPM) Mission: Overview and U.S. Status

    NASA Technical Reports Server (NTRS)

    Hou, Arthur Y.

    2010-01-01

    The Global Precipitation Measurement (GPM) Mission is an international satellite mission designed to unify and advance precipitation measurements from a constellation of research and operational microwave sensors. NASA and JAXA will deploy the GPM Core Observatory carrying an advanced radar-radiometer system to serve as a physics observatory and a transfer standard for inter-calibration of constellation radiometers. The GPM Core Observatory is scheduled for launch in July 2013. NASA will provide a second radiometer to be flown on a partner-provided GPM Low-Inclination Observatory to enhance the near real-time monitoring of hurricanes and mid-latitude storms. JAXA will also contribute data from the Global Change Observation Mission-Water (GCOM-W) satellite. Additional partnerships are under development to include microwave radiometers on the French-Indian Megha-Tropiques satellite and U.S. Defense Meteorological Satellite Program (DMSP) satellites, as well as cross-track scanning humidity sounders on operational satellites such as the NPP, POES, JPSS, and MetOp satellites, which are used to improve the precipitation sampling over land. Brazil has in its national space plan for a GPM low-inclination radiometer, and data from Chinese and Russian microwave radiometers could potentially become available through international collaboration under the auspices of the Committee on Earth Observation Satellites (CEOS) and Group on Earth Observations (GEO). The current generation of global rainfall products combines observations from a network of uncoordinated satellite missions using a variety of merging techniques. GPM will provide "next-generation" precipitation data products characterized by: (1) more accurate instantaneous precipitation measurement (especially for light rain and cold-season solid precipitation), (2) more frequent sampling by an expanded constellation of microwave radiometers including operational humidity sounders over land, (3) intercalibrated microwave

  3. The Global Precipitation Measurement (GPM) Mission: U.S. Program and Science Status

    NASA Astrophysics Data System (ADS)

    Hou, Arthur; Azarbarzin, Ardeshir; Kakar, Ramesh; Neeck, Steven

    2010-05-01

    The Global Precipitation Measurement (GPM) Mission is an international satellite mission designed to unify and advance precipitation measurements from a constellation of research and operational microwave sensors. NASA and JAXA will deploy the GPM Core Observatory carrying an advanced radar-radiometer system to serve as a physics observatory and a transfer standard for inter-calibration of constellation radiometers. The GPM Core Observatory is scheduled for launch in July 2013. In addition, NASA will provide a second radiometer to be flown on a partner-provided GPM Low-Inclination Observatory to enhance the near real-time monitoring of hurricanes and mid-latitude storms. JAXA will also contribute data from the Global Change Observation Mission-Water (GCOM-W) satellite. Additional partnerships are under development to include conical-scanning microwave imagers on the French-Indian Megha-Tropiques satellite and U.S. Defense Meteorological Satellite Program (DMSP) satellites, as well as cross-track scanning humidity sounders on operational satellites such as the National Polar-orbiting Operational Environmental Satellite System (NPOESS) Preparatory Project (NPP), POES, NPOESS, and European MetOp satellites, which are used to improve the precipitation sampling over land. Currently, Brazil has in its national space plan for a GPM low-inclination radiometer, and data from Chinese and Russian microwave radiometers could potentially become available through international collaboration under the auspices of the Committee on Earth Observation Satellites (CEOS) and Group on Earth Observations (GEO). The current generation of global rainfall products combines observations from a network of uncoordinated satellite missions using a variety of merging techniques. GPM will provide "next-generation" precipitation data products characterized by: (1) more accurate instantaneous precipitation measurement (especially for light rain and cold-season solid precipitation), (2) more

  4. Towards the Development of a Global Precipitation Measurement (GPM) Mission Concept

    NASA Technical Reports Server (NTRS)

    Shepherd, Marshall; Starr, David OC. (Technical Monitor)

    2001-01-01

    The scientific success of the Tropical Rainfall Measuring Mission (TRMM) and additional satellite-focused precipitation retrieval projects have paved the way for a more advanced global precipitation mission. A comprehensive global measuring strategy is currently under study - Global Precipitation Measurement (GPM). The GPM study could ultimately lead to the development of the Global Precipitation Mission. The intent of GPM is to address looming scientific questions arising in the context of global climate-water cycle interactions, hydrometeorology, weather prediction and prediction of freshwater resources, the global carbon cycle, and biogeochemical cycles. This talk overviews the status and scientific agenda of this proposed mission currently planned for launch in the 2007-2008 time frame. GPM is planning to expand the scope of precipitation measurement through the use of a constellation of 6-10 satellites, one of which will be an advanced TRMM-like "core" satellite carry dual-frequency Ku-Ka band radar and a microwave radiometer (e.g. TMI-like). The other constellation members will likely include new lightweight satellites and co-existing operational/research satellites carrying passive microwave radiometers. The goal behind the constellation is to achieve no worse than 3-hour sampling at any spot on the globe. The constellation's orbit architecture will consist of a mix of sun-synchronous and non-su n -synchronous satellites with the "core" satellite providing measurement of cloud-precipitation microphysical processes plus "training calibrating" information to be used with the retrieval algorithms for the constellation satellite measurements. The GPM is organized internationally, currently involving a partnership between NASA in the US, NASDA in Japan, and ESA in Europe (representing the European community). The program is expected to involve additional international partners, other federal agencies, and a diverse collection of scientists from academia

  5. The Global Precipitation Measurement (GPM) Mission: U.S. Program and Science Status

    NASA Astrophysics Data System (ADS)

    Hou, A.; Azarbarzin, A.; Kakar, R.; Neeck, S.

    2009-04-01

    The Global Precipitation Measurement (GPM) Mission is an international satellite mission designed to unify and advance precipitation measurements from a constellation of research and operational microwave sensors to provide next-generation precipitation data products for scientific research and societal applications. NASA and JAXA will deploy the GPM Core Observatory carrying an advanced radar-radiometer system to serve as a physics observatory and calibration reference for constellation radiometers. NASA will deploy the GPM Low-Inclination Observatory to enhance the near real-time monitoring of hurricanes and mid-latitude storms, and JAXA will contribute data from the Global Change Observation Mission-Water (GCOM-W) satellite. Partnerships are under development to include additional conical-scanning microwave imagers on the French-Indian Megha-Tropiques satellite and U.S. Defense Meteorological Satellite Program (DMSP) satellites, as well as cross-track scanning humidity sounders on operational satellites such as the National Polar-orbiting Operational Environmental Satellite System (NPOESS) Preparatory Project (NPP), POES, NPOESS, and European MetOp satellites, which are used to improve the precipitation sampling over land. In addition, Brazil has in its national space plan for a GPM low-inclination radiometer, and data from Chinese and Russian microwave radiometers could potentially become available through international collaboration under the auspices of the Committee on Earth Observation Satellites (CEOS) and Group on Earth Observations (GEO). As a science mission with integrated application goals, GPM is expected to (1) provide new measurement standards for precipitation estimation from space, (2) improve understanding of precipitation physics, the global water cycle variability, and freshwater availability, and (3) advance weather/climate/hydrological prediction capabilities to directly benefit the society. An overview of the GPM mission concept, program

  6. The Status of NASA's Global Precipitation Measurement (GPM) Mission 26 Months After Launch

    NASA Astrophysics Data System (ADS)

    Jackson, Gail; Huffman, George

    2016-04-01

    Water is essential to our planet Earth. Knowing when, where and how precipitation falls is crucial for understanding the linkages between the Earth's water and energy cycles and is extraordinarily important for sustaining life on our planet during climate change. The Global Precipitation Measurement (GPM) Core Observatory spacecraft launched February 27, 2014, is the anchor to the GPM international satellite mission to unify and advance precipitation measurements from a constellation of research and operational sensors to provide "next-generation" precipitation products [1-2]. GPM is currently a partnership between NASA and the Japan Aerospace Exploration Agency (JAXA). The unique 65o non-Sun-synchronous orbit at an altitude of 407 km for the GPM Core Observatory allows for highly sophisticated observations of precipitation in the mid-latitudes where a majority of the population lives. Indeed, the GOM Core Observatory serves as the cornerstone, as a physics observatory and a calibration reference to improve precipitation measurements by a constellation of 8 or more dedicated and operational, U.S. and international passive microwave sensors. GPM's requirements are to measure rain rates from 0.2 to 110 mm/hr and to detect and estimate falling snow. GPM has several retrieval product levels ranging from raw instrument data to Core and partner swath precipitation estimates to gridded and accumulated products and finally to multi-satellite merged products. The latter merged product, called IMERG, is available with a 5-hour latency with temporal resolution of 30 minutes and spatial resolution of 0.1o x 0.1o (~10km x 10km) grid box. Some products have a 1-hour latency for societal applications such as floods, landslides, hurricanes, blizzards, and typhoons and all have late-latency high-quality science products. The GPM mission is well on its way to providing essential data on precipitation (rain and snow) from micro to local to global scales via providing precipitation

  7. The Global Precipitation Measurement (GPM) Mission: Overview and U.S. Science Status

    NASA Technical Reports Server (NTRS)

    Hou, Arthur

    2007-01-01

    The Global Precipitation Measurement (GPM) Mission, an international satellite mission to unify and advance space-based precipitation measurements around the globe, is a science mission with integrated application goals. The mission is designed to (1) advance the knowledge of the global water cycle and freshwater availability, and (2) improve weather, climate, and hydrological prediction capabilities through more accurate and frequent measurements of global precipitation. The cornerstone of GPM is the deployment of a Core Spacecraft in a unique 65 deg-inclined orbit to serve as a physics observatory and a calibration reference to improve the accuracy of precipitation measurements by a heterogeneous constellation of dedicated and operational passive microwave sensors. The Core Spacecraft will carry a dual-frequency (Ku-Ka band) radar and a multi-channel microwave radiometer with high-frequency capabilities to provide measurements of 3-D precipitation structures and microphysical properties, which are key to achieving a better understanding of precipitation processes and improved retrieval algorithms for passive microwave radiometers. The GPM constellation is envisioned to comprise 5 or more conical-scanning microwave radiometers provided by partners, augmented by cross-track microwave sounders on operational satellites such as the National Polar-orbiting Operational Environmental Satellite System (NPOESS) Preparatory Project (NPP), POES, NPOESS, and MetOp satellites for improved sampling over land. The GPM Mission is currently a partnership between NASA and the Japan Aerospace Exploration Agency (JAXA), with opportunities for additional international partners in constellation satellites and ground validation. An overview of the GPM mission concept and science activities in the United States will be presented.

  8. Modeling Errors in Daily Precipitation Measurements: Additive or Multiplicative?

    NASA Technical Reports Server (NTRS)

    Tian, Yudong; Huffman, George J.; Adler, Robert F.; Tang, Ling; Sapiano, Matthew; Maggioni, Viviana; Wu, Huan

    2013-01-01

    The definition and quantification of uncertainty depend on the error model used. For uncertainties in precipitation measurements, two types of error models have been widely adopted: the additive error model and the multiplicative error model. This leads to incompatible specifications of uncertainties and impedes intercomparison and application.In this letter, we assess the suitability of both models for satellite-based daily precipitation measurements in an effort to clarify the uncertainty representation. Three criteria were employed to evaluate the applicability of either model: (1) better separation of the systematic and random errors; (2) applicability to the large range of variability in daily precipitation; and (3) better predictive skills. It is found that the multiplicative error model is a much better choice under all three criteria. It extracted the systematic errors more cleanly, was more consistent with the large variability of precipitation measurements, and produced superior predictions of the error characteristics. The additive error model had several weaknesses, such as non constant variance resulting from systematic errors leaking into random errors, and the lack of prediction capability. Therefore, the multiplicative error model is a better choice.

  9. Fatigue and Creep-Fatigue Deformation of an Ultra-Fine Precipitate Strengthened Advanced Austenitic Alloy

    SciTech Connect

    M.C. Carroll; L.J. Carroll

    2012-10-01

    An advanced austenitic alloy, HT-UPS (high-temperature ultrafine-precipitation-strengthened), has been identified as an ideal candidate material for the structural components of fast reactors and energy-conversion systems. HT-UPS alloys demonstrate improved creep resistance relative to 316 stainless steel (SS) through additions of Ti and Nb, which precipitate to form a widespread dispersion of stable nanoscale metallic carbide (MC) particles in the austenitic matrix. The low-cycle fatigue and creep-fatigue behavior of an HT-UPS alloy have been investigated at 650 °C and a 1.0% total strain, with an R-ratio of -1 and hold times at peak tensile strain as long as 150 min. The cyclic deformation response of HT-UPS is directly compared to that of standard 316 SS. The measured values for total cycles to failure are similar, despite differences in peak stress profiles and in qualitative observations of the deformed microstructures. Crack propagation is primarily transgranular in fatigue and creep-fatigue of both alloys at the investigated conditions. Internal grain boundary damage in the form of fine cracks resulting from the tensile hold is present for hold times of 60 min and longer, and substantially more internal cracks are quantifiable in 316 SS than in HT-UPS. The dislocation substructures observed in the deformed material differ significantly; an equiaxed cellular structure is observed in 316 SS, whereas in HT-UPS the microstructure takes the form of widespread and relatively homogenous tangles of dislocations pinned by the nanoscale MC precipitates. The significant effect of the fine distribution of precipitates on observed fatigue and creep-fatigue response is described in three distinct behavioral regions as it evolves with continued cycling.

  10. Focused beam reflectance measurement to monitor nimodipine precipitation process.

    PubMed

    Xu, Xiaoming; Siddiqui, Akhtar; Khan, Mansoor A

    2013-11-18

    Crystallization of nimodipine in liquid-filled soft gelatin capsule during storage was reported for some commercial products, resulting in product recalls due to product quality and more importantly safety concerns. In this study, a real time particle monitoring tool, focused beam reflectance measurement, was used to evaluate the precipitation conditions of nimodipine in co-solvents. Upon water addition, two particle populations were discovered, appearing at different percentage of water content. Two transitions (i.e. sudden increase in particle counts) were observed, possibility related to nucleation and crystal growth of nimodipine. Furthermore, lowering storage temperature increased the tendency of nimodipine precipitation. Most critically, it was determined that with certain excipient, the drug precipitation occurred at approximately 7% (w/w) water content. Considering that all the orally administered liquid filled soft gelatin capsule shells contain residue water content as plasticizer, moisture transfer from the shell to the formulation may occur during long term storage, resulting in drug precipitation, particularly under cold temperature conditions.

  11. Global Precipitation Measurement (GPM) Ground Validation (GV) Science Implementation Plan

    NASA Technical Reports Server (NTRS)

    Petersen, Walter A.; Hou, Arthur Y.

    2008-01-01

    For pre-launch algorithm development and post-launch product evaluation Global Precipitation Measurement (GPM) Ground Validation (GV) goes beyond direct comparisons of surface rain rates between ground and satellite measurements to provide the means for improving retrieval algorithms and model applications.Three approaches to GPM GV include direct statistical validation (at the surface), precipitation physics validation (in a vertical columns), and integrated science validation (4-dimensional). These three approaches support five themes: core satellite error characterization; constellation satellites validation; development of physical models of snow, cloud water, and mixed phase; development of cloud-resolving model (CRM) and land-surface models to bridge observations and algorithms; and, development of coupled CRM-land surface modeling for basin-scale water budget studies and natural hazard prediction. This presentation describes the implementation of these approaches.

  12. Assimilating the Global Precipitation Measurement (GPM) Estimates in the Canadian Precipitation Analysis (CaPA) Over North America.

    NASA Astrophysics Data System (ADS)

    Boluwade, A.; Rasmussen, P. F.; Stadnyk, T. A.; Fortin, V.; Guy, R.

    2015-12-01

    The importance of precipitation measurement using estimates from satellite products cannot be over emphasized. Observations from space using sensors mounted on satellites cover wider areas and provide high spatial and temporal resolution. The estimates derived from this process are very useful in integrated hydrologic modeling, weather forecasting and monitoring landslides, droughts and floods, etc. Example of a satellite precipitation product is the Tropical Rainfall Measurement Mission (TRMM) and Global Precipitation Mission (GPM). TRMM was primarily designed to measure heavy-to-moderate rainfall over tropical and subtropical regions. GPM was designed to extend, enhance, and improve TRMM precipitation data. The primary objective of this study is the assimilation GPM satellite based precipitation estimates into the Canadian Precipitation Analysis (CaPA). CaPA combines the Global Environmental Multi-Scale model (GEM) dataset and observed precipitation from monitoring stations to provide precipitation estimates at 6hr and 24hr time steps and spatial resolution of 10km covering North America. In the result, we used the Equitable Threat Score (ETS) as performance evaluation. GPM assimilation provides higher skill (ETS) at precipitation values below 3mm while being used as additional data source. GPM has better skill as background field at precipitation value above 3mm.

  13. Global Precipitation Measurement, Validation, and Applications Integrated Hydrologic Validation to Improve Physical Precipitation Retrievals for GPM

    NASA Technical Reports Server (NTRS)

    Peters-Lidar, Christa D.; Tian, Yudong; Kenneth, Tian; Harrison, Kenneth; Kumar, Sujay

    2011-01-01

    Land surface modeling and data assimilation can provide dynamic land surface state variables necessary to support physical precipitation retrieval algorithms over land. It is well-known that surface emission, particularly over the range of frequencies to be included in the Global Precipitation Measurement Mission (GPM), is sensitive to land surface states, including soil properties, vegetation type and greenness, soil moisture, surface temperature, and snow cover, density, and grain size. In order to investigate the robustness of both the land surface model states and the microwave emissivity and forward radiative transfer models, we have undertaken a multi-site investigation as part of the NASA Precipitation Measurement Missions (PMM) Land Surface Characterization Working Group. Specifically, we will demonstrate the performance of the Land Information System (LIS; http://lis.gsfc.nasa.gov; Peters-Lidard et aI., 2007; Kumar et al., 2006) coupled to the Joint Center for Satellite Data Assimilation (JCSDA's) Community Radiative Transfer Model (CRTM; Weng, 2007; van Deist, 2009). The land surface is characterized by complex physical/chemical constituents and creates temporally and spatially heterogeneous surface properties in response to microwave radiation scattering. The uncertainties in surface microwave emission (both surface radiative temperature and emissivity) and very low polarization ratio are linked to difficulties in rainfall detection using low-frequency passive microwave sensors (e.g.,Kummerow et al. 2001). Therefore, addressing these issues is of utmost importance for the GPM mission. There are many approaches to parameterizing land surface emission and radiative transfer, some of which have been customized for snow (e.g., the Helsinki University of Technology or HUT radiative transfer model;) and soil moisture (e.g., the Land Surface Microwave Emission Model or LSMEM).

  14. Calibration Plans for the Global Precipitation Measurement (GPM)

    NASA Technical Reports Server (NTRS)

    Bidwell, S. W.; Flaming, G. M.; Adams, W. J.; Everett, D. F.; Mendelsohn, C. R.; Smith, E. A.; Turk, J.

    2002-01-01

    The Global Precipitation Measurement (GPM) is an international effort led by the National Aeronautics and Space Administration (NASA) of the U.S.A. and the National Space Development Agency of Japan (NASDA) for the purpose of improving research into the global water and energy cycle. GPM will improve climate, weather, and hydrological forecasts through more frequent and more accurate measurement of precipitation world-wide. Comprised of U.S. domestic and international partners, GPM will incorporate and assimilate data streams from many spacecraft with varied orbital characteristics and instrument capabilities. Two of the satellites will be provided directly by GPM, the core satellite and a constellation member. The core satellite, at the heart of GPM, is scheduled for launch in November 2007. The core will carry a conical scanning microwave radiometer, the GPM Microwave Imager (GMI), and a two-frequency cross-track-scanning radar, the Dual-frequency Precipitation Radar (DPR). The passive microwave channels and the two radar frequencies of the core are carefully chosen for investigating the varying character of precipitation over ocean and land, and from the tropics to the high-latitudes. The DPR will enable microphysical characterization and three-dimensional profiling of precipitation. The GPM-provided constellation spacecraft will carry a GMI radiometer identical to that on the core spacecraft. This paper presents calibration plans for the GPM, including on-board instrument calibration, external calibration methods, and the role of ground validation. Particular emphasis is on plans for inter-satellite calibration of the GPM constellation. With its Unique instrument capabilities, the core spacecraft will serve as a calibration transfer standard to the GPM constellation. In particular the Dual-frequency Precipitation Radar aboard the core will check the accuracy of retrievals from the GMI radiometer and will enable improvement of the radiometer retrievals

  15. New Features of the Global Precipitation Measurement (GPM) Validation Network

    NASA Astrophysics Data System (ADS)

    Schwaller, M.; Morris, K. R.

    2014-12-01

    Various enhancements have been added to the Global Precipitation Measurement (GPM) Validation Network (VN) to evaluate the GPM satellite's instrument and data product performance. The GPM VN acquires data from the Dual-frequency Precipitation Radar (DPR) on GPM, the Precipitation Radar (PR) on the Tropical Rainfall Measuring Mission (TRMM) satellite, from microwave imagers on GPM, TRMM, and GPM constellation satellites, and from ground radar (GR) networks in the continental U.S. and participating international sites. The VN characterizes the variability and bias of precipitation retrievals between the satellite products and the GR in various precipitation regimes, with the goal of improving precipitation retrieval algorithms for the GPM instruments. The core VN dataset consists of WSR-88D GR data and matching satellite orbit subset data, primarily covering the eastern US. TRMM data range from August, 2006 to the present, and GPM and constellation data range from March, 2014 to the present. New features of the VN include the extension of the observation network from 21 weather service ground radars in the southeast US to 66 radars covering most of the eastern half of the US, and a radar in Alaska was also added to the network. Additional comparison parameters have also been added to the VN. These include ground radar polarimetric variables (Zdr, Kdp, RHOhv), microphysical variables (Dzero, Nw), and hydrometeor type classifications. New visualization tools and statistical methods are now also available to help compare ground radar and GPM DPR measurements for validation purposes. The VN also now includes an experimental GPM Microwave Imager (GMI)-to-ground radar geometry matching technique. For this product, the GMI near-surface rain rate field from the GPM GPROF algorithm is matched to the GR reflectivity and dual-polarization fields a) along the GMI line- of-sight, and b) as a vertical column above the GMI surface. The full VN software suite to produce the

  16. Measuring Snow Precipitation in New Zealand- Challenges and Opportunities.

    NASA Astrophysics Data System (ADS)

    Renwick, J. A.; Zammit, C.

    2015-12-01

    Monitoring plays a pivotal role in determining sustainable strategy for efficient overall management of the water resource. Though periodic monitoring provides some information, only long-term monitoring can provide data sufficient in quantity and quality to determine trends and develop predictive models. These can support informed decisions about sustainable and efficient use of water resources in New Zealand. However the development of such strategies is underpinned by our understanding and our ability to measure all inputs in headwaters catchments, where most of the precipitation is falling. Historically due to the harsh environment New Zealand has had little to no formal high elevation monitoring stations for all climate and snow related parameters outside of ski field climate and snow stations. This leads to sparse and incomplete archived datasets. Due to the importance of these catchments to the New Zealand economy (eg irrigation, hydro-electricity generation, tourism) NIWA has developed a climate-snow and ice monitoring network (SIN) since 2006. This network extends existing monitoring by electricity generator and ski stations and it is used by a number of stakeholders. In 2014 the network comprises 13 stations located at elevation above 700masl. As part of the WMO Solid Precipitation Intercomparison Experiment (SPICE), NIWA is carrying out an intercomparison of precipitation data over the period 2013-2015 at Mueller Hut. The site was commissioned on 11 July 2013, set up on the 17th September 2013 and comprises two Geonor weighing bucket raingauges, one shielded and the other un-shielded, in association with a conventional tipping bucket raingauge and conventional climate and snow measurements (temperature, wind, solar radiation, relative humidity, snow depth and snow pillow). The presentation aims to outline the state of the current monitoring network in New Zealand, as well as the challenge and opportunities for measurement of precipitation in alpine

  17. Precipitation Estimation Using Combined Radar/Radiometer Measurements Within the GPM Framework

    NASA Technical Reports Server (NTRS)

    Hou, Arthur

    2012-01-01

    The Global Precipitation Measurement (GPM) Mission is an international satellite mission specifically designed to unify and advance precipitation measurements from a constellation of research and operational microwave sensors. The GPM mission centers upon the deployment of a Core Observatory in a 65o non-Sun-synchronous orbit to serve as a physics observatory and a transfer standard for intersatellite calibration of constellation radiometers. The GPM Core Observatory will carry a Ku/Ka-band Dual-frequency Precipitation Radar (DPR) and a conical-scanning multi-channel (10-183 GHz) GPM Microwave Radiometer (GMI). The DPR will be the first dual-frequency radar in space to provide not only measurements of 3-D precipitation structures but also quantitative information on microphysical properties of precipitating particles needed for improving precipitation retrievals from microwave sensors. The DPR and GMI measurements will together provide a database that relates vertical hydrometeor profiles to multi-frequency microwave radiances over a variety of environmental conditions across the globe. This combined database will be used as a common transfer standard for improving the accuracy and consistency of precipitation retrievals from all constellation radiometers. For global coverage, GPM relies on existing satellite programs and new mission opportunities from a consortium of partners through bilateral agreements with either NASA or JAXA. Each constellation member may have its unique scientific or operational objectives but contributes microwave observations to GPM for the generation and dissemination of unified global precipitation data products. In addition to the DPR and GMI on the Core Observatory, the baseline GPM constellation consists of the following sensors: (1) Special Sensor Microwave Imager/Sounder (SSMIS) instruments on the U.S. Defense Meteorological Satellite Program (DMSP) satellites, (2) the Advanced Microwave Scanning Radiometer-2 (AMSR-2) on the GCOM-W1

  18. Current Scientific Progress and Future Scientific Prospects Enabled by Spaceborne Precipitation Radar Measurements

    NASA Technical Reports Server (NTRS)

    Smith, Eric A.; Im, Eastwood; Tripoli, Gregory J.; Yang, Song

    2008-01-01

    First, we examine current scientific progress and understanding that have been possible through use of spaceborne precipitation radar measurements being provided by the TRMM and CloudSat satellites. Second, we look across a future 20-year time frame to assess how and why anticipated improvements in space radar systems will further advance scientific progress into topic areas once considered beyond the realm of space-based remote sensing. JAXA's 13.8 GHz Ku-band cross-track scanning Precipitation Radar (PR) developed for flight on NASA's non-sun-synchronous, diurnally-precessing TRMM satellite, was the first Earth radar flown in space that was designed specifically for precipitation measurement. Its proven accuracy in measuring global rainfall in the tropics and sub-tropics and its unanticipated longevity in continuing these measurements beyond a full decade have established the standards against which all follow-up and future space radars will be evaluated. In regards to the current PR measurement time series, we will discuss a selection of major scientific discoveries and impacts which have set the stage for future radar measuring systems. In fact, the 2nd contemporary space radar applicable for terrestrial precipitation measurement, i.e., JPL-CSA's 94 GHz nadir-staring Cloud Profiling Radar (CPR) flown on NASA's sun-synchronous CloudSat satellite, although designed primarily for measurement of non-precipitating cloud hydrometeors and aerosols, has also unquestionably advanced precipitation measurement because CPR's higher frequency and greatly increased sensitivity (approximately 30 dBZ) has enabled global observations of light rain rate spectrum processes (i.e., rain rates below 0.05 mm per hourand of precipitation processes in the high troposphere (particularly ice phase processes). These processes are beyond reach of the TRMM radar because the PR sensitivity limit is approximately 17 dBZ which means its lower rain rate cutoff is around 0.3 mm per hour and its

  19. Scaling precipitation input to distributed hydrological models by measured snow distribution

    NASA Astrophysics Data System (ADS)

    Voegeli, Christian; Lehning, Michael; Wever, Nander; Bavay, Mathias; Bühler, Yves; Marty, Mauro; Molnar, Peter

    2016-04-01

    Precise knowledge about the snow distribution in alpine terrain is crucial for various applications such as flood risk assessment, avalanche warning or water supply and hydropower. To simulate the seasonal snow cover development in alpine terrain, the spatially distributed, physics-based model Alpine3D is suitable. The model is often driven by spatial interpolations from automatic weather stations (AWS). As AWS are sparsely spread, the data needs to be interpolated, leading to errors in the spatial distribution of the snow cover - especially on subcatchment scale. With the recent advances in remote sensing techniques, maps of snow depth can be acquired with high spatial resolution and vertical accuracy. Here we use maps of the snow depth distribution, calculated from summer and winter digital surface models acquired with the airborne opto-electronic scanner ADS to preprocess and redistribute precipitation input data for Alpine3D to improve the accuracy of spatial distribution of snow depth simulations. A differentiation between liquid and solid precipitation is made, to account for different precipitation patterns that can be expected from rain and snowfall. For liquid precipitation, only large scale distribution patterns are applied to distribute precipitation in the simulation domain. For solid precipitation, an additional small scale distribution, based on the ADS data, is applied. The large scale patterns are generated using AWS measurements interpolated over the domain. The small scale patterns are generated by redistributing the large scale precipitation according to the relative snow depth in the ADS dataset. The determination of the precipitation phase is done using an air temperature threshold. Using this simple approach to redistribute precipitation, the accuracy of spatial snow distribution could be improved significantly. The standard deviation of absolute snow depth error could be reduced by a factor of 2 to less than 20 cm for the season 2011/12. The

  20. The Global Precipitation Measurement (GPM) Mission: Overview and U.S. Status

    NASA Technical Reports Server (NTRS)

    Hou, Arthur Y.; Azarbarzin, Ardeshir A.; Kakar, Ramesh K.; Neeck, Steven

    2011-01-01

    The Global Precipitation Measurement (GPM) Mission is an international satellite mission specifically designed to unify and advance precipitation measurements from a constellation of research and operational microwave sensors. Building upon the success of the U.S.-Japan Tropical Rainfall Measuring Mission (TRMM), the National Aeronautics and Space Administration (NASA) of the United States and the Japan Aerospace and Exploration Agency (JAXA) will deploy in 2013 a GPM "Core" satellite carrying a KulKa-band Dual-frequency Precipitation Radar (DPR) and a conical-scanning multi-channel (10-183 GHz) GPM Microwave Imager (GMI) to establish a new reference standard for precipitation measurements from space. The combined active/passive sensor measurements will also be used to provide common database for precipitation retrievals from constellation sensors. For global coverage, GPM relies on existing satellite programs and new mission opportunities from a consortium of partners through bilateral agreements with either NASA or JAXA. Each constellation member may have its unique scientific or operational objectives but contributes microwave observations to GPM for the generation and dissemination of unified global precipitation data products. In addition to the DPR and GMI on the Core Observatory, the baseline GPM constellation consists of the following sensors: (1) Special Sensor Microwave Imager/Sounder (SSMIS) instruments on the U.S. Defense Meteorological Satellite Program (DMSP) satellites, (2) the Advanced Microwave Scanning Radiometer- 2 (AMSR-2) on the GCOM-Wl satellite of JAXA, (3) the Multi-Frequency Microwave Scanning Radiometer (MADRAS) and the multi-channel microwave humidity sounder (SAPHIR) on the French-Indian Megha-Tropiques satellite, (4) the Microwave Humidity Sounder (MHS) on the National Oceanic and Atmospheric Administration (NOAA)-19, (5) MHS instruments on MetOp satellites launched by the European Organisation for the Exploitation of Meteorological

  1. The Global Precipitation Measurement (GPM) Microwave Imager (GMI): Instrument Overview and Early On-Orbit Performance

    NASA Technical Reports Server (NTRS)

    Draper, David W.; Newell, David A.; Wentz, Frank J.; Krimchansky, Sergey; Jackson, Gail

    2015-01-01

    The Global Precipitation Measurement (GPM) mission is an international satellite mission that uses measurements from an advanced radar/radiometer system on a core observatory as reference standards to unify and advance precipitation estimates made by a constellation of research and operational microwave sensors. The GPM core observatory was launched on February 27, 2014 at 18:37 UT in a 65? inclination nonsun-synchronous orbit. GPM focuses on precipitation as a key component of the Earth's water and energy cycle, and has the capability to provide near-real-time observations for tracking severe weather events, monitoring freshwater resources, and other societal applications. The GPM microwave imager (GMI) on the core observatory provides the direct link to the constellation radiometer sensors, which fly mainly in polar orbits. The GMI sensitivity, accuracy, and stability play a crucial role in unifying the measurements from the GPM constellation of satellites. The instrument has exhibited highly stable operations through the duration of the calibration/validation period. This paper provides an overview of the GMI instrument and a report of early on-orbit commissioning activities. It discusses the on-orbit radiometric sensitivity, absolute calibration accuracy, and stability for each radiometric channel. Index Terms-Calibration accuracy, passive microwave remote sensing, radiometric sensitivity.

  2. Global Precipitation Measurement (GPM) Safety Inhibit Timeline Tool

    NASA Technical Reports Server (NTRS)

    Dion, Shirley

    2012-01-01

    The Global Precipitation Measurement (GPM) Observatory is a joint mission under the partnership by National Aeronautics and Space Administration (NASA) and the Japan Aerospace Exploration Agency (JAXA), Japan. The NASA Goddard Space Flight Center (GSFC) has the lead management responsibility for NASA on GPM. The GPM program will measure precipitation on a global basis with sufficient quality, Earth coverage, and sampling to improve prediction of the Earth's climate, weather, and specific components of the global water cycle. As part of the development process, NASA built the spacecraft (built in-house at GSFC) and provided one instrument (GPM Microwave Imager (GMI) developed by Ball Aerospace) JAXA provided the launch vehicle (H2-A by MHI) and provided one instrument (Dual-Frequency Precipitation Radar (DPR) developed by NTSpace). Each instrument developer provided a safety assessment which was incorporated into the NASA GPM Safety Hazard Assessment. Inhibit design was reviewed for hazardous subsystems which included the High Gain Antenna System (HGAS) deployment, solar array deployment, transmitter turn on, propulsion system release, GMI deployment, and DPR radar turn on. The safety inhibits for these listed hazards are controlled by software. GPM developed a "pathfinder" approach for reviewing software that controls the electrical inhibits. This is one of the first GSFC in-house programs that extensively used software controls. The GPM safety team developed a methodology to document software safety as part of the standard hazard report. As part of this process a new tool "safety inhibit time line" was created for management of inhibits and their controls during spacecraft buildup and testing during 1& Tat GSFC and at the Range in Japan. In addition to understanding inhibits and controls during 1& T the tool allows the safety analyst to better communicate with others the changes in inhibit states with each phase of hardware and software testing. The tool was very

  3. Optical alignment of the Global Precipitation Measurements (GPM) star trackers

    NASA Astrophysics Data System (ADS)

    Hetherington, Samuel; Osgood, Dean; McMann, Joe; Roberts, Viki; Gill, James; McLean, Kyle

    2013-09-01

    The optical alignment of the star trackers on the Global Precipitation Measurement (GPM) core spacecraft at NASA Goddard Space Flight Center (GSFC) was challenging due to the layout and structural design of the GPM Lower Bus Structure (LBS) in which the star trackers are mounted as well as the presence of the star tracker shades that blocked line-of-sight to the primary star tracker optical references. The initial solution was to negotiate minor changes in the original LBS design to allow for the installation of a removable item of ground support equipment (GSE) that could be installed whenever measurements of the star tracker optical references were needed. However, this GSE could only be used to measure secondary optical reference cube faces not used by the star tracker vendor to obtain the relationship information and matrix transformations necessary to determine star tracker alignment. Unfortunately, due to unexpectedly large orthogonality errors between the measured secondary adjacent cube faces and the lack of cube calibration data, we required a method that could be used to measure the same reference cube faces as originally measured by the vendor. We describe an alternative technique to theodolite autocollimation for measurement of an optical reference mirror pointing direction when normal incidence measurements are not possible. This technique was used to successfully align the GPM star trackers and has been used on a number of other NASA flight projects. We also discuss alignment theory as well as a GSFC-developed theodolite data analysis package used to analyze angular metrology data.

  4. Rocket measurements of energetic particles in the midlatitude precipitation zone

    NASA Technical Reports Server (NTRS)

    Voss, H. D.; Smith, L. G.; Braswell, F. M.

    1980-01-01

    Measurements of energetic ion and electron properties as a function of altitude in the midlatitude zone of nighttime energetic particle precipitation are reported. The measurements of particle fluxes, energy spectra and pitch angle distributions were obtained by a Langmuir probe, six energetic particle spectrometers and an electrostatic analyzer on board a Nike Apache rocket launched near the center of the midlatitude zone during disturbed conditions. It is found that the incident flux was primarily absorbed rather than backscattered, and consists of mainly energetic hydrogen together with some helium and a small energetic electron component. Observed differential energy spectra of protons having an exponential energy spectrum, and pitch angle distributions at various altitudes indicate that the energetic particle flux decreases rapidly for pitch angles less than 70 deg. An energetic particle energy flux of 0.002 ergs/sq cm per sec is calculated which indicates the significance of energetic particles as a primary nighttime ionization source for altitudes between 120 and 200 km in the midlatitude precipitation zone.

  5. Global Precipitation Measurement (GPM) Orbit Design and Autonomous Maneuvers

    NASA Technical Reports Server (NTRS)

    Folta, David; Mendelsohn, Chad; Mailhe, Laurie

    2003-01-01

    The NASA Goddard Space Flight Center's Global Precipitation Measurement (GPM) mission must meet the challenge of measuring worldwide precipitation every three hours. The GPM core spacecraft, part of a constellation, will be required to maintain a circular orbit in a high drag environment at a near-critical inclination. Analysis shows that a mean orbit altitude of 407 km is necessary to prevent ground track repeating. Combined with goals to minimize maneuver operation impacts to science data collection and to enable reasonable long-term orbit predictions, the GPM project has decided to fly the GSFC autonomous maneuver system, AutoCon(TM). This system is a follow-up version of the highly successful New Millennium Program technology flown onboard the Earth Observing-1 formation flying mission. This paper presents the driving science requirements and goals of the GPM mission and shows how they will be met. Selection of the mean semi-major axis, eccentricity, and the AV budget for several ballistic properties are presented. The architecture of the autonomous maneuvering system to meet the goals and requirements is presented along with simulations using GPM parameters. Additionally, the use of the GPM autonomous system to mitigate possible collision avoidance and to aid other spacecraft systems during navigation outages is explored.

  6. Validation and Error Characterization for the Global Precipitation Measurement

    NASA Technical Reports Server (NTRS)

    Bidwell, Steven W.; Adams, W. J.; Everett, D. F.; Smith, E. A.; Yuter, S. E.

    2003-01-01

    The Global Precipitation Measurement (GPM) is an international effort to increase scientific knowledge on the global water cycle with specific goals of improving the understanding and the predictions of climate, weather, and hydrology. These goals will be achieved through several satellites specifically dedicated to GPM along with the integration of numerous meteorological satellite data streams from international and domestic partners. The GPM effort is led by the National Aeronautics and Space Administration (NASA) of the United States and the National Space Development Agency (NASDA) of Japan. In addition to the spaceborne assets, international and domestic partners will provide ground-based resources for validating the satellite observations and retrievals. This paper describes the validation effort of Global Precipitation Measurement to provide quantitative estimates on the errors of the GPM satellite retrievals. The GPM validation approach will build upon the research experience of the Tropical Rainfall Measuring Mission (TRMM) retrieval comparisons and its validation program. The GPM ground validation program will employ instrumentation, physical infrastructure, and research capabilities at Supersites located in important meteorological regimes of the globe. NASA will provide two Supersites, one in a tropical oceanic and the other in a mid-latitude continental regime. GPM international partners will provide Supersites for other important regimes. Those objectives or regimes not addressed by Supersites will be covered through focused field experiments. This paper describes the specific errors that GPM ground validation will address, quantify, and relate to the GPM satellite physical retrievals. GPM will attempt to identify the source of errors within retrievals including those of instrument calibration, retrieval physical assumptions, and algorithm applicability. With the identification of error sources, improvements will be made to the respective calibration

  7. Precipitation measurement using SIR-C: A feasibility study

    NASA Technical Reports Server (NTRS)

    Ahamad, Atiq; Moore, Richard K.

    1993-01-01

    A precipitation detection and measurement experiment is planned for the SIR-C/X-SAR mission. This study was conducted to determine under what conditions an off-nadir experiment is feasible. The signal-to-clutter ratio, the signal-to-noise ratio, and the minimum detectable rain rate were investigated. Available models, used in previous studies, were used for the surface clutter and the rain echo. The study also considers the attenuation of the returns at X band. It was concluded that an off-nadir rain-measurement experiment is feasible only for rain rates greater than 10 mm/hr for look angles greater than 60 deg. For the range of look angles 5 less than theta(sub 1) less than 50, the rain rate required is very high for adequate signal-to-clutter ratio, and hence the feasibility of the experiment.

  8. Precipitable water extremes from ground-based GPS measurements and relationship with precipitation extremes over U.S.A

    NASA Astrophysics Data System (ADS)

    Wang, J.

    2010-12-01

    It becomes more and more important to study extreme weather and climate events because of their huge economical and societal impacts. There is also increasing concern on changes of extreme events in frequency and intensity as a result of human influences on climate. Heavy precipitation events are among many types of extreme events and have been studied extensively. Previous studies found statistically significant increases in heavy precipitation and its contribution to total annual precipitation over USA. Given the fact that the moisture supply is one of deciding factors for the precipitation intensity, it is important to document and understand the extremes of atmospheric precipitable water (PW, column-integrated water vapor amount) and their relationship with precipitation extremes. The data are required at daily (or shorter) time scales for the study of extreme events. In this study we use 30-min PW data derived from ground based GPS measurements and hourly precipitation data over the contiguous USA. We found 53 stations where the GPS and rain-gauge stations are within a 50-km distance and 50-m elevation of each other, and the data are available from 2002 to 2009. The main goal of this study is to answer the following four questions. First, how often do PW extremes in warm season (June, July and August) occur? The PW extreme is defined as values exceeding 95th percentile. Second, how many of them result in precipitation extremes? Third, what is the relationship between PW and precipitation extremes, i.e., temporal evolution and intensity correlation? Fourth, is it possible to predict precipitation extremes from PW ones?

  9. Determination of precipitation profiles from airborne passive microwave radiometric measurements

    NASA Technical Reports Server (NTRS)

    Kummerow, Christian; Hakkarinen, Ida M.; Pierce, Harold F.; Weinman, James A.

    1991-01-01

    This study presents the first quantitative retrievals of vertical profiles of precipitation derived from multispectral passive microwave radiometry. Measurements of microwave brightness temperature (Tb) obtained by a NASA high-altitude research aircraft are related to profiles of rainfall rate through a multichannel piecewise-linear statistical regression procedure. Statistics for Tb are obtained from a set of cloud radiative models representing a wide variety of convective, stratiform, and anvil structures. The retrieval scheme itself determines which cloud model best fits the observed meteorological conditions. Retrieved rainfall rate profiles are converted to equivalent radar reflectivity for comparison with observed reflectivities from a ground-based research radar. Results for two case studies, a stratiform rain situation and an intense convective thunderstorm, show that the radiometrically derived profiles capture the major features of the observed vertical structure of hydrometer density.

  10. Optical Alignment of the Global Precipitation Measurement (GPM) Star Trackers

    NASA Technical Reports Server (NTRS)

    Hetherington, Samuel; Osgood, Dean; McMann, Joe; Roberts, Viki; Gill, James; Mclean, Kyle

    2013-01-01

    The optical alignment of the star trackers on the Global Precipitation Measurement (GPM) core spacecraft at NASA Goddard Space Flight Center (GSFC) was challenging due to the layout and structural design of the GPM Lower Bus Structure (LBS) in which the star trackers are mounted as well as the presence of the star tracker shades that blocked line-of-sight to the primary star tracker optical references. The initial solution was to negotiate minor changes in the original LBS design to allow for the installation of a removable item of ground support equipment (GSE) that could be installed whenever measurements of the star tracker optical references were needed. However, this GSE could only be used to measure secondary optical reference cube faces not used by the star tracker vendor to obtain the relationship information and matrix transformations necessary to determine star tracker alignment. Unfortunately, due to unexpectedly large orthogonality errors between the measured secondary adjacent cube faces and the lack of cube calibration data, we required a method that could be used to measure the same reference cube faces as originally measured by the vendor. We describe an alternative technique to theodolite auto-collimation for measurement of an optical reference mirror pointing direction when normal incidence measurements are not possible. This technique was used to successfully align the GPM star trackers and has been used on a number of other NASA flight projects. We also discuss alignment theory as well as a GSFC-developed theodolite data analysis package used to analyze angular metrology data.

  11. Inference of precipitation through thermal infrared measurements of soil moisture

    NASA Technical Reports Server (NTRS)

    Wetzel, P. J.; Atlas, D.

    1981-01-01

    The physics of microwave radiative transfer is well understood so that causal models can be assembled which relate the observed brightness temperatures to assumed distributions of hydrometeors (both liquid and ice), non-precipitating clouds, water vapor oxygen, and surface conditions. Present models assume a Marshall Palmer size distribution of liquid hydrometers from the surface to the freezing level (near the 0 C isotherm) and a variable thickness of frozen hydrometeors above that with various reasonable distribution of the other relevant constituents. The validity of such models is discussed. All uncertainties in the rain rate retrieval algorithms can be expressed in terms of specific model uncertainties which can be addressed through appropriate measurements. Those factors which must be known to achieve umambiguous results can be identified so that rainfall measuring algorithms can be developed and improved. The emissivity of the underlying surface significantly affects the contrast that may be measured between areas covered by rain and those which are dry. Sensing strategies for measuring rain over the ocean and rain over land are reviewed.

  12. Reliability and Validity of Advanced Phonics Measures

    ERIC Educational Resources Information Center

    Doty, Sara J.; Hixson, Michael D.; Decker, Dawn M.; Reynolds, Jennifer L.; Drevon, Daniel D.

    2015-01-01

    Two studies explored the technical adequacy of various measures of advanced phonics skills. In Study 1, the advanced phonics measures consisted of pseudowords, real words, or a combination of both. Participants included 39 students in the third grade. Test-retest correlations for all measures were above 0.8 and interrater reliability was high.…

  13. Ambient flow studies and particulate collection measurements: A laminar flow, reduced entrainment electrostatic precipitator

    SciTech Connect

    Greiner, G.P.; Furlong, D.A.; Bahner, M.A.

    1989-05-01

    This report describes ambient temperature testing of an electrostatic precipitator having a portion of the main precipitator flow drawn through porous (fabric) plates. The effects of flow through the plates (side flow) on precipitator turbulence and particulate removal efficiency are investigated. Ambient temperature particulate removal efficiency measurements are conducted on both indoor air dust, and on injected coal fly ash. 24 figs., 10 tabs.

  14. World-wide association of timberline forest advance with microsite type along a precipitation gradient

    NASA Astrophysics Data System (ADS)

    Johnson, A. C.; Yeakley, A.

    2009-12-01

    Timberline forest advance associated with global climate change is occurring worldwide and is often associated with microsites. Microsites, controlled by topography, substrates, and plant cover, are localized regions dictating temperature, moisture, and solar radiation. These abiotic factors are integral to seedling survival. From a compilation of world-wide information on seedling regeneration on microsites at timberline, including our on-going research in the Pacific Northwest, we classified available literature into four microsite categories, related microsite category to annual precipitation, and used analysis of variance to detect statistical differences in microsite type and associated precipitation. We found statistical differences (p = 0.022) indicating the usefulness of understanding microsite/precipitation associations in detecting world-wide trends in timberline expansion. For example, wetter timberlines with downed wood, had regeneration associated with nurse logs, whereas on windy, drier landscapes, regeneration was typically associated with either leeward sides of tree clumps or on microsites protected from frost by overstory canopy. In our study of timberline expansion in the Pacific Northwest, we expect that such knowledge of microsite types associated with forest expansion will reveal a better understanding of mechanisms and rates of timberline forest advance during global warming.

  15. Japanese Global Precipitation Measurement (GPM) mission status and application of satellite-based global rainfall map

    NASA Astrophysics Data System (ADS)

    Kachi, Misako; Shimizu, Shuji; Kubota, Takuji; Yoshida, Naofumi; Oki, Riko; Kojima, Masahiro; Iguchi, Toshio; Nakamura, Kenji

    2010-05-01

    As accuracy of satellite precipitation estimates improves and observation frequency increases, application of those data to societal benefit areas, such as weather forecasts and flood predictions, is expected, in addition to research of precipitation climatology to analyze precipitation systems. There is, however, limitation on single satellite observation in coverage and frequency. Currently, the Global Precipitation Measurement (GPM) mission is scheduled under international collaboration to fulfill various user requirements that cannot be achieved by the single satellite, like the Tropical Rainfall Measurement Mission (TRMM). The GPM mission is an international mission to achieve high-accurate and high-frequent rainfall observation over a global area. GPM is composed of a TRMM-like non-sun-synchronous orbit satellite (GPM core satellite) and constellation of satellites carrying microwave radiometer instruments. The GPM core satellite carries the Dual-frequency Precipitation Radar (DPR), which is being developed by the Japan Aerospace Exploration Agency (JAXA) and the National Institute of Information and Communications Technology (NICT), and microwave radiometer provided by the National Aeronautics and Space Administration (NASA). Development of DPR instrument is in good progress for scheduled launch in 2013, and DPR Critical Design Review has completed in July - September 2009. Constellation satellites, which carry a microwave imager and/or sounder, are planned to be launched around 2013 by each partner agency for its own purpose, and will contribute to extending coverage and increasing frequency. JAXA's future mission, the Global Change Observation Mission (GCOM) - Water (GCOM-W) satellite will be one of constellation satellites. The first generation of GCOM-W satellite is scheduled to be launched in 2011, and it carries the Advanced Microwave Scanning Radiometer 2 (AMSR2), which is being developed based on the experience of the AMSR-E on EOS Aqua satellite

  16. ENVIRONMENTAL RESEARCH BRIEF: DEVELOPMENT OF GAS CLEANING TECHNOLOGY: DEMONSTRATION OF ADVANCED ELECTROSTATIC PRECIPITATOR TECHNOLOGY (INDIA ESP TRAINING)

    EPA Science Inventory

    The Brief discusses a demonstration of advanced electrostatic precipitator (ESP) diagnostics and technologies in India. Six Indian ESP specialists were selected by Southern Research Institute and their consultants, with the concurrence of EPA's project officer, to attend a course...

  17. High altitude airborne remote sensing mission using the advanced microwave precipitation radiometer (AMPR)

    NASA Technical Reports Server (NTRS)

    Galliano, J.; Platt, R. H.; Spencer, Roy; Hood, Robbie

    1991-01-01

    The advanced microwave precipitation radiometer (AMPR) is an airborne multichannel imaging radiometer used to better understand how the earth's climate structure works. Airborne data results from the October 1990 Florida thunderstorm mission in Jacksonville, FL, are described. AMPR data on atmospheric precipitation in mesoscale storms were retrieved at 10.7, 19.35, 37.1, and 85.5 GHz onboard the ER-2 aircraft at an altitude of 20 km. AMPR's three higher-frequency data channels were selected to operate at the same frequencies as the spaceborne special sensor microwave/imager (SSM/I) presently in orbit. AMPR uses two antennas to receive the four frequencies: the lowest frequency channel uses a 9.7-in aperture lens antennas, while the three higher-frequency channels share a separate 5.3-in aperture lens antenna. The radiometer's temperature resolution performance is summarized.

  18. Advances in noninvasive bone measurement

    SciTech Connect

    Mazess, R.B.; Barden, H.; Vetter, J.; Ettinger, M.

    1989-01-01

    Several noninvasive measurement methods are used for evaluation of metabolic disease. Single-photon (/sup 125/I) scans of the peripheral skeleton are useful in some diseases but are ineffective in osteoporosis (even on the distal radius or os calcis) because they cannot predict spinal or femoral density. Also, peripheral measurements show high percentages of false negatives, that is many patients with fractures have normal peripheral density. Dual-photon (/sup 153/Gd) scans of the spine, femur, and total skeleton are precise and accurate (2% error) and provide direct measurements of bone strength at fracture sites. This gives the best discrimination of abnormality and the most sensitive monitoring. Quantitative computed computed tomography (QCT) allows measurement of the spine but not the critical proximal femur area. QCT has a large accuracy error because (a) the limited area measured (under 5 cm3) fails to represent the total vertebral body, (b) technical errors, and (c) variable fat and osteoid influence the results. 25 references.

  19. Benefits of an Advanced Quantitative Precipitation Information System - San Francisco Bay Area Case Study

    NASA Astrophysics Data System (ADS)

    Cifelli, R.; Johnson, L. E.; White, A. B.

    2014-12-01

    Advancements in monitoring and prediction of precipitation and severe storms can provide significant benefits for water resource managers, allowing them to mitigate flood damage risks, capture additional water supplies and offset drought impacts, and enhance ecosystem services. A case study for the San Francisco Bay area provides the context for quantification of the benefits of an Advanced Quantitative Precipitation Information (AQPI) system. The AQPI builds off more than a decade of NOAA research and applications of advanced precipitation sensors, data assimilation, numerical models of storms and storm runoff, and systems integration for real-time operations. An AQPI would dovetail with the current National Weather Service forecast operations to provide higher resolution monitoring of rainfall events and longer lead time forecasts. A regional resource accounting approach has been developed to quantify the incremental benefits assignable to the AQPI system; these benefits total to $35 M/yr in the 9 county Bay region. Depending on the jurisdiction large benefits for flood damage avoidance may accrue for locations having dense development in flood plains. In other locations forecst=based reservoir operations can increase reservoir storage for water supplies. Ecosystem services benefits for fisheries may be obtained from increased reservoir storage and downstream releases. Benefits in the transporation sectors are associated with increased safety and avoided delays. Compared to AQPI system implementation and O&M costs over a 10 year operations period, a benefit - cost (B/C) ratio is computed which ranges between 2.8 to 4. It is important to acknowledge that many of the benefits are dependent on appropriate and adequate response by the hazards and water resources management agencies and citizens.

  20. Wind induced errors on solid precipitation measurements: an evaluation using time-dependent turbulence simulations

    NASA Astrophysics Data System (ADS)

    Colli, Matteo; Lanza, Luca Giovanni; Rasmussen, Roy; Mireille Thériault, Julie

    2014-05-01

    Among the different environmental sources of error for ground based solid precipitation measurements, wind is the main responsible for a large reduction of the catching performance. This is due to the aero-dynamic response of the gauge that affects the originally undisturbed airflow causing the deformation of the snowflakes trajectories. The application of composite gauge/wind shield measuring configurations allows the improvements of the collection efficiency (CE) at low wind speeds (Uw) but the performance achievable under severe airflow velocities and the role of turbulence still have to be explained. This work is aimed to assess the wind induced errors of a Geonor T200B vibrating wires gauge equipped with a single Alter shield. This is a common measuring system for solid precipitation, which constitutes of the R3 reference system in the ongoing WMO Solid Precipitation InterComparison Experiment (SPICE). The analysis is carried out by adopting advanced Computational Fluid Dynamics (CFD) tools for the numerical simulation of the turbulent airflow realized in the proximity of the catching section of the gauge. The airflow patterns were computed by running both time-dependent (Large Eddies Simulation) and time-independent (Reynolds Averaged Navier-Stokes) simulations. on the Yellowstone high performance computing system of the National Center for Atmospheric Research. The evaluation of CE under different Uw conditions was obtained by running a Lagrangian model for the calculation of the snowflakes trajectories building on the simulated airflow patterns. Particular attention has been paid to the sensitivity of the trajectories to different snow particles sizes and water content (corresponding to dry and wet snow). The results will be illustrated in comparative form between the different methodologies adopted and the existing infield CE evaluations based on double shield reference gauges.

  1. On the microwave measurement of precipitation in tropics

    NASA Technical Reports Server (NTRS)

    Weng, Fuzhong; Vonder Haar, Thomas H.

    1992-01-01

    The difference between the brightness temperature structure over a typical tropical rain system and that of the midlatitude thunderstorms is examined. It is also determined how the brightness temperature and the rain rate relationship at the microwave frequencies deviates from that in the thunderstorms. It is shown, in particular, that the theoretical brightness temperature and rain rate relationship at 19.35 GHz provides good estimates of the surface rain rates for either convective or stratiform precipitation, but the relationship at 37 and 85.5 GHz may result in a significant overestimation of surface rain rate, especially for stratiform precipitation.

  2. Correction of electronic record for weighing bucket precipitation gauge measurements

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Electronic sensors generate valuable streams of forcing and validation data for hydrologic models, but are often subject to noise, which must be removed as part of model input and testing database development. We developed Automated Precipitation Correction Program (APCP) for weighting bucket preci...

  3. New conjunctive CubeSat and balloon measurements to quantify rapid energetic electron precipitation

    NASA Astrophysics Data System (ADS)

    Blum, L. W.; Schiller, Q.; Li, X.; Millan, R. M.; Halford, A.; Woodger, L. A.; Anderson, B.

    2013-12-01

    Particle precipitation into the atmosphere is a critical part of radiation belt electron loss, and without quantified understanding of this loss mechanism, we are unable to fully understand acceleration mechanisms. In particular, rapid electron precipitation is often observed at low altitude on a variety of timescales ranging from short bursts of less than 1 second (microbursts) to broader regions of precipitation extending a few degrees in latitude (termed precipitation bands, following Blake et al., 1996). These precipitation bands have been hypothesized to be an integral contributor to relativistic electron precipitation loss but quantification of their net effect is still needed. Here we investigate precipitation bands as measured from low earth orbit (LEO) by the NSF/CSSWE CubeSat. Two precipitation bands of MeV electrons were observed by CSSWE on Jan 18 and 19, 2013, concurrent with precipitation seen by the 2013 NASA/BARREL campaign. Using the array of BARREL balloon measurements to constrain the temporal and spatial features of the precipitation event measured by CSSWE, we estimate the net electron loss due to these precipitation bands. This loss is found to be significant in the context of the total outer radiation belt content at the time, suggesting precipitation bands can play a critical role in radiation belt losses. These observations are placed in context by examining the statistical distributions of precipitation bands observed by the SAMPEX satellite, also at LEO, over the course of its 20 year mission to understand the role of these rapid precipitation events in storm-time radiation belt dynamics.

  4. Precipitation-attenuation studies based on measurements of ATS-6 20/30-GHz beacon signals at Clarksburg, Maryland

    NASA Technical Reports Server (NTRS)

    Fang, D. J.; Harris, J. M.

    1976-01-01

    Radiometric sky temperature and minute precipitation measurements were intended to broaden the data base required to advance the understanding of the propagation characteristics of the earth-satellite path at frequencies over 10 GHz. Analyses of the data collected from the measurement program have established a detailed correlation between the satellite signal and the signals from auxiliary ground-based measurements. The indirectly derived statistics agreed reasonably well (or can be reconciled) with the earlier published results. The correlations may therefore be used for indirectly estimating long term cumulative attenuation statistics in the absence of direct satellite signal measurements.

  5. Specifics of the hail parameter measurements using the optical precipitation gauge

    NASA Astrophysics Data System (ADS)

    Kalchikhin, V. V.; Kobzev, A. A.; Korolkov, V. A.; Tikhomirov, A. A.

    2015-11-01

    There are specifics of use of the obtaining and analyzing precipitation particle shadow images method for the hail precipitation investigations. Descriptions of the method and operation of the new optical rain gauge measuring system are presented. There are estimations of the device capabilities and prospects of its use for measurement of hail characteristics.

  6. Accurate Characterization of Winter Precipitation Using In-Situ Instrumentation, CSU-CHILL Radar, and Advanced Scattering Methods

    NASA Astrophysics Data System (ADS)

    Newman, A. J.; Notaros, B. M.; Bringi, V. N.; Kleinkort, C.; Huang, G. J.; Kennedy, P.; Thurai, M.

    2015-12-01

    We present a novel approach to remote sensing and characterization of winter precipitation and modeling of radar observables through a synergistic use of advanced in-situ instrumentation for microphysical and geometrical measurements of ice and snow particles, image processing methodology to reconstruct complex particle three-dimensional (3D) shapes, computational electromagnetics to analyze realistic precipitation scattering, and state-of-the-art polarimetric radar. Our in-situ measurement site at the Easton Valley View Airport, La Salle, Colorado, shown in the figure, consists of two advanced optical imaging disdrometers within a 2/3-scaled double fence intercomparison reference wind shield, and also includes PLUVIO snow measuring gauge, VAISALA weather station, and collocated NCAR GPS advanced upper-air system sounding system. Our primary radar is the CSU-CHILL radar, with a dual-offset Gregorian antenna featuring very high polarization purity and excellent side-lobe performance in any plane, and the in-situ instrumentation site being very conveniently located at a range of 12.92 km from the radar. A multi-angle snowflake camera (MASC) is used to capture multiple different high-resolution views of an ice particle in free-fall, along with its fall speed. We apply a visual hull geometrical method for reconstruction of 3D shapes of particles based on the images collected by the MASC, and convert these shapes into models for computational electromagnetic scattering analysis, using a higher order method of moments. A two-dimensional video disdrometer (2DVD), collocated with the MASC, provides 2D contours of a hydrometeor, along with the fall speed and other important parameters. We use the fall speed from the MASC and the 2DVD, along with state parameters measured at the Easton site, to estimate the particle mass (Böhm's method), and then the dielectric constant of particles, based on a Maxwell-Garnet formula. By calculation of the "particle-by-particle" scattering

  7. The Advanced Noise Control Fan Baseline Measurements

    NASA Technical Reports Server (NTRS)

    McAllister, Joseph; Loew, Raymond A.; Lauer, Joel T.; Stuliff, Daniel L.

    2009-01-01

    The NASA Glenn Research Center s (NASA Glenn) Advanced Noise Control Fan (ANCF) was developed in the early 1990s to provide a convenient test bed to measure and understand fan-generated acoustics, duct propagation, and radiation to the farfield. As part of a complete upgrade, current baseline and acoustic measurements were documented. Extensive in-duct, farfield acoustic, and flow field measurements are reported. This is a follow-on paper to documenting the operating description of the ANCF.

  8. EGPM - The proposed European contribution to the Global Precipitation Measurement (GPM) mission

    NASA Astrophysics Data System (ADS)

    Mugnai, A.; Egpm Mission Advisory Group

    2003-04-01

    At the beginning of January 2002, an international scientific consortium (the EGPM Science Team) constituted by numerous scientists involved in several disciplines related to precipitation, submitted to the European Space Agency (ESA) a proposal titled "EGPM: European contribution to the Global Precipitation Mission" in response to ESA's second call for proposals for Earth Explorer Opportunity Missions (EEOMs). The principle objective of the EGPM proposal was to encourage ESA to directly engage in the international organization for the Global Precipitation Measurement (GPM) mission formulated by NASA and NASDA, by providing one member of the GPM constellation of satellites aimed at providing frequent global rainfall observations for an extended operations period starting in the time frame of 2007. Noteworthy, a large part of the European scientific and operational community is strongly interested in GPM. Especially, the operational community related to NWP, nowcasting and hydrological hazards would take advantage of Europe being part of the constellation, because this would guarantee direct access to real-time data. The proposed EGPM satellite should satisfy, in association with the overall GPM constellation, the following "regional" requirements: - Improve the rainfall estimation accuracy with respect to SSM/I; - Enhance the detectability of light rain and snowfall, specifically over land, as appropriate for Northern Europe and Canada and in mid-latitude oceanic perturbations; - Provide a significant contribution to the monitoring and the understanding of hazardous and flash-flood producing storms along the Mediterranean coasts; - Improve the forecast skill of global and regional NWP models through data assimilation of precipitation measurements; - Provide direct-read-out data for real-time applications, as well as global data acquisition. To this end, the scientific payload of the EGPM satellite would consist of an advanced conically scanning microwave radiometer

  9. Characterization of intermetallic precipitates in a Nimonic alloy by ultrasonic velocity measurements

    SciTech Connect

    Murthy, G.V.S. Sridhar, G.; Kumar, Anish; Jayakumar, T.

    2009-03-15

    Ultrasonic velocity measurements have been carried out in Nimonic 263 specimens thermally aged at 923 and 1073 K for durations up to 75 h and correlated with the results of hardness measurements and electron microscopy studies. The ultrasonic velocities and hardness results obtained in the specimens thermally aged at both temperatures clearly indicated that ultrasonic velocity is more sensitive to the initiation of the precipitation, whereas the influence of precipitation on hardness can be observed only after the precipitates attain a minimum size to influence the movement of dislocations. Further, ultrasonic velocity measurements also revealed faster kinetics and a lesser amount of precipitation at 1073 K compared to 923 K due to higher solubility of precipitate-forming elements.

  10. HOAPS and ERA-Interim precipitation over the sea: validation against shipboard in situ measurements

    NASA Astrophysics Data System (ADS)

    Bumke, Karl; König-Langlo, Gert; Kinzel, Julian; Schröder, Marc

    2016-06-01

    The satellite-derived HOAPS (Hamburg Ocean Atmosphere Parameters and Fluxes from Satellite Data) and ECMWF (European Centre for Medium-Range Weather Forecasts) ERA-Interim reanalysis data sets have been validated against in situ precipitation measurements from ship rain gauges and optical disdrometers over the open ocean by applying a statistical analysis for binary estimates. For this purpose collocated pairs of data were merged within a certain temporal and spatial threshold into single events, according to the satellites' overpass, the observation and the ERA-Interim times. HOAPS detects the frequency of precipitation well, while ERA-Interim strongly overestimates it, especially in the tropics and subtropics. Although precipitation rates are difficult to compare because along-track point measurements are collocated with areal estimates and the number of available data are limited, we find that HOAPS underestimates precipitation rates, while ERA-Interim's Atlantic-wide average precipitation rate is close to measurements. However, when regionally averaged over latitudinal belts, deviations between the observed mean precipitation rates and ERA-Interim exist. The most obvious ERA-Interim feature is an overestimation of precipitation in the area of the intertropical convergence zone and the southern subtropics over the Atlantic Ocean. For a limited number of snow measurements by optical disdrometers, it can be concluded that both HOAPS and ERA-Interim are suitable for detecting the occurrence of solid precipitation.

  11. Basic Requirements for Collecting, Documenting, and Reporting Precipitation and Stormwater-Flow Measurements

    USGS Publications Warehouse

    Church, Peter E.; Granato, Gregory E.; Owens, David W.

    1999-01-01

    Accurate and representative precipitation and stormwater-flow data are crucial for use of highway- or urban-runoff study results, either individually or in a regional or national synthesis of stormwater-runoff data. Equally important is information on the level of accuracy and representativeness of this precipitation and stormwaterflow data. Accurate and representative measurements of precipitation and stormwater flow, however, are difficult to obtain because of the rapidly changing spatial and temporal distribution of precipitation and flows during a storm. Many hydrologic and hydraulic factors must be considered in performing the following: selecting sites for measuring precipitation and stormwater flow that will provide data that adequately meet the objectives and goals of the study, determining frequencies and durations of data collection to fully characterize the storm and the rapidly changing stormwater flows, and selecting methods that will yield accurate data over the full range of both rainfall intensities and stormwater flows. To ensure that the accuracy and representativeness of precipitation and stormwater-flow data can be evaluated, decisions as to (1) where in the drainage system precipitation and stormwater flows are measured, (2) how frequently precipitation and stormwater flows are measured, (3) what methods are used to measure precipitation and stormwater flows, and (4) on what basis are these decisions made, must all be documented and communicated in an accessible format, such as a project description report, a data report or an appendix to a technical report, and (or) archived in a State or national records center. A quality assurance/quality control program must be established to ensure that this information is documented and reported, and that decisions made in the design phase of a study are continually reviewed, internally and externally, throughout the study. Without the supporting data needed to evaluate the accuracy and representativeness

  12. Drop Size Distribution Measurements Supporting the NASA Global Precipitation Measurement Mission: Infrastructure and Preliminary Results

    NASA Technical Reports Server (NTRS)

    Petersen, Walter A.; Carey, Lawerence D.; Gatlin, Patrick N.; Wingo, Matthew; Tokay, Ali; Wolff, David B.; Bringi, V. N.

    2011-01-01

    Global Precipitation Measurement Mission (GPM) retrieval algorithm validation requires datasets that characterize the 4-D structure, variability, and correlation properties of hydrometeor particle size distributions (PSD) and accumulations over satellite fields of view (5 -- 50 km). Key to this process is the combined use of disdrometer and polarimetric radar platforms. Here the disdrometer measurements serve as a reference for up-scaling dual-polarimetric radar observations of the PSD to the much larger volumetric sampling domain of the radar. The PSD observations thus derived provide a much larger data set for assessing DSD variability, and satellite-based precipitation retrieval algorithm assumptions, in all three spatial dimensions for a range of storm types and seasons. As one component of this effort, the GPM Ground Validation program recently acquired five 3rd generation 2D Video disdrometers as part of its Disdrometer and Radar Observations of Precipitation Facility (DROP), currently hosted in northern Alabama by the NASA Marshall Space Flight Center and the University of Alabama in Huntsville. These next-generation 2DVDs were operated and evaluated in different phases of data collection under the scanning domain of the UAH ARMOR C-band dual-polarimetric radar. During this period approximately 7500 minutes of PSD data were collected and processed to create gamma size distribution parameters using a truncated method of moments approach. After creating the gamma parameter datasets the DSDs were then used as input to T-matrix code for computation of polarimetric radar moments at C-band. The combined dataset was then analyzed with two basic objectives in mind: 1) the investigation of seasonal variability in the rain PSD parameters as observed by the 2DVDs; 2) the use of combined polarimetric moments and observed gamma distribution parameters in a functional form to retrieve PSD parameters in 4-D using the ARMOR radar for precipitation occurring in different

  13. Nonintrusive temperature measurements on advanced turbomachinery components

    SciTech Connect

    Noel, B.W.; Turley, W.D.; Lewis, W.

    1992-12-31

    A nonintrusive, noncontacting method we developed for temperature measurements in hostile environments is well-suited for measurements on advanced turbine components. The method is not only superior to thermocouples in sufficiently difficult environments, but also is the only known method for making measurements in situations where no form of pyrometry works. We demonstrated the method, which uses laser-induced fluorescence of thermographic phosphors bonded to the component surfaces, on turbine blades and vanes in developmental turbine engines. The method is extendable to the much-higher temperatures expected inside advanced turbomachinery. Of particular note is the adaptability of the method to surface-temperature measurements on ceramics operating at high temperatures. In this temperature range, the ceramics become translucent, and surface emissivity becomes meaningless. We shall discuss the method, its advantages and limitations, recent test results on operating turbine engines, and the extension to ceramic components.

  14. Advanced Measurement Systems Available to PIWG Members

    NASA Technical Reports Server (NTRS)

    Anderson, Robert; Lei, Jih-Fen (Technical Monitor)

    2002-01-01

    It was developed advanced measurement technologies to meet NASA goals: reduce design cycle time, reduce emission, reduce testing time, increase safety. The technology are saving money. This technology are available now for technology transfer: optical diagnostics, the film technology and MEMS devices.

  15. Recent advancement of turbulent flow measurement techniques

    NASA Technical Reports Server (NTRS)

    Battle, T.; Wang, P.; Cheng, D. Y.

    1974-01-01

    Advancements of the fluctuating density gradient cross beam laser Schlieren technique, the fluctuating line-reversal temperature measurement and the development of the two-dimensional drag-sensing probe to a three-dimensional drag-sensing probe are discussed. The three-dimensionality of the instantaneous momentum vector can shed some light on the nature of turbulence especially with swirling flow. All three measured fluctuating quantities (density, temperature, and momentum) can provide valuable information for theoreticians.

  16. Advanced optical blade tip clearance measurement system

    NASA Technical Reports Server (NTRS)

    Ford, M. J.; Honeycutt, R. E.; Nordlund, R. E.; Robinson, W. W.

    1978-01-01

    An advanced electro-optical system was developed to measure single blade tip clearances and average blade tip clearances between a rotor and its gas path seal in an operating gas turbine engine. This system is applicable to fan, compressor, and turbine blade tip clearance measurement requirements, and the system probe is particularly suitable for operation in the extreme turbine environment. A study of optical properties of blade tips was conducted to establish measurement system application limitations. A series of laboratory tests was conducted to determine the measurement system's operational performance characteristics and to demonstrate system capability under simulated operating gas turbine environmental conditions. Operational and environmental performance test data are presented.

  17. Measuring and modelling precipitation components in an Oriental beech stand of the Hyrcanian region, Iran

    NASA Astrophysics Data System (ADS)

    Rahmani, Ramin; Sadoddin, Amir; Ghorbani, Somayeh

    2011-07-01

    SummaryInterception loss from the canopy is a major pathway for the loss of water from forest ecosystems. This study was conducted in an Oriental beech stand, neighboring Gorgan, representing typical forest characteristics of the Hyrcanian region. The Hyrcanian region is situated to the south of the Caspian Sea and covers approximately 1.8 million ha of the northern foothills of the Alborz Mountains in northern Iran. This region is characterised by temperate deciduous forests with Oriental beech stands, formed mainly of Fagus orientalis. Because these beech stands occupy 80% of the Hyrcanian region, rainfall interception via the tree canopy is an important pathway for water loss in this region. The main objectives of this study were to determine and model the precipitation components including stemflow, throughfall, net precipitation, and interception loss using gross precipitation and to understand how the diameter classes influence precipitation partitioning by comparing precipitation components across the tree diameter classes. A total of 31 beech trees with the following classes of diameter were randomly chosen: 11 trees of 30-60 cm (young), 10 trees of 60-100 cm (middle-aged), and 10 trees of 100-130 cm (old) of Diameter at Breast Height (DBH). Field measurements of gross precipitation, stemflow, and throughfall were made for 33 rainfall events over a period of 12 months from November 2005. Then, based on these measurements, net precipitation and interception loss were calculated. The value of gross precipitation was approximately 827 mm. Interception loss estimated to be about 53%, 57%, and 60% of gross precipitation corresponding to the tree diameter classes of 30-60, 60-100, and 100-130 cm, respectively. ANOVA results show that the values of the mean of precipitation components were significantly different across the diameter classes. There was an indirect relationship between tree diameter and the volumes of stemflow, throughfall, and net precipitation

  18. Measurement of atmospheric precipitable water using a solar radiometer. [water vapor absorption effects

    NASA Technical Reports Server (NTRS)

    Pitts, D. E.; Dillinger, A. E.; Mcallum, W. E.

    1974-01-01

    A technique is described and tested that allows the determination of atmospheric precipitable water from two measurements of solar intensity: one in a water-vapor absorption band and another in a nearby spectral region unaffected by water vapor.

  19. Quantification of precipitation measurement discontinuity induced by wind shields on national gauges

    USGS Publications Warehouse

    Yang, D.; Goodison, B.E.; Metcalfe, J.R.; Louie, P.; Leavesley, G.; Emerson, D.; Hanson, C.L.; Golubev, V.S.; Elomaa, E.; Gunther, T.; Pangburn, T.; Kang, E.; Milkovic, J.

    1999-01-01

    Various combinations of wind shields and national precipitation gauges commonly used in countries of the northern hemisphere have been studied in this paper, using the combined intercomparison data collected at 14 sites during the World Meteorological Organization's (WMO) Solid Precipitation Measurement Intercomparison Project. The results show that wind shields improve gauge catch of precipitation, particularly for snow. Shielded gauges, on average, measure 20-70% more snow than unshielded gauges. Without a doubt, the use of wind shields on precipitation gauges has introduced a significant discontinuity into precipitation records, particularly in cold and windy regions. This discontinuity is not constant and it varies with wind speed; temperature, and precipitation type. Adjustment for this discontinuity is necessary to obtain homogenous precipitation data for climate change and hydrological studies. The relation of the relative catch ratio (RCR, ratio of measurements of shielded gauge to unshielded gauge) versus wind speed and temperature has been developed for Alter and Tretyakov wind shields. Strong linear relations between measurements of shielded gauge and unshielded gauge have also been found for different precipitation types. The linear relation does not fully take into account the varying effect of wind and temperature on gauge catch. Overadjustment by the linear relation may occur at those sites with lower wind speeds, and underadjustment may occur at those stations with higher wind speeds. The RCR technique is anticipated to be more applicable in a wide range of climate conditions. The RCR technique and the linear relation have been tested at selected WMO intercomparison stations, and reasonable agreement between the adjusted amounts and the shielded gauge measurement was obtained at most of the sites. Test application of the developed methodologies to a regional or national network is therefore recommended to further evaluate their applicability in

  20. Advanced Engineering Technology for Measuring Performance.

    PubMed

    Rutherford, Drew N; D'Angelo, Anne-Lise D; Law, Katherine E; Pugh, Carla M

    2015-08-01

    The demand for competency-based assessments in surgical training is growing. Use of advanced engineering technology for clinical skills assessment allows for objective measures of hands-on performance. Clinical performance can be assessed in several ways via quantification of an assessee's hand movements (motion tracking), direction of visual attention (eye tracking), levels of stress (physiologic marker measurements), and location and pressure of palpation (force measurements). Innovations in video recording technology and qualitative analysis tools allow for a combination of observer- and technology-based assessments. Overall the goal is to create better assessments of surgical performance with robust validity evidence.

  1. Beryllium-7 and (210)Pb atmospheric deposition measured in moss and dependence on cumulative precipitation.

    PubMed

    Krmar, M; Mihailović, D T; Arsenić, I; Radnović, D; Pap, I

    2016-01-15

    This paper focuses on analysis of the time series of (7)Be and (210)Pb activity measured in moss, and the amount, as well as duration of precipitation, to gain a better understanding of the possible relationships between airborne radionuclide deposition and precipitation. Here we consider whether the amount of these airborne radionuclides in moss samples is a cumulative measure of radionuclide deposition and decay, and a new approach for analyses of the relationships between precipitation and moss activity concentrations is suggested. Through these analyses it was shown that comparison of cumulative activity measured at one location using moss, normalized by values of cumulative amount or duration of precipitation, showed different regimes of airborne radionuclide deposition. PMID:26461139

  2. Beryllium-7 and (210)Pb atmospheric deposition measured in moss and dependence on cumulative precipitation.

    PubMed

    Krmar, M; Mihailović, D T; Arsenić, I; Radnović, D; Pap, I

    2016-01-15

    This paper focuses on analysis of the time series of (7)Be and (210)Pb activity measured in moss, and the amount, as well as duration of precipitation, to gain a better understanding of the possible relationships between airborne radionuclide deposition and precipitation. Here we consider whether the amount of these airborne radionuclides in moss samples is a cumulative measure of radionuclide deposition and decay, and a new approach for analyses of the relationships between precipitation and moss activity concentrations is suggested. Through these analyses it was shown that comparison of cumulative activity measured at one location using moss, normalized by values of cumulative amount or duration of precipitation, showed different regimes of airborne radionuclide deposition.

  3. Advances in Global Water Cycle Science Made Possible by Global Precipitation Mission (GPM)

    NASA Technical Reports Server (NTRS)

    Smith, Eric A.; Starr, David OC. (Technical Monitor)

    2001-01-01

    Within this decade the internationally sponsored Global Precipitation Mission (GPM) will take an important step in creating a global precipitation observing system from space. One perspective for understanding the nature of GPM is that it will be a hierarchical system of datastreams from very high caliber combined dual frequency radar/passive microwave (PMW) rain-radiometer retrievals, to high caliber PMW rain-radiometer only retrievals, and on to blends of the former datastreams with other less-high caliber PMW-based and IR-based rain retrievals. Within the context of NASA's role in global water cycle science and its own Global Water & Energy Cycle (GWEC) program, GPM is the centerpiece mission for improving our understanding of the global water cycle from a space-based measurement perspective. One of the salient problems within our current understanding of the global water and energy cycle is determining whether a change in the rate of the water cycle is accompanying changes in global temperature. As there are a number of ways in which to define a rate-change of the global water cycle, it is not entirely clear as to what constitutes such a determination, This paper presents an overview of the Global Precipitation Mission and how its datasets can be used in a set of quantitative tests within the framework of the oceanic and continental water budget equations to determine comprehensively whether substantive rate changes do accompany perturbations in global temperatures and how such rate changes manifest themselves in both water storage and water flux transport processes.

  4. Measuring Combustion Advance in Solid Propellants

    NASA Technical Reports Server (NTRS)

    Yang, L. C.

    1986-01-01

    Set of gauges on solid-propellant rocket motor with electrically insulating case measures advance of combustion front and local erosion rates of propellant and insulation. Data furnished by gauges aid in motor design, failure analysis, and performance prediction. Technique useful in determining propellant uniformity and electrical properties of exhaust plum. Gauges used both in flight and on ground. Foilgauge technique also useful in basic research on pulsed plasmas or combustion of solids.

  5. Monitoring bacterially induced calcite precipitation in porous media using magnetic resonance imaging and flow measurements.

    PubMed

    Sham, E; Mantle, M D; Mitchell, J; Tobler, D J; Phoenix, V R; Johns, M L

    2013-09-01

    A range of nuclear magnetic resonance (NMR) techniques are employed to provide novel, non-invasive measurements of both the structure and transport properties of porous media following a biologically mediated calcite precipitation reaction. Both a model glass bead pack and a sandstone rock core were considered. Structure was probed using magnetic resonance imaging (MRI) via a combination of quantitative one-dimensional profiles and three-dimensional images, applied before and after the formation of calcite in order to characterise the spatial distribution of the precipitate. It was shown through modification and variations of the calcite precipitation treatment that differences in the calcite fill would occur but all methods were successful in partially blocking the different porous media. Precipitation was seen to occur predominantly at the inlet of the bead pack, whereas precipitation occurred almost uniformly along the sandstone core. Transport properties are quantified using pulse field gradient (PFG) NMR measurements which provide probability distributions of molecular displacement over a set observation time (propagators), supplementing conventional permeability measurements. Propagators quantify the local effect of calcite formation on system hydrodynamics and the extent of stagnant region formation. Collectively, the combination of NMR measurements utilised here provides a toolkit for determining the efficacy of a biological-precipitation reaction for partially blocking porous materials. PMID:23872026

  6. Microburst Precipitation Measured with the FIREBIRD-II CubeSats

    NASA Astrophysics Data System (ADS)

    Crew, A. B.; Spence, H. E.; Blake, J. B.; Klumpar, D. M.; Larsen, B.; O'Brien, T. P., III; Driscoll, S.; Handley, M.; Legere, J.; Longworth, S.; Mosleh, E.; Smith, S. S.; Springer, L.; Widholm, M.

    2015-12-01

    Focused Investigations of Relativistic Electron Burst Intensity, Range, and Dynamics II (FIREBIRD-II) is an NSF CubeSat mission specifically designed to address key science questions about microbursts. Launched on January 31, 2015 it consists of a pair of identical 1.5U CubeSats, which measure electron microburst precipitation in low-Earth Orbit. Microbursts, which are short (~100ms) intense bursts of electron precipitation to the Earth's atmosphere, are one particular form of electron loss from the Earth's radiation belts and have often been associated with intense chorus wave activity. Each spacecraft carries a pair of solid state detectors to measure the precipitating electrons in 6 energy channels from 200 keV to 1 MeV in energy at 18.75 ms time resolution. We present observations of both individual microburst events (timing, size scales, spectra) as well as larger trends in microburst precipitation observed over the course of the entire mission to date.

  7. Millimeter wave radiative transfer studies for precipitation measurements

    NASA Technical Reports Server (NTRS)

    Vivekanandan, J.; Evans, Frank

    1989-01-01

    Scattering calculations using the discrete dipole approximation and vector radiative transfer calculations were performed to model multiparameter radar return and passive microwave emission for a simple model of a winter storm. The issue of dendrite riming was addressed by computing scattering properties of thin ice disks with varying bulk density. It was shown that C-band multiparameter radar contains information about particle density and the number concentration of the ice particles. The radiative transfer modeling indicated that polarized multifrequency passive microwave emission may be used to infer some properties of ice hydrometers. Detailed radar modeling and vector radiative transfer modeling is in progress to enhance the understanding of simultaneous radar and radiometer measurements, as in the case of the proposed TRMM field program. A one-dimensional cloud model will be used to simulate the storm structure in detail and study the microphysics, such as size and density. Multifrequency polarized radiometer measurements from the SSMI satellite instrument will be analyzed in relation to dual-frequency and dual-polarization radar measurements.

  8. Advanced Microgravity Acceleration Measurement Systems Being Developed

    NASA Technical Reports Server (NTRS)

    Sicker, Ronald J.; Kacpura, Thomas J.

    2002-01-01

    The Advanced Microgravity Acceleration Measurement Systems (AMAMS) project at the NASA Glenn Research Center is part of the Instrument Technology Development program to develop advanced sensor systems. The primary focus of the AMAMS project is to develop microelectromechanical (MEMS) acceleration sensor systems to replace existing electromechanical-sensor-based systems presently used to assess relative gravity levels aboard spacecraft. These systems are used in characterizing both vehicle and payload responses to low-gravity vibroacoustic environments. The collection of microgravity acceleration data has cross-disciplinary utility to the microgravity life and physical sciences and the structural dynamics communities. The inherent advantages of semiconductor-based systems are reduced size, mass, and power consumption, while providing enhanced stability.

  9. Central Andean temperature and precipitation measurements and its homogenization

    NASA Astrophysics Data System (ADS)

    Hunziker, Stefan; Gubler, Stefanie

    2015-04-01

    Observation of climatological parameters and the homogenization of these time series have a well-established history in western countries. This is not the case for many other countries, such as Bolivia and Peru. In Bolivia and Peru, the organization of measurements, quality of measurement equipment, equipment maintenance, training of staff and data management are fundamentally different compared to the western standard. The data needs special attention, because many problems are not detected by standard quality control procedures. Information about the weather stations, best achieved by station visits, is very beneficial. If the cause of the problem is known, some of the data may be corrected. In this study, cases of typical problems and measurement errors will be demonstrated. Much of research on homogenization techniques (up to subdaily scale) has been completed in recent years. However, data sets of the quality of western station networks have been used, and little is known about the performance of homogenization methods on data sets from countries such as Bolivia and Peru. HOMER (HOMogenizaton softwarE in R) is one of the most recent and widely used homogenization softwares. Its performance is tested on Peruvian-like data that has been sourced from Swiss stations (similar station density and metadata availability). The Swiss station network is a suitable test bed, because climate gradients are strong and the terrain is complex, as is also found in the Central Andes. On the other hand, the Swiss station network is dense, and long time series and extensive metadata are available. By subsampling the station network and omitting the metadata, the conditions of a Peruvian test region are mimicked. Results are compared to a dataset homogenized by THOMAS (Tool for Homogenization of Monthly Data Series), the homogenization tool used by MeteoSwiss.

  10. Prediction and measurement of effect of chelating selectivity on precipitation reactions.

    PubMed

    Kelly, J J; Sutton, D C

    1966-11-01

    A theoretical treatment of precipitation equilibrium in the presence of a chelating agent has been expanded to include the common ion effect on precipitation reactions. The extent of precipitation can be predicted over the full range of pH for any metal for which the solubility product of the precipitate and the stability constants for a complex are known. The expanded equation has been used in this investigation to predict the extent of precipitation for several metals in the presence of ethylenediaminetetra-acetic acid (EDTA) with common précipitants such as hydroxide, oxalate, sulphate, sulphide and 8-hydroxyquinoline, but may be applied to any system containing other chelating agents. The limits of precipitation in terms of pM', the negative logarithm of the concentration of unprecipitated metal ion, are presented graphically as a function of pH for a system containing axed amounts of precipitating and complexing agents. Measurements for observed reactions at two pH levels, 5 and 10, are compared with the calculated predictions of the equation. Thirty-five metals were investigated.

  11. Data Visualization and Analysis Tools for the Global Precipitation Measurement (GPM) Validation Network

    NASA Technical Reports Server (NTRS)

    Morris, Kenneth R.; Schwaller, Mathew

    2010-01-01

    The Validation Network (VN) prototype for the Global Precipitation Measurement (GPM) Mission compares data from the Tropical Rainfall Measuring Mission (TRMM) satellite Precipitation Radar (PR) to similar measurements from U.S. and international operational weather radars. This prototype is a major component of the GPM Ground Validation System (GVS). The VN provides a means for the precipitation measurement community to identify and resolve significant discrepancies between the ground radar (GR) observations and similar satellite observations. The VN prototype is based on research results and computer code described by Anagnostou et al. (2001), Bolen and Chandrasekar (2000), and Liao et al. (2001), and has previously been described by Morris, et al. (2007). Morris and Schwaller (2009) describe the PR-GR volume-matching algorithm used to create the VN match-up data set used for the comparisons. This paper describes software tools that have been developed for visualization and statistical analysis of the original and volume matched PR and GR data.

  12. Advanced Ceramics Property and Performance Measurements

    NASA Technical Reports Server (NTRS)

    Jenkins, Michael; Salem, Jonathan; Helfinstine, John; Quinn, George; Gonczy, Stephen

    2015-01-01

    Mechanical and physical properties of ceramic bodies can be difficult to measure correctly unless the proper techniques are used. The Advanced Ceramics Committee of ASTM, C-28, has developed dozens of consensus test standards and practices to measure various properties of a ceramic monolith, composite, or coating. The standards give the what, how, how not, and why for measurement of many mechanical, physical, thermal, and performance properties. Using these standards will provide accurate, reliable, and complete data for rigorous comparisons with other test results from your test lab, or another. The C-28 Committee has involved academics, producers, and users of ceramics to write and continually update more than 45 standards since the committees inception in 1986. Included in this poster is a pictogram of the C-28 standards and information on how to obtain individual copies with full details or the complete collection of all of the standards in one volume.

  13. Ground validation of satellite measurements of precipitation using upgraded dual polarization WSR-88D radar network

    NASA Astrophysics Data System (ADS)

    Chen, H.; Chandrasekar, C. V.

    2013-12-01

    The Global Precipitation Measurement (GPM) core satellite is scheduled for launch in February 2014, just a couple of months after the AGU's 2013 annual fall meeting. The GPM mission is expected to provide accurate and frequent observations of global precipitation which will play an important role in improving weather, climate, and hydrological prediction capabilities. As an indispensable part of GPM mission, ground validation will focus on the demonstration and evaluation of space based precipitation classification and retrieval algorithms. Among various validation tools, dual-polarization radar is a powerful equipment that can be used for accurate surface rainfall measurement. Recently, the Next-Generation Radar (NEXRAD) network has been upgraded with dual-polarization capabilities. The polarization diversity radars have great potential for understanding the precipitation microphysics and cross validation of space based observations. For direct comparison between space- and ground-based radar systems, Bolen and Chandrasekar (2003) proposed a methodology to align the measurement from these two systems. This alignment method has shown a great superiority by comparing the Tropical Rainfall Measuring Mission (TRMM) precipitation radar (PR) reflectivity measurements and ground radar observations. This paper will first present the rationale and opportunities of the usage of dual-polarization radar in validation of GPM precipitation retrieval algorithms. The main focus will be on the dual-polarization based rainfall microphysics retrievals, including the rain drop size distribution (DSD), quantitative precipitation estimation, and hydrometeor classifications. Dual-polarization radar observations from the WSR-88D network will be used extensively, especially when there are satellite overpasses during the post launch ear of GPM, for cross-validating the DSD retrieval algorithms and rainfall relations in different climatological regions. The dual-polarization algorithm for

  14. Classification of Tropical Oceanic Precipitation using High-Altitude Aircraft Microwave and Electric Field Measurements

    NASA Technical Reports Server (NTRS)

    Hood, Robbie E.; Cecil, Daniel J.; LaFontaine, Frank J.; Blakeslee, Richard J.; Mach, Douglas m.; Heymsfield, Gerald M.; Marks, Frank D., Jr.; Zipser, Edward J.

    2004-01-01

    During the 1998 and 2001 hurricane seasons of the western Atlantic Ocean and Gulf of Mexico, the Advanced Microwave Precipitation Radiometer (AMPR), the ER-2 Doppler (EDOP) radar, and the Lightning Instrument Package (LIP) were flown aboard the NASA ER-2 high-altitude aircraft as part of the Third Convection and Moisture Experiment (CAMEX-3) and the Fourth Convection and Moisture Experiment (CAMEX-4). Several hurricanes, tropical storms, and other precipitation systems were sampled during these experiments. An oceanic rainfall screening technique has been developed using AMPR passive microwave observations of these systems collected at frequencies of 10.7, 19.35, 37.1, and 85.5 GHz. This technique combines the information content of the four AMPR frequencies regarding the gross vertical structure of hydrometeors into an intuitive and easily executable precipitation mapping format. The results have been verified using vertical profiles of EDOP reflectivity and lower-altitude horizontal reflectivity scans collected by the NOAA WP3D Orion radar. Matching the rainfall classification results with coincident electric field information collected by the LIP readily identifies convective rain regions within the precipitation fields. This technique shows promise as a real-time research and analysis tool for monitoring vertical updraft strength and convective intensity from airborne platforms such as remotely operated or uninhabited aerial vehicles. The technique is analyzed and discussed for a wide variety of precipitation types using the 26 August 1998 observations of Hurricane Bonnie near landfall.

  15. Classification of Tropical Oceanic Precipitation using High Altitude Aircraft: Microwave and Electric Field Measurements

    NASA Technical Reports Server (NTRS)

    Hood, Robbie E.; Cecil, Daniel; LaFontaine, Frank J.; Blakeslee, Richard; Mach, Douglas; Heymsfield, Gerald; Marks, Frank, Jr.; Zipser, Edward

    2004-01-01

    During the 1998 and 2001 hurricane seasons of the western Atlantic Ocean and Gulf of Mexico, the Advanced Microwave Precipitation Radiometer (AMPR), the ER-2 Doppler (EDOP) radar, and the Lightning Instrument Package (LIP) were flown aboard the National Aeronautics and Space Administration ER-2 high altitude aircraft as part of the Third Convection and Moisture Experiment (CAMEX-3) and the Fourth Convection and Moisture Experiment (CAMEX-4). Several hurricanes, tropical storms, and other precipitation systems were sampled during these experiments. An oceanic rainfall screening technique has been developed using AMPR passive microwave observations of these systems collected at frequencies of 10.7, 19.35,37.1, and 85.5 GHz. This technique combines the information content of the four AMPR frequencies regarding the gross vertical structure of hydrometeors into an intuitive and easily executable precipitation mapping format. The results have been verified using vertical profiles of EDOP reflectivity and lower altitude horizontal reflectivity scans collected by the National Oceanic and Atmospheric Administration WP-3D Orion radar. Matching the rainfall classification results with coincident electric field information collected by the LIP readily identifies convective rain regions within the precipitation fields. This technique shows promise as a real-time research and analysis tool for monitoring vertical updraft strength and convective intensity from airborne platforms such as remotely operated or uninhabited aerial vehicles. The technique is analyzed and discussed for a wide variety of precipitation types using the 26 August 1998 observations of Hurricane Bonnie near landfall.

  16. Evaluation of candidate rain gages for upgrading precipitation measurement tools for the National Atmospheric Deposition Program

    USGS Publications Warehouse

    Gordon, John D.

    2003-01-01

    The National Atmospheric Deposition Program (NADP) was established in 1977 to investigate atmospheric deposition and its effects on the environment. Since its establishment, precipitation records have been obtained at all NADP sites using a gage developed approximately 50 years ago-the Belfort 5-780 mechanical rain gage. In 1998 and 1999, a study was done by the U.S. Geological Survey to evaluate four recently developed, technologically advanced rain gages as possible replacement candidates for the mechanical gage currently (2002) in use by the NADP. The gage types evaluated were the Belfort 3200, Geonor T-200, ETI Noah II, and the OTT PLUVIO. The Belfort 5-780 was included in the study to compare the performance of the rain gage currently (2002) used by NADP to the performance of the more recently developed gages. As a reference gage, the NovaLynx Model 260-2510 National Weather Service type stick gage also was included in the study. Two individual gages of each type were included in the study to evaluate precision between gages of the same type. A two-phase evaluation was completed. Phase I consisted of indoor bench tests with known amounts of simulated rainfall applied in 20 individual tests. Phase II consisted of outdoor testing by collecting precipitation during a 26-week period near Bay St. Louis, Mississippi. The ETI Noah II, OTT PLUVIO, and NovaLynx stick gages consistently recorded depths more commensurate with the amounts of applied simulated rainfall in Phase I testing than the Geonor T-200, Belfort 5-780, and Belfort 3200 gages. Gages where both the median difference between the measured and applied simulated rainfall and the interquartile range of all of their measured minus applied simulated rainfall differences were small (less than or equal to 0.01 inch) were judged to have performed very well in Phase I testing. The median and interquartile-range values were 0.01 inch or less for each of the ETI Noah II gages, OTT PLUVIO gages, and NovaLynx stick

  17. Effects of precipitation on sonic anemometer measurements of turbulent fluxes in the atmospheric surface layer

    NASA Astrophysics Data System (ADS)

    Zhang, Rongwang; Huang, Jian; Wang, Xin; Zhang, Jun A.; Huang, Fei

    2016-06-01

    Effects caused by precipitation on the measurements of three-dimensional sonic anemometer are analyzed based on a field observational experiment conducted in Maoming, Guangdong Province, China. Obvious fluctuations induced by precipitation are observed for the outputs of sonic anemometer-derived temperature and wind velocity components. A technique of turbulence spectra and cospectra normalized in the framework of similarity theory is utilized to validate the measured variables and calculated fluxes. It is found that the sensitivity of sonic anemometer-derived temperature to precipitation is significant, compared with that of the wind velocity components. The spectra of wind velocity and cospectra of momentum flux resemble the standard universal shape with the slopes of the spectra and cospectra at the inertial subrange, following the -2/3 and -4/3 power law, respectively, even under the condition of heavy rain. Contaminated by precipitation, however, the spectra of temperature and cospectra of sensible heat flux do not exhibit a universal shape and have obvious frequency loss at the inertial subrange. From the physical structure and working principle of sonic anemometer, a possible explanation is proposed to describe this difference, which is found to be related to the variations of precipitation particles. Corrections for errors of sonic anemometer-derived temperature under precipitation is needed, which is still under exploration.

  18. Leveraging Improvements in Precipitation Measuring from GPM Mission to Achieve Prediction Improvements in Climate, Weather and Hydrometeorology

    NASA Technical Reports Server (NTRS)

    Smith, Eric A.

    2002-01-01

    The main scientific goal of the GPM mission, currently planned for start in the 2007 time frame, is to investigate important scientific problems arising within the context of global and regional water cycles. These problems cut across a hierarchy of scales and include climate-water cycle interactions, techniques for improving weather and climate predictions, and better methods for combining observed precipitation with hydrometeorological prediction models for applications to hazardous flood-producing storms, seasonal flood/draught conditions, and fresh water resource assessments. The GPM mission will expand the scope of precipitation measurement through the use of a constellation of some 9 satellites, one of which will be an advanced TRMM-like "core" satellite carrying a dual-frequency Ku-Ka band precipitation radar and an advanced, multifrequency passive microwave radiometer with vertical-horizontal polarization discrimination. The other constellation members will include new dedicated satellites and co-existing Operational/research satellites carrying similar (but not identical) passive microwave radiometers. The goal of the constellation is to achieve approximately 3-hour sampling at any spot on the globe. The constellation's orbit architecture will consist of a mix of sun-synchronous and non-sun-synchronous satellites with the core satellite providing measurements of cloud-precipitation microphysical processes plus calibration-quality rainrate retrievals to be used with the other retrieval information to ensure bias-free constellation coverage. GPM is organized internationally, currently involving a partnership between NASA in the US and the National Space Development Agency in Japan. Additionally, the program is actively pursuing agreements with other international partners and domestic scientific agencies and institutions, as well as participation by individual scientists from academia, government, and the private sector to fulfill mission goals and to pave

  19. A Data System Architecture for Measurement Based Systems: Precipitation Processing System

    NASA Technical Reports Server (NTRS)

    Stocker, Erich Franz

    2003-01-01

    NASA s Earth Science Enterprise (ESE) is changing focus from single satellite missions to measurement oriented programs. An example of this paradigm shift is the Global Precipitation Measurement (GPM) project. GPM is conceptualized as a rolling-wave of measurement possibilities all focused on the key precipitation parameter. In response to this shift to measurement programs and also integral to the ESE s new strategy for processing and management its data, a measurement based approach is also critical for data processing system that support measurement programs like GPM. This paper provides an overview of the paradigm shift from mission to measurement. It also presents a summary of the ESE s new strategy for its data systems. Building on this background the paper details the architectural, design and implementation aspects of the Precipitation Processing System (PPS). The PPS is an evolution of a single point system developed for the Tropical Rainfall Measurement Mission to a generic precipitation data system. The paper provides the context within which PPS will support the GPM program.

  20. Precipitation measurement intercomparison in the Qilian Mountains, north-eastern Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Chen, R.; Liu, J.; Kang, E.; Yang, Y.; Han, C.; Liu, Z.; Song, Y.; Qing, W.; Zhu, P.

    2015-10-01

    An experimental field study of wind-induced bias in precipitation measurements was conducted from September 2010 to April 2015 at a grassland site (99°52.9´ E, 38°16.1´ N; 2980 m) in the Hulu watershed in the Qilian Mountains, on the north-eastern Tibetan Plateau, in China. The experiment included (1) an unshielded Chinese standard precipitation gauge (CSPGUN; orifice diameter = 20 cm, height = 70 cm), (2) a single Alter shield around a CSPG (CSPGSA), (3) a CSPG in a pit (CSPGPIT) and (4) a Double-Fence International Reference (DFIR) with a Tretyakov-shielded CSPG (CSPGDFIR). The catch ratio (CR) used the CSPGDFIR as a reference (CR = CSPGX/CSPGDFIR, %; X denotes UN, SA or PIT). The results show that the CSPGSA, CSPGPIT and CSPGDIFR caught 0.9, 4.5 and 3.4 % more rainfall; 7.7, 15.6 and 14.2 % more mixed precipitation (snow with rain, rain with snow); 11.1, 16.0 and 20.6 % more snowfall and 2.0, 6.0 and 5.3 % more precipitation (of all types), respectively, than the CSPGUN from September 2012 to April 2015. The CSPGPIT and CSPGDFIR caught 3.6 and 2.5 % more rainfall; 7.3 and 6.0 % more mixed precipitation; 4.4 and 8.5 % more snowfall; and 3.9 and 3.2 % more total precipitation, respectively, than the CSPGSA. However, the CSPGDFIR caught 1.0 % less rainfall; 1.2 % less mixed precipitation; 3.9 % more snowfall and 0.6 % less total precipitation than the CSPGPIT. From most to least precipitation measured, the instruments ranked as follows: for rain and mixed precipitation, CSPGPIT > CSPGDFIR > CSPGSA > CSPGUN; for snowfall, CSPGDFIR > CSPGPIT > CSPGSA > CSPGUN. The CR vs. 10 m wind speed for the period of precipitation indicated that with increasing wind speed from 0 to 8.0 m s-1, the CRUN/DFIR and CRSA/DFIR for rainfall decreased slightly. For mixed precipitation, the wind speed showed no significant effect on CRUN/DFIR and CRSA/DFIR below 3.5 m s-1. For snowfall, the CRUN/DFIR and CRSA/DFIR vs. wind speed showed that CR decreased with increasing wind speed. The

  1. Actual evapotranspiration and precipitation measured by lysimeters: a comparison with eddy covariance and tipping bucket

    NASA Astrophysics Data System (ADS)

    Gebler, S.; Hendricks Franssen, H.-J.; Pütz, T.; Post, H.; Schmidt, M.; Vereecken, H.

    2015-05-01

    This study compares actual evapotranspiration (ETa) measurements by a set of six weighable lysimeters, ETa estimates obtained with the eddy covariance (EC) method, and evapotranspiration calculated with the full-form Penman-Monteith equation (ETPM) for the Rollesbroich site in the Eifel (western Germany). The comparison of ETa measured by EC (including correction of the energy balance deficit) and by lysimeters is rarely reported in the literature and allows more insight into the performance of both methods. An evaluation of ETa for the two methods for the year 2012 shows a good agreement with a total difference of 3.8% (19 mm) between the ETa estimates. The highest agreement and smallest relative differences (< 8%) on a monthly basis between both methods are found in summer. ETa was close to ETPM, indicating that ET was energy limited and not limited by water availability. ETa differences between lysimeter and EC were mainly related to differences in grass height caused by harvest and the EC footprint. The lysimeter data were also used to estimate precipitation amounts in combination with a filter algorithm for the high-precision lysimeters recently introduced by Peters et al. (2014). The estimated precipitation amounts from the lysimeter data differ significantly from precipitation amounts recorded with a standard rain gauge at the Rollesbroich test site. For the complete year 2012 the lysimeter records show a 16 % higher precipitation amount than the tipping bucket. After a correction of the tipping bucket measurements by the method of Richter (1995) this amount was reduced to 3%. With the help of an on-site camera the precipitation measurements of the lysimeters were analyzed in more detail. It was found that the lysimeters record more precipitation than the tipping bucket, in part related to the detection of rime and dew, which contribute 17% to the yearly difference between both methods. In addition, fog and drizzle explain an additional 5.5% of the total

  2. Biases in Total Precipitable Water Vapor Climatologies from Atmospheric Infrared Sounder and Advanced Microwave Scanning Radiometer

    NASA Technical Reports Server (NTRS)

    Fetzer, Eric J.; Lambrigtsen, Bjorn H.; Eldering, Annmarie; Aumann, Hartmut H.; Chahine, Moustafa T.

    2006-01-01

    We examine differences in total precipitable water vapor (PWV) from the Atmospheric Infrared Sounder (AIRS) and the Advanced Microwave Scanning Radiometer (AMSR-E) experiments sharing the Aqua spacecraft platform. Both systems provide estimates of PWV over water surfaces. We compare AIRS and AMSR-E PWV to constrain AIRS retrieval uncertainties as functions of AIRS retrieved infrared cloud fraction. PWV differences between the two instruments vary only weakly with infrared cloud fraction up to about 70%. Maps of AIRS-AMSR-E PWV differences vary with location and season. Observational biases, when both instruments observe identical scenes, are generally less than 5%. Exceptions are in cold air outbreaks where AIRS is biased moist by 10-20% or 10-60% (depending on retrieval processing) and at high latitudes in winter where AIRS is dry by 5-10%. Sampling biases, from different sampling characteristics of AIRS and AMSR-E, vary in sign and magnitude. AIRS sampling is dry by up to 30% in most high-latitude regions but moist by 5-15% in subtropical stratus cloud belts. Over the northwest Pacific, AIRS samples conditions more moist than AMSR-E by a much as 60%. We hypothesize that both wet and dry sampling biases are due to the effects of clouds on the AIRS retrieval methodology. The sign and magnitude of these biases depend upon the types of cloud present and on the relationship between clouds and PWV. These results for PWV imply that climatologies of height-resolved water vapor from AIRS must take into consideration local meteorological processes affecting AIRS sampling.

  3. Comprehensive comparison of precipitation measurement systems for convective and non-convective events

    NASA Astrophysics Data System (ADS)

    Filipović, N.; Steinacker, R.; Dorninger, M.; Tüchler, L.

    2012-04-01

    During the field phase of Convective and Orographically-induced Precipitation Study (COPS) the supersite "S" was equipped with several collocated precipitation measuring devices including rainfall weighing gauge, tipping bucket gauge, optical disdrometer, and vertically pointing micro rain radar. Precipitation measurements from two scanning C-band radars covering the area of the eastern Black Forest were available for comparison with the surface-based measurements, as well as data of a wind-temperature radar collocated with above mentioned rainfall instruments at the supersite "S". In this study we present a comprehensive comparison of precipitation measurements for selected IOP-days during the COPS field phase. One issue of this study was to compare the rainfall amount estimated by several measurement devices during defined rainfall episodes under consideration of the differences in sampling strategy of the different instruments. Another goal was to test the rainfall sensors for their ability to catch the temporal variability of rainfall. We investigate time correlation of the rainfall and the autocorrelation of the measurements stratified after convective and non-convective events. Dependence of the observed measurement differences on the rainfall intensity was also investigated. Since the sampling characteristics (sample volume, sampling time) varies notably between the instruments used for comparison appropriate matching of the temporal and spatial scale of the different observations was done with a particular attention given to the differences in the height of the measurements. Due to the simultaneous observations of the two scanning C-band radars over the area of the supersite "S" it is possible to estimate the specific measurement error of the radars, relative to the precipitation amount observed on the ground. Using disdrometer and vertically pointing micro rain radar in conjunction with scanning radar data above, reflectivity factor of a scanned

  4. ANDES Measurements for Advanced Reactor Systems

    NASA Astrophysics Data System (ADS)

    Plompen, A. J. M.; Hambsch, F.-J.; Kopecky, S.; Nyman, M.; Rouki, C.; Salvador Castiñeira, P.; Schillebeeckx, P.; Belloni, F.; Berthoumieux, E.; Gunsing, F.; Lampoudis, C.; Calviani, M.; Guerrero, C.; Cano-Ott, D.; Gonzalez Romero, E.; Aïche, M.; Jurado, B.; Mathieu, L.; Derckx, X.; Farget, F.; Rodrigues Tajes, C.; Bacquias, A.; Dessagne, Ph.; Kerveno, M.; Borcea, C.; Negret, A.; Colonna, N.; Goncalves, I.; Penttilä, H.; Rinta-Antila, S.; Kolhinen, V. S.; Jokinen, A.

    2014-05-01

    A significant number of new measurements was undertaken by the ANDES “Measurements for advanced reactor systems” initiative. These new measurements include neutron inelastic scattering from 23Na, Mo, Zr, and 238U, neutron capture cross sections of 238U, 241Am, neutron induced fission cross sections of 240Pu, 242Pu, 241Am, 243Am and 245Cm, and measurements that explore the limits of the surrogate technique. The latter study the feasibility of inferring neutron capture cross sections for Cm isotopes, the neutron-induced fission cross section of 238Pu and fission yields and fission probabilities through full Z and A identification in inverse kinematics for isotopes of Pu, Am, Cm and Cf. Finally, four isotopes are studied which are important to improve predictions for delayed neutron precursors and decay heat by total absorption gamma-ray spectrometry (88Br, 94Rb, 95Rb, 137I). The measurements which are performed at state-of-the-art European facilities have the ambition to achieve the lowest possible uncertainty, and to come as close as is reasonably achievable to the target uncertainties established by sensitivity studies. An overview is presented of the activities and achievements, leaving detailed expositions to the various parties contributing to the conference.

  5. Actual evapotranspiration and precipitation measured by lysimeters: a comparison with eddy covariance and tipping bucket

    NASA Astrophysics Data System (ADS)

    Gebler, S.; Hendricks Franssen, H.-J.; Pütz, T.; Post, H.; Schmidt, M.; Vereecken, H.

    2014-12-01

    This study compares actual evapotranspiration (ETa) measurements by a set of six weighable lysimeters, ETa estimates obtained with the eddy covariance (EC) method, and potential crop evapotranspiration according to FAO (ETc-FAO) for the Rollesbroich site in the Eifel (Western Germany). The comparison of ETa measured by EC (including correction of the energy balance deficit) and by lysimeters is rarely reported in literature and allows more insight into the performance of both methods. An evaluation of ETa for the two methods for the year 2012 shows a good agreement with a total difference of 3.8% (19 mm) between the ETa estimates. The highest agreement and smallest relative differences (<8%) on monthly basis between both methods are found in summer. ETa was close to ETc-FAO, indicating that ET was energy limited and not limited by water availability. ETa differences between lysimeter, ETc-FAO, and EC were mainly related to differences in grass height caused by harvesting management and the EC footprint. The lysimeter data were also used to estimate precipitation amounts in combination with a filter algorithm for high precision lysimeters recently introduced by Peters et al. (2014). The estimated precipitation amounts from the lysimeter data show significant differences compared to the precipitation amounts recorded with a standard rain gauge at the Rollesbroich test site. For the complete year 2012 the lysimeter records show a 16% higher precipitation amount than the tipping bucket. With the help of an on-site camera the precipitation measurements of the lysimeters were analyzed in more detail. It was found that the lysimeters record more precipitation than the tipping bucket in part related to the detection of rime and dew, which contributes 17% to the yearly difference between both methods. In addition, fog and drizzle explain an additional 5.5% of the total difference. Larger differences are also recorded for snow and sleet situations. During snowfall, the

  6. Bias corrections of precipitation measurements across experimental sites in different ecoclimatic regions of western Canada

    NASA Astrophysics Data System (ADS)

    Pan, Xicai; Yang, Daqing; Li, Yanping; Barr, Alan; Helgason, Warren; Hayashi, Masaki; Marsh, Philip; Pomeroy, John; Janowicz, Richard J.

    2016-10-01

    This study assesses a filtering procedure on accumulating precipitation gauge measurements and quantifies the effects of bias corrections for wind-induced undercatch across four ecoclimatic regions in western Canada, including the permafrost regions of the subarctic, the Western Cordillera, the boreal forest, and the prairies. The bias corrections increased monthly precipitation by up to 163 % at windy sites with short vegetation and sometimes modified the seasonal precipitation regime, whereas the increases were less than 13 % at sites shielded by forest. On a yearly basis, the increase of total precipitation ranged from 8 to 20 mm (3-4 %) at sites shielded by vegetation and 60 to 384 mm (about 15-34 %) at open sites. In addition, the bias corrections altered the seasonal precipitation patterns at some windy sites with high snow percentage ( > 50 %). This study highlights the need for and importance of precipitation bias corrections at both research sites and operational networks for water balance assessment and the validation of global/regional climate-hydrology models.

  7. Early assessment of Integrated Multi-satellite Retrievals for Global Precipitation Measurement over China

    NASA Astrophysics Data System (ADS)

    Guo, Hao; Chen, Sheng; Bao, Anming; Behrangi, Ali; Hong, Yang; Ndayisaba, Felix; Hu, Junjun; Stepanian, Phillip M.

    2016-07-01

    Two post-real time precipitation products from the Integrated Multi-satellite Retrievals for Global Precipitation Measurement Mission (IMERG) are systematically evaluated over China with China daily Precipitation Analysis Product (CPAP) as reference. The IMERG products include the gauge-corrected IMERG product (IMERG_Cal) and the version of IMERG without direct gauge correction (IMERG_Uncal). The post-research TRMM Multisatellite Precipitation Analysis version 7 (TMPA-3B42V7) is also evaluated concurrently with IMERG for better perspective. In order to be consistent with CPAP, the evaluation and comparison of selected products are performed at 0.25° and daily resolutions from 12 March 2014 through 28 February 2015. The results show that: Both IMERG and 3B42V7 show similar performances. Compared to IMERG_Uncal, IMERG_Cal shows significant improvement in overall and conditional bias and in the correlation coefficient. Both IMERG_Cal and IMERG_Uncal perform relatively poor in winter and over-detect slight precipitation events in northwestern China. As an early validation of the GPM-era IMERG products that inherit the TRMM-era global satellite precipitation products, these findings will provide useful feedbacks and insights for algorithm developers and data users over China and beyond.

  8. Heavy precipitation retrieval from combined satellite observations and ground-based lightning measurements

    NASA Astrophysics Data System (ADS)

    Mugnai, A.; Dietrich, S.; Casella, D.; di Paola, F.; Formenton, M.; Sanò, P.

    2010-09-01

    We have developed a series of algorithms for the retrieval of precipitation (especially, heavy precipitation) over the Mediterranean area using satellite observations from the available microwave (MW) radiometers onboard low Earth orbit (LEO) satellites and from the visible-infrared (VIS-IR) SEVIRI radiometer onboard the European geosynchronous (GEO) satellite Meteosat Second Generation (MSG), in conjunction with lightning data from ground-based networks - such as ZEUS and LINET. These are: • A new approach for precipitation retrieval from space (which we call the Cloud Dynamics and Radiation Database approach, CDRD) that incorporates lightning and environmental/dynamical information in addition to the upwelling microwave brightness temperatures (TB’s) so as to reduce the retrieval uncertainty and improve the retrieval performance; • A new combined MW-IR technique for producing frequent precipitation retrievals from space (which we call PM-GCD technique), that uses passive-microwave (PM) retrievals in conjunction with lightning information and the Global Convection Detection (GCD) technique to discriminate deep convective clouds within the GEO observations; • A new morphing approach (which we call the Lightning-based Precipitation Evolving Technique, L-PET) that uses the available lightning measurements for propagating the rainfall estimates from satellite-borne MW radiometers to a much higher time resolution than the MW observations. We will present and discuss our combined MW/IR/lightning precipitation algorithms and analyses with special reference to some case studies over the western Mediterranean.

  9. Characteristics of global precipitable water in ENSO events revealed by COSMIC measurements

    NASA Astrophysics Data System (ADS)

    Teng, Wen-Hsin; Huang, Ching-Yuang; Ho, Shu-Peng; Kuo, Ying-Hwa; Zhou, Xin-Jia

    2013-08-01

    Precipitable water (PW) retrievals from FORMOSAT-3/Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) Global Positioning System (GPS) radio occultation (RO) measurements were analyzed and compared with those derived from Special Sensor Microwave/Imager (SSM/I) and Advanced Microwave Scanning Radiometer for Earth Observation System (AMSR-E) during the El Niño-Southern Oscillation (ENSO) events from 2007 to 2011. For the three ENSO events in 2007-2011, monthly mean binned COSMIC PW results are in a very high correlation (up to 0.98) with those of SSM/I and AMSR-E over the ocean, generally with root-mean-square differences less than 4 mm. PW retrievals from the three satellites are also of similar latitudinal variations. However, the PW is slightly underestimated by GPS RO, in particular, in the tropical regions. This underestimate may be caused partially by the fact that not all RO measurements can reach the surface. Inter-satellite PW anomaly comparisons for the winter months in the ENSO events, with respect to those during the neutral (non-ENSO) months, show consistent ENSO signals with major PW anomaly near the central Pacific in the warm event and near the Indonesian region and east of Australia in the two cold events. However, the 2007/2008 La Niña is somewhat less correlated for COSMIC with AMSR-E and SSM/I. For the stronger 2010/2011 La Niña, their PW anomalies are in higher correlations of about 0.8.

  10. Supporting Hydrometeorological Research and Applications with Global Precipitation Measurement (GPM) Products and Services

    NASA Technical Reports Server (NTRS)

    Liu, Zhong; Ostrenga, D.; Vollmer, B.; Deshong, B.; MacRitchie, K.; Greene, M.; Kempler, S.

    2016-01-01

    Precipitation is an important dataset in hydrometeorological research and applications such as flood modeling, drought monitoring, etc. On February 27, 2014, the NASA Global Precipitation Measurement (GPM) mission was launched to provide the next-generation global observations of rain and snow (http:pmm.nasa.govGPM). The GPM mission consists of an international network of satellites in which a GPM Core Observatory satellite carries both active and passive microwave instruments to measure precipitation and serve as a reference standard, to unify precipitation measurements from a constellation of other research and operational satellites. The NASA Goddard Earth Sciences (GES) Data and Information Services Center (DISC) hosts and distributes GPM data. The GES DISC is home to the data archive for the GPM predecessor, the Tropical Rainfall Measuring Mission (TRMM). GPM products currently available include the following:1. Level-1 GPM Microwave Imager (GMI) and partner radiometer products2. Goddard Profiling Algorithm (GPROF) GMI and partner products (Level-2 and Level-3)3. GPM dual-frequency precipitation radar and their combined products (Level-2 and Level-3)4. Integrated Multi-satellitE Retrievals for GPM (IMERG) products (early, late, and final run)GPM data can be accessed through a number of data services (e.g., Simple Subset Wizard, OPeNDAP, WMS, WCS, ftp, etc.). A newly released Unified User Interface or UUI is a single interface to provide users seamless access to data, information and services. For example, a search for precipitation products will not only return TRMM and GPM products, but also other global precipitation products such as MERRA (Modern Era Retrospective-Analysis for Research and Applications), GLDAS (Global Land Data Assimilation Systems), etc.New features and capabilities have been recently added in GIOVANNI to allow exploring and inter-comparing GPM IMERG (Integrated Multi-satelliE Retrievals for GPM) half-hourly and monthly precipitation

  11. A method for measuring precipitation parameters and raindrop size distributions using radar reflectivity and optical extinction

    NASA Technical Reports Server (NTRS)

    Ulbrich, C. W.; Atlas, D.

    1977-01-01

    A method of determining precipitation parameters from two remotely measurable quantities, the radar reflectivity factor and the optical extinction, is described. The raindrop size spectrum is approximated by a two-parameter exponential form; when these parameters are evaluated in terms of the radar reflectivity factor and the optical extinction, an exponential spectrum is obtained that is generally in very good agreement with the observed size spectrum. Other calculated precipitation parameters, such as rainfall rate and liquid water content, which are derived from the exponential approximation, also agree with experimental data. It is indicated that other combinations of two remote measurables can also be used to obtain more accurate estimates of precipitation parameters than can be obtained by the use of an empirical relationship.

  12. GPS Precipitable Water Measurements Used in the Analysis of California and Nevada Climate

    NASA Astrophysics Data System (ADS)

    Means, James Douglas

    Precipitable water (integrated water vapor) can be obtained from zenith travel-time delays of Global Positioning System (GPS) signals, if the atmospheric pressure and temperature at the site are known. There have been large numbers of GPS receivers deployed for geophysics research programs, but unfortunately most of these receivers do not have co-located barometers and thermometers. In this paper archived zenith delays are combined with estimates of GPS site station pressure and temperature from the North American Regional Reanalysis, in order to generate a seven year record of precipitable water at more than 500 sites. The precipitable water values calculated using this method have been found to be in good agreement with GPS precipitable water values from stations with barometers, as well as with radiosonde measurements of precipitable water. Precipitable water has a wide variation across the region, from just a few millimeters in the driest conditions to over 50 mm during strong episodes of the North American Monsoon. The spatial and temporal variations of precipitable water are examined, including the annual and diurnal cycles. Strong annual cycles are seen at almost all sites, and diurnal cycles are also present, increasing away from bodies of water and toward the south, where they reach more than 10% of the daily mean. Precipitable water is found to follow a lognormal distribution at all sites in the region, with some stations showing a small bimodal characteristic due to the influence of the North American Monsoon. An index is proposed that measures the bimodality and hence the "monsooniness" of a site. The elevation dependence of the precipitable water is examined and found to have an exponential decrease which is quite tightly followed in the fall, winter and spring, but more loosely in the summer. It has a greater scale height than has previously been measured elsewhere, ranging from 2.4 km in the winter to 3.1 km in the summer. The landward penetration of

  13. Developments and applications of the Global Satellite Mapping of Precipitation (GSMaP) for the Global Precipitation Measurement (GPM)

    NASA Astrophysics Data System (ADS)

    Kachi, Misako; Aonashi, Kazumasa; Kubota, Takuji; Shige, Shoichi; Ushio, Tomoo; Mega, Tomoaki; Yamamoto, Munehisa; Hamada, Atsushi; Seto, Shinta; Takayabu, Yukari N.; Oki, Riko

    2016-04-01

    The Global Satellite Mapping of Precipitation (GSMaP) is a global rainfall map based on a blended Microwave-Infrared product and has been developed in Japan for the Global Precipitation Measurement (GPM) mission. To fulfill gaps of passive microwave observations, we developed a method to interpolate observations between each microwave imager by utilizing information from the Infrared imagers on board the geostationary satellites, and achieved production of an hourly global rainfall map in 0.1-degree latitude/longitude grid. The latest GSMaP version 6 product was released in September 2014 to the public as one of Japanese GPM products after the launch of the GPM Core Observatory, which is Japan and U.S. joint mission and carrying both the Dual-frequency Precipitation Radar (DPR) and GPM Microwave Imager (GMI), in February 2014. In the next version (version 7), which is scheduled to be released in the summer 2016, we plan to apply databases produced from DPR instead of those from PR, and to introduce snow retrieval algorithm for the passive microwave instruments that have higher frequency channels. The GSMaP near-real-time version (GSMaP_NRT) product is available 4-hour after observation through the "JAXA Global Rainfall Watch" web site (http://sharaku.eorc.jaxa.jp/GSMaP) since 2008. To assure near-real-time data availability, the GSMaP_NRT system simplified part of the algorithm and its processing procedure. Therefore, the GSMaP_NRT product gives higher priority to data latency than accuracy. Since its data release, GSMaP_NRT data has been used by various users for various purposes, such as rainfall monitoring, flood alert and warning, drought monitoring, crop yield forecast, and agricultural insurance. There are, however, several requirements from users for GSMaP improvements not only for accuracy but also specification. Among those requests for data specification, the most popular ones are shortening of data latency time and higher horizontal resolution. To reduce

  14. Simultaneous measurements of waves and precipitating electrons near the equator in the outer radiation belt

    NASA Technical Reports Server (NTRS)

    Imhof, W. L.; Robinson, R. M.; Collin, H. L.; Wygant, J. R.; Anderson, R. R.

    1994-01-01

    An investigation of wave-particle interactions is made using several simultaneous electron and wave measurements performed at near-equatorial positions from the Combined Release and Radiation Effects Satellite (CRRES) satellite. Bursts of electron precipitation were observed, most frequently at local times near dawn. Examples of bursts are presented in which the fluxes of the precipitating electrons and the wave intensities are correlated with coefficients as high as 0.7. During bursts the frequencies of the enhanced waves spanned a wide range from 311 Hz to 3.11 kHz, and the energies of the enhanced electrons were in the range 1.7 keV to 288 keV. The changes of the precipitating fluxes were generally less pronounced at the lowest energies. On the basis of electron-cyclotron resonant calculations using the cold plasma densities and ambient magnetic fields taken from the CRRES measurements it was found that the wave frequencies and precipitating electron energies were generally consistent with those expected from electron resonance with parallel propagating whistler waves. The electron data of principal concern here were acquired in and about the loss cone with narrow angular resolution spectrometers covering the energy range 340 eV to 5 MeV. The wave data included electric field measurements spanning frequencies from 5 Hz to 400 kHz and magnetic field measurements from 5 Hz to 10 kHz.

  15. Status of High Latitude Precipitation Estimates: The Role of GPM in Advancing our Current Understanding

    NASA Astrophysics Data System (ADS)

    Behrangi, A.; Richardson, M.; Christensen, M.; Huffman, G. J.; Adler, R. F.; Stephens, G. L.; Lambrigtsen, B.

    2015-12-01

    This presentation reviews the current status of precipitation estimation from observation and reanalysis at high latitudes and discusses new insights gained by GPM. An intercomparison of high-latitude precipitation characteristics from observation-based and reanalysis products is performed. Precipitation products from GPM and the cloud profiling radar on the CloudSat satellite provide an independent assessment to other products which have already been widely used, these being the observationally-based GPCP, GPCC and CMAP and the reanalyses ERA-Interim, MERRA and NCEP-DOE. Seasonal and annual total precipitation in both hemispheres poleward of 55° latitude is considered in all products, and GPM and CloudSat products are used to assess frequency of precipitation occurrence by phase, defined as rain, snow or mixed phase. Estimates of snowfall over Antarctica and Greenland are compared from various products. A number of disagreements on regional or seasonal scales are identified which will be reported and discussed. These estimates from observations and reanalyses provide useful insights for diagnostic assessment of precipitation products in high latitudes, quantifying the current uncertainties among observations and reanalyses, and establishing a benchmark for assessment of climate models.

  16. Solid Precipitation Measurement Intercomparison in Bismarck, North Dakota, from 1988 through 1997

    USGS Publications Warehouse

    Ryberg, Karen R.; Emerson, Douglas G.; Macek-Rowland, Kathleen M.

    2009-01-01

    A solid precipitation measurement intercomparison was recommended by the World Meteorological Organization (WMO) and was initiated after approval by the ninth session of the Commission for Instruments and Methods of Observation. The goal of the intercomparison was to assess national methods of measuring solid precipitation against methods whose accuracy and reliability were known. A field study was started in Bismarck, N. Dak., during the 1988-89 winter as part of the intercomparison. The last official field season of the WMO intercomparison was 1992-93; however, the Bismarck site continued to operate through the winter of 1996-97. Precipitation events at Bismarck were categorized as snow, mixed, or rain on the basis of descriptive notes recorded as part of the solid precipitation intercomparison. The rain events were not further analyzed in this study. Catch ratios (CRs) - the ratio of the precipitation catch at each gage to the true precipitation measurement (the corrected double fence intercomparison reference) - were calculated. Then, regression analysis was used to develop equations that model the snow and mixed precipitation CRs at each gage as functions of wind speed and temperature. Wind speed at the gages, functions of temperature, and upper air conditions (wind speed and air temperature at 700 millibars pressure) were used as possible explanatory variables in the multiple regression analysis done for this study. The CRs were modeled by using multiple regression analysis for the Tretyakov gage, national shielded gage, national unshielded gage, AeroChem gage, national gage with double fence, and national gage with Wyoming windshield. As in earlier studies by the WMO, wind speed and air temperature were found to influence the CR of the Tretyakov gage. However, in this study, the temperature variable represented the average upper air temperature over the duration of the event. The WMO did not use upper air conditions in its analysis. The national shielded and

  17. The development of a model to infer precipitation from microwave measurements

    NASA Technical Reports Server (NTRS)

    Fowler, M. G.; Hardy, K. R.; Sze, N. D.

    1976-01-01

    To permit the inference of precipitation amounts from radiometric measurements, a radiative interaction model was developed. This model uses a simple computational scheme to determine the effects of rain upon brightness temperatures and can be used with a statistical inversion procedure to invert for rain rate. Precipitating cloud models was also developed and used with the microwave model for frequencies of 19.35 and 37 GHz to determine the variability of the microwave-rain rate relationship on a global and seasonal basis.

  18. Mars heavy ion precipitating flux as measured by Mars Atmosphere and Volatile EvolutioN

    NASA Astrophysics Data System (ADS)

    Leblanc, F.; Modolo, R.; Curry, S.; Luhmann, J.; Lillis, R.; Chaufray, J. Y.; Hara, T.; McFadden, J.; Halekas, J.; Eparvier, F.; Larson, D.; Connerney, J.; Jakosky, B.

    2015-11-01

    In the absence of an intrinsic dipole magnetic field, Mars' O+ planetary ions are accelerated by the solar wind. Because of their large gyroradius, a population of these planetary ions can precipitate back into Mars' upper atmosphere with enough energy to eject neutrals into space via collision. This process, referred to as sputtering, may have been a dominant atmospheric loss process during earlier stages of our Sun. Yet until now, a limited number of observations have been possible; Analyzer of Space Plasmas and Energetic Atoms-3/Mars Express observed such a precipitation only during extreme conditions, suggesting that sputtering might be not as intense as theoretically predicted. Here we describe one example of precipitation of heavy ions during quiet solar conditions. Between November 2014 and April 2015, the average precipitating flux is significant and in agreement with predictions. From these measured precipitating fluxes, we estimate that a maximum of 1.0 × 1024 O/s could have been lost due to sputtering.

  19. Remote sensing of precipitable water over the oceans from Nimbus-7 microwave measurements

    NASA Technical Reports Server (NTRS)

    Prabhakara, C.; Change, H. D.; Chang, A. T. C.

    1981-01-01

    Global maps of precipitable water over derived from scanning multichannel microwave radiometer (SMMR) data reveal salient features associated with ocean currents and the large scale general circulation in the atmosphere. Nimbus-7 SMMR brightness temperature measurements in the 21 and 18 GHz channels are used to sense the precipitable water in the atmospheric over oceans. The difference in the brightness temperature (T sub 21 -T sub 18), both in the horizontal and vertical polarization, is found to be essentially a function of the precipitable water in the atmosphere. An equation, based on the physical consideration of the radiative transfer in the microwave region, is developed to relate the precipitable water to (T sub 21 - T sub 18). It shows that the signal (T sub 21- T sub 18) does not suffer severely from the noise introduced by variations in the sea surface temperature, surface winds, and liquid water content in non rain clouds. The rms deviation between the estimated precipitable water from SMMR data and that given by the closely coincident ship radiosondes is about 0.25 g/ sq cm

  20. Global precipitation measurement (GPM) mission and its application for flood monitoring

    NASA Astrophysics Data System (ADS)

    Kachi, Misako; Oki, Riko; Shimizu, Shuji; Kojima, Masahiro

    2006-12-01

    The Global Precipitation Measurement (GPM) mission is an expanded follow-on mission of the current Tropical Rainfall Measuring Mission (TRMM). The concept of GPM is, 1) TRMM-like, non-sun-synchronous core satellite carrying the Dual-frequency Precipitation Radar (DPR) to be developed by Japan and a microwave radiometer to be developed by United States, and 2) constellation of satellites in polar orbit, each carrying a microwave radiometer provided by international partner. The constellation system of GPM will make it possible every three-hour global precipitation measurement. Because of its concept on focusing high-accurate and high-frequent global precipitation observation, GPM has a unique position among future Earth observation missions. GPM international partnerships will embody concept of GEOSS. Observation data acquired by the GPM mission are expected to be used for both Earth environmental research and various societal benefit areas. One of most expected application fields is weather prediction. Use of high-frequent observation in numerical weather prediction models will improve weather forecasting especially for extreme events such as tropical cyclones and heavy rain. Another example is application to flood monitoring and forecasting. Recent increasing needs of real-time flood information required from many countries especially in Asia will strongly support operational application of GPM products in this field.

  1. Methods and Results for a Global Precipitation Measurement (GPM) Validation Network Prototype

    NASA Technical Reports Server (NTRS)

    Morris, Kenneth R.; Schwaller, Mathew R.

    2010-01-01

    As one component of a ground validation system to meet requirements for the upcoming Global Precipitation Measurement (GPM) mission, a quasi-operational prototype a system to compare satellite- and ground-based radar measurements has been developed. This prototype, the GPM Validation Network (VN), acquires data from the Precipitation Radar (PR) on the Tropical Rainfall Measuring Mission (TRMM) satellite and from ground radar (GR) networks in the continental U.S. and participating international sites. PR data serve as a surrogate for similar observations from the Dual-frequency Precipitation Radar (DPR) to be present on GPM. Primary goals of the VN prototype are to understand and characterize the variability and bias of precipitation retrievals between the PR and GR in various precipitation regimes at large scales, and to improve precipitation retrieval algorithms for the GPM instruments. The current VN capabilities concentrate on comparisons of the base reflectivity observations between the PR and GR, and include support for rain rate comparisons. The VN algorithm resamples PR and GR reflectivity and other 2-D and 3-D data fields to irregular common volumes defined by the geometric intersection of the instrument observations, and performs statistical comparisons of PR and GR reflectivity and estimated rain rates. Algorithmic biases and uncertainties introduced by traditional data analysis techniques are minimized by not performing interpolation or extrapolation of data to a fixed grid. The core VN dataset consists of WSR-88D GR data and matching PR orbit subset data covering 21 sites in the southeastern U. S., from August, 2006 to the present. On average, about 3.5 overpass events per month for these WSR-88D sites meet VN criteria for significant precipitation, and have matching PR and GR data available. This large statistical sample has allowed the relative calibration accuracy and stability of the individual ground radars, and the quality of the PR reflectivity

  2. Multiscale Modeling of Inclusions and Precipitation Hardening in Metal Matrix Composites: Application to Advanced High-Strength Steels

    SciTech Connect

    Askari, Hesam A.; Zbib, Hussein M.; Sun, Xin

    2013-06-30

    In this study, the strengthening effect of inclusions and precipitates in metals is investigated within a multiscale approach that utilizes models at various length scales, namely, Molecular Mechanics (MM), discrete Dislocation Dynamics (DD), and an Eigenstrain Inclusion Method (EIM). Particularly, precipitates are modeled as hardsoft particles whose stress fields interact with dislocations. The stress field resulting from the elastic mismatch between the particles and the matrix is accounted for through the EIM. While the MM method is employed for the purpose of developing rules for DD for short range interaction between a single dislocation and an inclusion, the DD method is used to predict the strength of the composite resulting from the interaction between ensembles of dislocations and particles. As an application to this method, the mechanical behavior of Advanced High Strength Steel (AHSS) is investigated and the results are then compared to the experimental data. The results show that the finely dispersive precipitates can strengthen the material by pinning the dislocations up to a certain shear stress and retarding the recovery, as well as annihilation of dislocations. The DD results show that strengthening due to nano sized particles is a function of the density and size of the precipitates. This size effect is then explained using a mechanistic model developed based on dislocation-particle interaction.

  3. Quantifying Systematic Errors and Total Uncertainties in Satellite-based Precipitation Measurements

    NASA Astrophysics Data System (ADS)

    Tian, Y.; Peters-Lidard, C. D.

    2010-12-01

    Determining the uncertainties in precipitation measurements by satellite remote sensing is of fundamental importance to many applications. These uncertainties result mostly from the interplay of systematic errors and random errors. In this presentation, we will summarize our recent efforts in quantifying the error characteristics in satellite-based precipitation estimates. Both systematic errors and total uncertainties have been analyzed for six different TRMM-era precipitation products (3B42, 3B42RT, CMORPH, PERSIANN, NRL and GSMaP). For systematic errors, we devised an error decomposition to separate errors in precipitation estimates into three independent components, hit biases, missed precipitation and false precipitation. This decomposition scheme reveals more error features and provides a better link to the error sources than conventional analysis, because in the latter these error components tend to cancel one another when aggregated or averaged in space or time. Our analysis reveals that the six different products share many error features. For example, they all detected strong precipitation (> 40 mm/day) well, but with various biases. They tend to over-estimate in summer and under-estimate in winter. They miss a significant amount of light precipitation (< 10 mm/day). In addition, hit biases and missed precipitation are the two leading error sources. However, their systematic errors also exhibit substantial differences, especially in winter and over rough topography, which greatly contribute to the uncertainties. To estimate the measurement uncertainties, we calculated the measurement spread from the ensemble of these six quasi-independent products. A global map of measurement uncertainties was thus produced. The map yields a global view of the error characteristics and their regional and seasonal variations, and reveals many undocumented error features over areas with no validation data available. The uncertainties are relatively small (40-60%) over the

  4. Retrieving moisture profiles from precipitable water measurements using a variational data assimilation approach

    SciTech Connect

    Guo, Y.R.; Zou, X.; Kuo, Y.H.

    1996-04-01

    Atmospheric moisture distribution is directly related to the formation of clouds and precipitation and affects the atmospheric radiation and climate. Currently, several remote sensing systems can measure precipitable water (PW) with fairly high accuracy. As part of the development of an Integrated Data Assimilation and Sounding System in support of the Atmospheric Radiation Measurement Program, retrieving the 3-D water vapor fields from PW measurements is an important problem. A new four dimensional variational (4DVAR) data assimilation system based on the Penn State/National Center for Atmospheric Research (NCAR) mesoscale model (MM5) has been developed by Zou et al. (1995) with the adjoint technique. In this study, we used this 4DVAR system to retrieve the moisture profiles. Because we do not have a set of real observed PW measurements now, the special soundings collected during the Severe Environmental Storm and Mesoscale Experiment (SESAME) in 1979 were used to simulate a set of PW measurements, which were then assimilated into the 4DVAR system. The accuracy of the derived water vapor fields was assessed by direct comparison with the detailed specific humidity soundings. The impact of PW assimilation on precipitation forecast was examined by conducting a series of model forecast experiments started from the different initial conditions with or without data assimilation.

  5. Influence of particle charging on TEOM measurements in the presence of an electrostatic precipitator

    NASA Astrophysics Data System (ADS)

    Meyer, N. K.; Lauber, A.; Nussbaumer, T.; Burtscher, H.

    2009-03-01

    The efficiency of an electrostatic precipitator (ESP) for reducing wood combustion emissions was investigated. Real-time measurements were conducted by directly reading the change in frequency of the tapered element in a Thermo Scientific 1400a TEOM. These measurements have been shown to be influenced by the charge on the aerosols reaching the tapered element such that the TEOM overestimates mass concentration. This electrostatic effect was crosschecked with particle mass concentration and particle number concentration measurements where no influence was observed. Placing a radioactive neutraliser prior to the TEOM leads to agreement between observed ESP efficiencies as measured by both the TEOM, mass filters and a CPC.

  6. Advanced Chemical Precipitation Softening. Training Module 2.217.4.77.

    ERIC Educational Resources Information Center

    McMullen, L. D.

    This document is an instructional module package prepared in objective form for use by an instructor familiar with the operation and maintenance of a chemical precipitation softening system. Included are objectives, instructor guides, student handouts and transparency masters. This is the third level of a three module series. This module considers…

  7. Modeling investigation of the stability and irradiation-induced evolution of nanoscale precipitates in advanced structural materials

    SciTech Connect

    Wirth, Brian

    2015-04-08

    Materials used in extremely hostile environment such as nuclear reactors are subject to a high flux of neutron irradiation, and thus vast concentrations of vacancy and interstitial point defects are produced because of collisions of energetic neutrons with host lattice atoms. The fate of these defects depends on various reaction mechanisms which occur immediately following the displacement cascade evolution and during the longer-time kinetically dominated evolution such as annihilation, recombination, clustering or trapping at sinks of vacancies, interstitials and their clusters. The long-range diffusional transport and evolution of point defects and self-defect clusters drive a microstructural and microchemical evolution that are known to produce degradation of mechanical properties including the creep rate, yield strength, ductility, or fracture toughness, and correspondingly affect material serviceability and lifetimes in nuclear applications. Therefore, a detailed understanding of microstructural evolution in materials at different time and length scales is of significant importance. The primary objective of this work is to utilize a hierarchical computational modeling approach i) to evaluate the potential for nanoscale precipitates to enhance point defect recombination rates and thereby the self-healing ability of advanced structural materials, and ii) to evaluate the stability and irradiation-induced evolution of such nanoscale precipitates resulting from enhanced point defect transport to and annihilation at precipitate interfaces. This project will utilize, and as necessary develop, computational materials modeling techniques within a hierarchical computational modeling approach, principally including molecular dynamics, kinetic Monte Carlo and spatially-dependent cluster dynamics modeling, to identify and understand the most important physical processes relevant to promoting the “selfhealing” or radiation resistance in advanced materials containing

  8. Temperature and precipitation fluctuations in the Czech Republic during the period of instrumental measurements

    NASA Astrophysics Data System (ADS)

    Brázdil, Rudolf; Zahradníček, Pavel; Pišoft, Petr; Štěpánek, Petr; Bělínová, Monika; Dobrovolný, Petr

    2012-10-01

    The history of early meteorological observations using instruments in the Czech Lands is described (the longest temperature series for Prague-Klementinum starts in 1775, precipitation series for Brno in 1803). Using the PRODIGE method, long-term monthly temperature and precipitation series from selected secular stations were homogenised (for 10 and 12 stations, respectively). All the seasonal and annual temperature series for the common period 1882-2010 show a significant positive linear trend with accelerated warming from the 1970s onwards. No significant linear trends were disclosed in the series of seasonal and annual precipitation totals. Correlation coefficients between the Czech series analysed decrease as distances between measuring stations increase. A sharper decrease of correlations for precipitation totals displays much weaker spatial relationships than those for mean temperatures. The highest correlations between all stations appeared in 1921-1950, the lowest in 1891-1920 (temperature) and 1981-2010 (precipitation). Wavelet analysis reveals that very distinct annual cycles as well as the slightly weaker semi-annual ones are better expressed for temperature series than for precipitation. Statistically significant cycles longer than 1 year are temporally unstable and sporadic for precipitation, while in the temperature series cycles of 7.4-7.7 and 17.9-18.4 years were recorded as significant by all stations in 1882-2010 (quasi-biennial cycle of 2.1-2.2 years for half the stations). Czech homogenous temperature series correlate best with those of the Northern Hemisphere for annual, spring and summer values (with significant correlation coefficients between 0.60 and 0.70), but this relation is temporally unstable. Circulation indices, such as the North Atlantic Oscillation Index (NAOI) and the Central European Zonal Index (CEZI), may explain the greater part of Czech temperature variability, especially from December to March and for the winter; however

  9. Frequency of tropical precipitating clouds as observed by the Tropical Rainfall Measuring Mission Precipitation Radar and ICESat/Geoscience Laser Altimeter System

    NASA Astrophysics Data System (ADS)

    Casey, Sean P. F.; Dessler, Andrew E.; Schumacher, Courtney

    2007-07-01

    Convective clouds in the tropics can be grouped into three categories: shallow clouds with cloud top heights near 2 km above the surface, midlevel congestus clouds with tops near the 0°C level, and deep convective clouds capped by the tropopause. This trimodal distribution is visible in cloud data from the Geoscience Laser Altimeter System (GLAS), carried aboard the Ice, Cloud, and land Elevation Satellite (ICESat), as well as in precipitation data from the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR). Fractional areal coverage (FAC) data is calculated at each of the three levels to describe how often optically thick clouds or precipitation are seen at each level. By dividing the FAC of TRMM PR-observed precipitation by the FAC of thick GLAS/ICESat-observed clouds, we derive the fraction of clouds that are precipitating. We find that the tropical mean precipitating cloud fraction is low: 3.7% for shallow clouds, 6.5% for midlevel clouds, and 24.1% for deep clouds.

  10. Precipitation Estimates for Hydroelectricity

    NASA Technical Reports Server (NTRS)

    Tapiador, Francisco J.; Hou, Arthur Y.; de Castro, Manuel; Checa, Ramiro; Cuartero, Fernando; Barros, Ana P.

    2011-01-01

    Hydroelectric plants require precise and timely estimates of rain, snow and other hydrometeors for operations. However, it is far from being a trivial task to measure and predict precipitation. This paper presents the linkages between precipitation science and hydroelectricity, and in doing so it provides insight into current research directions that are relevant for this renewable energy. Methods described include radars, disdrometers, satellites and numerical models. Two recent advances that have the potential of being highly beneficial for hydropower operations are featured: the Global Precipitation Measuring (GPM) mission, which represents an important leap forward in precipitation observations from space, and high performance computing (HPC) and grid technology, that allows building ensembles of numerical weather and climate models.

  11. Coordinated measurements of low-energy electron precipitation and scintilations/TEC in the auroral oval

    SciTech Connect

    Basu, S.; Mackenzie, E.; Basu, S.

    1983-11-01

    A geostationary satellite transmitting at 244 MHz was employed in a coordinated observation study of low energy electron precipitation in the auroral oval from DMSP/F2 (a satellite in sun-synchronous circular orbit) and phase and amplitude scintillations from Goose Bay, Labrador. Total electron content and magnetometer measurements indicate that the precipitation event onset was 10 min prior to the DMSP pass. Within this time scale, the ionization generated in the F region could reach the topside, so that the thermal sensor on board the DMSP satellite could measure a factor of 2-3 density enhancement. The phase-to-amplitude ratio changed drastically by comparison to quiet magnetic times, implying that increased convection velocities during magnetic disturbances were partially responsible for the enhanced phase scintillation. 49 references.

  12. A Study of Realistic Sampling-Variability Effects on Precipitation Measurements

    NASA Astrophysics Data System (ADS)

    O'Dell, K.; Larsen, M.

    2015-12-01

    Previous studies have investigated the effects of sampling variability on precipitation measurements using analytically driven simulation models. To explore the effects with more realism, data-derived distribution functions were used to develop a drop­-by-drop rain event simulation. Data based probability distributions for the number of raindrop arrivals in each sample and the event averaged drop size distribution were found using measurements of several precipitation events recorded by a two dimensional video disdrometer. Using these probability distribution functions, Monte-Carlo simulated rain events were developed and explored. The simulated events were sampled at intervals of several different durations associated with different average numbers of raindrops in each sample. The simulations reveal new insights to exploring the sample-size dependent convergence and distribution of bulk rainfall quantities (e.g. Z, R, Dm) as compared to the intrinsic ensemble values.

  13. Tropical intercontinental optical measurement network of aerosol, precipitable water and total column ozone

    NASA Technical Reports Server (NTRS)

    Holben, B. N.; Tanre, D.; Reagan, J. A.; Eck, T. F.; Setzer, A.; Kaufman, Y. A.; Vermote, E.; Vassiliou, G. D.; Lavenu, F.

    1992-01-01

    A new generation of automatic sunphotometers is used to systematically monitor clear sky total column aerosol concentration and optical properties, precipitable water and total column ozone diurnally and annually in West Africa and South America. The instruments are designed to measure direct beam sun, solar aureole and sky radiances in nine narrow spectral bands from the UV to the near infrared on an hourly basis. The instrumentation and the algorithms required to reduce the data for subsequent analysis are described.

  14. A method to measure winter precipitation and sublimation under global warming conditions

    NASA Astrophysics Data System (ADS)

    Herndl, Markus; Slawitsch, Veronika; von Unold, Georg

    2016-04-01

    Winter precipitation and snow sublimation are fundamental components of the alpine moisture budget. Much work has been done in the study of these processes and its important contribution to the annual water balance. Due to the above-average sensitivity of the alpine region to climate change, a change in the importance and magnitude of these water balance parameters can be expected. To determine these effects, a lysimeter-facility enclosed in an open-field climate manipulation experiment was established in 2015 at AREC Raumberg-Gumpenstein which is able to measure winter precipitation and sublimation under global warming conditions. In this facility, six monolithic lysimeters are equipped with a snow cover monitoring system, which separates the snow cover above the lysimeter automatically from the surrounding snow cover. Three of those lysimeters were exposed to a +3°C scenario and three lysimeters to ambient conditions. Weight data are recorded every minute and therefore it is possible to get high-resolution information about the water balance parameter in winter. First results over two snow event periods showed that the system can measure very accurately winter precipitation and sublimation especially in comparison with other measurement systems and usually used models. Also first trends confirm that higher winter temperatures may affect snow water equivalent and snow cover duration. With more data during the next years using this method, it is possible to quantify the influence of global warming on water balance parameters during the winter periods.

  15. On improving rainfall and solid precipitation weighing-gauge measurements using laboratory experiments

    NASA Astrophysics Data System (ADS)

    Colli, Matteo; Landolt, Scott; Rasmussen, Roy; Govanni Lanza, Luca; La Barbera, Paolo

    2013-04-01

    Short interval snowfall, drizzle and light rainfall events can be hard to measure with precipitation gauges due to sampling limitations, wind effects, and noise. The noise observed in the data sampling can often be greater than the detectable signal from a real precipitation event. In addition wind effects can induce differential air pressure on the measurement devices inside the gauges increasing the signal noise. Various algorithms have been devised to help reduce noise and other unwanted effects in precipitation gauge measurements. Most of these algorithms have focused on the removal of wind effects, while others have focused on reducing temperature dependencies. Recent laboratory testing has demonstrated the ability to reproduce some of these anomalies observed in precipitation measurements during field trial campaigns. Assessing the factors contributing to these anomalies is required to accurately simulate these conditions in the laboratory. It is also important to understand these factors to support the selection of the appropriate natural conditions to be simulated in the laboratory environment. This work details the wind-free laboratory testing of some of the above-mentioned effects in order to develop a measurement interpretation algorithm capable of improving the accuracy of the Geonor T-200B vibrating wire gauge and the OTT Pluvio2 weighing gauge. Specifically, these experiments will examine the effects of temperature oscillations on the various gauge components, as well as snow capping and the potential heat-plume problem associated with heating the gauge orifices. These experiments use an artificial snow-generation machine: a snowflake simulation system in which snowflake sizes and snowfall rates can be controlled in a wind-free environment. The positive outcome of this preliminary phase would result in the transfer of the tested methodologies to the on-going WMO Solid Precipitation InterComparison Experiment (SPICE) campaign. The laboratory

  16. Reconstructing solid precipitation from snow depth measurements and a land surface model

    NASA Astrophysics Data System (ADS)

    Cherry, Jessie Ellen; Tremblay, L. Bruno; DéRy, Stephen J.; Stieglitz, Marc

    2005-09-01

    The amount and distribution of snowfall in the Arctic has significant effects on global climate. However, measurements of snowfall from gauges are strongly biased. A new method is described for reconstructing snowfall from observed snow depth records, meteorological observations, and running the NASA Seasonal-to-Interannual Prediction Project Catchment Land Surface Model (NSIPP CLSM) in an inverse mode. This method is developed and tested with observations from Reynolds Creek Experimental Watershed. Results show snowfall can be accurately reconstructed on the basis of how much snow must have fallen to produce the observed snow depth. The mean cumulative error (bias) of the reconstructed precipitation for 11 snow seasons is 29 mm snow water equivalent (SWE) for the corrected gauge measurement compared to ‒77 mm SWE for the precipitation from the corrected snow gauges. This means the root-mean-square error of reconstructed solid precipitation is 30% less than that of gauge corrections. The intended application of this method is the pan-Arctic landmass, where estimates of snowfall are highly uncertain but where more than 60 years of historical snow depth and air temperature records exist.

  17. Reconstructing solid precipitation from snow depth measurements and a land surface model

    NASA Astrophysics Data System (ADS)

    Cherry, Jessie Ellen; Tremblay, L. Bruno; Déry, Stephen J.; Stieglitz, Marc

    2005-09-01

    The amount and distribution of snowfall in the Arctic has significant effects on global climate. However, measurements of snowfall from gauges are strongly biased. A new method is described for reconstructing snowfall from observed snow depth records, meteorological observations, and running the NASA Seasonal-to-Interannual Prediction Project Catchment Land Surface Model (NSIPP CLSM) in an inverse mode. This method is developed and tested with observations from Reynolds Creek Experimental Watershed. Results show snowfall can be accurately reconstructed on the basis of how much snow must have fallen to produce the observed snow depth. The mean cumulative error (bias) of the reconstructed precipitation for 11 snow seasons is 29 mm snow water equivalent (SWE) for the corrected gauge measurement compared to -77 mm SWE for the precipitation from the corrected snow gauges. This means the root-mean-square error of reconstructed solid precipitation is 30% less than that of gauge corrections. The intended application of this method is the pan-Arctic landmass, where estimates of snowfall are highly uncertain but where more than 60 years of historical snow depth and air temperature records exist.

  18. Precipitation susceptibility in marine stratocumulus and shallow cumulus from airborne measurements

    NASA Astrophysics Data System (ADS)

    Jung, Eunsil; Albrecht, Bruce A.; Sorooshian, Armin; Zuidema, Paquita; Jonsson, Haflidi H.

    2016-09-01

    Precipitation tends to decrease as aerosol concentration increases in warm marine boundary layer clouds at fixed liquid water path (LWP). The quantitative nature of this relationship is captured using the precipitation susceptibility (So) metric. Previously published works disagree on the qualitative behavior of So in marine low clouds: So decreases monotonically with increasing LWP or cloud depth (H) in stratocumulus clouds (Sc), while it increases and then decreases in shallow cumulus clouds (Cu). This study uses airborne measurements from four field campaigns on Cu and Sc with similar instrument packages and flight maneuvers to examine if and why So behavior varies as a function of cloud type. The findings show that So increases with H and then decreases in both Sc and Cu. Possible reasons for why these results differ from those in previous studies of Sc are discussed.

  19. Performance of the Falling Snow Retrieval Algorithms for the Global Precipitation Measurement (GPM) Mission

    NASA Technical Reports Server (NTRS)

    Skofronick-Jackson, Gail; Munchak, Stephen J.; Ringerud, Sarah

    2016-01-01

    Retrievals of falling snow from space represent an important data set for understanding the Earth's atmospheric, hydrological, and energy cycles, especially during climate change. Estimates of falling snow must be captured to obtain the true global precipitation water cycle, snowfall accumulations are required for hydrological studies, and without knowledge of the frozen particles in clouds one cannot adequately understand the energy and radiation budgets. While satellite-based remote sensing provides global coverage of falling snow events, the science is relatively new and retrievals are still undergoing development with challenges remaining). This work reports on the development and testing of retrieval algorithms for the Global Precipitation Measurement (GPM) mission Core Satellite, launched February 2014.

  20. Global Precipitation Measurement (GPM) Spacecraft Lithium Ion Battery Micro-Cycling Investigation

    NASA Technical Reports Server (NTRS)

    Dakermanji, George; Lee, Leonine; Spitzer, Thomas

    2016-01-01

    The Global Precipitation Measurement (GPM) spacecraft was jointly developed by NASA and JAXA. It is a Low Earth Orbit (LEO) spacecraft launched on February 27, 2014. The power system is a Direct Energy Transfer (DET) system designed to support 1950 watts orbit average power. The batteries use SONY 18650HC cells and consist of three 8s by 84p batteries operated in parallel as a single battery. During instrument integration with the spacecraft, large current transients were observed in the battery. Investigation into the matter traced the cause to the Dual-Frequency Precipitation Radar (DPR) phased array radar which generates cyclical high rate current transients on the spacecraft power bus. The power system electronics interaction with these transients resulted in the current transients in the battery. An accelerated test program was developed to bound the effect, and to assess the impact to the mission.

  1. Combining and comparing weather radar measurements and rain gauge measurements of precipitation in a fruit growing area

    NASA Astrophysics Data System (ADS)

    Sivertsen, T. H.; Rafoss, T.

    2003-04-01

    A small fruit growing area of southern Norway is chosen as a pilot area. This area contains four automated meteorological stations owned by The Norwegian Crop Research Institute. The measurements made at the stations are hourly recordings of precipitation, air temperature, leaf wetness and relative humidity of the air, plus some additional measurements at some stations. The area has a relatively smooth topography with hills and no mountains. The highest point is located about 300 m above the sea level, and the lowest 15 m above sea level. The remote sensing research group at The Norwegian Meteorological Institute is providing the hourly radar measurements of precipitation, from two different weather radars. All the precipitation data used is documented according to a system developed by The Norwegian Crop Research Institute, and for the growing season ahead data will be distributed to the local private extension service, but this year there will be no development of biological models serving the fruit growers (apple scab etc) using all the additional relevant data. The outcome of the use of the operational use of the data in the coming growing season, will be comparing the data from the different sources, and looking closer at the possible significance of the use of a documentation system for the data from different sources. Finally the quality of the data is discussed, as well as the possible steps to be taken for future and extended use of such data.

  2. On the consistency of 2-D video disdrometers in measuring microphysical parameters of solid precipitation

    NASA Astrophysics Data System (ADS)

    Bernauer, F.; Hürkamp, K.; Rühm, W.; Tschiersch, J.

    2015-08-01

    Detailed characterization and classification of precipitation is an important task in atmospheric research. Line scanning 2-D video disdrometer devices are well established for rain observations. The two orthogonal views taken of each hydrometeor passing the sensitive area of the instrument qualify these devices especially for detailed characterization of nonsymmetric solid hydrometeors. However, in case of solid precipitation, problems related to the matching algorithm have to be considered and the user must be aware of the limited spatial resolution when size and shape descriptors are analyzed. Clarifying the potential of 2-D video disdrometers in deriving size, velocity and shape parameters from single recorded pictures is the aim of this work. The need of implementing a matching algorithm suitable for mixed- and solid-phase precipitation is highlighted as an essential step in data evaluation. For this purpose simple reproducible experiments with solid steel spheres and irregularly shaped Styrofoam particles are conducted. Self-consistency of shape parameter measurements is tested in 38 cases of real snowfall. As a result, it was found that reliable size and shape characterization with a relative standard deviation of less than 5 % is only possible for particles larger than 1 mm. For particles between 0.5 and 1.0 mm the relative standard deviation can grow up to 22 % for the volume, 17 % for size parameters and 14 % for shape descriptors. Testing the adapted matching algorithm with a reproducible experiment with Styrofoam particles, a mismatch probability of less than 3 % was found. For shape parameter measurements in case of real solid-phase precipitation, the 2-DVD shows self-consistent behavior.

  3. The Southern-Appalachians Precipitation Measurement and Hydrology Project - A Prototype for Middle Mountains Everywhere

    NASA Astrophysics Data System (ADS)

    Barros, A. P.; Wilson, A. M.; Tao, J.; Miller, D.

    2012-12-01

    -mountains of the Himalayas and the cloud forests of the American Cordillera. The TRMM (Tropical Rainfall Measurement Mission) prompted a great leap forward in our understanding of the water cycle in mountainous regions. However, estimates of rainfall errors indicate that near 90% of the instances when raingauges record rainfall and the PR misses detection correspond to LR events. The upcoming Global Precipitation Measurement (GPM) mission will bring much improved temporal sampling frequency and higher accuracy. Nevertheless, to capture the spatial (and temporal) variability of precipitation in mountainous regions at the resolution required by science and applications, there is a critical need to downscale satellite-based precipitation products to the space-time scales at which hydrological processes work. One approach is the integration of satellite- and ground-based observations and models. This implies that a set of observations can be interpreted and placed in the correct environmental context to provide physically-meaningful constraints to the models. An overview of findings of the Southern-Appalachians Precipitation Measurement (PMM) project including headwater hydrology and ongoing downscaling efforts will be presented.

  4. Using laboratory experiments to improve reliability in rainfall and solid precipitation weighing-gauge measurements

    NASA Astrophysics Data System (ADS)

    Landolt, S.; Colli, M.; La Barbera, P.; Lanza, L. G.; Rasmussen, R.

    2012-12-01

    Snowfall, drizzle and light rainfall events (defined as events with intensities < 12 mm/h) can often be hard to detect over a short-time resolution due to sampling limitations, wind effects, and noise influencing the weighing-gauge measurements. In many instances, the noise observed in the data sampling can often be greater than the detectable signal from a real precipitation event. Wind can be one of the largest contributors to gauge undercatch, and can also increase noise due to wind pumping on the measurement devices inside the gauges. Various algorithms have been devised to help reduce noise and other unwanted effects in precipitation gauge measurements. Most of these algorithms have focused on the removal of wind effects, while others have focused on reducing temperature dependencies and snow capping. Recent laboratory testing has demonstrated the ability to reproduce some of these anomalies observed in precipitation measurements during field trial campaigns. Assessing the factors contributing to these anomalies is required to accurately simulate these conditions in the laboratory. It is also important to understand these factors to support the selection of the appropriate natural conditions to be simulated in the laboratory environment. Significant research has already been undertaken to measure the influence of wind affecting the gauges. This work details the wind-free laboratory testing of some of the above-mentioned algorithms developed to improve measurement accuracy from the Geonor T-200b vibrating wire gauge and the OTT Pluvio2 weighing gauges. Specifically, these experiments will examine the effects of temperature oscillations and their subsequent effects on the various gauge components, as well as snow capping and the potential heat-plume problem associated with heating the gauges. These experiments employ an artificial snow-generation machine; a snowflake simulation system in which snowflake sizes and snowfall rates can be controlled in a wind

  5. Relationship of Global Precipitation Measurement (GPM) Mission to Global Change Research

    NASA Technical Reports Server (NTRS)

    Smith, Eric A.; Starr, David OC. (Technical Monitor)

    2002-01-01

    In late 2001, the Global Precipitation Measurement (GPM) mission was approved as a new start by the National Aeronautics and Space Administration (NASA). This new mission is motivated by a number of scientific questions that are posed over a range of space and time scales that generally fall within the discipline of the global water and energy cycle (GWEC). Recognizing that satellite rainfall datasets are now a foremost tool for understanding global climate variability out to decadal scales and beyond, for improving weather forecasting, and for producing better predictions of hydrometeorological processes including short-term hazardous flooding and seasonal fresh water resources assessment, a comprehensive and internationally sanctioned global measuring strategy has led to the GPM mission. The GPM mission plans to expand the scope of rainfall measurement through use of a multi-member satellite constellation that will be contributed by a number of world nations. This talk overviews the GPM scientific research program that has been fostered within NASA, then focuses on scientific progress that is being made in various research areas in the course of the mission formulation phase that are of interest to the global change scientific community. This latter part of the talk addresses research issues that have become central to the GPM science implementation plan concerning: (1) the rate of global water cycling through the atmosphere and surface and the relationship of precipitation variability to the sustained rate of the water cycle; (2) the relationship between climate change and cloud macrophysical- microphysical processes; and (3) the general improvement in measuring precipitation at the fundamental microphysical level that will take place during the GPM era and an explanation of how these improvements are expected to come about.

  6. Influence of precipitation on (7)Be concentrations in air as measured by CTBTO global monitoring system.

    PubMed

    Kusmierczyk-Michulec, J; Gheddou, A; Nikkinen, M

    2015-06-01

    Data collected by the International Monitoring System (IMS) during 2009-2012 were used to study influence of precipitation and relative humidity on changes in (7)Be concentrations in atmosphere. The significant decrease in (7)Be concentrations, corresponding to measurements collected by stations located within Intertropical Convergence Zone (ITCZ) is demonstrated. This effect can be attributed to the process of enhanced wet deposition within the ITCZ. To quantify this effect data collected by IMS stations within ITCZ were thoroughly analyzed. It was found that the atmospheric content of (7)Be strongly decreases under the rain conditions. The rain mediated depletion of (7)Be to half of its before rain value, needs about 62 h in case of light precipitation, while in the case of moderate precipitation about 38 h is needed. In addition the evaluated impact of humidity showed that increase in relative humidity by 20%, for example from 70% ± 5% to 90% ± 5% causes almost a double decrease in beryllium concentration in surface air.

  7. Evidence of Urban Precipitation Anomalies from Satellite and Ground-Based Measurements

    NASA Technical Reports Server (NTRS)

    Shepherd, J. Marshall; Manyin, M.; Negri, Andrew

    2004-01-01

    Urbanization is one of the extreme cases of land use change. Most of world's population has moved to urban areas. Although currently only 1.2% of the land is considered urban, the spatial coverage and density of cities are expected to rapidly increase in the near future. It is estimated that by the year 2025, 60% of the world's population will live in cities. Human activity in urban environments also alters weather and climate processes. However, our understanding of urbanization on the total Earth-weather-climate system is incomplete. Recent literature continues to provide evidence that anomalies in precipitation exist over and downwind of major cities. Current and future research efforts are actively seeking to verify these literature findings and understand potential cause-effect relationships. The novelty of this study is that it utilizes rainfall data from multiple satellite data sources (e.g. TRMM precipitation radar, TRMM-geosynchronous-rain gauge merged product, and SSM/I) and ground-based measurements to identify spatial anomalies and temporal trends in precipitation for cities around the world. Early results will be presented and placed within the context of weather prediction, climate assessment, and societal applications.

  8. Evidence of Urban Precipitation Anomalies from Satellite and Ground-Based Measurements

    NASA Technical Reports Server (NTRS)

    Shepherd, J. M.; Manyin, M.; Negri, A.

    2004-01-01

    Urbanization is one of the extreme cases of land use change. Most of world s population has moved to urban areas. Although currently only 1.2% of the land is considered urban, the spatial coverage and density of cities are expected to rapidly increase in the near future. It is estimated that by the year 2025,60% of the world s population will live in cities. Human activity in urban environments also alters weather and climate processes. However, our understanding of urbanization on the total Earth-weather-climate system is incomplete. Recent literature continues to provide evidence that anomalies in precipitation exist over and downwind of major cities. Current and future research efforts are actively seeking to verify these literature findings and understand potential cause- effect relationships. The novelty of this study is that it utilizes rainfall data from multiple satellite data sources (e.g. TRMM precipitation radar, TRMM-geosynchronous-rain gauge merged product, and SSM/I) and ground-based measurements to identify spatial anomalies and temporal trends in precipitation for cities around the world. Early results will be presented and placed within the context of weather prediction, climate assessment, and societal applications.

  9. MARG - A Low Cost Solid State Microwave Areal Precipitation Measurement System

    NASA Astrophysics Data System (ADS)

    Paulitsch, Helmut; Dombai, Ferenc; Cremonini, Roberto; Bechini, Renzo

    2014-05-01

    Water is an essential resource for us so the measurements of its movement throughout the whole cycle is very important. The rainfall is discontinuous in space and in time having large natural variability unlike many other meteorological parameters. The widely used method for getting relatively accurate precipitation data over land is the combination of radar rainfall estimations and rain gauge data. The typically used radar data is coming from long-range weather radars operating in C or S band, or from mini radars operating in X band which is attenuating heavily in strong precipitation. Using such radar data we are facing several constraints: operating costs and limitations of long range radars, X band radars can be blocked totally in heavy thunderstorms even in short range, dual polarization solutions are expensive, etc. Recognizing that an important gap exists in instrumental precipitation measurements over land a consortium has been organized and a project has been established to develop a new measurement device, the so called Microwave Areal Rain Gauge (MARG). MARG is based on FMCW radar principle using solid state transmitter and digital signal processing and operating in C band. The MARG project aims to provide an innovative, real-time, low-cost, user friendly and accurate sensor technology to monitor and to measure continuously the rainfall intensity distribution over an area around some thousand square km. The MARG project proposal has been granted by the EU in FP7-SME-2012 funding scheme. The developed instrument is able to monitor in real-time intensity and spatial distribution of rainfall in rural and urban environments and can be operated by commercial weather data and value-added forecast product suppliers. To achieve sufficient isolation between the transmitter and receiver modules, and to avoid using complex and expensive microwave components, two parabolic antennae are used to transmit and receive the FMCW signal. The radar frontend operates in the

  10. The magnet measurement facility for the Advanced Photon Source

    SciTech Connect

    Kim, S.H.; Doose, C.; Hogrefe, R.; Kim, K.; Merl, R.

    1993-10-01

    A magnet measurement facility has been developed to measure the prototype and production magnets for the Advance Photon Source. The measurement facility is semi-automatic in measurement control and data analysis. One dipole system and three rotating coil measurement systems for quadrupole and sextupole magnets and corresponding probe coils are described.

  11. ASSESSMENT OF THE STATE OF PRECIPITATION IN ALUMINUM CASTING A356.2 ALLOY USING NONDESTRUCTIVE MICROSTRUCTURE ELECTRONIC PROPERTY MEASUREMENTS

    SciTech Connect

    Kiattisaksri, P.; Gibbs, P. J.; Koenig, K.; Pfeif, E. A.; Mishra, B.; Olson, D. L.; Lasseigne, A. N.; Mendez, P. F.

    2010-02-22

    Application of nondestructive electronic property measurements to assess the strengthening of Mg{sub 2}Si precipitates in aluminum A356.2 casting has been demonstrated. The results indicated the evolution of precipitation phase through over aging with increased cooling time or thickness of the cast part. The classical optimum precipitation behavior has been characterized and verified with thermal analysis, thermoelectric power, low frequency impedance, and micro hardness measurements. A proposed practice to use nondestructive electronic property measurement tools to assess aluminum casting for acceptable mechanical properties after mold shake out is presented.

  12. Comparison of global precipitation climatology products derived from ground- and satellite-based measurements

    NASA Astrophysics Data System (ADS)

    Liu, Zhong

    2014-11-01

    Satellite-based products increasingly take an important role in filling data gaps in data sparse regions around the world. In recent years, precipitation products that utilize multi-satellite and multi-sensor datasets have been gaining more popularity than products from a single sensor or satellite. Adjusted with gauge and ground radar data, satellitebased products have been significantly improved. However the history of satellite-based precipitation products is relatively short compared to the length of 30 years in the definition for climatology from the World Meteorological Organization (WMO). For example, the NASA/JAXA Tropical Rainfall Measuring Mission (TRMM) has been in operation for over 16 years since 1997. The length of TRMM is far shorter than those from ground observations, raising a question whether TRMM climatology products are good enough for research and applications. In this study, three climatologies derived from ground observations (Global Precipitation Climatology Centre (GPCC) and Willmott and Matsuura (WM)) and a blended product (the TRMM Multi-Satellite Precipitation Analysis (TMPA) monthly product or 3B43) are compared on a global scale to assess the performance and weaknesses of the TMPAderived climatology. Results show that the 3B43 climatology matches well with the two gauge-based climatologies in all seasons in terms of spatial distribution, zonal means as well as seasonal variations. However, high variations in rain rates are found in light rain regions such as the Sahara Desert. Large negative biases (3B43

  13. Tropical Rainfall Measuring Mission (TRMM) Precipitation Data and Services for Research and Applications

    NASA Technical Reports Server (NTRS)

    Liu, Zhong; Ostrenga, Dana; Teng, William; Kempler, Steven

    2012-01-01

    Precipitation is a critical component of the Earth's hydrological cycle. Launched on 27 November 1997, TRMM is a joint U.S.-Japan satellite mission to provide the first detailed and comprehensive data set of the four-dimensional distribution of rainfall and latent heating over vastly under-sampled tropical and subtropical oceans and continents (40 S - 40 N). Over the past 14 years, TRMM has been a major data source for meteorological, hydrological and other research and application activities around the world. The purpose of this short article is to inform that the NASA Goddard Earth Sciences Data and Information Services Center (GES DISC) provides TRMM archive and near-real-time precipitation data sets and services for research and applications. TRMM data consist of orbital data from TRMM instruments at the sensor s resolution, gridded data at a range of spatial and temporal resolutions, subsets, ground-based instrument data, and ancillary data. Data analysis, display, and delivery are facilitated by the following services: (1) Mirador (data search and access); (2) TOVAS (TRMM Online Visualization and Analysis System); (3) OPeNDAP (Open-source Project for a Network Data Access Protocol); (4) GrADS Data Server (GDS); and (5) Open Geospatial Consortium (OGC) Web Map Service (WMS) for the GIS community. Precipitation data application services are available to support a wide variety of applications around the world. Future plans include enhanced and new services to address data related issues from the user community. Meanwhile, the GES DISC is preparing for the Global Precipitation Measurement (GPM) mission which is scheduled for launch in 2014.

  14. Initial Evaluation of Dual Frequency Radar (DPR) on Global Precipitation Measurement (GPM) Core Observatory and Global Precipitation Map (GSMaP)

    NASA Astrophysics Data System (ADS)

    Oki, R.; Kachi, M.; Kubota, T.; Masaki, T.; Kaneko, Y.; Takayabu, Y. N.; Iguchi, T.; Nakamura, K.

    2014-12-01

    The Global Precipitation Measurement (GPM) Core Observatory was successfully launched on February 28, 2014 (JST) from the JAXA Tanegashima Space Center by the H-IIA F23 rocket. The GPM mission is a satellite program led by Japan and the U.S. to measure the global distribution of precipitation accurately in a sufficient frequency. The GPM Core Observatory carries the Dual-frequency Precipitation Radar (DPR) developed by the Japan Aerospace Exploration Agency (JAXA) and the National Institute of Information and Communications Technology (NICT), and GPM Microwave Imager (GMI) developed by the National Aeronautics and Space Administration (NASA). The frequent precipitation measurement about every three hours will be achieved by constellation satellites with microwave radiometers or microwave sounders, which are provided by international partners. JAXA also provides the Global Change Observation Mission (GCOM) - Water (GCOM-W) named "SHIZUKU," as one of the constellation satellites. The Japanese GPM research project conducts scientific activities on algorithm development, ground validation, application research. JAXA develops the DPR Level 1 algorithm, and the NASA-JAXA Joint Algorithm Team develops the DPR Level 2 and DPR-GMI combined Level 2 algorithms. JAXA also develops the new version of Global Satellite Mapping of Precipitation (GSMaP) algorithm, which is hourly and 0.1-degree spatial resolution rain map, as one of the national products.After the 2-months initial checkout of the satellite and the sensors, calibration and validation of DPR and other products have been implemented toward the public release. For DPR evaluation includes: (1) sensitivity, observation range, etc., (2) consistency with TRMM, (3) comparison with ground rain gauge data, (4) ground based Ka radar validation and others. Initial results of quick data evaluation, validation and status of data processing will be presented.

  15. NMR measurement of hydrodynamic dispersion in porous media subject to biofilm mediated precipitation reactions.

    PubMed

    Fridjonsson, Einar O; Seymour, Joseph D; Schultz, Logan N; Gerlach, Robin; Cunningham, Alfred B; Codd, Sarah L

    2011-03-01

    Noninvasive measurements of hydrodynamic dispersion by nuclear magnetic resonance (NMR) are made in a model porous system before and after a biologically mediated precipitation reaction. Traditional magnetic resonance imaging (MRI) was unable to detect the small scale changes in pore structure visualized during light microscopy analysis after destructive sampling of the porous medium. However, pulse gradient spin echo nuclear magnetic resonance (PGSE NMR) measurements clearly indicated a change in hydrodynamics including increased pore scale mixing. These changes were detected through time-dependent measurement of the propagator by PGSE NMR. The dynamics indicate an increased pore scale mixing which alters the preasymptotic approach to asymptotic Gaussian dynamics governed by the advection diffusion equation. The methods described here can be used in the future to directly measure the transport of solutes in biomineral-affected porous media and contribute towards reactive transport models, which take into account the influence of pore scale changes in hydrodynamics.

  16. Evaluation of TRMM multi-satellite precipitation analysis (TMPA) against terrestrial measurement over a humid sub-tropical basin, India

    NASA Astrophysics Data System (ADS)

    Kumar, Dheeraj; Gautam, Amar Kant; Palmate, Santosh S.; Pandey, Ashish; Suryavanshi, Shakti; Rathore, Neha; Sharma, Nayan

    2016-04-01

    To support the GPM mission which is homologous to its predecessor, the Tropical Rainfall Measuring Mission (TRMM), this study has been undertaken to evaluate the accuracy of Tropical Rainfall Measuring Mission multi-satellite precipitation analysis (TMPA) daily-accumulated precipitation products for 5 years (2008-2012) using the statistical methods and contingency table method. The analysis was performed on daily, monthly, seasonal and yearly basis. The TMPA precipitation estimates were also evaluated for each grid point i.e. 0.25° × 0.25° and for 18 rain gauge stations of the Betwa River basin, India. Results indicated that TMPA precipitation overestimates the daily and monthly precipitation in general, particularly for the middle sub-basin in the non-monsoon season. Furthermore, precision of TMPA precipitation estimates declines with the decrease of altitude at both grid and sub-basin scale. The study also revealed that TMPA precipitation estimates provide better accuracy in the upstream of the basin compared to downstream basin. Nevertheless, the detection capability of daily TMPA precipitation improves with increase in altitude for drizzle rain events. However, the detection capability decreases during non-monsoon and monsoon seasons when capturing moderate and heavy rain events, respectively. The veracity of TMPA precipitation estimates was improved during the rainy season than during the dry season at all scenarios investigated. The analyses suggest that there is a need for better precipitation estimation algorithm and extensive accuracy verification against terrestrial precipitation measurement to capture the different types of rain events more reliably over the sub-humid tropical regions of India.

  17. The pioneer study of fog detection and horizontal precipitation measurement at subtropical highland of Taiwan

    NASA Astrophysics Data System (ADS)

    Lin, P. H.; Lai, K. L.

    2010-07-01

    Heavy rainfall in highland caused by the interaction of tropical storms and sharp terrain is one of the major natural disasters in Taiwan. But there is no quantitative measurement on the fog and its horizontal precipitation (HP) to estimate the storage of water by plants in the highland region of Taiwan. In this pioneer study, we studied the fog detection and its horizontal precipitation amount, existence length and monthly variation at Kuan-Wu recreation area in Shei-Pa National Park of Taiwan. The 20-year (1988~2007) record length of meteorological data at Kuan-Wu was analyzed first to build up the background information of the local weather. The FDID (fog detection and interception device) including two fog detectors, two fog collectors and auto-shooting digital camera was delivered in this field program. The parallel experiment indoor with a fog tunnel also confirms the performance of polypropylene net used in FDID. FDID has collected data in the field over one year, and the preliminary results show that some components of FDID present the capability of fog event detection and give quantitative data of fog interception. The digital images in 5-min interval via fog collector data detected over 90% happening of fog event in the data available days. Through the RGB diagnosis in different pixel domains (different distances to the camera) on the digital images, the fog events are distinguished into light, medium and heavy fog events. The characteristics of daily and monthly variations of fog events could be explained through the terrain and local climate effects well. We also found the horizontal precipitation from fog provides ~11% extra water amount in the no-rain days. The happened possibility of fog & stratus cloud with The MTSAT geostationary IR channels by Central Weather Bureau is also validated by the FDID in-situ measurement. It shows that the remote sensing product of fog detection in nighttime has good correlation with FDID ground measurement.

  18. High resolution hydrological modeling with measured precipitation data for the city of Amsterdam

    NASA Astrophysics Data System (ADS)

    van Vossen, Jojanneke; Schuurmans, Hanneke; Siemerink, Martijn; van Leeuwen, Elgard; Oudhuis, Richard

    2014-05-01

    Assessing measures to reduce flooding in densely populated urban areas require a high level of detail to properly analyse the hydrological response to precipitation events. This means detailed data (for example elevation and landuse) and fast models that can cope with this level of detail. This also indicates the value of having a similar level of detail in precipitation data. We present an approach in which Dutch National Rainfall Radar data are combined with a new approach to hydrological modeling called 3di. This is illustrated for a case in the city of Amsterdam to assess the effects of precipitation events and the possibilities for suitable measures in the public space to reduce the effects of flooding. Dutch National Rainfall Radar is a consortium of water authorities and the industry and scientific experts/universities/research centers to improve the available radar data in the Netherlands. This is achieved by making a composite of the radar stations in The Netherlands together with German and Belgian radar stations. In addition, the composite image is calibrated with local rainfall stations. 3Di is a novel approach to calculate the hydrological response of catchments as a function of properties, such as surface elevation and land use. Because of the ability of the model to take the detail of the elevation and land-use (both 0,5x0m5 meter) into the calculations, this model allows for a very detailed modeling of the hydrological response of urban areas to precipitation events. In addition, the model is extremely fast and allows for real-time and interactive changes in the geometry, making it a very powerful tool to assess the effects of measures in the public space for reducing flooding. We illustrate this approach for a case for the city of Amsterdam, a densely populated, low-lying city in The Netherlands. The obtained level of detail allows to study which houses are flooded, which roads remain available for emergency services etc. The model is used to show

  19. Surge Pressure Mitigation in the Global Precipitation Measurement Mission Core Propulsion System

    NASA Technical Reports Server (NTRS)

    Scroggins, Ashley R.; Fiebig, Mark D.

    2014-01-01

    The Global Precipitation Measurement (GPM) mission is an international partnership between NASA and JAXA whose Core spacecraft performs cutting-edge measurements of rainfall and snowfall worldwide and unifies data gathered by a network of precipitation measurement satellites. The Core spacecraft's propulsion system is a blowdown monopropellant system with an initial hydrazine load of 545 kg in a single composite overwrapped propellant tank. At launch, the propulsion system contained propellant in the tank and manifold tubes upstream of the latch valves, with low-pressure helium gas in the manifold tubes downstream of the latch valves. The system had a relatively high beginning-of- life pressure and long downstream manifold lines; these factors created conditions that were conducive to high surge pressures. This paper discusses the GPM project's approach to surge mitigation in the propulsion system design. The paper describes the surge testing program and results, with discussions of specific difficulties encountered. Based on the results of surge testing and pressure drop analyses, a unique configuration of cavitating venturis was chosen to mitigate surge while minimizing pressure losses during thruster maneuvers. This paper concludes with a discussion of overall lessons learned with surge pressure testing for NASA Goddard spacecraft programs.

  20. Variability of precipitation in complex terrain and the investigation of representativeness of measurements for the Matre catchment area, Western Norway.

    NASA Astrophysics Data System (ADS)

    Skjerdal, M.; Reuder, J.; Villanger, F.

    2009-04-01

    Orography is strongly affecting precipitation. Especially over complex terrain, the precipitation fields can show high spatial variability even over very small scales. Along the Western coast of Norway with its large precipitation amounts of up to above 3000 mm per year, an improved understanding of the spatial precipitation patterns is of large socio-economic impact, as it can improve both the prediction of floods and landslides and the water management for hydro power plants. The producers of hydroelectric power continuously want the water resources to be utilized in the best suited way. Control and supervision of the water resources are therefore of the utmost economic importance. To get an overview over the water resource situation, it is essential to know about the spatial and temporal distribution of precipitation. In cooperation with the Norwegian power company BKK, 20 HOBO rain gauges and two Aanderaa weather stations have been deployed between 22 and 898 meters above sea level in the catchment area for the Matre water system in Western Norway in the period May - October 2009. The main purpose of the project is to investigate the horizontal variability and the altitude dependence of precipitation in complex terrain under different synoptic conditions in this catchment area. Moreover, the representativeness of a few single point measurements on the total precipitation amount of the whole catchment area has been addressed. The total amount of precipitation recorded by the 20 rain gauges during the deployment period ranges between 535 mm and 1190 mm, which indicate the large variability within the catchment area. Analysis of the data with respect to wind direction shows that 75 % of the total precipitation amount during the measurement period arrives when the wind direction is S - SW. During a high precipitation event, which will be investigated in more detail, amounts of precipitation between 58 mm - 121 mm within a 24-hour period have been observed during a

  1. Measuring advances in HVAC distribution system designs

    SciTech Connect

    Franconi, Ellen

    1998-07-01

    Substantial commercial building energy savings have been achieved by improving the performance of the HVAC distribution system. The energy savings result from distribution system design improvements, advanced control capabilities, and use of variable-speed motors. Yet, much of the commercial building stock remains equipped with inefficient systems. Contributing to this is the absence of a definition for distribution system efficiency as well as the analysis methods for quantifying performance. This research investigates the application of performance indices to assess design advancements in commercial building thermal distribution systems. The index definitions are based on a first and second law of thermodynamics analysis of the system. The second law or availability analysis enables the determination of the true efficiency of the system. Availability analysis is a convenient way to make system efficiency comparisons since performance is evaluated relative to an ideal process. A TRNSYS simulation model is developed to analyze the performance of two distribution system types, a constant air volume system and a variable air volume system, that serve one floor of a large office building. Performance indices are calculated using the simulation results to compare the performance of the two systems types in several locations. Changes in index values are compared to changes in plant energy, costs, and carbon emissions to explore the ability of the indices to estimate these quantities.

  2. Measuring Advances in HVAC Distribution System Design

    SciTech Connect

    Franconi, E.

    1998-05-01

    Substantial commercial building energy savings have been achieved by improving the performance of the HV AC distribution system. The energy savings result from distribution system design improvements, advanced control capabilities, and use of variable-speed motors. Yet, much of the commercial building stock remains equipped with inefficient systems. Contributing to this is the absence of a definition for distribution system efficiency as well as the analysis methods for quantifying performance. This research investigates the application of performance indices to assess design advancements in commercial building thermal distribution systems. The index definitions are based on a first and second law of thermodynamics analysis of the system. The second law or availability analysis enables the determination of the true efficiency of the system. Availability analysis is a convenient way to make system efficiency comparisons since performance is evaluated relative to an ideal process. A TRNSYS simulation model is developed to analyze the performance of two distribution system types, a constant air volume system and a variable air volume system, that serve one floor of a large office building. Performance indices are calculated using the simulation results to compare the performance of the two systems types in several locations. Changes in index values are compared to changes in plant energy, costs, and carbon emissions to explore the ability of the indices to estimate these quantities.

  3. In situ measurements and radar observations of a severe storm - Electricity, kinematics, and precipitation

    NASA Technical Reports Server (NTRS)

    Byrne, G. J.; Few, A. A.; Stewart, M. F.; Conrad, A. C.; Torczon, R. L.

    1987-01-01

    Electric field measurements made inside a multicell severe storm in Oklahoma in 1983 with a balloon-borne instrument are presented. The properties of the electric charge regions, such as altitude, thickness, and charge concentrations, are studied. These measurements are analzyed with meteorological measurements of temperature and humidity, and balloon tracking and radar observations. The relation between the electric charge structure and the precipitation and kinematic features of the storm is examined. The data reveal that the cell exhibits a bipolar charge structure with negative charge below positive charge. The average charge concentrations of the two regions are estimated as -1.2 and 0.15 nC/cu m, respectively; the upper positive charge is about 6 km in vertical extent, and the lower negative charge is less than 1 km in vertical extent.

  4. Charge measurements of particles exiting electrostatic precipitators. Final report Oct 78-Oct 79

    SciTech Connect

    McDonald, J.R.; Anderson, M.H.; Mosley, R.B.

    1980-04-01

    The report gives results of an investigation of particle charging in positive and negative corona discharge as a function of temperature from 38 to 343C in order to establish, especially at hot-side electrostatic precipitator (ESP) temperatures, the relative effectiveness of the two possible methods of charging. Charge values on individual particles exiting two laboratory ESPs were measured in an experimental apparatus utilizing a Millikan cell. Measurements were directed at fine particles with radii between 0.3 and 1.5 micrometers. Measurements were obtained for redispersed fly ash particles carried in air at temperatures from 38 to 343C. The electrode geometries and electrical operating conditions utilized were typical of full-scale ESPs.

  5. The comparison of IR and MW ground-based measurements of total precipitable water

    NASA Astrophysics Data System (ADS)

    Berezin, I. A.; Virolainen, Ya. A.; Timofeyev, Yu. M.; Poberovskii, A. V.

    2016-05-01

    Water vapor is one of the basic climate gases playing a key role in various processes at different altitudes of the Earth's atmosphere. An intercomparison and validation of different total precipitable water (TPW) measurement methods are important for determining the true accuracy of these methods, the shared use of data from multiple sources, the creation of data archives of different measurements, etc. In this paper, the TPW values obtained from measurements of solar IR spectral radiation (~8-9 μm absorption band) and thermal MW radiation of the atmosphere (1.35 cm absorption line) for 138 days of observation are compared. Measurements have been carried out from March 2013 to June 2014 at Peterhof station of the St. Petersburg State University in (59.88° N, 29.82° E). It is shown that MW measurements usually give higher TPW values than IR measurements. The bias between the two methods varies from 1 to 8% for small and large TPW values, respectively. With increasing TPW values, the bias reduces and for TPW > 1 cm it is ~1%. Standard deviation (SD) between the two methods reaches 7% for TPW < 0.4 cm and 3-5% for TPW > 1 cm. These data show the high quality of both remote sensing methods. Moreover, the IR measurements have a higher accuracy than MW measurements for small TPW values.

  6. Advanced interferometric profile measurements through refractive media

    SciTech Connect

    Koev, Stephan T.; Ghodssi, Reza

    2008-09-15

    Optical profilers are valuable tools for the characterization of microelectromechanical systems (MEMSs). They use phase sifting interferometry (PSI) or vertical scanning interferometry to measure the topography of microscale structures with nanometer resolution. However, for many emerging MEMS applications, the sample needs to be imaged while placed in a liquid or in a package with a glass window. The increased refractive index of the transparent medium degrades the interference image contrast and prevents any measurement of the sample. We report on the modification of a Veeco NT1100 optical profiler to enable PSI measurements through refractive media. This approach can be applied to any other optical profiler with PSI capability. The modification consists in replacing the original illumination source with a custom-built narrow linewidth source, which increases the coherence length of the light and the contrast of the interference image. We present measurements taken with the modified configuration on samples covered with 3 mm water or 500 {mu}m glass, and we compare them to measurements of uncovered samples. We show that the measurement precision is only slightly reduced by the water and glass, and that it is still sufficiently high for typical MEMS applications. The described method can be readily used for measuring through other types and thicknesses of refractive materials.

  7. Global Precipitation Measurement. Report 1; Summary of the First GPM Partners Planning Workshop

    NASA Technical Reports Server (NTRS)

    Shepherd, J. Marshall; Mehta, Amita; Smith, Eric A. (Editor); Adams, W. James (Editor)

    2002-01-01

    This report provides a synopsis of the proceedings of the First Global Precipitation Measurement (GPM) Partners Planning Workshop held at the University of Maryland, College Park, from May 16 to 18, 2001. GPM consists of a multi-member global satellite constellation (i.e., an international set of satellite missions) and the accompanying scientific research program, with the main goal of providing frequent, accurate, and globally distributed precipitation measurements essential in understanding several fundamental issues associated with the global water and energy cycle (GWEC). The exchange of scientific and technical information at this and subsequent GPM workshops between representatives from around the world represents a key step in the formulation phase of GPM mission development. The U.S. National Aeronautics and Space Agency (NASA), the National Space Development Agency of Japan (NASDA), and other interested agencies from nations around the world seek to observe, understand, and model the Earth system to learn how it is changing and what consequences these changes have on life, particularly as they pertain to hydrological processes and the availability of fresh water resources. GWEN processes are central to a broader understanding of the Earth system.

  8. Calcite precipitation rates in the field: Measurement and prediction for a travertine-depositing stream

    SciTech Connect

    Herman, J.S.; Lorah, M.M. )

    1988-10-01

    Rates of calcite precipitation from a travertine-depositing stream were determined from changes in stream composition between consecutive sampling points and were compared with rates predicted from a laboratory-derived rate law. The agreement in rates was generally within an order of magnitude and routinely within a factor of 3. Least agreement between measured and predicted rates was obtained for sections of flowpath where relatively little change in bulk chemical composition occurred, which were the sections with the greatest mass transfer calculation error, and for the stream segment including a waterfall, which was the section with the greatest error in estimated surface area. Reaction rate obtained from the mass of calcite precipitated onto seed crystals placed in the stream significantly underestimated the mass transfer rate. For the travertine-depositing stream of Warm River Cave and Falling Spring Creek, Virginia, the coupling of equilibrium speciation models with mass balance calculations and simple field measurements allowed successful field-based quantification of reaction rates.

  9. Multidirectional mobilities: Advanced measurement techniques and applications

    NASA Astrophysics Data System (ADS)

    Ivarsson, Lars Holger

    Today high noise-and-vibration comfort has become a quality sign of products in sectors such as the automotive industry, aircraft, components, households and manufacturing. Consequently, already in the design phase of products, tools are required to predict the final vibration and noise levels. These tools have to be applicable over a wide frequency range with sufficient accuracy. During recent decades a variety of tools have been developed such as transfer path analysis (TPA), input force estimation, substructuring, coupling by frequency response functions (FRF) and hybrid modelling. While these methods have a well-developed theoretical basis, their application combined with experimental data often suffers from a lack of information concerning rotational DOFs. In order to measure response in all 6 DOFs (including rotation), a sensor has been developed, whose special features are discussed in the thesis. This transducer simplifies the response measurements, although in practice the excitation of moments appears to be more difficult. Several excitation techniques have been developed to enable measurement of multidirectional mobilities. For rapid and simple measurement of the loaded mobility matrix, a MIMO (Multiple Input Multiple Output) technique is used. The technique has been tested and validated on several structures of different complexity. A second technique for measuring the loaded 6-by-6 mobility matrix has been developed. This technique employs a model of the excitation set-up, and with this model the mobility matrix is determined from sequential measurements. Measurements on ``real'' structures show that both techniques give results of similar quality, and both are recommended for practical use. As a further step, a technique for measuring the unloaded mobilities is presented. It employs the measured loaded mobility matrix in order to calculate compensation forces and moments, which are later applied in order to compensate for the loading of the

  10. Ground-Based Cloud and Atmospheric Boundary Layer Observations for the Project: High Definition Clouds and Precipitation for Advancing Climate Prediction, HD(CP)2

    NASA Astrophysics Data System (ADS)

    Hirsikko, A.; Ebell, K.; Ulrich, U.; Schween, J. H.; Bohn, B.; Görsdorf, U.; Leinweber, R.; Päschke, E.; Baars, H.; Seifert, P.; Klein Baltink, H.

    2014-12-01

    The German research initiative ''High Definition Clouds and Precipitation for advancing Climate Prediction, HD(CP)2'' aims for an improved representation of clouds and precipitation in climate models. Model development and its evaluation require comprehensive observational datasets. A specific work package was established to create uniform and documented observational datasets for the HD(CP)2 data base. Datasets included ground-based remote-sensing (Doppler lidars, ceilometers, microwave radiometers, and cloud radars) and in-situ (meteorological and radiation sensors) measurements. Four supersites (Jülich ObservatorY for Cloud Evolution (JOYCE), Lindenberg Meteorological Observatory - Richard Assmann Observatory (RAO), and Leipzig Aerosol and Cloud Remote Observations System (LACROS) in Germany, and Cabauw experimental site for atmospheric research (Cesar) in the Netherlands) are finalizing the operational procedures to provide quality controlled (and calibrated if possible) remote-sensing and in-situ observations, retrievals on atmospheric boundary layer state (e.g. winds, mixing layer height, humidity and temperature), and cloud macro and micro physical properties with uncertainty estimations or at least quality flags. During the project new processing and retrieval methods were developed if no commonly agreed or satisfying methods were available. Especially, large progress was made concerning uncertainty estimation and automated quality control. Additionally, the data from JOYCE are used in a radiative closure studies under cloudy conditions to evaluate retrievals of cloud properties. The current status of work progress will be presented.

  11. Comparison of precipitation chemistry measurements obtained by the Canadian Air and Precipitation Monitoring Network and National Atmospheric Deposition Program for the period 1995-2004

    USGS Publications Warehouse

    Wetherbee, Gregory A.; Shaw, Michael J.; Latysh, Natalie E.; Lehmann, Christopher M.B.; Rothert, Jane E.

    2010-01-01

    Precipitation chemistry and depth measurements obtained by the Canadian Air and Precipitation Monitoring Network (CAPMoN) and the US National Atmospheric Deposition Program/National Trends Network (NADP/NTN) were compared for the 10-year period 1995–2004. Colocated sets of CAPMoN and NADP instrumentation, consisting of precipitation collectors and rain gages, were operated simultaneously per standard protocols for each network at Sutton, Ontario and Frelighsburg, Ontario, Canada and at State College, PA, USA. CAPMoN samples were collected daily, and NADP samples were collected weekly, and samples were analyzed exclusively by each network’s laboratory for pH, H + , Ca2+  , Mg2+  , Na + , K + , NH+4 , Cl − , NO−3 , and SO2−4 . Weekly and annual precipitation-weighted mean concentrations for each network were compared. This study is a follow-up to an earlier internetwork comparison for the period 1986–1993, published by Alain Sirois, Robert Vet, and Dennis Lamb in 2000. Median weekly internetwork differences for 1995–2004 data were the same to slightly lower than for data for the previous study period (1986–1993) for all analytes except NO−3 , SO2−4 , and sample depth. A 1994 NADP sampling protocol change and a 1998 change in the types of filters used to process NADP samples reversed the previously identified negative bias in NADP data for hydrogen-ion and sodium concentrations. Statistically significant biases (α = 0.10) for sodium and hydrogen-ion concentrations observed in the 1986–1993 data were not significant for 1995–2004. Weekly CAPMoN measurements generally are higher than weekly NADP measurements due to differences in sample filtration and field instrumentation, not sample evaporation, contamination, or analytical laboratory differences.

  12. At-line benzene monitor for measuring benzene in precipitate hydrolysis aqueous

    SciTech Connect

    Jenkins, W.J.

    1992-10-14

    A highly accurate and repeatable at-line benzene monitor (ALBM) has been developed to measure the benzene concentration in precipitate hydrolysis aqueous (PHA) in the DWPF. This analyzer was conceived and jointly developed within SRTC by the Analytical Development and the Defense Waste Process Technology Sections with extensive support from the Applied Statistics Group and the TNX Operations Section. It is recommended that an ALBM specifically adapted to DWPF analytical requirements be used to measure benzene in PHA; calibrations be performed using a 10% methanol solution matrix (for standard stability); and based on experience gained in development at TNX, the services of ADS and ASG be employed to both adapt the ALBM to DWPF requirements and develop statistical control procedures.

  13. Measurement of precipitation induced FUV emission and Geocoronal Lyman Alpha from the IMI mission

    NASA Technical Reports Server (NTRS)

    Mende, Stephen B.; Fuselier, S. A.; Rairden, R. L.

    1995-01-01

    This final report describes the activities of the Lockheed Martin Palo Alto Research Laboratory in studying the measurement of ion and electron precipitation induced Far Ultra-Violet (FUV) emissions and Geocoronal Lyman Alpha for the NASA Inner Magnetospheric Imager (IMI) mission. this study examined promising techniques that may allow combining several FUV instruments that would separately measure proton aurora, electron aurora, and geocoronal Lyman alpha into a single instrument operated on a spinning spacecraft. The study consisted of two parts. First, the geocoronal Lyman alpha, proton aurora, and electron aurora emissions were modeled to determine instrument requirements. Second, several promising techniques were investigated to determine if they were suitable for use in an IMI-type mission. Among the techniques investigated were the Hydrogen gas cell for eliminating cold geocoronal Lyman alpha emissions, and a coded aperture spectrometer with sufficient resolution to separate Doppler shifted Lyman alpha components.

  14. Assimilation of Precipitation Measurement Missions Microwave Radiance Observations With GEOS-5

    NASA Technical Reports Server (NTRS)

    Jin, Jianjun; Kim, Min-Jeong; McCarty, Will; Akella, Santha; Gu, Wei

    2015-01-01

    The Global Precipitation Mission (GPM) Core Observatory satellite was launched in February, 2014. The GPM Microwave Imager (GMI) is a conically scanning radiometer measuring 13 channels ranging from 10 to 183 GHz and sampling between 65 S 65 N. This instrument is a successor to the Tropical Rainfall Measurement Mission (TRMM) Microwave Imager (TMI), which has observed 9 channels at frequencies ranging 10 to 85 GHz between 40 S 40 N since 1997. This presentation outlines the base procedures developed to assimilate GMI and TMI radiances in clear-sky conditions, including quality control methods, thinning decisions, and the estimation of, observation errors. This presentation also shows the impact of these observations when they are incorporated into the GEOS-5 atmospheric data assimilation system.

  15. Lessons Learned during Thermal Hardware Integration on the Global Precipitation Measurement Satellite

    NASA Technical Reports Server (NTRS)

    Cottingham, Christine; Dwivedi, Vivek H.; Peters, Carlton; Powers, Daniel; Yang, Kan

    2012-01-01

    The Global Precipitation Measurement mission is a joint NASA/JAXA mission scheduled for launch in late 2013. The integration of thermal hardware onto the satellite began in the Fall of 2010 and will continue through the Summer of 2012. The thermal hardware on the mission included several constant conductance heat pipes, heaters, thermostats, thermocouples radiator coatings and blankets. During integration several problems arose and insights were gained that would help future satellite integrations. Also lessons learned from previous missions were implemented with varying degrees of success. These insights can be arranged into three categories. 1) the specification of flight hardware using analysis results and the available mechanical resources. 2) The integration of thermal flight hardware onto the spacecraft, 3) The preparation and implementation of testing the thermal flight via touch tests, resistance measurements and thermal vacuum testing.

  16. Simultaneous measurements of stable water isotopes in near-surface vapor and precipitation to constrain below-cloud processes

    NASA Astrophysics Data System (ADS)

    Graf, Pascal; Sodemann, Harald; Pfahl, Stephan; Schneebeli, Marc; Ventura, Jordi Figueras i.; Leuenberger, Andreas; Grazioli, Jacopo; Raupach, Tim; Berne, Alexis; Wernli, Heini

    2016-04-01

    Present-day observations of stable water isotopes (SWI) in precipitation on monthly time scales are abundant and the processes governing the variation of SWI on these time scales have been investigated by many studies. However, also on much shorter time scales of hours mesoscale meteorological processes lead to significant variations of SWIs, which are important to understand. There are only few studies investigating the variations of SWI on this short time scale, for which, e.g., frontal dynamics, convection and cloud microphysics play an essential role. In particular, the isotopic composition of both near-surface vapor and precipitation is significantly influenced by below-cloud processes that include precipitation evaporation and isotopic exchange between falling precipitation and surrounding vapor. In this study, simultaneous measurements of SWI in near-surface vapor and precipitation with high (sub-hourly) temporal resolution in combination with observational data from radars, disdrometers, radiosondes and standard meteorological instruments are used for a detailed analysis of the relative importance of below-cloud and in-cloud (i.e., precipitation formation) processes during the course of three rain events in Switzerland in spring 2014. Periods are identified when the isotopic composition of near-surface vapor and equilibrium vapor above liquid rain drops agree and when they differ due to either evaporation of precipitation or incomplete equilibration of precipitation with surrounding vapor. These findings are verified by the supporting observational data. In addition, calculations with a simple rain-shaft model fed with observational data are compared to the actual isotopic composition of precipitation. This combination of isotope measurements and model calculations allows us to test the sensitivity of the precipitation isotope signal to rain intensity, drop-size distribution and temperature and humidity profiles.

  17. Advances in measuring single-cell pharmacology in vivo.

    PubMed

    Vinegoni, Claudio; Dubach, J Matthew; Thurber, Greg M; Miller, Miles A; Mazitschek, Ralph; Weissleder, Ralph

    2015-09-01

    Measuring key pharmacokinetic and pharmacodynamic parameters in vivo at the single cell level is likely to enhance drug discovery and development. In this review, we summarize recent advances in this field and highlight current and future capabilities. PMID:26024776

  18. Admiralty Inlet Advanced Turbulence Measurements: May 2015

    DOE Data Explorer

    Kilcher, Levi

    2015-05-18

    This data is from measurements at Admiralty Head, in Admiralty Inlet (Puget Sound) in May of 2015. The measurements were made using Inertial Motion Unit (IMU) equipped ADVs mounted on a 'StableMoor' (Manufacturer: DeepWater Buoyancy) buoy and a Tidal Turbulence Mooring (TTM). These platforms position ADV heads above the seafloor to make mid-depth turbulence measurements. The inertial measurements from the IMU allows for removal of mooring motion in post processing. The mooring and buoy motion has been removed from the stream-wise and vertical velocity signals (u, w). The lateral (v) velocity has some 'persistent motion contamination' due to mooring sway. The TTM was deployed with one ADV, it's position was: 48 09.145', -122 41.209' The StableMoor was deployed twice, the first time it was deployed in 'wing-mode' with two ADVs ('Port' and 'Star') at: 48 09.166', -122 41.173' The second StableMoor deployment was in 'Nose' mode with one ADV at: 48 09.166', -122 41.174' Units ----- - Velocity data (_u, urot, uacc) is in m/s. - Acceleration (Accel) data is in m/s^2. - Angular rate (AngRt) data is in rad/s. - The components of all vectors are in 'ENU' orientation. That is, the first index is True East, the second is True North, and the third is Up (vertical). - All other quantities are in the units defined in the Nortek Manual. Motion correction and rotation into the ENU earth reference frame was performed using the Python-based open source DOLfYN library (http://lkilcher.github.io/dolfyn/). Details on motion correction can be found there. Additional details on TTM measurements at this site can be found in the included Marine Energy Technology Symposium paper.

  19. Admiralty Inlet Advanced Turbulence Measurements: June 2014

    DOE Data Explorer

    Kilcher, Levi

    2014-06-30

    This data is from measurements at Admiralty Head, in Admiralty Inlet (Puget Sound) in June of 2014. The measurements were made using Inertial Motion Unit (IMU) equipped ADVs mounted on Tidal Turbulence Mooring's (TTMs). The TTM positions the ADV head above the seafloor to make mid-depth turbulence measurements. The inertial measurements from the IMU allows for removal of mooring motion in post processing. The mooring motion has been removed from the stream-wise and vertical velocity signals (u, w). The lateral (v) velocity has some 'persistent motion contamination' due to mooring sway. Each ttm was deployed with two ADVs. The 'top' ADV head was positioned 0.5m above the 'bottom' ADV head. The TTMs were placed in 58m of water. The position of the TTMs were: ttm01 : (48.1525, -122.6867) ttm01b : (48.15256666, -122.68678333) ttm02b : (48.152783333, -122.686316666) Deployments TTM01b and TTM02b occurred simultaneously and were spaced approximately 50m apart in the cross-stream direction. Units ----- - Velocity data (_u, urot, uacc) is in m/s. - Acceleration (Accel) data is in m/s^2. - Angular rate (AngRt) data is in rad/s. - The components of all vectors are in 'ENU' orientation. That is, the first index is True East, the second is True North, and the third is Up (vertical). - All other quantities are in the units defined in the Nortek Manual. Motion correction and rotation into the ENU earth reference frame was performed using the Python-based open source DOLfYN library (http://lkilcher.github.io/dolfyn/). Details on motion correction can be found there. Additional details on TTM measurements at this site can be found in the included Marine Energy Technology Symposium paper.

  20. Measurement of Low Amounts of Precipitable Water Vapor Using Ground-Based Millimeterwave Radiometry

    NASA Technical Reports Server (NTRS)

    Racette, Paul E.; Westwater, Ed R.; Han, Yong; Gasiewski, Albin J.; Klein, Marian; Cimini, Domenico; Jones, David C.; Manning, WIll; Kim, Edward J.; Wang, James R.

    2003-01-01

    Extremely dry conditions characterized by amounts of precipitable water vapor (PWV) as as 1-2 mm commonly occur in high-latitude regions during the winter months. While such atmospheres carry only a few percent of the latent heat energy compared to tropical atmospheres, the effects of low vapor amounts on the polar radiation budget - both directly through modulation of longwave radiation and indirectly through the formation of clouds - are considerable. Accurate measurements of precipitable water vapor (PWV) during such dry conditions are needed to improve polar radiation models for use in understanding and predicting change in the climatically sensitive polar regions. To this end, the strong water vapor absorption at 183.310 GHz provides a unique means of measuring low amounts of PWV. Weighting function analysis, forward model calculations based upon a 7-year radiosonde dataset, and retrieval simulations consistently predict that radiometric measurements made using several millimeter-wavelength (MMW) channels near the 183 GHz line, together with established microwave (MW) measurements at the 22.235 GHz water vapor line and -3 1 GHz atmospheric absorption window can be used to determine within 5% uncertainty the full range of PWV expected in the Arctic. This unique collective capability stands in spite of accuracy limitations stemming from uncertainties due to the sensitivity of the vertical distribution of temperature and water vapor at MMW channels. In this study the potential of MMW radiometry using the 183 GHz line for measuring low amounts of PWV is demonstrated both theoretically and experimentally. The study uses data obtained during March 1999 as part of an experiment conducted at the Department of Energy s Cloud and Radiation Testbed (CART) near Barrow, Alaska. Several radiometers from both NOAA and NASA were deployed during the experiment to provide the first combined MMW and MW ground-based data set during dry arctic conditions. Single-channel retrievals

  1. Evaluating the Global Precipitation Measurement mission with NOAA/NSSL Multi-Radar Multisensor: current status and future directions.

    NASA Astrophysics Data System (ADS)

    Kirstetter, P. E.; Hong, Y.; Gourley, J. J.; Carr, N.; Petersen, W. A.; Schwaller, M.; Anagnostou, E. N.; Kummerow, C. D.; Ferraro, R. R.; Wang, N. Y.; Tanelli, S.; Turk, J.; Huffman, G. J.

    2015-12-01

    Accurate characterization of uncertainties in precipitation estimates derived from space-borne measurements is critical for many applications including water budget studies or prediction of natural hazards caused by extreme rainfall events. The GPM precipitation Level II (active and passive) and Level III (IMERG) estimates are compared to the NEXRAD-based precipitation estimates derived from NOAA/NSSL's Multi-Radar, Multi-Sensor (MRMS) platform. The NEXRAD network has undergone an upgrade in technology with dual-polarization capabilities and the MRMS products, after having been adjusted by rain gauges and passing several quality controls and filtering procedures, are 1) accurate with known uncertainty bounds and 2) measured at a resolution below the pixel sizes any GPM estimates. They are used by a number of NASA investigators to evaluate Level II and Level III satellite precipitation algorithms. A comparison framework was developed to examine the consistency of the ground and space-based sensors in term of precipitation detection, typology (e.g. convective, stratiform) and quantification. At the Level II precipitation features are introduced to analyze satellite estimates under various precipitation processes. Specific factors for passive (e.g. surface conditions for GMI) and active (e.g. attenuation of the radar signal, non uniform beam filling for DPR) sensors are investigated. Prognostic analysis directly provides feedback to algorithm developers on how to improve the satellite estimates. Comparison with TRMM products serves as a benchmark to evaluate GPM precipitation estimates. A the Level III the contribution of Level II is explicitly characterized and a rigorous characterization is performed to migrate across scales fully understanding the propagation of errors. This cross products characterization acts as a bridge to intercalibrate microwave measurements from the GPM constellation satellites and propagate to the combined and global precipitation estimates

  2. Advance particle and Doppler measurement methods

    NASA Technical Reports Server (NTRS)

    Busch, C.

    1985-01-01

    Particle environments, i.e., rain, ice, and snow particles are discussed. Two types of particles addressed are: (1) the natural environment in which airplanes fly and conduct test flights; and (2) simulation environments that are encountered in ground-test facilities such as wind tunnels, ranges, etc. There are characteristics of the natural environment that one wishes to measure. The liquid water content (LWC) is the one that seems to be of most importance; size distribution may be of importance in some applications. Like snow, the shape of the particle may be an important parameter to measure. As one goes on to environment in simulated tests, additional parameters may be required such as velocity distribution, the velocity lag of the particle relative to the aerodynamic flow, and the trajectory of the particle as it goes through the aerodynamic flow and impacts on the test object.

  3. Advanced giant magnetoresistance technology for measurement applications

    NASA Astrophysics Data System (ADS)

    Weiss, Roland; Mattheis, Roland; Reiss, Günter

    2013-08-01

    Giant magnetoresistance (GMR) sensors are considered one of the first real applications of nanotechnology. They consist of nm-thick layered structures where ferromagnetic metals are sandwiched by nonmagnetic metals. Such multilayered films produce a large change in resistance (typically 10 to 20%) when subjected to a magnetic field, compared with a maximum change of a few per cent for other types of magnetic sensors. This technology has been intensively used in read heads for hard disk drives and now increasingly finds applications due to the high sensitivity and signal-to-noise ratio. Additionally these sensors are compatible with miniaturization and thus offer a high spatial resolution combined with a frequency range up to the 100 MHz regime and simple electronic conditioning. In this review, we first discuss the basics of the underlying magnetoresistance effects in layered structures and then present three prominent examples for future applications: in the field of current sensing the new GMR sensors offer high bandwidth and good accuracy in a space-saving open loop measurement configuration. In rotating systems they can be used for multiturn angle measurements, and in biotechnology the detection of magnetic particles enables the quantitative measurement of biomolecule concentrations.

  4. Advanced (Measurement) Applications of Curriculum-Based Measurement in Reading

    ERIC Educational Resources Information Center

    Petscher, Yaacov; Cummings, Kelli Dawn; Biancarosa, Gina; Fien, Hank

    2013-01-01

    The purpose of this article is to provide a commentary on the current state of several measurement issues pertaining to curriculum-based measures of reading (R-CBM). We begin by providing an overview of the utility of R-CBM, followed by a presentation of five specific measurements considerations: (a) the reliability of R-CBM oral reading fluency…

  5. Solutions Network Formulation Report. The Potential Contributions of the Global Precipitation Measurement Mission to Estuary Management in Acadia National Park

    NASA Technical Reports Server (NTRS)

    Anderson, Daniel; Hilbert, Kent; Lewis, David

    2007-01-01

    This candidate solution suggests the use of GPM precipitation observations to enhance the Acadia National Park NLERDSS. Simulated GPM data should provide measurements that would enable analysis of how precipitation affects runoff and nutrient load in the park?s wetlands. This solution benefits society by aiding park and resource managers in making predictions based on hypothetical changes and in identifying effective mitigation scenarios. This solution supports the Coastal Management, Water Management, and Ecological Forecasting National Applications.

  6. Airborne full polarization radiometry using the MSFC Advanced Microwave Precipitation Radiometer (AMPR)

    NASA Technical Reports Server (NTRS)

    Gasiewski, Al J.; Kunkee, D. B.

    1993-01-01

    The applications of vertically and horizontally polarized brightness temperatures in both atmospheric and surface remote sensing have been long recognized by many investigators, particularly those studying SMMR and SSM/I data. Here, the large contrast between the first two Stokes' parameters (T(sub V) and T(sub H)) can be used for detection of sea ice, measurement of ocean surface wind speed, and measurement of cloud and water vapor opacity. High-resolution aircraft data from instruments such as the NASA/MSFC AMPR is crucial for verifying radiative transfer models and developing retrieval algorithms. Currently, the AMPR is outfitted with single-polarization channels at 10, 18, 37 and 85 GHz. To increase its utility, it is proposed that additional orthogonal linearly polarized channels be added to the AMPR. Since the AMPR's feedhorns are already configured for dual orthogonal linearly polarized modes, this would require only a duplication of the currently existing receivers. To circumvent the resulting polarization basis skew caused by the cross-track scanning mechanism, the technique of Electronic Polarization Basis Rotation is proposed to be implemented. Implementation of EPBR requires precise measurement of the third Stokes parameter and will eliminate polarization skew by allowing the feedhorn basis skew angle to be corrected in software. In addition to upgrading AMPR to dual polarization capability (without skew), the modifications will provide an opportunity to demonstrate EPBR on an airborne platform. This is a highly desirable intermediate step prior to satellite implementation.

  7. One decade of imaging precipitation measurement by 2D-video-distrometer

    NASA Astrophysics Data System (ADS)

    Schönhuber, M.; Lammer, G.; Randeu, W. L.

    2007-04-01

    The 2D-Video-Distrometer (2DVD) is a ground-based point-monitoring precipitation gauge. From each particle reaching the measuring area front and side contours as well as fall velocity and precise time stamp are recorded. In 1991 the 2DVD development has been started to clarify discrepancies found when comparing weather radar data analyses with literature models. Then being manufactured in a small scale series the first 2DVD delivery took place in 1996, 10 years back from now. An overview on present 2DVD features is given, and it is presented how the instrument was continuously improved in the past ten years. Scientific merits of 2DVD measurements are explained, including drop size readings without upper limit, drop shape and orientation angle information, contours of solid and melting particles, and an independent measurement of particles' fall velocity also in mixed phase events. Plans for a next generation instrument are described, by enhanced user-friendliness the unique data type shall be opened to a wider user community.

  8. Measurement and modeling of advanced coal conversion processes

    SciTech Connect

    Solomon, P.R.; Serio, M.A.; Hamblen, D.G.; Smoot, L.D.; Brewster, B.S. Brigham Young Univ., Provo, UT )

    1991-01-01

    The overall objective of this program is the development of predictive capability for the design, scale up, simulation, control and feedstock evaluation in advanced coal conversion devices. This program will merge significant advances made in measuring and quantitatively describing the mechanisms in coal conversion behavior. Comprehensive computer codes for mechanistic modeling of entrained-bed gasification. Additional capabilities in predicting pollutant formation will be implemented and the technology will be expanded to fixed-bed reactors.

  9. Measuring Dust Exposure with the Thermal Precipitator in Collieries and Foundries

    PubMed Central

    Roach, S. A.

    1959-01-01

    The standard thermal precipitator has been modified for field surveys of airborne dust exposure so as to make it more portable. A microprojector is used when assessing the samples and for coal-mine dusts the counts are restricted to the range 0·5 to 5 microns. In industrial environments the dust concentration appears to vary with a standard deviation of more than 50% of the mean. Part of this variability is due to errors of the thermal precipitator. The standard error of a count of a sample is about 10% to 15% in practical work and the combined effect of this and other errors is that the standard error of a single result is about 15%. However, in practice this can be neglected since the dust concentration itself is so variable. A more important source of error is the bias, due to overlapping among the particles on the cover glasses. The count may give a serious underestimate of the number of airborne particles if high sample densities are used. The product of average concentration and duration of exposure is probably a good index of the dose of dust retained in a man's lungs. The duration of exposure is measured by a simple time study made at the same time as the concentration is measured. Samples are taken near workers chosen at random to give unbiased estimates of the dust exposure. Ideally successive samples are taken alongside different workers. However, in a survey at a colliery it was not possible to do this and each day had to be spent with one collier. The mean dust exposure of the coal-getters was 2,860 particle-hours per shift, of those on stone work 2,250 particle-hours per shift, and the remainder had a mean dust exposure of 1,010 particle-hours per shift. In a survey at a steel works successive samples could be taken alongside different workers. It was found that the dustiness was unrelated to the apparently dusty processes and as the dust was very fine it was suspected that it was the normal atmospheric pollution of the neighbourhood. This was

  10. Global Precipitation Measurement (GPM) Microwave Imager Falling Snow Retrieval Algorithm Performance

    NASA Astrophysics Data System (ADS)

    Skofronick Jackson, Gail; Munchak, Stephen J.; Johnson, Benjamin T.

    2015-04-01

    Retrievals of falling snow from space represent an important data set for understanding the Earth's atmospheric, hydrological, and energy cycles. While satellite-based remote sensing provides global coverage of falling snow events, the science is relatively new and retrievals are still undergoing development with challenges and uncertainties remaining. This work reports on the development and post-launch testing of retrieval algorithms for the NASA Global Precipitation Measurement (GPM) mission Core Observatory satellite launched in February 2014. In particular, we will report on GPM Microwave Imager (GMI) radiometer instrument algorithm performance with respect to falling snow detection and estimation. Since GPM's launch, the at-launch GMI precipitation algorithms, based on a Bayesian framework, have been used with the new GPM data. The at-launch database is generated using proxy satellite data merged with surface measurements (instead of models). One year after launch, the Bayesian database will begin to be replaced with the more realistic observational data from the GPM spacecraft radar retrievals and GMI data. It is expected that the observational database will be much more accurate for falling snow retrievals because that database will take full advantage of the 166 and 183 GHz snow-sensitive channels. Furthermore, much retrieval algorithm work has been done to improve GPM retrievals over land. The Bayesian framework for GMI retrievals is dependent on the a priori database used in the algorithm and how profiles are selected from that database. Thus, a land classification sorts land surfaces into ~15 different categories for surface-specific databases (radiometer brightness temperatures are quite dependent on surface characteristics). In addition, our work has shown that knowing if the land surface is snow-covered, or not, can improve the performance of the algorithm. Improvements were made to the algorithm that allow for daily inputs of ancillary snow cover

  11. Flow measurements in semiconductor processing; New advances in measurement technology

    NASA Astrophysics Data System (ADS)

    Tison, S. A.; Calabrese, A. M.

    1998-11-01

    Gas flow measurement, control, and distribution are an integral part in meeting present and future semiconductor processing requirements (1). Changes in processing and environmental concerns have put additional pressure not only on accurate measurement of the gas flow, but also in reducing flows. To address the need for more accurate metering of gas flows, NIST has developed primary flow standards which have uncertainties of 0.1% of reading or better over the flow range of 10-9 mol/s to 10-3 mol/s (0.001 sccm to 1000 sccm). These standards have been used to test NIST-designed high repeatability flow transfer standards (2) which can be used to document and improve flow measurements in the semiconductor industry (3). In particular two flowmeters have been developed at NIST; the first is a pressure-based flow sensor and the second a Doppler-shift flowmeter, both of which can be used for in-situ calibration of thermal mass flow controllers or for direct metering of process gases.

  12. Lead precipitation fluxes at tropical oceanic sites determined from /sup 210/Pb measurements

    SciTech Connect

    Settle, D.M.; Patterson, C.C.; Turekian, K.K.; Cochran, J.K.

    1982-02-20

    Concentrations of lead, /sup 210/Pb, and /sup 210/Po were measured in rain selected for least influence by local sources of contamination at several tropical and subtropical islands (Enewetak; Pigeon Key, Florida; and American Samoa) and shipboard stations (near Bermuda and Tahiti). Ratios expressed as ng Pb/dpm /sup 210/Pb in rain were 250--900 for Pigeon Key (assuming 12% adsorption for /sup 210/Pb and no adsorption for lead), depending on whether the air masses containing the analyzed rain came from the Caribbean or from the continent, respectively; about 390 for the northern Sargasso Sea downwind from emissions of industrial lead in North America; 65 for Enewetak, remote from continental emissions of industrial lead in the northern hemisphere; and 14 near Tahiti, a remote location in the southern hemisphere where industrial lead emissions to the atmosphere are much less than in the northern hemisphere. (The American Samoa sample yielded a higher ratio than Tahiti; the reason for this is not clear but may be due to local Pb sources). The corresponding fluxes of lead to the oceans, based on measured or modeled /sup 210/Pb precipitation fluxes, are about 4 ng Pb/cm/sup 2/y for Tahiti, 10 for Enewetak, and 270 for the Sargasso Sea site, and between 110 to 390 at Pigeon Key.

  13. Measurement of irradiation effects in precipitate hardened aluminum using nonlinear ultrasonic principles (in-situ)

    SciTech Connect

    Reinhardt, B. T.; Parks, D. A.; Tittmann, B. R.

    2012-05-17

    Currently nuclear power plants are reaching the end of their initial design life. Yet, in order to meet the energy demands, twenty year extensions have been granted to many nuclear reactor facilities. These extensions will be ending by the year 2035, leaving a large gap in the available energy supply. In order to extend the life of these facilities it will imperative to develop techniques capable detecting damage in the aging nuclear facilities. However, the high temperature and high neutron flux environment limits the materials available for use in the nuclear reactor. Because of this limitation little NDE based inspection has been implemented in high radiation environments. Yet recent developments in the understanding of Aluminum Nitride (AlN) piezoelectric sensors high temperature and radiation dependent behavior have opened the door for in-situ experimentation. An experiment was designed to monitor the propagation of an ultrasonic wave in a precipitate hardened aluminum specimen while being subjected to radiation at the Pennsylvania State Universities Breazeale Reactor. Measurements of harmonic generation were made up to 1.85x10{sup 18} fluence with significant spectral difference between the pre-irradiated state and the post irradiated state. The connection between micro-structural material changes and harmonic measurements are addressed.

  14. Instrumenting Wildlife Water Developments to Measure Precipitation and Estimate Runoff in Remote Catchments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In Nevada, available data on precipitation and runoff in remote catchments are extremely limited. The National Weather Service’s Cooperative Observer Network (COOP) includes 178 weather stations, most of which collect precipitation data and qualitative weather observations. Most of these stations ar...

  15. Using Wildlife Water Developments to Measure Precipitation and Estimate Runoff in Remote Catchments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In Nevada, available data on precipitation and runoff in remote catchments is extremely limited. The National Weather Service’s Cooperative Observer Network (COOP) includes 178 weather stations, most of which collect precipitation data and qualitative weather observations. Most of these stations a...

  16. Snowfall Measurements at a Boreal Forest Site in Saskatchewan/Canada: Contribution to WMO Solid Precipitation Intercomparison Experiment (SPICE)

    NASA Astrophysics Data System (ADS)

    Yang, D.

    2015-12-01

    Snowfall is important to cold region climate and hydrology including Canada. Large uncertainties and biases exist in gauge-measured precipitation datasets and products. These uncertainties affect important decision-making, water resources assessments, climate change analyses, and calibrations of remote sensing algorithms and land surface models. Efforts have been made at both the national and international levels to quantity the errors/biases in precipitation measurements, such as the WMO Solid Precipitation Intercomparison Experiment (WMO-SPICE). As part of Canada's contribution to the WMO SPICE project, a test site has been set up in the southern Canadian Boreal forest to compare the DFIR and bush gauge and test other instruments. Snowfall and meteorological data have been collected over the past 2 winters. This presentation will summarize the results of recent data analyses, evaluate the performance of various gauges for snowfall observations in the northern regions, and discuss future perspectives regarding cold/mountain region precipitation research. The methods and results of this research will improve precipitation measurements and data quality over the cold and mountain regions, directly supporting the WMO SPICE and the MOUNTerrain projects.

  17. Reconstruction of Winter and July Precipitation in the US Southwest using minimum blue intensity measurements from Pseudotsuga menziesii

    NASA Astrophysics Data System (ADS)

    Graham, R.; Woodhouse, C. A.; Griffin, D.; Meko, D. M.; Touchan, R.; Leavitt, S. W.; Castro, C. L.

    2012-12-01

    Tree ring research has demonstrated that the latewood measurements of conifers contain information on the variability of the North American Monsoon while the earlywood measurements reflect cool season moisture variability in the US Southwest. Here we use minimum blue intensity a reflected light image technique to investigate the potential for additional seasonal climatic information. This paper presents the first reconstruction of January through April and July (JFMA_J) precipitation (AD 1680-2010) from Rhyolite Canyon, Chiricahua Mountains, Arizona, based on minimum blue intensity measurements of the annual latewood of Douglas fir (Pseudotsuga menziesii (Mirb.) Franco). Winter and July precipitation variation (JFMA_J) were reconstructed, suggesting these months may be a critical composite for the moisture important for growth in this region. The wettest years occurred in the early AD 1980s and the driest years occurred around AD 1810. In the Southwest, where annual precipitation is divided between winter and summer seasons, the new 330 year precipitation reconstruction provides information about past climate variability over both precipitation seasons in the Chiricahua Mountains of Arizona.

  18. Recent advances in optical measurement methods in physics and chemistry

    SciTech Connect

    Gerardo, J.B.

    1985-01-01

    Progress being made in the development of new scientific measurement tools based on optics and the scientific advances made possible by these new tools is impressive. In some instances, new optical-based measurement methods have made new scientific studies possible, while in other instances they have offered an improved method for performing these studies, e.g., better signal-to-noise ratio, increased data acquisition rate, remote analysis, reduced perturbation to the physical or chemical system being studied, etc. Many of these advances were made possible by advances in laser technology - spectral purity, spectral brightness, tunability, ultrashort pulse width, amplitude stability, etc. - while others were made possible by improved optical components - single-made fibers, modulators, detectors, wavelength multiplexes, etc. Attention is limited to just a few of many such accomplishments made recently at Sandia. 17 references, 16 figures.

  19. Effect of Combined Spaceborne Microwave and Continuous Lightning Measurements on Precipitation Forecasts of the 1998 Ground-Hog Day Storm

    NASA Technical Reports Server (NTRS)

    Weinman, James A.; Chang, Dong-Eon; Morales, Carlos A.

    2000-01-01

    We evaluated the impact of several newly available sources of meteorological data on mesoscale model forecasts of precipitation produced by the extra-tropical cyclone that struck Florida on February 2, 1998. Precipitation distributions of convective rainfall events were derived from Special Sensor Microwave Imager (SSM/I) and Multi-Channel Passive Microwave Sensor (TMI) microwave radiometric data by means of the Goddard PROFiling (GPROF) algorithm. Continuous lightning distributions were obtained from sferics measurements obtained from a network of VLF radio receivers. Histograms of coincident sferics frequency distributions were matched to those of precipitation to derive bogus convective rainfall rates from the continuously available sferics measurements. SSM/I and TMI microwave data were used to derive Integrated Precipitable Water (IPW) distributions. The TMI also provided sea surface temperatures (SSTS) of the Loop Current and Gulf Stream with improved structural detail. A series of experiments assimilated IPW and latent heating from the bogus convective rainfall for six-hours in the MM5 mesoscale forecast model to produce nine-hour forecasts of all rainfall as well as other weather parameters. Although continuously assimilating latent heating only slightly improved the surface pressure distribution forecast, it significantly improved the precipitation forecasts. Correctly locating convective rainfall was found critical for assimilating latent heating in the forecast model, but measurement of the rainfall intensity proved to be less important. The improved SSTs also had a positive impact on rainfall forecasts for this case. Assimilating bogus rainfall in the model produced nine-hour forecasts of radar reflectivity distributions that agreed well with coincident observations from the TRMM spaceborne precipitation radar, ground based radar and spaceborne microwave measurements.

  20. The Global Precipitation Measurement (GPM) Spacecraft Power System Design and Orbital Performance

    NASA Technical Reports Server (NTRS)

    Dakermanji, George; Burns, Michael; Lee, Leonine; Lyons, John; Kim, David; Spitzer, Thomas; Kercheval, Bradford

    2016-01-01

    The Global Precipitation Measurement (GPM) spacecraft was jointly developed by National Aeronautics and Space Administration (NASA) and Japan Aerospace Exploration Agency (JAXA). It is a Low Earth Orbit (LEO) spacecraft launched on February 27, 2014. The spacecraft is in a circular 400 Km altitude, 65 degrees inclination nadir pointing orbit with a three year basic mission life. The solar array consists of two sun tracking wings with cable wraps. The panels are populated with triple junction cells of nominal 29.5% efficiency. One axis is canted by 52 degrees to provide power to the spacecraft at high beta angles. The power system is a Direct Energy Transfer (DET) system designed to support 1950 Watts orbit average power. The batteries use SONY 18650HC cells and consist of three 8s x 84p batteries operated in parallel as a single battery. The paper describes the power system design details, its performance to date and the lithium ion battery model that was developed for use in the energy balance analysis and is being used to predict the on-orbit health of the battery.

  1. Global Precipitation Measurement. Report 2; Benefits of Partnering with GPM Mission

    NASA Technical Reports Server (NTRS)

    Stocker, Erich F.; Smith, Eric A. (Editor); Adams, W. James (Editor); Starr, David OC. (Technical Monitor)

    2002-01-01

    An important goal of the Global Precipitation Measurement (GPM) mission is to maximize participation by non-NASA partners both domestic and international. A consequence of this objective is the provision for NASA to provide sufficient incentives to achieve partner buy-in and commitment to the program. NASA has identified seven specific areas in which substantive incentives will be offered: (1) partners will be offered participation in governance of GPM mission science affairs including definition of data products; (2) partners will be offered use of NASA's TDRSS capability for uplink and downlink of commands and data in regards to partner provided spacecraft; (3) partners will be offered launch support for placing partner provided spacecraft in orbit conditional upon mutually agreeable co-manifest arrangements; (4) partners will be offered direct data access at the NASA-GPM server level rather than through standard data distribution channels; (5) partners will be offered the opportunity to serve as regional data archive and distribution centers for standard GPM data products; and (6) partners will be offered the option to insert their own specialized filtering and extraction software into the GPM data processing stream or to obtain specialized subsets and products over specific areas of interest (7) partners will be offered GPM developed software tools that can be run on their platforms. Each of these incentives, either individually or in combination, represents a significant advantage to partners who may wish to participate in the GPM mission.

  2. Precipitation of radiation belt electrons by man-made waves A comparison between theory and measurement

    NASA Technical Reports Server (NTRS)

    Inan, U. S.; Chang, H. C.; Helliwell, R. A.; Imhof, W. L.; Reagan, J. B.; Walt, M.

    1985-01-01

    The temporal and spectral shape and the absolute flux level of particle pulses precipitated by a VLF transmitter are examined from a theoretical point of view. A test-particle model of the gyroresonant wave-particle interaction is applied to the parameters of the observed cases for calculating the precipitation characteristics. The temporal shapes of the precipitation pulses are found to be controlled (1) by the pitch angle dependence of the particle distribution near the edge of the loss cone and (2) by the multiple interaction of the particles with the waves due to significant atmospheric backscatter.

  3. Measuring Alumna Career Advancement: An Approach Based on Educational Expectations.

    ERIC Educational Resources Information Center

    Ben-Ur, Tamar; Rogers, Glen

    Alverno College (Wisconsin), a women's liberal arts college, has developed an Alumni Career Level Classification (AACLC) scheme to measure alumna career advancement and demonstrate institutional accountability. This validation study was part of a larger longitudinal study of two entire cohorts of students entering the college in 1976 and 1977, of…

  4. Electrostatic precipitator manual

    SciTech Connect

    McDonald, J.R.; Dean, A.H.

    1982-01-01

    Studies performed by various individuals and organizations on the application of electrostatic precipitators to the collection of fly ash produced in the combustion of pulverized fuel are summarized in this manual. The scope of the studies evaluated include full scale precipitators and laboratory investigations. It covers measurement of fly ash resistivity, rapping reentrainment, conditioning agents, fundamental operations of hot-side precipitators. The major chapter headings are: Terminology and General Design Features Associated with Electrostatic Precipitators Used to Collect Fly Ash Particles; Fundamental Principles of Electrostatic Precipitation; Limiting Factors Affecting Precipitator Performance; Use of Electrostatic Precipitators for the Collection of Fly Ash; Analysis of Factors influencing ESP Performance; Emissions from Electrostatic Precipitators; Choosig an Electrostatic Precipitator: Cold-side versus Hot-side; Safety Aspects of Working with Electrostatic Precipitators; Maintenance Procedures; Troubleshooting; An Electrostatic Precipitator Computer Model; Features of a Well-equipped Electrostatic Precipitator.

  5. Fluid and structural measurements to advance gas turbine technology

    NASA Technical Reports Server (NTRS)

    Hartmann, M. J.

    1980-01-01

    In the present paper, the current status of fluid and structural measurements is reviewed, and some potential improvements in gas turbine machinery, directly associated with the new measuring capability are discussed. Some considerations concerning the impact of the new capability on the methods and approaches that will be used in the further development of advanced technology, in general, and to aeropropulsion gas turbine machinery, in particular, are presented.

  6. Laboratory measurements of oil mist concentrations using filters and an electrostatic precipitator.

    PubMed

    Leith, D; Leith, F A; Boundy, M G

    1996-12-01

    This study investigated the potential for mineral oil mist to evaporate, during sampling, from filters and electrostatic precipitator substrates used to assess personal exposure. If sample evaporation occurs, reported mist concentrations will underestimate true exposure. Mineral oil used as a machining fluid is not normally considered volatile; however, when dispersed as mist its aggregate surface area is so high that significant evaporation can occur. National Institute for Occupational Safety and Health Method 5026 specifies that oil mist concentrations should be determined by collecting mist on filters of mixed cellulose esters (MCE) or polyvinyl chloride (PVC). Collected mist droplets remain dispersed on the filter surface and in contact with passing air while sampling continues, conditions that can lead to sample evaporation. Less evaporation should occur for samples taken with an electrostatic precipitator, where mist droplets are separated from the airflow by electrostatic force and coalesce on the precipitator wall to form a film with relatively low surface area. Collection of mineral oil mist was investigated using a precipitator designed for personal sampling and using either an MCE or a PVC filter. The amounts of oil mist collected using the precipitator were significantly higher than the amounts collected using the filters, p < 0.001. Further tests in which clean air passed through mist-loaded precipitators and filters showed that the precipitator retained substantially more collected mist than both filters, p < 0.001, and further suggested that the MCE filter retained more mist than the PVC filter, p = 0.059. Differences in sample collection and retention between the precipitator and the filters were particularly pronounced at mist loadings below 1 mg.

  7. Advanced Microgravity Acceleration Measurement Systems (AMAMS) Being Developed

    NASA Technical Reports Server (NTRS)

    Sicker, Ronald J.; Kacpura, Thomas J.

    2003-01-01

    The Advanced Microgravity Acceleration Measurement Systems (AMAMS) project is part of NASA s Instrument Technology Development program to develop advanced sensor systems. The primary focus of the AMAMS project is to develop microelectromechanical systems (MEMS) for acceleration sensor systems to replace existing electromechanical sensor systems presently used to assess relative gravity levels aboard spacecraft. These systems are used to characterize both vehicle and payload responses to low-gravity vibroacoustic environments. The collection of microgravity acceleration data is useful to the microgravity life sciences, microgravity physical sciences, and structural dynamics communities. The inherent advantages of semiconductor-based systems are reduced size, mass, and power consumption, with enhanced long-term calibration stability.

  8. Real-time QEXAFS spectroscopy measures rapid precipitate formation at the mineral-water interface.

    PubMed

    Siebecker, Matthew; Li, Wei; Khalid, Syed; Sparks, Donald

    2014-01-01

    Reactions at the mineral-water interface are central to numerous geochemical processes and have consequences at local, regional and global scales. They are also important in materials science research. Kinetics greatly influences mineral-water interface reactions; however, there are few kinetic data in real-time and at the molecular scale. Here we report real-time data illustrating the rapid formation of nickel aluminium-layered double hydroxide precipitates at the mineral-water interface in a flow environment in as little as 31-40 min. Layered double hydroxides have a variety of applications in environmental remediation and materials science. The real-time data shown here enhance our fundamental understanding of the kinetics of mineral-water interface processes, such as adsorption, dissolution and precipitation, by illustrating their rapid and simultaneous occurrence in a dynamic environment. Both precipitation and adsorption can occur on the same rapid timescale. PMID:25233849

  9. Photothermal cathode measurements at the Advanced Photon Source.

    SciTech Connect

    Sun, Y.-E.; Lewellen, J. W.; Feldman, D. W.; Univ. of Maryland

    2006-01-01

    The Advanced Photon Source (APS) ballistic bunch compression (BBC) gun in the Injector Test Stand (ITS) presently uses an M-type thermionic dispenser cathode as a photocathode. This photothermal cathode offers substantial advantages over conventional metal photocathodes, including easy replacement and easy cleaning via the cathode's built-in heater. We present the results of photoemission measurements as a function of cathode heater power, laser pulse energy, and applied rf field strength.

  10. Advances in Non-Contact Measurement of Creep Properties

    NASA Technical Reports Server (NTRS)

    Hyers, Robert; Canepari, Stacy; White, Erica Bischoff; Cretegny, Laurent; Rogers, jan

    2009-01-01

    As the required service temperatures for superalloys increases, so do the demands on testing for development of these alloys. Non-contact measurement of creep of refractory metals using electrostatic levitation has been demonstrated at temperatures up to 2300 C using samples of only 20-40 mg. These measurements load the spherical specimen by inertial forces due to rapid rotation. However, the first measurements relied on photon pressure to accelerate the samples to the high rotational rates of thousands of rotations per second, limiting the applicability to low stresses and high temperatures. Recent advances in this area extend this measurement to higher stresses and lower-temperatures through the use of an induction motor to drive the sample to such high rotational speeds. Preliminary results on new measurements on new materials will be presented.

  11. Evaluating the Global Precipitation Measurement Mission with NOAA/NSSL Multi-Radar Multisensor: Past, Current Status and Future Directions.

    NASA Astrophysics Data System (ADS)

    Kirstetter, P. E.; Hong, Y.; Gourley, J. J.; Carr, N.; Petersen, W. A.; Schwaller, M.; Anagnostou, E. N.; Kummerow, C. D.; Ferraro, R. R.; Wang, N. Y.

    2014-12-01

    Accurate characterization of uncertainties in precipitation estimates derived from space-borne measurements is critical for many applications including water budget studies or prediction of natural hazards caused by extreme rainfall events. GPM precipitation level II estimates are compared to the NEXRAD-based precipitation estimates derived from NOAA/NSSL's Multi-Radar, Multisensor (MRMS) platform. The NEXRAD network has undergone an upgrade in technology with dual-polarization capabilities. These new polarimetric variables are being incorporated in MRMS to improve quality control of reflectivity data and to correct for partial beam blockages. The MRMS products, after having been adjusted by rain gauges and passing several quality controls and filtering procedures, are 1) accurate with known uncertainty bounds and 2) measured at a resolution below the pixel sizes of the GPM radar and radiometer observations. They are used by a number of NASA investigators to evaluate level II and level III satellite rainfall algorithms. The at-launch GPM Radiometer algorithm uses matches of coincident overpasses of various radiometers with surface rainfall from the MRMS database developed for the GPM project. Statistics from TRMM level II products serve as a benchmark to evaluate GPM precipitation estimates. Comparisons have been carried out at fine scale (e.g. instantaneous and 5 km for DPR) within a comparison framework developed to examine the consistency of the ground and space-based sensors in term of precipitation detection, characterization (e.g. convective, stratiform) and quantification. Specific error factors for passive (e.g. surface conditions for GMI) and active (e.g. attenuation of the radar signal, non uniform beam filling for DPR) sensors are investigated. Systematic biases and random errors quantified at the satellite estimation scale are useful for satellite-based Level III precipitation products. An online validation tool was designed to provide, for the first

  12. Measurement and modeling of strain fields in zirconium hydrides precipitated at a stress concentration

    SciTech Connect

    Allen, Gregory B.; Kerr, Matthew; Daymond, Mark R.

    2012-10-23

    Hydrogen adsorption into zirconium, as a result of corrosion in aqueous environments, leads to the precipitation of a secondary brittle hydride phase. These hydrides tend to first form at stress concentrations such as fretting flaws or cracks in engineering components, potentially degrading the structural integrity of the component. One mechanism for component failure is a slow crack growth mechanism known as Delayed Hydride Cracking (DHC), where hydride fracture occurs followed by crack arrest in the ductile zirconium matrix. The current work employs both an experimental and a modeling approach to better characterize the effects and behavior of hydride precipitation at such stress concentrations. Strains around stress concentrations containing hydrides were mapped using High Energy X-ray Diffraction (HEXRD). These studies highlighted important differences in the behavior of the hydride phase and the surrounding zirconium matrix, as well as the strain associated with the precipitation of the hydride. A finite element model was also developed and compared to the X-ray strain mapping results. This model provided greater insight into details that could not be obtained directly from the experimental approaches, as well as providing a framework for future modeling to predict the effects of hydride precipitation under varied conditions.

  13. Voice measures of workload in the advanced flight deck

    NASA Technical Reports Server (NTRS)

    Schneider, Sid J.; Alpert, Murray; Odonnell, Richard

    1989-01-01

    Voice samples were obtained from 14 male subjects under high and low workload conditions. Acoustical analysis of the voice suggested that high workload conditions can be revealed by their effects on the voice over time. Aircrews in the advanced flight deck will be voicing short, imperative sentences repeatedly. A drop in the energy of the voice, as reflected by reductions in amplitude and frequency over time, and the failure to achieve old amplitude and frequency levels after rest periods, can signal that the workload demands of the situation are straining the speaker. This kind of measurement would be relatively unaffected by individual differences in acoustical measures.

  14. Testing data evaluation strategies for estimating precipitation and actual evaporation from precision lysimeter measurements

    NASA Astrophysics Data System (ADS)

    Schrader, Frederik; Durner, Wolfgang; Fank, Johann; Pütz, Thomas; Wollschläger, Ute

    2014-05-01

    Weighing lysimeters have long been recognized as valuable tools not only for monitoring of groundwater recharge and solute transport, but also for the determination of the soil water balance and quantification of water exchange processes at the soil-plant-atmosphere interface. If well embedded into an equally-vegetated environment, they reach a hitherto unprecedented accuracy in estimating precipitation (P) by rain, dew, fog, rime and snow, as well as actual evapotranspiration (ET). At the same time, they largely avoid errors made by traditional micrometeorological instruments, such as the wind error of Hellman rain samplers or the influence of subsurface heterogeneity on readings from in situ instrumentation of soil water state variables. Beginning in 2008, the Helmholtz Association established a network of terrestrial environmental observatories (TERENO) that aim at long-term monitoring of climate and land-use change consequences. A total of 126 identically designed large weighing lysimeters, operating at a sampling frequency of 1 min-1, were installed for this purpose, which raises the demand for standardized data processing methods. In theory, estimating P and ET from these measurements is straightforward: An increase in the combined mass of the soil monolith and the collected seepage water indicates P, while a decrease indicates ET. However, in practice, lysimeter data are prone to numerous sources of error, including, but not limited to, outliers, systematic errors due to plant growth and removal, data gaps, and stochastic fluctuations. The latter pose a particularly challenging problem - if we would directly calculate P and ET from a time-series that is affected by random noise, every positive fluctuation would be interpreted as P and every negative one as ET. Consequently, we would overestimate both quantities by far. The aim of this study was to evaluate algorithms that focus on eliminating the effect of these fluctuations and to estimate actual fluxes

  15. Measuring patient-reported outcomes in advanced gastric cancer

    PubMed Central

    Xu, Jianming; Evans, TR Jeffry; Coon, Cheryl; Copley-Merriman, Kati; Su, Yun

    2013-01-01

    Background Gastric cancer (GC), one of the most common cancers in the world, is often diagnosed at an advanced stage and associated with a poor prognosis. Quality of life and patient-reported outcomes (PROs) are important considerations when treating GC patients. The aim of this study was to identify existing PRO instruments that would be appropriate for use in GC trials. Methods Data were obtained from a systematic literature review and interviews with clinical experts. A literature search was conducted using OVID (EMBASE and MEDLINE) and yielded 1,008 abstracts; 92 assessed PROs in an advanced GC. Results Key symptoms and functional impacts identified through the literature and expert input included abdominal pain or pain at the site of distant metastases, dysphagia and other symptoms related to eating, and digestive symptoms. The liver and lungs were the most frequent locations of metastases, leading to dyspnea, abdominal fullness, and jaundice. Symptoms related to changes in bowel habits appeared to be more frequent and pronounced in Asian patients, possibly due to the higher prevalence of GC in the body of the stomach in this population. The five most commonly used PRO instruments were identified, but their validity in advanced-stage GC patients remains unclear. Conclusions The symptoms and functional impacts identified here should be confirmed with robust input from advanced-stage GC patients. Optimal measurement of PROs in GC should account for patient burden and possible differences between Asian and non-Asian patients. PMID:24062809

  16. Estimation of base station position using timing advance measurements

    NASA Astrophysics Data System (ADS)

    Raitoharju, Matti; Ali-Löytty, Simo; Wirola, Lauri

    2011-10-01

    Timing Advance is used in TDMA (Time Division Multiple Access) systems, such as GSM and LTE, to synchronize the mobile phone to the cellular BS (Base Station). Mobile phone positioning can use TA measurements if BS positions are known, but in many cases BS positions are not in the public domain. In this work we study how to use a set of TA measurements taken by mobile phones at known positions to estimate the position of a BS. This paper describes two methods -- GMF (Gaussian Mixture Filter) and PMF (Point Mass Filter) for estimation of the BS position. Positioning performance is evaluated using simulated and real measurements. In suburban field tests, TA measurements suffice to determine BS position with an error comparable to the TA granularity (550m). GMF computes BS position much faster than PMF and is only slightly less accurate.

  17. Modeling COSMO-SkyMed measurements of precipitating clouds over the sea using simultaneous weather radar observations

    NASA Astrophysics Data System (ADS)

    Roberto, N.; Baldini, L.; Facheris, L.; Chandrasekar, V.

    2014-07-01

    Several satellite missions employing X-band synthetic aperture radar (SAR) have been activated to provide high-resolution images of normalized radar cross-sections (NRCS) on land and ocean for numerous applications. Rainfall and wind affect the sea surface roughness and consequently the NRCS from the combined effects of corrugation due to impinging raindrops and surface wind. X-band frequencies are sensitive to precipitation: intense convective cells result in irregularly bright and dark patches in SAR images, masking changes in surface NRCS. Several works have modeled SAR images of intense precipitation over land; less adequately investigated is the precipitation effect over the sea surface. These images are analyzed in this study by modeling both the scattering and attenuation of radiation by hydrometeors in the rain cells and the NRCS surface changes using weather radar precipitation estimates as input. The reconstruction of X-band SAR returns in precipitating clouds is obtained by the joint utilization of volume reflectivity and attenuation, the latter estimated by coupling ground-based radar measurements and an electromagnetic model to predict the sea surface NRCS. Radar signatures of rain cells were investigated using X-band SAR images collected from the COSMO-SkyMed constellation of the Italian Space Agency. Two case studies were analyzed. The first occurred over the sea off the coast of Louisiana (USA) in summer 2010 with COSMO-SkyMed (CSK®) ScanSar mode monitoring of the Deepwater Horizon oil spill. Simultaneously, the NEXRAD S-band Doppler radar (KLIX) located in New Orleans was scanning the same portion of ocean. The second case study occurred in Liguria (Italy) on November 4, 2011, during an extraordinary flood event. The same events were observed by the Bric della Croce C-band dual polarization radar located close to Turin (Italy). The polarimetric capability of the ground radars utilized allows discrimination of the composition of the precipitation

  18. Application of advanced data assimilation techniques to the study of cloud and precipitation feedbacks in the tropical climate system

    NASA Astrophysics Data System (ADS)

    Posselt, Derek J.

    The research documented in this study centers around two topics: evaluation of the response of precipitating cloud systems to changes in the tropical climate system, and assimilation of cloud and precipitation information from remote-sensing platforms. The motivation for this work proceeds from the following outstanding problems: (1) Use of models to study the response of clouds to perturbations in the climate system is hampered by uncertainties in cloud microphysical parameterizations. (2) Though there is an ever-growing set of available observations, cloud and precipitation assimilation remains a difficult problem, particularly in the tropics. (3) Though it is widely acknowledged that cloud and precipitation processes play a key role in regulating the Earth's response to surface warming, the response of the tropical hydrologic cycle to climate perturbations remains largely unknown. The above issues are addressed in the following manner. First, Markov chain Monte Carlo (MCMC) methods are used to quantify the sensitivity of the NASA Goddard Cumulus Ensemble (GCE) cloud resolving model (CRM) to changes in its cloud odcrnpbymiC8l parameters. TRMM retrievals of precipitation rate, cloud properties, and radiative fluxes and heating rates over the South China Sea are then assimilated into the GCE model to constrain cloud microphysical parameters to values characteristic of convection in the tropics, and the resulting observation-constrained model is used to assess the response of the tropical hydrologic cycle to surface warming. The major findings of this study are the following: (1) MCMC provides an effective tool with which to evaluate both model parameterizations and the assumption of Gaussian statistics used in optimal estimation procedures. (2) Statistics of the tropical radiation budget and hydrologic cycle can be used to effectively constrain CRM cloud microphysical parameters. (3) For 2D CRM simulations run with and without shear, the precipitation efficiency of

  19. Precipitation-chemistry measurements from the California Acid Deposition Monitoring Program, 1985-1990

    USGS Publications Warehouse

    Blanchard, Charles L.; Tonnessen, Kathy A.

    1993-01-01

    The configuration of the California Acid Deposition Monitoring Program (CADMP) precipitation network is described and quality assurance results summarized. Comparison of CADMP and the National Acid Deposition Program/National Trends Network (NADP/NTN) data at four parallel sites indicated that mean depth-weighted differences were less than 3 μeq ℓ−1 for all ions, being statistically significant for ammonium, sulfate and hydrogen ion. These apparently small differences were 15–30% of the mean concentrations of ammonium, sulfate and hydrogen ion. Mean depth-weighted concentrations and mass deposition rates for the period 1985–1990 are summarized; the latter were highest either where concentrations or precipitation depths were relatively high.

  20. Characterization of the precipitates in Al-Li(8090) alloy using thermal measurements and TEM examinations

    NASA Astrophysics Data System (ADS)

    Gaber, A.; Afify, N.

    2002-04-01

    Variation of thermophysical properties of Al-Li (8090) quenched from the solid solution state (803 K) during heating (10 K/min) has been used to determine the temperatures at which the phase transformations take place. Transmission electron microscopic examinations were used to characterize the developed precipitates. It has been shown that the thermal properties can be used as a powerful tool for detecting phase transformations. Microstructural examinations after aging at 373, 438, 563 and 673 K revealed the formation of GP zones, δ‧-(Al 3Li), T B-(Al 7Cu 4Li) and T 2-(Al 6CuLi 3) precipitates, respectively. δ‧-particles and T B-(Al 7Cu 4Li) were observed to be nucleated intragranularly, whereas T 2-particles were observed to grow on the grain boundaries.

  1. (228)Ra and (226)Ra measurement on a BaSO4 co-precipitation source.

    PubMed

    Medley, Peter; Martin, Paul; Bollhöfer, Andreas; Parry, David

    2014-10-14

    One of the most commonly-used methods for determination of (226)Ra, particularly in water samples, utilises co-precipitation of Ra with BaSO4, followed by microfiltration to produce a source for alpha counting. This paper describes two extensions to BaSO4 co-precipitation methods which enable determination of (228)Ra using the same source. The adaptations presented here do not introduce any contaminants that will affect the separation of radium or alpha counting for (226)Ra, and can be used for re-analysis of already existing sources prepared by BaSO4 co-precipitation. The first adaptation uses detection of (228)Ac on the source by gamma spectrometry. The detection efficiency is high, allowing analysis of water samples at sufficiently low activity to be suitable in testing for compliance with drinking water quality standards. As (228)Ac grows in quickly, taking less than 2 days to reach equilibrium with the (228)Ra parent, this can also be useful in radiological emergency response situations. The second adaptation incorporates a method for the digestion of BaSO4 sources, allowing separation of thorium and subsequent determination of (228)Th activity. Although ingrowth periods for (228)Th can be lengthy, very low detection limits for (228)Ra can be achieved with this technique.

  2. (228)Ra and (226)Ra measurement on a BaSO4 co-precipitation source.

    PubMed

    Medley, Peter; Martin, Paul; Bollhöfer, Andreas; Parry, David

    2014-10-14

    One of the most commonly-used methods for determination of (226)Ra, particularly in water samples, utilises co-precipitation of Ra with BaSO4, followed by microfiltration to produce a source for alpha counting. This paper describes two extensions to BaSO4 co-precipitation methods which enable determination of (228)Ra using the same source. The adaptations presented here do not introduce any contaminants that will affect the separation of radium or alpha counting for (226)Ra, and can be used for re-analysis of already existing sources prepared by BaSO4 co-precipitation. The first adaptation uses detection of (228)Ac on the source by gamma spectrometry. The detection efficiency is high, allowing analysis of water samples at sufficiently low activity to be suitable in testing for compliance with drinking water quality standards. As (228)Ac grows in quickly, taking less than 2 days to reach equilibrium with the (228)Ra parent, this can also be useful in radiological emergency response situations. The second adaptation incorporates a method for the digestion of BaSO4 sources, allowing separation of thorium and subsequent determination of (228)Th activity. Although ingrowth periods for (228)Th can be lengthy, very low detection limits for (228)Ra can be achieved with this technique. PMID:25464199

  3. Advanced Measurement Devices for the Microgravity Electromagnetic Levitation Facility EML

    NASA Technical Reports Server (NTRS)

    Brillo, Jurgen; Fritze, Holger; Lohofer, Georg; Schulz, Michal; Stenzel, Christian

    2012-01-01

    This paper reports on two advanced measurement devices for the microgravity electromagnetic levitation facility (EML), which is currently under construction for the use onboard the "International Space Station (ISS)": the "Sample Coupling Electronics (SCE)" and the "Oxygen Sensing and Control Unit (OSC)". The SCE measures by a contactless, inductive method the electrical resistivity and the diameter of a spherical levitated metallic droplet by evaluating the voltage and electrical current applied to the levitation coil. The necessity of the OSC comes from the insight that properties like surface tension or, eventually, viscosity cannot seriously be determined by the oscillating drop method in the EML facility without knowing the conditions of the surrounding atmosphere. In the following both measurement devices are explained and laboratory test results are presented.

  4. Advances in measuring ocean salinity with an optical sensor

    NASA Astrophysics Data System (ADS)

    Le Menn, M.; de Bougrenet de la Tocnaye, J. L.; Grosso, P.; Delauney, L.; Podeur, C.; Brault, P.; Guillerme, O.

    2011-11-01

    Absolute salinity measurement of seawater has become a key issue in thermodynamic models of the oceans. One of the most direct ways is to measure the seawater refractive index which is related to density and can therefore be related to the absolute salinity. Recent advances in high resolution position sensitive devices enable us to take advantage of small beam deviation measurements using refractometers. This paper assesses the advantages of such technology with respect to the current state-of-the-art technology. In particular, we present the resolution dependence on refractive index variations and derive the limits of such a solution for designing seawater sensors well suited for coastal and deep-sea applications. Particular attention has been paid to investigate the impact of environmental parameters, such as temperature and pressure, on an optical sensor, and ways to mitigate or compensate them have been suggested here. The sensor has been successfully tested in a pressure tank and in open oceans 2000 m deep.

  5. The pulsed response of soil respiration to precipitation in an African savanna ecosystem: a coupled measurement and modeling approach

    NASA Astrophysics Data System (ADS)

    Fan, Z.; Neff, J. C.; Hanan, N. P.

    2014-12-01

    Savannas cover 60% of the African continent and play an essential role in the global carbon (C) cycle. To better characterize the physical controls over soil respiration in these settings, half-hourly observations of volumetric soil-water content, temperature, and the concentration of carbon dioxide (CO2) at different soil depths were continually measured from 2005 to 2007 under trees ("sub-canopy") and between trees ("inter-canopy") in a savanna vegetation near Skukuza, Kruger National Park, South Africa. The measured soil climate and CO2 concentration data were assimilated into a process-based model that estimates the CO2 production and flux with coupled dynamics of dissolved organic C (DOC) and microbial biomass C. Our results show that temporal and spatial variations in CO2 flux were strongly influenced by precipitation and vegetation cover, with two times greater CO2 flux in the sub-canopy plots (~2421 g CO2 m-2 yr-1) than in the inter-canopy plots (~1290 g CO2 m-2 yr-1). Precipitation influenced soil respiration by changing soil temperature and moisture; however, our modeling analysis suggests that the pulsed response of soil respiration to precipitation [known as "Birch effect (BE)"] is a key control on soil fluxes at this site. At this site, BE contributed to approximately 50% and 65% of heterotrophic respiration or 20% and 39% of soil respiration in the sub-canopy and inter-canopy plots, respectively. These results suggest that pulsed response of respiration to precipitation is an important component of the C cycle of savannas and should be considered in both measurement and modeling studies of carbon exchange in similar ecosystems.

  6. Estimating Watershed-Averaged Precipitation and Evapotranspiration Fluxes using Streamflow Measurements in a Semi-Arid, High Altitude Montane Catchment

    NASA Astrophysics Data System (ADS)

    Herrington, C.; Gonzalez-Pinzon, R.

    2014-12-01

    Streamflow through the Middle Rio Grande Valley is largely driven by snowmelt pulses and monsoonal precipitation events originating in the mountain highlands of New Mexico (NM) and Colorado. Water managers rely on results from storage/runoff models to distribute this resource statewide and to allocate compact deliveries to Texas under the Rio Grande Compact agreement. Prevalent drought conditions and the added uncertainty of climate change effects in the American southwest have led to a greater call for accuracy in storage model parameter inputs. While precipitation and evapotranspiration measurements are subject to scaling and representativeness errors, streamflow readings remain relatively dependable and allow watershed-average water budget estimates. Our study seeks to show that by "Doing Hydrology Backwards" we can effectively estimate watershed-average precipitation and evapotranspiration fluxes in semi-arid landscapes of NM using fluctuations in streamflow data alone. We tested this method in the Valles Caldera National Preserve (VCNP) in the Jemez Mountains of central NM. This method will be further verified by using existing weather stations and eddy-covariance towers within the VCNP to obtain measured values to compare against our model results. This study contributes to further validate this technique as being successful in humid and semi-arid catchments as the method has already been verified as effective in the former setting.

  7. Advanced Measurements of Silicon Carbide Ceramic Matrix Composites

    SciTech Connect

    Farhad Farzbod; Stephen J. Reese; Zilong Hua; Marat Khafizov; David H. Hurley

    2012-08-01

    Silicon carbide (SiC) is being considered as a fuel cladding material for accident tolerant fuel under the Light Water Reactor Sustainability (LWRS) Program sponsored by the Nuclear Energy Division of the Department of Energy. Silicon carbide has many potential advantages over traditional zirconium based cladding systems. These include high melting point, low susceptibility to corrosion, and low degradation of mechanical properties under neutron irradiation. In addition, ceramic matrix composites (CMCs) made from SiC have high mechanical toughness enabling these materials to withstand thermal and mechanical shock loading. However, many of the fundamental mechanical and thermal properties of SiC CMCs depend strongly on the fabrication process. As a result, extrapolating current materials science databases for these materials to nuclear applications is not possible. The “Advanced Measurements” work package under the LWRS fuels pathway is tasked with the development of measurement techniques that can characterize fundamental thermal and mechanical properties of SiC CMCs. An emphasis is being placed on development of characterization tools that can used for examination of fresh as well as irradiated samples. The work discuss in this report can be divided into two broad categories. The first involves the development of laser ultrasonic techniques to measure the elastic and yield properties and the second involves the development of laser-based techniques to measurement thermal transport properties. Emphasis has been placed on understanding the anisotropic and heterogeneous nature of SiC CMCs in regards to thermal and mechanical properties. The material properties characterized within this work package will be used as validation of advanced materials physics models of SiC CMCs developed under the LWRS fuels pathway. In addition, it is envisioned that similar measurement techniques can be used to provide process control and quality assurance as well as measurement of

  8. Duskside relativistic electron precipitation as measured by SAMPEX: A statistical survey

    NASA Astrophysics Data System (ADS)

    Comess, Max D.; Smith, David M.; Selesnick, Richard S.; Millan, Robyn M.; Sample, John G.

    2013-08-01

    Evidence for duskside relativistic electron precipitation (DREP) within the Earth's outer radiation belt has historically been seen in a few sets of high altitude balloon data (MAXIS, MINIS, INTERBOA), and in satellite data. We present statistical evidence that the relativistic electron precipitation events from the outer radiation belt with e-folding energies > 0.5 MeV are concentrated in the dusk-to-midnight sector, based on a survey of data collected by the SAMPEX satellite from 1992 to 2004. A correlation between spectral hardness and duskside MLT is observed in our sample, the largest studied to date. Out of 9380 precipitation events within the bounce loss cone, 1048 are observed to have exponentially falling spectra with e-folding energies above 0.5 MeV ("hard events") and 1648 events below 0.2 MeV. Of the hard events, 81% occur within 12 h to 24 h MLT, compared to only 37% of events having e-folding energies below 0.2 MeV. With microbursts removed from this softer population the percentage of duskside events rises to 46%. The hard events occur at slightly elevated levels of geomagnetic activity (Ap and Dst) relative to softer nonmicroburst events, but these correlations are much weaker than for microbursts. The hard events are observed to peak in occurrence at L ~ 5.5, significantly higher than nonmicroburst softer events, even though the opposite might be expected from compression of the magnetosphere due to the more negative average Dst of the hard events. The hard events are most prevalent during the declining phase of the 11 year solar cycle.

  9. On the potential of 2-D-Video Disdrometer technique to measure micro physical parameters of solid precipitation

    NASA Astrophysics Data System (ADS)

    Bernauer, F.; Hürkamp, K.; Rühm, W.; Tschiersch, J.

    2015-03-01

    Detailed characterization and classification of precipitation is an important task in atmospheric research. Line scanning 2-D-video disdrometer technique is well established for rain observations. The two orthogonal views taken of each hydrometeor passing the sensitive area of the instrument qualify this technique especially for detailed characterization of non symmetric solid hydrometeors. However, in case of solid precipitation problems related to the matching algorithm have to be considered and the user must be aware of the limited spacial resolution when size and shape descriptors are analyzed. This work has the aim of clarifying the potential of 2-D-video disdrometer technique in deriving size, velocity and shape parameters from single recorded pictures. The need of implementing a matching algorithm suitable for mixed and solid phase precipitation is highlighted as an essential step in data evaluation. For this purpose simple reproducible experiments with solid steel spheres and irregularly shaped styrofoam particles are conducted. Self-consistency of shape parameter measurements is tested in 40 cases of real snow fall. As result it was found, that reliable size and shape characterization with a relative standard deviation of less than 5% is only possible for particles larger than 1 mm. For particles between 0.5 and 1.0 mm the relative standard deviation can grow up to 22% for the volume, 17% for size parameters and 14% for shape descriptors. Testing the adapted matching algorithm with a reproducible experiment with styrofoam particles a mismatch probability of less than 2.5% was found. For shape parameter measurements in case of real solid phase precipitation the 2DVD shows self-consistent behavior.

  10. Probing the impact of different aerosol sources on cloud microphysics and precipitation through in-situ measurements of chemical mixing state

    NASA Astrophysics Data System (ADS)

    Prather, K. A.; Suski, K.; Cazorla, A.; Cahill, J. F.; Creamean, J.; Collins, D. B.; Heymsfield, A.; Roberts, G. C.; DeMott, P. J.; Sullivan, R. C.; Rosenfeld, D.; Comstock, J. M.; Tomlinson, J. M.

    2011-12-01

    Aerosol particles play a crucial role in affecting cloud processes by serving as cloud nuclei. However, our understanding of which particles actually form cloud and ice nuclei limits our ability to treat aerosols properly in climate models. In recent years, it has become possible to measure the chemical composition of individual cloud nuclei within the clouds using on-line mass spectrometry. In-situ high time resolution chemistry can now be compared with cloud physics measurements to directly probe the impact of aerosol chemistry on cloud microphysics. This presentation will describe results from two recent field campaigns, CalWater in northern California and ICE-T in the western Caribbean region. Ground-based and aircraft measurements will be presented of aerosol mixing state, cloud microphysics, and meteorology. Results from single particle mass spectrometry will show the sources of the cloud seeds, including dust, biomass burning, sea spray, and biological particles. Details will be provided on how we are now able to probe the sources and cycling of atmospheric aerosols by measuring individual aerosols, cloud nuclei, and precipitation chemistry. The important role of dust, both Asian and African, and bioparticles in forming ice nuclei will be discussed. Finally, a summary will be provided discussing how these new in-situ measurements are being used to advance our understanding of complex atmospheric processes, and improve our understanding of aerosol impacts on climate.

  11. Select Methodology for Validating Advanced Satellite Measurement Systems

    NASA Technical Reports Server (NTRS)

    Larar, Allen M.; Zhou, Daniel K.; Liu, Xi; Smith, William L.

    2008-01-01

    Advanced satellite sensors are tasked with improving global measurements of the Earth's atmosphere, clouds, and surface to enable enhancements in weather prediction, climate monitoring capability, and environmental change detection. Measurement system validation is crucial to achieving this goal and maximizing research and operational utility of resultant data. Field campaigns including satellite under-flights with well calibrated FTS sensors aboard high-altitude aircraft are an essential part of the validation task. This presentation focuses on an overview of validation methodology developed for assessment of high spectral resolution infrared systems, and includes results of preliminary studies performed to investigate the performance of the Infrared Atmospheric Sounding Interferometer (IASI) instrument aboard the MetOp-A satellite.

  12. A comparison of NEXRAD WSR-88D rain estimates with gauge measurements for high and low reflectivity gradient precipitation events.

    SciTech Connect

    Jendrowski, P.; Kelly, D. S.; Klazura, G. E.; Thomale, J. M.

    1999-04-14

    Rain gauge measurements were compared with radar-estimated storm total precipitation for 43 rain events that occurred at ten locations. Gauge-to-radar ratios (G/R) were computed for each case. The G/R ratio is strongly related to precipitation type, with the mean G/R slightly less than 1.00 for high-reflectivity gradient cases and greater than 2.00 (factor of 2 radar underestimation) for low-reflectivity gradient cases. both precipitation types indicated radar underestimate at the nearest ranges. However, the high-reflectivity gradient cases indicated radar overestimation at further ranges, while the low-reflectivity gradient cases indicated significant radar underestimation at all ranges. Occurrences of radar overestimates may have been related to high reflectivity returns from melting ice, bright-band effects in stratiform systems and hail from convective systems. Bright-band effects probably were responsible for improving the radar underestimates in the second range interval (50-99.9 km) for the low-reflectivity gradient cases. Other possibilities for radar overestimates are anomalous propagation (AP) of the radar beam. Smith, et al. (1996) concluded that bright band and AP lead to systematic overestimate of rainfall at intermediate ranges.

  13. Advanced multi-frequency radar: Design, preliminary measurements and particle size distribution retrieval

    NASA Astrophysics Data System (ADS)

    Majurec, Ninoslav

    In the spring of 2001 the Microwave Remote Sensing Laboratory (MIRSL) at the University of Massachusetts began the development of an advanced Multi-Frequency Radar (AMFR) system for studying clouds and precipitation. This mobile radar was designed to consist of three polarimetric Doppler subsystems operating at Ku-band (13.4 GHz), Ka-band (35.6 GHz) and W-band (94.92 GHz). This combination of frequency bands allows a measurement of a wide range of atmospheric targets ranging from weakly reflecting clouds to strong precipitation. The antenna beamwidths at each frequency were intentionally matched, ensuring consistent sampling volume. Multi-frequency radar remote sensing techniques are not widely used because few multi-frequency radars are available to the science community. One exception is the 33 GHz/95 GHz UMass Cloud Profiling Radar System (CPRS), which AMFR is intended to replace. AMFR's multi-parameter capabilities are designed for characterizing the complex microphysics of layer clouds and precipitation processes in winter storms. AMFR will also play an important role in developing algorithms and validating measurements for an upcoming generation of space-borne radars. The frequency bands selected for AMFR match those of several sensors that have been deployed or are under development. These include the Japanese Aerospace Exploration Agencies (JAXA's) Tropical Rainfall Measuring Mission (TRMM) satellite Ku-band (13 GHz) radar, the CloudSat W-band (95 GHz) radar, and the Global Precipitation Mission (GPM) satellite radars at Ku-band and Ka-band. This dissertation describes the AMFR hardware design and development. Compared to CPRS, the addition of one extra frequency band (Ku) will extend AMFR's measurement capabilities towards the larger particle sizes (precipitation). AMFR's design is based around high-power klystron amplifiers. This ensures complete coherency (CPRS uses magnetrons and coherent-on-receive technique). The partial loss in sensitivity due to

  14. Use of combined radar and radiometer systems in space for precipitation measurement: Some ideas

    NASA Technical Reports Server (NTRS)

    Moore, R. K.

    1981-01-01

    A brief survey is given of some fundamental physical concepts of optimal polarization characteristics of a transmission path or scatter ensemble of hydrometers. It is argued that, based on this optimization concept, definite advances in remote atmospheric sensing are to be expected. Basic properties of Kennaugh's optimal polarization theory are identified.

  15. Impact of precipitating ice on the simulation of a heavy rainfall event with advanced research WRF using two bulk microphysical schemes

    NASA Astrophysics Data System (ADS)

    Efstathiou, G. A.; Zoumakis, N. M.; Melas, D.; Kassomenos, P.

    2012-11-01

    In this study, the Weather Research and Forecasting (WRF) model version 3.2 is used to examine the impact of precipitating ice and especially snow-graupel partitioning in the simulation of a heavy rainfall event over Chalkidiki peninsula in Northern Greece. This major precipitation event, associated with a case of cyclogenesis over the Aegean Sea, occurred on the 8th of October 2006 causing severe flooding and damage. Two widely used microphysical parameterizations, the Purdue Lin (PLIN) and WRF Single-Moment 6-class scheme (WSM6) are compared with available raingauge measurements over the complex topography of Chalkidiki. To further investigate the importance of snow and graupel relative mass content and the treatment of precipitating ice sedimentation velocity, two older versions of the WSM6 scheme were compiled and run with the current model. The verification results indicate that all simulations were found to match raingauge data more closely over the eastern mountainous Chalkidiki peninsula where maximum accumulations were observed. In other stations all schemes overestimate 24h accumulated rainfall except a station situated at the western part of the peninsula, where none of the simulations was able to reproduce observed rainfall. Graupel dominance in PLIN generates rapid precipitation fallout at the point of maximum predicted 24h accumulation. Similar behavior is shown in WSM6 from WRF version 2, but with significant less rainfall. Increasing snow amounts aloft, due to the unified treatment of precipitating ice in WSM6 from WRF version 3, modifies rain dynamics which decrease rainfall rates, but increases 24h accumulations. A sensitivity experiment where PLIN is used with snow accretion by graupel turned off, indicated that this process seems to be the most important factor controlling the differences in surface precipitation between PLIN and WSM6 from WRF version 3, determining the spatial and temporal distribution of this heavy precipitation event. The

  16. Measuring respiration rates in marine fish larvae: challenges and advances.

    PubMed

    Peck, M A; Moyano, M

    2016-01-01

    Metabolic costs can be extremely high in marine fish larvae and gaining reliable estimates of the effects of intrinsic and extrinsic factors on those costs is important to understand environmental constraints on early growth and survival. This review provides an historical perspective of measurements of larval marine fish respiration (O2 consumption) including the methods (Winkler, manometric, polarographic, paramagnetic and optodes) and systems (closed system to intermittent-flow) used. This study compares and systematically reviews the results (metabolic rates, ontogenetic changes and taxonomic differences) obtained from 59 studies examining 53 species from 30 families. Standard (anaesthetized or darkness), routine and active respiration rates were reported in 14, 94 and 8% of the studies and much more work has been performed on larvae of temperate (88%) compared with tropical (9%) and polar (3%) species. More than 35% of the studies have been published since 2000 owing to both advances in oxygen sensors and the growing emphasis on understanding physiological effects of environmental change. Common protocols are needed to facilitate cross-taxa comparisons such as the effect of temperature (Q10 : 1·47-3·47), body mass (slope of allometric changes in O2 consumption rate from 0·5 to 1·3) and activity level on metabolic costs as measured via respiration rate. A set of recommendations is provided that will make it easier for researchers to design measurement systems, to judge the reliability of measurements and to make inter-comparisons among studies and species.

  17. Advanced Active-Magnetic-Bearing Thrust-Measurement System

    NASA Technical Reports Server (NTRS)

    Imlach, Joseph; Kasarda, Mary; Blumber, Eric

    2008-01-01

    An advanced thrust-measurement system utilizes active magnetic bearings to both (1) levitate a floating frame in all six degrees of freedom and (2) measure the levitation forces between the floating frame and a grounded frame. This system was developed for original use in measuring the thrust exerted by a rocket engine mounted on the floating frame, but can just as well be used in other force-measurement applications. This system offers several advantages over prior thrust-measurement systems based on mechanical support by flexures and/or load cells: The system includes multiple active magnetic bearings for each degree of freedom, so that by selective use of one, some, or all of these bearings, it is possible to test a given article over a wide force range in the same fixture, eliminating the need to transfer the article to different test fixtures to obtain the benefit of full-scale accuracy of different force-measurement devices for different force ranges. Like other active magnetic bearings, the active magnetic bearings of this system include closed-loop control subsystems, through which the stiffness and damping characteristics of the magnetic bearings can be modified electronically. The design of the system minimizes or eliminates cross-axis force-measurement errors. The active magnetic bearings are configured to provide support against movement along all three orthogonal Cartesian axes, and such that the support along a given axis does not produce force along any other axis. Moreover, by eliminating the need for such mechanical connections as flexures used in prior thrust-measurement systems, magnetic levitation of the floating frame eliminates what would otherwise be major sources of cross-axis forces and the associated measurement errors. Overall, relative to prior mechanical-support thrust-measurement systems, this system offers greater versatility for adaptation to a variety of test conditions and requirements. The basic idea of most prior active

  18. Application of the Precipitation Runoff Modeling System to measure impacts of forest fire on watershed hydrology

    NASA Astrophysics Data System (ADS)

    Driscoll, J. M.

    2015-12-01

    Precipitation in the southwestern United States falls primarily in areas of higher elevation. Drought conditions over the past five years have limited snowpack and rainfall, increasing the vulnerability to and frequency of forest fires in these montane regions. In June 2012, the Little Bear fire burned approximately 69 square miles (44,200 acres) in high-elevation forests of the Rio Hondo headwater catchments, south-central New Mexico. Burn severity was high or moderate on 53 percent of the burn area. The Precipitation Runoff Modeling System (PRMS) is a publically-available watershed model developed by the U.S. Geological Survey (USGS). PRMS data are spatially distributed using a 'Geospatial Fabric' developed at a national scale to define Hydrologic Response Units (HRUs), based on topography and points of interest (such as confluences and streamgages). The Little Bear PRMS study area is comprised of 22 HRUs over a 587 square-mile area contributing to the Rio Hondo above Chavez Canyon streamgage (USGS ID 08390020), in operation from 2008 to 2014. Model input data include spatially-distributed climate data from the National Aeronautics and Space Administration (NASA) DayMet and land cover (such as vegetation and soil properties) data from the USGS Geo Data Portal. Remote sensing of vegetation over time has provided a spatial distribution of recovery and has been applied using dynamic parameters within PRMS on the daily timestep over the study area. Investigation into the source and timing of water budget components in the Rio Hondo watershed may assist water planners and managers in determining how the surface-water and groundwater systems will react to future land use/land cover changes. Further application of PRMS in additional areas will allow for comparison of streamflow before and following wildfire conditions, and may lead to better understanding of the changes in watershed-scale hydrologic processes in the Southwest through post-fire watershed recovery.

  19. COSMO-SkyMed measurements in precipitation over the sea: analysis of Louisiana summer thunderstorms by simultaneous weather radar observations

    NASA Astrophysics Data System (ADS)

    Roberto, N.; Baldini, L.; Gorgucci, E.; Facheris, L.; Chandrasekar, V.

    2012-04-01

    Radar signatures of rain cells are investigated using X-band synthetic aperture radar (X-SAR) images acquired from COSMO-SkyMed constellation over oceans off the coast of Louisiana in summer 2010 provided by ASI archive. COSMO-SkyMed (CSK) monitoring of Deepwater Horizon oil spill provided a big amount of data during the period April-September 2010 and in July-August when several thunderstorms occurred in that area. In X-SAR images, radar signatures of rain cells over the sea usually consist of irregularly shaped bright and dark patches. These signatures originate from 1) the scattering and attenuation of radiation by hydrometers in the rain cells and 2) the modification of the sea roughness induced by the impact of raindrops and by wind gusts associated with rain cell. However, the interpretation of precipitation signatures in X-SAR images is not completely straightforward, especially over sea. Coincident measurements from ground based radars and an electromagnetic (EM) model predicting radar returns from the sea surface corrugated by rainfall are used to support the analysis. A dataset consisting of 4 CSK images has been collected over Gulf of Mexico while a WSR-88D NEXRAD S-band Doppler radar (KLIX) located in New Orleans was scanning the nearby portion of ocean. Terrestrial measurements have been used to reconstruct the component of X-SAR returns due to precipitation by modifying the known technique applied on measurements over land (Fritz et al. 2010, Baldini et al. 2011). Results confirm that the attenuation signature in X-SAR images collected over land, particularly pronounced in the presence of heavy precipitation cells, can be related to the S-band radar reflectivity integrated along the same path. The Normalized Radar Cross Section (NRCS) of land is considered to vary usually up to a few dBs in case of rain but with strong dependency on the specific type and conditions of land cover. While the NRCS of sea surface in clear weather condition can be

  20. Field measures show methanotroph sensitivity to soil moisture follows precipitation regime of the grassland sites across the US Great Plains

    NASA Astrophysics Data System (ADS)

    Koyama, A.; Webb, C. T.; Johnson, N. G.; Brewer, P. E.; von Fischer, J. C.

    2015-12-01

    Methane uptake rates are known to have temporal variation in response to changing soil moisture levels. However, the relative importance of soil diffusivity vs. methanotroph physiology has not been disentangled to date. Testing methanotroph physiology in the laboratory can lead to misleading results due to changes in the fine-scale habitat where methanotrophs reside. To assay the soil moisture sensitivity of methanotrophs under field conditions, we studied 22 field plots scattered across eight Great Plains grassland sites that differed in precipitation regime and soil moisture, making ca. bi-weekly measures during the growing seasons over three years. Quantification of methanotroph activity was achieved from chamber-based measures of methane uptake coincident with SF6-derived soil diffusivity, and interpretation in a reaction-diffusion model. At each plot, we also measured soil water content (SWC), soil temperature and inorganic nitrogen (N) contents. We also assessed methanotroph community composition via 454 sequencing of the pmoA gene. Statistical analyses showed that methanotroph activity had a parabolic response with SWC (concave down), and significant differences in the shape of this response among sites. Moreover, we found that the SWC at peak methanotroph activity was strongly correlated with mean annual precipitation (MAP) of the site. The sequence data revealed distinct composition patterns, with structure that was associated with variation in MAP and soil texture. These results suggest that local precipitation regime shapes methanotroph community composition, which in turn lead to unique sensitivity of methane uptake rates with soil moisture. Our findings suggest that methanotroph activity may be more accurately modeled when the biological and environmental responses are explicitly described.

  1. Probabilistic seismic demand analysis using advanced ground motion intensity measures

    USGS Publications Warehouse

    Tothong, P.; Luco, N.

    2007-01-01

    One of the objectives in performance-based earthquake engineering is to quantify the seismic reliability of a structure at a site. For that purpose, probabilistic seismic demand analysis (PSDA) is used as a tool to estimate the mean annual frequency of exceeding a specified value of a structural demand parameter (e.g. interstorey drift). This paper compares and contrasts the use, in PSDA, of certain advanced scalar versus vector and conventional scalar ground motion intensity measures (IMs). One of the benefits of using a well-chosen IM is that more accurate evaluations of seismic performance are achieved without the need to perform detailed ground motion record selection for the nonlinear dynamic structural analyses involved in PSDA (e.g. record selection with respect to seismic parameters such as earthquake magnitude, source-to-site distance, and ground motion epsilon). For structural demands that are dominated by a first mode of vibration, using inelastic spectral displacement (Sdi) can be advantageous relative to the conventionally used elastic spectral acceleration (Sa) and the vector IM consisting of Sa and epsilon (??). This paper demonstrates that this is true for ordinary and for near-source pulse-like earthquake records. The latter ground motions cannot be adequately characterized by either Sa alone or the vector of Sa and ??. For structural demands with significant higher-mode contributions (under either of the two types of ground motions), even Sdi (alone) is not sufficient, so an advanced scalar IM that additionally incorporates higher modes is used.

  2. Measurement of gamma' precipitates in a nickel-based superalloy using energy-filtered transmission electron microscopy coupled with automated segmenting techniques.

    PubMed

    Tiley, J S; Viswanathan, G B; Shiveley, A; Tschopp, M; Srinivasan, R; Banerjee, R; Fraser, H L

    2010-08-01

    Precipitates of the ordered L1(2) gamma' phase (dispersed in the face-centered cubic or FCC gamma matrix) were imaged in Rene 88 DT, a commercial multicomponent Ni-based superalloy, using energy-filtered transmission electron microscopy (EFTEM). Imaging was performed using the Cr, Co, Ni, Ti and Al elemental L-absorption edges in the energy loss spectrum. Manual and automated segmentation procedures were utilized for identification of precipitate boundaries and measurement of precipitate sizes. The automated region growing technique for precipitate identification in images was determined to measure accurately precipitate diameters. In addition, the region growing technique provided a repeatable method for optimizing segmentation techniques for varying EFTEM conditions. PMID:20434346

  3. Measurement of gamma' precipitates in a nickel-based superalloy using energy-filtered transmission electron microscopy coupled with automated segmenting techniques.

    PubMed

    Tiley, J S; Viswanathan, G B; Shiveley, A; Tschopp, M; Srinivasan, R; Banerjee, R; Fraser, H L

    2010-08-01

    Precipitates of the ordered L1(2) gamma' phase (dispersed in the face-centered cubic or FCC gamma matrix) were imaged in Rene 88 DT, a commercial multicomponent Ni-based superalloy, using energy-filtered transmission electron microscopy (EFTEM). Imaging was performed using the Cr, Co, Ni, Ti and Al elemental L-absorption edges in the energy loss spectrum. Manual and automated segmentation procedures were utilized for identification of precipitate boundaries and measurement of precipitate sizes. The automated region growing technique for precipitate identification in images was determined to measure accurately precipitate diameters. In addition, the region growing technique provided a repeatable method for optimizing segmentation techniques for varying EFTEM conditions.

  4. Precipitation measurements with GNSS polarimetric Radio Occultations: Status of the ROHP-PAZ mission and anticipated retrievals

    NASA Astrophysics Data System (ADS)

    Padullés, Ramon; Cardellach, Estel; de la Torre Juárez, Manuel; Tomás, Sergio; Turk, F. Joseph; Ao, Chi O.; Rius, Toni; Oliveras, Santi

    2016-04-01

    The upcoming ROHP-PAZ (Radio Occultations and Heavy Precipitation experiment aboard the spanish PAZ satellite) mission aims to detect, for the first time, precipitation using Global Navigation Satellite System Radio Occultations (GNSS-RO). The electromagnetic signals coming from the GNSS satellites travel tangentially through the atmosphere and will be collected in the PAZ Low Earth Orbiter at two polarizations (vertical and horizontal). This sounding-like technique of the atmosphere will measure all the atmospheric phenomena that are inducing depolarization effects, in addition to all the thermodynamic profiles that standard RO are nowadays providing. The main contributors to depolarization in the troposphere are known to be the hydrometeors, both rain drops from heavy precipitation events and horizontally oriented ice particles in the top of clouds. Their effects on the GNSS signals were predicted in Cardellach et. al. 2015 (IEEE Trans. Geosci. Remote Sens.), and measured in the ROHP-PAZ field campaign Padullés et. al. 2016 (Atmos. Chem. Phys.). Prior to the launch, a complete characterization of all the possible effects, including hydrometeors but also taking into account other elements was needed. To do so, actual data from the COSMIC - FORMOSAT 3 mission (Radio Occultation events) have been collocated with the TRMM, GPM and CloudSat missions (precipitation and clouds missions). Thousands of events have been analyzed, in terms of SNR and phase delays. For the same events, the effect of hydrometeors has been simulated as well as the most known ionospheric effects, such as Faraday Rotation and Cotton-Mouton effects. And finally, the predicted noise, actual measurements of the antenna pattern and some tolerance in the purity of the emitted signal have been included. This has resulted in an extensive data base that is key in the understanding of the upcoming actual data, as well as for the characterization of all the unpredicted effects. We will discuss here the

  5. A Feasibility Study for Simultaneous Measurements of Water Vapor and Precipitation Parameters using a Three-frequency Radar

    NASA Technical Reports Server (NTRS)

    Meneghini, R.; Liao, L.; Tian, L.

    2005-01-01

    The radar return powers from a three-frequency radar, with center frequency at 22.235 GHz and upper and lower frequencies chosen with equal water vapor absorption coefficients, can be used to estimate water vapor density and parameters of the precipitation. A linear combination of differential measurements between the center and lower frequencies on one hand and the upper and lower frequencies on the other provide an estimate of differential water vapor absorption. The coupling between the precipitation and water vapor estimates is generally weak but increases with bandwidth and the amount of non-Rayleigh scattering of the hydrometeors. The coupling leads to biases in the estimates of water vapor absorption that are related primarily to the phase state and the median mass diameter of the hydrometeors. For a down-looking radar, path-averaged estimates of water vapor absorption are possible under rain-free as well as raining conditions by using the surface returns at the three frequencies. Simulations of the water vapor attenuation retrieval show that the largest source of error typically arises from the variance in the measured radar return powers. Although the error can be mitigated by a combination of a high pulse repetition frequency, pulse compression, and averaging in range and time, the radar receiver must be stable over the averaging period. For fractional bandwidths of 20% or less, the potential exists for simultaneous measurements at the three frequencies with a single antenna and transceiver, thereby significantly reducing the cost and mass of the system.

  6. Measuring the Resilience of Advanced Life Support Systems

    NASA Technical Reports Server (NTRS)

    Bell, Ann Maria; Dearden, Richard; Levri, Julie A.

    2002-01-01

    Despite the central importance of crew safety in designing and operating a life support system, the metric commonly used to evaluate alternative Advanced Life Support (ALS) technologies does not currently provide explicit techniques for measuring safety. The resilience of a system, or the system s ability to meet performance requirements and recover from component-level faults, is fundamentally a dynamic property. This paper motivates the use of computer models as a tool to understand and improve system resilience throughout the design process. Extensive simulation of a hybrid computational model of a water revitalization subsystem (WRS) with probabilistic, component-level faults provides data about off-nominal behavior of the system. The data can then be used to test alternative measures of resilience as predictors of the system s ability to recover from component-level faults. A novel approach to measuring system resilience using a Markov chain model of performance data is also developed. Results emphasize that resilience depends on the complex interaction of faults, controls, and system dynamics, rather than on simple fault probabilities.

  7. Lidar and Radar Measurements of the melting layer in the frame of the Convective and Orographically-induced Precipitation Study

    NASA Astrophysics Data System (ADS)

    Di Girolamo, Paolo; Summa, Donato; Bhawar, Rohini; Di Iorio, Tatiana; Vaughan, Geraint; Norton, Emily; Peters, Gerhard

    2009-03-01

    During the Convective and Orographically-induced Precipitation Study (COPS), lidar dark bands were observed by the Univ. of BASILicata Raman lidar system (BASIL) on several IOPs and SOPs (among others, 23 July, 15 August, 17 August). Dark band signatures appear in the lidar measurements of particle backscattering at 355, 532 and 1064 nm and particle extinction at 355 and 532 nm, as well as in particle depolarization measurements. Lidar data are supported by measurements from the University of Hamburg cloud radar MIRA 36 (36 GHz), the University of Hamburg dual-polarization micro rain radars (24.1 GHz) and the University of Manchester Radio UHF clear air wind profiler (1.29 GHz). Results from BASIL and the radars are illustrated and discussed to support in the comprehension of the microphysical and scattering processes responsible for the appearance of the lidar dark band and radar bright band.

  8. TRMM Precipitation Radar Reflectivity Profiles Compared to High-Resolution Airborne and Ground-Based Radar Measurements

    NASA Technical Reports Server (NTRS)

    Heymsfield, G. M.; Geerts, B.; Tian, L.

    1999-01-01

    In this paper, TRMM (Tropical Rainfall Measuring Mission Satellite) Precipitation Radar (PR) products are evaluated by means of simultaneous comparisons with data from the high-altitude ER-2 Doppler Radar (EDOP), as well as ground-based radars. The comparison is aimed primarily at the vertical reflectivity structure, which is of key importance in TRMM rain type classification and latent heating estimation. The radars used in this study have considerably different viewing geometries and resolutions, demanding non-trivial mapping procedures in common earth-relative coordinates. Mapped vertical cross sections and mean profiles of reflectivity from the PR, EDOP, and ground-based radars are compared for six cases. These cases cover a stratiform frontal rainband, convective cells of various sizes and stages, and a hurricane. For precipitating systems that are large relative to the PR footprint size, PR reflectivity profiles compare very well to high-resolution measurements thresholded to the PR minimum reflectivity, and derived variables such as bright band height and rain types are accurate, even at high PR incidence angles. It was found that for, the PR reflectivity of convective cells small relative to the PR footprint is weaker than in reality. Some of these differences can be explained by non-uniform beam filling. For other cases where strong reflectivity gradients occur within a PR footprint, the reflectivity distribution is spread out due to filtering by the PR antenna illumination pattern. In these cases, rain type classification may err and be biased towards the stratiform type, and the average reflectivity tends to be underestimated. The limited sensitivity of the PR implies that the upper regions of precipitation systems remain undetected and that the PR storm top height estimate is unreliable, usually underestimating the actual storm top height. This applies to all cases but the discrepancy is larger for smaller cells where limited sensitivity is compounded

  9. Advanced quantitative measurement methodology in physics education research

    NASA Astrophysics Data System (ADS)

    Wang, Jing

    The ultimate goal of physics education research (PER) is to develop a theoretical framework to understand and improve the learning process. In this journey of discovery, assessment serves as our headlamp and alpenstock. It sometimes detects signals in student mental structures, and sometimes presents the difference between expert understanding and novice understanding. Quantitative assessment is an important area in PER. Developing research-based effective assessment instruments and making meaningful inferences based on these instruments have always been important goals of the PER community. Quantitative studies are often conducted to provide bases for test development and result interpretation. Statistics are frequently used in quantitative studies. The selection of statistical methods and interpretation of the results obtained by these methods shall be connected to the education background. In this connecting process, the issues of educational models are often raised. Many widely used statistical methods do not make assumptions on the mental structure of subjects, nor do they provide explanations tailored to the educational audience. There are also other methods that consider the mental structure and are tailored to provide strong connections between statistics and education. These methods often involve model assumption and parameter estimation, and are complicated mathematically. The dissertation provides a practical view of some advanced quantitative assessment methods. The common feature of these methods is that they all make educational/psychological model assumptions beyond the minimum mathematical model. The purpose of the study is to provide a comparison between these advanced methods and the pure mathematical methods. The comparison is based on the performance of the two types of methods under physics education settings. In particular, the comparison uses both physics content assessments and scientific ability assessments. The dissertation includes three

  10. Global Precipitation Measurement (GPM) and International Space Station (ISS) Coordination for CubeSat Deployments to Minimize Collision Risk

    NASA Technical Reports Server (NTRS)

    Pawloski, James H.; Aviles, Jorge; Myers, Ralph; Parris, Joshua; Corley, Bryan; Hehn, Garrett; Pascucci, Joseph

    2016-01-01

    The Global Precipitation Measurement Mission (GPM) is a joint U.S. and Japan mission to observe global precipitation, extending the Tropical Rainfall Measuring Mission (TRMM), which was launched by H-IIA from Tanegashima in Japan on February 28TH, 2014 directly into its 407km operational orbit. The International Space Station (ISS) is an international human research facility operated jointly by Russia and the USA from NASA's Johnson Space Center (JSC) in Houston Texas. Mission priorities lowered the operating altitude of ISS from 415km to 400km in early 2105, effectively placing both vehicles into the same orbital regime. The ISS has begun a program of deployments of cost effective CubeSats from the ISS that allow testing and validation of new technologies. With a major new asset flying at the same effective altitude as the ISS, CubeSat deployments became a serious threat to GPM and therefore a significant indirect threat to the ISS. This paper describes the specific problem of collision threat to GPM and risk to ISS CubeSat deployment and the process that was implemented to keep both missions safe from collision and maximize their project goals.

  11. Impact of Measurement System Characteristics on Advanced Sounder Information Content

    NASA Technical Reports Server (NTRS)

    Larar, Allen M.; Liu, Xu; Zhou, Daniel K.

    2011-01-01

    Advanced satellite sensors are tasked with improving global observations of the Earth's atmosphere, clouds, and surface to enable enhancements in weather prediction, climate monitoring capability, and environmental change detection. Achieving such an improvement in geophysical information inferred from these observations requires optimal usage of data from current systems as well as instrument system enhancements for future sensors. This presentation addresses results of tradeoff studies evaluating the impact of spectral resolution, spectral coverage, instrument noise, and a priori knowledge on remote sensing system information content, with a specific emphasis on thermodynamic state and trace species information obtainable from advanced atmospheric sounders. Particular attention will be devoted toward information achievable from the Atmospheric InfraRed Sounder (AIRS) on the NASA EOS Aqua satellite in orbit since 2002, the Infrared Atmospheric Sounding Interferometer (IASI) aboard MetOp-A since 2006, and the Cross-track Infrared Sounder (CrIS) instrument to fly aboard the NPP and JPSS series of satellites expected to begin in late 2011. While all of these systems cover nearly the same infrared spectral extent, they have very different number of channels, instrument line shapes, coverage continuity, and instrument noise. AIRS is a grating spectrometer having 2378 discrete spectral channels ranging from about 0.4 to 2.2/cm resolution; IASI is a Michelson interferometer with 8461 uniformly-spaced spectral channels of 0.5/cm (apodized) resolution; and CrIS is a Michelson interferometer having 1305 spectral channels of 0.625, 1.250, and 2.50/cm (unapodized) spectral resolution, respectively, over its three continuous but non-overlapping bands. Results of tradeoff studies showing information content sensitivity to assumed measurement system characteristics will be presented.

  12. Measurement of ice nucleation-active bacteria on plants and in precipitation by quantitative PCR.

    PubMed

    Hill, Thomas C J; Moffett, Bruce F; Demott, Paul J; Georgakopoulos, Dimitrios G; Stump, William L; Franc, Gary D

    2014-02-01

    Ice nucleation-active (INA) bacteria may function as high-temperature ice-nucleating particles (INP) in clouds, but their effective contribution to atmospheric processes, i.e., their potential to trigger glaciation and precipitation, remains uncertain. We know little about their abundance on natural vegetation, factors that trigger their release, or persistence of their ice nucleation activity once airborne. To facilitate these investigations, we developed two quantitative PCR (qPCR) tests of the ina gene to directly count INA bacteria in environmental samples. Each of two primer pairs amplified most alleles of the ina gene and, taken together, they should amplify all known alleles. To aid primer design, we collected many new INA isolates. Alignment of their partial ina sequences revealed new and deeply branching clades, including sequences from Pseudomonas syringae pv. atropurpurea, Ps. viridiflava, Pantoea agglomerans, Xanthomonas campestris, and possibly Ps. putida, Ps. auricularis, and Ps. poae. qPCR of leaf washings recorded ∼10(8) ina genes g(-1) fresh weight of foliage on cereals and 10(5) to 10(7) g(-1) on broadleaf crops. Much lower populations were found on most naturally occurring vegetation. In fresh snow, ina genes from various INA bacteria were detected in about half the samples but at abundances that could have accounted for only a minor proportion of INP at -10°C (assuming one ina gene per INA bacterium). Despite this, an apparent biological source contributed an average of ∼85% of INP active at -10°C in snow samples. In contrast, a thunderstorm hail sample contained 0.3 INA bacteria per INP active at -10°C, suggesting a significant contribution to this sample. PMID:24317082

  13. Measurement of ice nucleation-active bacteria on plants and in precipitation by quantitative PCR.

    PubMed

    Hill, Thomas C J; Moffett, Bruce F; Demott, Paul J; Georgakopoulos, Dimitrios G; Stump, William L; Franc, Gary D

    2014-02-01

    Ice nucleation-active (INA) bacteria may function as high-temperature ice-nucleating particles (INP) in clouds, but their effective contribution to atmospheric processes, i.e., their potential to trigger glaciation and precipitation, remains uncertain. We know little about their abundance on natural vegetation, factors that trigger their release, or persistence of their ice nucleation activity once airborne. To facilitate these investigations, we developed two quantitative PCR (qPCR) tests of the ina gene to directly count INA bacteria in environmental samples. Each of two primer pairs amplified most alleles of the ina gene and, taken together, they should amplify all known alleles. To aid primer design, we collected many new INA isolates. Alignment of their partial ina sequences revealed new and deeply branching clades, including sequences from Pseudomonas syringae pv. atropurpurea, Ps. viridiflava, Pantoea agglomerans, Xanthomonas campestris, and possibly Ps. putida, Ps. auricularis, and Ps. poae. qPCR of leaf washings recorded ∼10(8) ina genes g(-1) fresh weight of foliage on cereals and 10(5) to 10(7) g(-1) on broadleaf crops. Much lower populations were found on most naturally occurring vegetation. In fresh snow, ina genes from various INA bacteria were detected in about half the samples but at abundances that could have accounted for only a minor proportion of INP at -10°C (assuming one ina gene per INA bacterium). Despite this, an apparent biological source contributed an average of ∼85% of INP active at -10°C in snow samples. In contrast, a thunderstorm hail sample contained 0.3 INA bacteria per INP active at -10°C, suggesting a significant contribution to this sample.

  14. Measurement of Ice Nucleation-Active Bacteria on Plants and in Precipitation by Quantitative PCR

    PubMed Central

    Moffett, Bruce F.; DeMott, Paul J.; Georgakopoulos, Dimitrios G.; Stump, William L.; Franc, Gary D.

    2014-01-01

    Ice nucleation-active (INA) bacteria may function as high-temperature ice-nucleating particles (INP) in clouds, but their effective contribution to atmospheric processes, i.e., their potential to trigger glaciation and precipitation, remains uncertain. We know little about their abundance on natural vegetation, factors that trigger their release, or persistence of their ice nucleation activity once airborne. To facilitate these investigations, we developed two quantitative PCR (qPCR) tests of the ina gene to directly count INA bacteria in environmental samples. Each of two primer pairs amplified most alleles of the ina gene and, taken together, they should amplify all known alleles. To aid primer design, we collected many new INA isolates. Alignment of their partial ina sequences revealed new and deeply branching clades, including sequences from Pseudomonas syringae pv. atropurpurea, Ps. viridiflava, Pantoea agglomerans, Xanthomonas campestris, and possibly Ps. putida, Ps. auricularis, and Ps. poae. qPCR of leaf washings recorded ∼108 ina genes g−1 fresh weight of foliage on cereals and 105 to 107 g−1 on broadleaf crops. Much lower populations were found on most naturally occurring vegetation. In fresh snow, ina genes from various INA bacteria were detected in about half the samples but at abundances that could have accounted for only a minor proportion of INP at −10°C (assuming one ina gene per INA bacterium). Despite this, an apparent biological source contributed an average of ∼85% of INP active at −10°C in snow samples. In contrast, a thunderstorm hail sample contained 0.3 INA bacteria per INP active at −10°C, suggesting a significant contribution to this sample. PMID:24317082

  15. Advances in the Rising Bubble Technique for discharge measurement

    NASA Astrophysics Data System (ADS)

    Hilgersom, Koen; Luxemburg, Willem; Willemsen, Geert; Bussmann, Luuk

    2014-05-01

    Already in the 19th century, d'Auria described a discharge measurement technique that applies floats to find the depth-integrated velocity (d'Auria, 1882). The basis of this technique was that the horizontal distance that the float travels on its way to the surface is the image of the integrated velocity profile over depth. Viol and Semenov (1964) improved this method by using air bubbles as floats, but still distances were measured manually until Sargent (1981) introduced a technique that could derive the distances from two photographs simultaneously taken from each side of the river bank. Recently, modern image processing techniques proved to further improve the applicability of the method (Hilgersom and Luxemburg, 2012). In the 2012 article, controlling and determining the rising velocity of an air bubble still appeared a major challenge for the application of this method. Ever since, laboratory experiments with different nozzle and tube sizes lead to advances in our self-made equipment enabling us to produce individual air bubbles with a more constant rising velocity. Also, we introduced an underwater camera to on-site determine the rising velocity, which is dependent on the water temperature and contamination, and therefore is site-specific. Camera measurements of the rising velocity proved successful in a laboratory and field setting, although some improvements to the setup are necessary to capture the air bubbles also at depths where little daylight penetrates. References D'Auria, L.: Velocity of streams; A new method to determine correctly the mean velocity of any perpendicular in rivers and canals, (The) American Engineers, 3, 1882. Hilgersom, K.P. and Luxemburg, W.M.J.: Technical Note: How image processing facilitates the rising bubble technique for discharge measurement, Hydrology and Earth System Sciences, 16(2), 345-356, 2012. Sargent, D.: Development of a viable method of stream flow measurement using the integrating float technique, Proceedings of

  16. Validation of TRMM Precipitation Radar Through Comparison of its Multi-Year Measurements to Ground-Based Radar

    NASA Technical Reports Server (NTRS)

    Liao, Liang; Meneghini, Robert

    2010-01-01

    A procedure to accurately resample spaceborne and ground-based radar data is described, and then applied to the measurements taken from the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) and the ground-based Weather Surveillance Radar-1988 Doppler (WSR-88D or WSR) for the validation of the PR measurements and estimates. Through comparisons with the well-calibrated, non-attenuated WSR at Melbourne, Florida for the period 1998-2007, the calibration of the Precipitation Radar (PR) aboard the TRMM satellite is checked using measurements near the storm top. Analysis of the results indicates that the PR, after taking into account differences in radar reflectivity factors between the PR and WSR, has a small positive bias of 0.8 dB relative to the WSR, implying a soundness of the PR calibration in view of the uncertainties involved in the comparisons. Comparisons between the PR and WSR reflectivities are also made near the surface for evaluation of the attenuation-correction procedures used in the PR algorithms. It is found that the PR attenuation is accurately corrected in stratiform rain but is underestimated in convective rain, particularly in heavy rain. Tests of the PR estimates of rainfall rate are conducted through comparisons in the overlap area between the TRMM overpass and WSR scan. Analyses of the data are made both on a conditional basis, in which the instantaneous rain rates are compared only at those pixels where both the PR and WSR detect rain, and an unconditional basis, in which the area-averaged rain rates are estimated independently for the PR and WSR. Results of the conditional rain comparisons show that the PR-derived rain is about 9% greater and 19% less than the WSR estimates for stratiform and convective storms, respectively. Overall, the PR tends to underestimate the conditional mean rain rate by 8% for all rain categories, a finding that conforms to the results of the area-averaged rain (unconditional) comparisons.

  17. Advanced optical measuring systems for measuring the properties of fluids and structures

    NASA Technical Reports Server (NTRS)

    Decker, A. J.

    1986-01-01

    Four advanced optical models are reviewed for the measurement of visualization of flow and structural properties. Double-exposure, diffuse-illumination, holographic interferometry can be used for three-dimensional flow visualization. When this method is combined with optical heterodyning, precise measurements of structural displacements or fluid density are possible. Time-average holography is well known as a method for displaying vibrational mode shapes, but it also can be used for flow visualization and flow measurements. Deflectometry is used to measure or visualize the deflection of light rays from collimation. Said deflection occurs because of refraction in a fluid or because of reflection from a tilted surface. The moire technique for deflectometry, when combined with optical heterodyning, permits very precise measurements of these quantities. The rainbow schlieren method of deflectometry allows varying deflection angles to be encoded with colors for visualization.

  18. Runoff, precipitation, mass balance, and ice velocity measurements at South Cascade Glacier, Washington, 1993 balance year

    USGS Publications Warehouse

    Krimmel, R.M.

    1994-01-01

    Winter snow accumulation and summer snow, firn, and ice ablation were measured at South Cascade Glacier, Wash., to determine the winter and net balance for the 1993 balance year. The 1993 winter balance, averaged over the glacier, was 1.98 meters, and the net balance was -1.23 meters. This negative valance continued a trend of negative balance years beginning in 1977. Air temperature, barometric pressure, and runoff from this glacier basin and an adjacent non-glacierized basin were also continuously measured. Surface ice velocity was measured over an annual period. This report makes all these data available to users throughout the glaciological and climato1ogical community.

  19. Fine precipitation scenarios of AlZnMg(Cu) alloys revealed by advanced atomic-resolution electron microscopy study Part I: Structure determination of the precipitates in AlZnMg(Cu) alloys

    SciTech Connect

    Liu, J.Z.; Chen, J.H.; Yuan, D.W.; Wu, C.L.; Zhu, J.; Cheng, Z.Y.

    2015-01-15

    Although they are among the most important precipitation-hardened materials for industry applications, the high-strength AlZnMg(Cu) alloys have thus far not yet been understood adequately about their underlying precipitation scenarios in relation with the properties. This is partly due to the fact that the structures of a number of different precipitates involved in electron microscopy in association with quantitative image simulations have to be employed; a systematic study of these hardening precipitates in different alloys is also necessary. In Part I of the present study, it is shown that there are five types of structurally different precipitates including the equilibrium η-phase precipitate. Using two state-of-the-art atomic-resolution imaging techniques in electron microscopy in association with quantitative image simulations, we have determined and clarified all the unknown precipitate structures. It is demonstrated that atomic-resolution imaging can directly suggest approximate structure models, whereas quantitative image analysis can refine the structure details that are much smaller than the resolution of the microscope. This combination is crucially important for solving the difficult structure problems of the strengthening precipitates in AlZnMg(Cu) alloys. - Highlights: Part I: • We determine and verify all the key precipitate structures in AlMgZn(Cu) alloys. • We employ aberration-corrected scanning transmission electron microscopy (STEM). • We use aberration-corrected high-resolution TEM (HRTEM) for the investigations. • We obtain atomic-resolution images of the precipitates and model their structures. • We refine all precipitate structures with quantitative image simulation analysis. Part II: • The hardening precipitates in AlZnMg alloys shall be classified into two groups. • Two precipitation scenarios coexist in the alloys. • The precipitation behavior of such an alloy depends on the alloy's composition. • Very detailed phase

  20. Laboratory Measurements of Self-Potential (SP) During Biologically-Induced Precipitation of Calcite

    NASA Astrophysics Data System (ADS)

    Naudet, V.; Maineult, A.; Menez, B.; Zamora, M.

    2007-05-01

    Self-potential (or natural electrical field) data often provide complementary information for hydrological and environmental applications. Particularly, this method can be used to detect and quantify the variations of fluid flow or chemistry, as SP field results mainly from pressure and concentration gradients. Recent laboratory and field works have demonstrated that bacterial activity can also impact on this natural electrical field, even though the chemical and/or physical processes involved are still not well understood. It seems that direct transfer of electrons through biofilms triggers an electrical signal. Moreover, in an indirect way, the bacterial activity affects the fluid composition and the solute concentrations, as well as the properties of the surface of the mineral matrix, and thus changes the SP response. In order to provide some insights into the link between bacterial activity, chemistry and geophysics, we performed some laboratory experiments in sand-boxes. In particular, we studied the chemical and electrical response to the hydrolysis of urea by Bacillus pasteurii in presence of calcium. Schematically, bacteria were confined in the centre of the sand-box to avoid chemotactic migration. The sand was fully saturated with a nutrient solution containing urea (5 g/L), NaCl (8 g/L) and CaCl2-2(H2O) (2.8 g/L). The SP field was recorded continuously using small unpolarizable electrodes placed inside the sand. The chemical evolution of the solution at different distances from the centre of the box was daily analyzed. We report our preliminary results. The chemical evolution with time evidences at least two phases. First, a strong ammonium production, associated with the biodegradation of the urea, and a concomitant decrease of calcium ion content, due to the precipitation of calcite. Then, the biodegradation rate decreases or even goes to zero, while the by-products diffuse from the centre of the sand-box toward its borders. The SP variations are

  1. Precipitation measurement using SIR-C: A feasibility study. Investigation at nadir

    NASA Technical Reports Server (NTRS)

    Ahamad, Atiq; Moore, Richard K.

    1993-01-01

    The most significant limitation of the imaging SAR in rain measurements is the ground return coupled to the rain cell. Here we report a study of the possibility of using the X-SAR and the C-band channel of SIR-C for rain measurement. Earlier signal-to-clutter calculations rule out the use of X-SAR at steeper off-vertical angles of incidence (i.e., 20 less than theta less than 50). Only rain rates greater than 30 mm/hr at angles of incidence greater than 60 degrees showed good signal-to-clutter ratio (SCR). This study involved calculations at vertical incidence. There is adequate signal-to-noise ratio (SNR) at vertical incidence, but the presence of high-range side-lobe levels leads to small SCR for measurement over oceans at both X and C bands. For larger rain thickness (greater than two km), the SCR gets better and smaller rain rates (greater than 10 mm/hr) can be measured. However, rain measurements over forests seem to be feasible at nadir even for smaller rain thickness (less than two km). We conclude that X band may be usable over the forest at vertical incidence to measure rain rates greater than five mm/hr even for shallow rain thickness and over ocean for large rain thickness.

  2. SUMMARY REPORT ON RESEARCH RESULTS FROM THE ADVANCE MEASUREMENT INITIATIVE (AMI)

    EPA Science Inventory

    EPA created the Advanced Measurement Initiative (AMI) to permit the early and inexpensive evaluation of innovative advanced technology and to encourage broad and rapid application in EPA operations. The AMI program focused on improving EPA's technological capabilities and acceler...

  3. Advanced materials characterization based on full field deformation measurements

    NASA Astrophysics Data System (ADS)

    Carpentier, A. Paige

    Accurate stress-strain constitutive properties are essential for understanding the complex deformation and failure mechanisms for materials with highly anisotropic mechanical properties. Among such materials, glass-fiber- and carbon-fiber-reinforced polymer--matrix composites play a critical role in advanced structural designs. The large number of different methods and specimen types currently required to generate three-dimensional allowables for structural design slows down the material characterization. Also, some of the material constitutive properties are never measured due to the prohibitive cost of the specimens needed. This work shows that simple short-beam shear (SBS) specimens are well-suited for measurement of multiple constitutive properties for composite materials and that can enable a major shift toward accurate material characterization. The material characterization is based on the digital image correlation (DIC) full-field deformation measurement. The full-field-deformation measurement enables additional flexibility for assessment of stress--strain relations, compared to the conventional strain gages. Complex strain distributions, including strong gradients, can be captured. Such flexibility enables simpler test-specimen design and reduces the number of different specimen types required for assessment of stress--strain constitutive behavior. Two key elements show advantage of using DIC in the SBS tests. First, tensile, compressive, and shear stress--strain relations are measured in a single experiment. Second, a counter-intuitive feasibility of closed-form stress and modulus models, normally applicable to long beams, is demonstrated for short-beam specimens. The modulus and stress--strain data are presented for glass/epoxy and carbon/epoxy material systems. The applicability of the developed method to static, fatigue, and impact load rates is also demonstrated. In a practical method to determine stress-strain constitutive relations, the stress

  4. Dynamics of mineral crystallization from precipitated slab-derived fluid phase: first in situ synchrotron X-ray measurements

    NASA Astrophysics Data System (ADS)

    Malaspina, Nadia; Alvaro, Matteo; Campione, Marcello; Wilhelm, Heribert; Nestola, Fabrizio

    2015-03-01

    Remnants of the fluid phase at ultrahigh pressure (UHP) in subduction environments may be preserved as primary multiphase inclusions in UHP minerals. The mode of crystallization of daughter minerals during precipitation within the inclusion and/or the mechanism of interaction between the fluid at supercritical conditions and the host mineral are still poorly understood from a crystallographic point of view. A case study is represented by garnet-orthopyroxenites from the Maowu Ultramafic Complex (China) deriving from harzburgite precursors metasomatized at ~4 GPa, 750 °C by a silica- and incompatible trace element-rich fluid phase. This metasomatism produced poikilitic orthopyroxene and inclusion-rich garnet porphyroblasts. Solid multiphase primary inclusions in garnet display a size within a few tens of micrometres and negative crystal shapes. Infilling minerals (spinel: 10-20 vol%; amphibole, chlorite, talc, mica: 80-90 vol%) occur with constant volume proportions and derive from trapped solute-rich aqueous fluids. To constrain the possible mode of precipitation of daughter minerals, we performed for the first time a single-crystal X-ray diffraction experiment by synchrotron radiation at Diamond Light Source. In combination with electron probe microanalyses, this measurement allowed the unique identification of each mineral phase and reciprocal orientations. We demonstrated the epitaxial relationship between spinel and garnet and between some hydrous minerals. Such information is discussed in relation to the physico-chemical aspects of nucleation and growth, shedding light on the mode of mineral crystallization from a fluid phase trapped at supercritical conditions.

  5. Advanced Techniques for Power System Identification from Measured Data

    SciTech Connect

    Pierre, John W.; Wies, Richard; Trudnowski, Daniel

    2008-11-25

    Time-synchronized measurements provide rich information for estimating a power-system's electromechanical modal properties via advanced signal processing. This information is becoming critical for the improved operational reliability of interconnected grids. A given mode's properties are described by its frequency, damping, and shape. Modal frequencies and damping are useful indicators of power-system stress, usually declining with increased load or reduced grid capacity. Mode shape provides critical information for operational control actions. This project investigated many advanced techniques for power system identification from measured data focusing on mode frequency and damping ratio estimation. Investigators from the three universities coordinated their effort with Pacific Northwest National Laboratory (PNNL). Significant progress was made on developing appropriate techniques for system identification with confidence intervals and testing those techniques on field measured data and through simulation. Experimental data from the western area power system was provided by PNNL and Bonneville Power Administration (BPA) for both ambient conditions and for signal injection tests. Three large-scale tests were conducted for the western area in 2005 and 2006. Measured field PMU (Phasor Measurement Unit) data was provided to the three universities. A 19-machine simulation model was enhanced for testing the system identification algorithms. Extensive simulations were run with this model to test the performance of the algorithms. University of Wyoming researchers participated in four primary activities: (1) Block and adaptive processing techniques for mode estimation from ambient signals and probing signals, (2) confidence interval estimation, (3) probing signal design and injection method analysis, and (4) performance assessment and validation from simulated and field measured data. Subspace based methods have been use to improve previous results from block processing

  6. Advancing nursing leadership: a model for program implementation and measurement.

    PubMed

    Omoike, Osei; Stratton, Karen M; Brooks, Beth A; Ohlson, Susan; Storfjell, Judy Lloyd

    2011-01-01

    Despite the abundant literature documenting the need for nurse management education and career development, only recently have professional standards been targeted for this group. Competency standards for nurse leaders repeatedly identify systems-level concepts including finance and budget, communication skills, strategic management, human resources management, change management, and computer technology skills. However, educational initiatives to meet these standards are still at the early stages and most nurse leaders continue to acquire knowledge and experience through "on-the-job" training. This article will illustrate the need for partnerships and collaboration between academia and hospitals to advance nursing leadership to the next century. In addition, a tool to measure the impact of a graduate certificate program in nursing administration on nurse leader competencies is presented. Overall, the certificate program has been successful in multiple ways; it has "graduated" almost 80 nurse leaders, improved participant competence in their role at the systems level, as well as providing an impetus for completion of a graduate degree post program. PMID:21900817

  7. Laser precipitation monitor for measurement of drop size and velocity of moving spray-plate sprinklers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sprinkler drop size distribution and associated drop velocities have a major influence on sprinkler performance in regards to application intensity, uniformity of water application, wind drift, evaporation losses and kinetic energy transferred to the soil surface. Sprinkler drop size measurements a...

  8. Comparison of sprinkler droplet size and velocity measurements using a laser precipitation meter and photographic method

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Kinetic energy of water droplets has a substantial effect on development of a soil surface seal and infiltration rate of bare soil. Methods for measuring sprinkler droplet size and velocity needed to calculate droplet kinetic energy have been developed and tested over the past 50 years, each with ad...

  9. Solutions Network Formulation Report. The Potential Contributions of the Global Precipitation Measurement Mission to Phosphorus Reduction Efforts in the Florida Everglades

    NASA Technical Reports Server (NTRS)

    Anderson, Daniel; Hilbert, Kent; Lewis, David

    2009-01-01

    This candidate solution suggests the use of GPM precipitation observations to enhance the CERP. Specifically, GPM measurements could augment in situ precipitation data that are used to model agricultural phosphorus discharged into the Everglades. This solution benefits society by aiding water resource managers in identifying effective phosphorus reduction scenarios and thereby returning the Everglades to a more natural state. This solution supports the Water Management, Coastal Management, and Ecological Forecasting National Applications.

  10. Simultaneous measurements of wire electrode surface contamination and corona discharge characteristics in an air-cleaning electrostatic precipitator

    SciTech Connect

    Kanazawa, Seiji; Ohkubo, Toshikazu; Nomoto, Yukiharu; Adachi, Takayoshi; Chang, J.S.

    1997-01-01

    Contamination of the corona wire in a wire-to-plate type air-cleaning electrostatic precipitator is studied experimentally. In order to enhance the contamination of wire, air containing dusts is directly supplied to a part of the wire electrode. Spores of Lycopodium and cigarette smoke particles are used as test dusts. Simultaneous measurements of wire electrode optical images and corona discharge modes are carried out during contamination processes. Results show that corona discharge modes and optical emission from the wire electrode change with time due to the surface contamination. In the case of cigarette smoke, after a time elapsed, streamer coronas appear due to the buildup of smoke particles on the wire surface. After the first streamer generation, the corona current fluctuates with time because the formation and diminution of the projections occur alternately at the different parts on the wire electrode surface.

  11. Fine precipitation scenarios of AlZnMg(Cu) alloys revealed by advanced atomic-resolution electron microscopy study Part II: Fine precipitation scenarios in AlZnMg(Cu) alloys

    SciTech Connect

    Liu, J.Z.; Chen, J.H.; Liu, Z.R.; Wu, C.L.

    2015-01-15

    Although they are among the most important precipitation-hardened materials for industry applications, the high-strength AlZnMg(Cu) alloys have thus far not yet been understood adequately about their underlying precipitation scenarios in relation with the properties. This is partly due to the fact that the structures of a number of different precipitates involved in the alloys are unknown, and partly due to the complexity that the precipitation behaviors of the alloys may be closely related to the alloy's composition. In Part I of the present study, we have determined all the unknown precipitate structures in the alloys. Here in Part II, using atomic-resolution electron microscopy in association with the first principles energy calculations, we further studied and correlated the phase/structure transformation/evolution among these hardening precipitates in relation with the alloy's composition. It is shown that there are actually two coexisting classes of hardening precipitates in these alloys: the first class includes the η′-precipitates and their early-stage Guinier–Preston (GP-η′) zones; the second class includes the precursors of the equilibrium η-phase (referred to η{sub p}, or η-precursor) and their early-stage Guinier–Preston (GP-η{sub p}) zones. The two coexisting classes of precipitates correspond to two precipitation scenarios. - Highlights: • We determine and verify all the key precipitate structures in AlMgZn(Cu) alloys. • We employ aberration-corrected scanning transmission electron microscopy (STEM). • We use aberration-corrected high-resolution TEM (HRTEM) for the investigations. • We obtain atomic-resolution images of the precipitates and model their structures. • We refine all precipitate structures with quantitative image simulation analysis. • The hardening precipitates in AlZnMg alloys shall be classified into two groups. • Two precipitation scenarios coexist in the alloys. • The precipitation behavior of such an

  12. A review of hemorheology: Measuring techniques and recent advances

    NASA Astrophysics Data System (ADS)

    Sousa, Patrícia C.; Pinho, Fernando T.; Alves, Manuel A.; Oliveira, Mónica S. N.

    2016-02-01

    Significant progress has been made over the years on the topic of hemorheology, not only in terms of the development of more accurate and sophisticated techniques, but also in terms of understanding the phenomena associated with blood components, their interactions and impact upon blood properties. The rheological properties of blood are strongly dependent on the interactions and mechanical properties of red blood cells, and a variation of these properties can bring further insight into the human health state and can be an important parameter in clinical diagnosis. In this article, we provide both a reference for hemorheological research and a resource regarding the fundamental concepts in hemorheology. This review is aimed at those starting in the field of hemodynamics, where blood rheology plays a significant role, but also at those in search of the most up-to-date findings (both qualitative and quantitative) in hemorheological measurements and novel techniques used in this context, including technical advances under more extreme conditions such as in large amplitude oscillatory shear flow or under extensional flow, which impose large deformations comparable to those found in the microcirculatory system and in diseased vessels. Given the impressive rate of increase in the available knowledge on blood flow, this review is also intended to identify areas where current knowledge is still incomplete, and which have the potential for new, exciting and useful research. We also discuss the most important parameters that can lead to an alteration of blood rheology, and which as a consequence can have a significant impact on the normal physiological behavior of blood.

  13. Measuring up: Advances in How We Assess Reading Ability

    ERIC Educational Resources Information Center

    Sabatini, John; Albro, Elizabeth; O'Reilly, Tenaha

    2012-01-01

    In recent decades, the science of reading acquisition, processes, and individual differences in general and special populations has been continuously advancing through interdisciplinary research in cognitive, psycholinguistic, developmental, genetic, neuroscience, cross-language studies, and experimental comparison studies of effective…

  14. Precipitation measurements for earth-space communications: Accuracy requirements and ground-truth techniques

    NASA Technical Reports Server (NTRS)

    Ippolito, L. J.; Kaul, R.

    1981-01-01

    Rainfall which is regarded as one of the more important observations for the measurements of this most variable parameter was made continuously, across large areas and over the sea. Ships could not provide the needed resolution nor could available radars provide the needed breadth of coverage. Microwave observations from the Nimbus-5 satellite offered some hope. Another possibility was suggested by the results of many comparisons between rainfall and the clouds seen in satellite pictures. Sequences of pictures from the first geostationary satellites were employed and a general correspondence between rain and the convective clouds visible in satellite pictures was found. It was demonstrated that the agreement was best for growing clouds. The development methods to infer GATE rainfall from geostationary satellite images are examined.

  15. Development and application of new methods to retrieve vertical structure of precipitation above the ARM CART sites from MMCR measurements

    SciTech Connect

    Matrosov, Sergey

    2010-12-15

    The main objective of this project was to develop, validate and apply remote sensing methods to retrieve vertical profiles of precipitation over the DOE ARM CART sites using currently available remote sensors. While the ARM Program invested very heavily into developments of remote sensing methods and instruments for water vapor and non-precipitating cloud parameter retrievals, precipitation retrievals and studies lagged behind. Precipitation, however, is a crucial part of the water cycle, and without detailed information on rainfall and snowfall, significant improvements in the atmospheric models of different scales (i.e., one of the ARM Program's main goals) is difficult to achieve. Characterization of the vertical atmospheric column above the CART sites is also incomplete without detailed precipitation information, so developments of remote sensing methods for retrievals of parameters in precipitating cloud condition was essential. Providing modelers with retrieval results was also one of the key objectives of this research project.

  16. Pre-Launch Performance Evaluations of Falling Snow using the Global Precipitation Measurement (GPM) Radiometer Retrieval Algorithm

    NASA Astrophysics Data System (ADS)

    Skofronick Jackson, G.; Munchak, S. J.; Johnson, B. T.

    2013-12-01

    Retrievals of falling snow from space represent an important data set for understanding the Earth's atmospheric, hydrological, and energy cycles. Estimates of falling snow must be captured to obtain the true global precipitation water cycle, snowfall accumulations are required for hydrological studies, and without knowledge of the frozen particles in clouds one cannot adequately understand the energy and radiation budgets. This work reports on the development and pre-launch testing of retrieval algorithms for the Global Precipitation Measurement (GPM) mission Core Observatory satellite, to be launched in early 2014. In particular, we will report on GPM Microwave Imager (GMI) radiometer instrument algorithm performance with respect to falling snow detection and estimation. While satellite-based remote sensing can provide global coverage of falling snow events, the science is relatively new and retrievals are still undergoing development with challenges remaining. Estimates of falling snow from ground and space based sensors have been difficult due to the physical characteristics of snowflakes including their complex shapes, sizes, fall patterns, melting fractions, and densities; and their remotely sensed radiative characteristics. While these challenges remain, knowledge of their impact on expected retrieval results is an important key for understanding falling snow retrieval estimations. Our earlier work in this field has shown, through both theoretical and observational studies, that falling snow rates of approximately 0.5 mm/hr (melted) can be detected from GMI (Skofronick-Jackson, et al., IEEE Trans. Geoscience and Remote Sensing, 2013, Munchak and Skofronick-Jackson, Atmospheric Research, 2013). Throughout 2013, the at-launch GMI precipitation algorithms (called GPROF2014), based on a Bayesian framework, have been revised and delivered to the GPM data processing center with the final algorithm to be delivered in September 2013. The Bayesian framework for GMI

  17. Precipitation Climatology over Mediterranean Basin from Ten Years of TRMM Measurements

    NASA Technical Reports Server (NTRS)

    Mehta, Amita V.; Yang, Song

    2008-01-01

    Climatological features of mesoscale rain activities over the Mediterranean region between 5 W-40 E and 28 N-48 N are examined using the Tropical Rainfall Measuring Mission (TRMM) 3B42 and 2A25 rain products. The 3B42 rainrates at 3-hourly, 0.25 deg x 0.25 deg spatial resolution for the last 10 years (January 1998 to July 2007) are used to form and analyze the 5-day mean and monthly mean climatology of rainfall. Results show considerable regional and seasonal differences of rainfall over the Mediterranean Region. The maximum rainfall (3-5 mm/day) occurs over the mountain regions of Europe, while the minimum rainfall is observed over North Africa (approximately 0.5 mm/day). The main rainy season over the Mediterranean Sea extends from October to March, with maximum rainfall occurring during November-December. Over the Mediterranean Sea, an average rainrate of approximately 1-2 mm/day is observed, but during the rainy season there is 20% larger rainfall over the western Mediterranean Sea than that over the eastern Mediterranean Sea. During the rainy season, mesoscale rain systems generally propagate from west to east and from north to south over the Mediterranean region, likely to be associated with Mediterranean cyclonic disturbances resulting from interactions among large-scale circulation, orography, and land-sea temperature contrast.

  18. Measurement of storage ring motion at the advanced light source

    SciTech Connect

    Krebs, G.F.

    1997-05-01

    The mechanical stability of the Advanced Light Source storage ring is examined over a period of 1.5 years from the point of view of floor motion. The storage ring beam position monitor stability is examined under various operating conditions.

  19. Defining Neighborhood Boundaries for Social Measurement: Advancing Social Work Research

    ERIC Educational Resources Information Center

    Foster, Kirk A.; Hipp, J. Aaron

    2011-01-01

    Much of the current neighborhood-based research uses variables aggregated on administrative boundaries such as zip codes, census tracts, and block groups. However, other methods using current technological advances in geographic sciences may broaden our ability to explore the spatial concentration of neighborhood factors affecting individuals and…

  20. The impact of a windshield in a tipping bucket rain gauge on the reduction of losses in precipitation measurements during snowfall events

    NASA Astrophysics Data System (ADS)

    Buisan, Samuel T.; Collado, Jose Luis; Alastrue, Javier

    2016-04-01

    The amount of snow available controls the ecology and hydrological response of mountainous areas and cold regions and affects economic activities including winter tourism, hydropower generation, floods and water supply. An accurate measurement of snowfall accumulation amount is critical and source of error for a better evaluation and verification of numerical weather forecast, hydrological and climate models. It is well known that the undercatch of solid precipitation resulting from wind-induced updrafts at the gauge orifice is the main factor affecting the quality and accuracy of the amount of snowfall precipitation. This effect can be reduced by the use of different windshields. Overall, Tipping Bucket Rain Gauges (TPBRG) provide a large percentage of the precipitation amount measurements, in all climate regimes, estimated at about 80% of the total of observations by automatic instruments. In the frame of the WMO-SPICE project, we compared at the Formigal-Sarrios station (Spanish Pyrenees, 1800 m a.s.l.) the measured precipitation in two heated TPBRGs, one of them protected with a single alter windshield in order to reduce the wind bias. Results were contrasted with measured precipitation using the SPICE reference gauge (Pluvio2 OTT) in a Double Fence Intercomparison Reference (DFIR). Results reported that shielded reduces undercatch up to 40% when wind speed exceeds 6 m/s. The differences when compared with the reference gauge reached values higher than 70%. The inaccuracy of these measurements showed a significant impact in nowcasting operations and climatology in Spain, especially during some heavy snowfall episodes. Also, hydrological models showed a better agreement with the observed rivers flow when including the precipitation not accounted during these snowfall events. The conclusions of this experiment will be used to take decisions on the suitability of the installation of windshields in stations characterized by a large quantity of snowfalls during the

  1. Advances in Measurement of Skin Friction in Airflow

    NASA Technical Reports Server (NTRS)

    Brown, James L.; Naughton, Jonathan W.

    2006-01-01

    The surface interferometric skin-friction (SISF) measurement system is an instrument for determining the distribution of surface shear stress (skin friction) on a wind-tunnel model. The SISF system utilizes the established oil-film interference method, along with advanced image-data-processing techniques and mathematical models that express the relationship between interferograms and skin friction, to determine the distribution of skin friction over an observed region of the surface of a model during a single wind-tunnel test. In the oil-film interference method, a wind-tunnel model is coated with a thin film of oil of known viscosity and is illuminated with quasi-monochromatic, collimated light, typically from a mercury lamp. The light reflected from the outer surface of the oil film interferes with the light reflected from the oil-covered surface of the model. In the present version of the oil-film interference method, a camera captures an image of the illuminated model and the image in the camera is modulated by the interference pattern. The interference pattern depends on the oil-thickness distribution on the observed surface, and this distribution can be extracted through analysis of the image acquired by the camera. The oil-film technique is augmented by a tracer technique for observing the streamline pattern. To make the streamlines visible, small dots of fluorescentchalk/oil mixture are placed on the model just before a test. During the test, the chalk particles are embedded in the oil flow and produce chalk streaks that mark the streamlines. The instantaneous rate of thinning of the oil film at a given position on the surface of the model can be expressed as a function of the instantaneous thickness, the skin-friction distribution on the surface, and the streamline pattern on the surface; the functional relationship is expressed by a mathematical model that is nonlinear in the oil-film thickness and is known simply as the thin-oil-film equation. From the

  2. VOCs elimination and health risk reduction in e-waste dismantling workshop using integrated techniques of electrostatic precipitation with advanced oxidation technologies.

    PubMed

    Chen, Jiangyao; Huang, Yong; Li, Guiying; An, Taicheng; Hu, Yunkun; Li, Yunlu

    2016-01-25

    Volatile organic compounds (VOCs) emitted during the electronic waste dismantling process (EWDP) were treated at a pilot scale, using integrated electrostatic precipitation (EP)-advanced oxidation technologies (AOTs, subsequent photocatalysis (PC) and ozonation). Although no obvious alteration was seen in VOC concentration and composition, EP technology removed 47.2% of total suspended particles, greatly reducing the negative effect of particles on subsequent AOTs. After the AOT treatment, average removal efficiencies of 95.7%, 95.4%, 87.4%, and 97.5% were achieved for aromatic hydrocarbons, aliphatic hydrocarbons, halogenated hydrocarbons, as well as nitrogen- and oxygen-containing compounds, respectively, over 60-day treatment period. Furthermore, high elimination capacities were also seen using hybrid technique of PC with ozonation; this was due to the PC unit's high loading rates and excellent pre-treatment abilities, and the ozonation unit's high elimination capacity. In addition, the non-cancer and cancer risks, as well as the occupational exposure cancer risk, for workers exposed to emitted VOCs in workshop were reduced dramatically after the integrated technique treatment. Results demonstrated that the integrated technique led to highly efficient and stable VOC removal from EWDP emissions at a pilot scale. This study points to an efficient approach for atmospheric purification and improving human health in e-waste recycling regions.

  3. Measurement and capture of fine and ultrafine particles from a pilot-scale pulverized coal combustor with an electrostatic precipitator

    SciTech Connect

    Ying Li; Achariya Suriyawong; Michael Daukoru; Ye Zhuang; Pratim Biswas

    2009-05-15

    Experiments were carried out in a pilot-scale pulverized coal combustor at the Energy and Environmental Research Center (EERC) burning a Powder River Basin (PRB) subbituminous coal. A scanning mobility particle sizer (SMPS) and an electrical low-pressure impactor (ELPI) were used to measure the particle size distributions (PSDs) in the range of 17 nm to 10 m at the inlet and outlet of the electrostatic precipitator (ESP). At the ESP inlet, a high number concentration of ultrafine particles was found, with the peak at approximately 75 nm. A trimodal PSD for mass concentration was observed with the modes at approximately 80-100 nm, 1-2 {mu}m, and 10 {mu}m. The penetration of ultrafine particles through the ESP increased dramatically as particle size decreased below 70 nm, attributable to insufficient or partial charging of the ultrafine particles. Injection of nanostructured fine-particle sorbents for capture of toxic metals in the flue gas caused high penetration of the ultrafine particles through the ESP. The conventional ESP was modified to enhance charging using soft X-ray irradiation. A slipstream of flue gas was introduced from the pilot-scale facility and passed through this modified ESP. Enhancement of particle capture was observed with the soft X-ray irradiation when moderate voltages were used in the ESP, indicating more efficient charging of fine particles. 32 refs., 5 figs., 1 tab.

  4. Measurement and capture of fine and ultrafine particles from a pilot-scale pulverized coal combustor with an electrostatic precipitator.

    PubMed

    Li, Ying; Suriyawong, Achariya; Daukoru, Michael; Zhuang, Ye; Biswas, Pratim

    2009-05-01

    Experiments were carried out in a pilot-scale pulverized coal combustor at the Energy and Environmental Research Center (EERC) burning a Powder River Basin (PRB) subbituminous coal. A scanning mobility particle sizer (SMPS) and an electrical low-pressure impactor (ELPI) were used to measure the particle size distributions (PSDs) in the range of 17 nm to 10 microm at the inlet and outlet of the electrostatic precipitator (ESP). At the ESP inlet, a high number concentration of ultrafine particles was found, with the peak at approximately 75 nm. A trimodal PSD for mass concentration was observed with the modes at approximately 80-100 nm, 1-2 microm, and 10 microm. The penetration of ultrafine particles through the ESP increased dramatically as particle size decreased below 70 nm, attributable to insufficient or partial charging of the ultrafine particles. Injection of nanostructured fine-particle sorbents for capture of toxic metals in the flue gas caused high penetration of the ultrafine particles through the ESP. The conventional ESP was modified to enhance charging using soft X-ray irradiation. A slipstream of flue gas was introduced from the pilot-scale facility and passed through this modified ESP. Enhancement of particle capture was observed with the soft X-ray irradiation when moderate voltages were used in the ESP, indicating more efficient charging of fine particles.

  5. The Magnitude and Variability of Global and Regional Precipitation Based on the 22-Year GPCP (Global Precipitation Climatology Project) and Three-Year TRMM (Tropical Rainfall Measuring Mission) Data Sets

    NASA Technical Reports Server (NTRS)

    Adler, Robert F.; Curtis, Scott; Huffman, George; Bolvin, David; Nelkin, Eric

    2001-01-01

    This paper gives an overview of the analysis of global precipitation over the last few decades and the impact of the new TRMM precipitation observations. The 20+ year, monthly, globally complete precipitation analysis of the World Climate Research Program's (WCRP/GEWEX) Global Precipitation Climatology Project (GPCP) is used to study global and regional variations and trends and is compared to the much shorter TRMM (Tropical Rainfall Measuring Mission) tropical data set. The GPCP data set shows no significant trend in precipitation over the twenty years, unlike the positive trend in global surface temperatures over the past century. The global trend analysis must be interpreted carefully, however, because the inhomogeneity of the data set makes detecting a small signal very difficult, especially over this relatively short period. Identifying regional trends in precipitation may be more practical. From 1979 to 1999 the northern mid-latitudes appear to be drying, the southern mid-latitudes have gotten wetter, and there is a mixed signal in the tropics. The relation between this field of trends and the relation to the frequency of El Nino events during this time period is explored. Monthly anomalies of precipitation are related to ENSO variations with clear signals extending into middle and high latitudes of both hemispheres. The El Nino and La Nina mean anomalies are near mirror images of each other and when combined produce an ENSO signal with significant spatial continuity over large distances. These El Nino minus La Nina composites of normalized precipitation show the usual positive, or wet, anomaly over the central and eastern Pacific Ocean with the negative, or dry, anomaly over the maritime continent along with an additional negative anomaly over Brazil and the Atlantic Ocean extending into Africa and a positive anomaly over the Horn of Africa and the western Indian Ocean. A number of the features are shown to extend into high latitudes. Positive anomalies

  6. Variations and Trends in Global and Regional Precipitation Based on the 22-Year GPCP (Global Precipitation Climatology Project) and Three-Year TRMM (Tropical Rainfall Measuring Mission) Data Sets

    NASA Technical Reports Server (NTRS)

    Adler, Robert F.; Curtis, Scott; Huffman, George; Bolvin, David; Nelkin, Eric; Einaudi, Franco (Technical Monitor)

    2001-01-01

    This paper gives an overview of the analysis of global precipitation over the last few decades and the impact of the new TRMM precipitation observations. The 20+ year, monthly, globally complete precipitation analysis of the World Climate Research Program's (WCRP/GEWEX) Global Precipitation Climatology Project (GPCP) is used to study global and regional variations and trends and is compared to the much shorter TRMM(Tropical Rainfall Measuring Mission) tropical data set. The GPCP data set shows no significant trend in global precipitation over the twenty years, unlike the positive trend in global surface temperatures over the past century. The global trend analysis must be interpreted carefully, however, because the inhomogeneity of the data set makes detecting a small signal very difficult, especially over this relatively short period. The relation of global (and tropical) total precipitation and ENSO events is quantified with no significant signal when land and ocean are combined. Identifying regional trends in precipitation may be more practical. From 1979 to 2000 the tropics have pattern of regional rainfall trends that has an ENSO-like pattern with features of both the El Nino and La Nina. This feature is related to a possible trend in the frequency of ENSO events (either El Nino or La Nina) over the past 20 years. Monthly anomalies of precipitation are related to ENSO variations with clear signals extending into middle and high latitudes of both hemispheres. The El Nino and La Nina mean anomalies are near mirror images of each other and when combined produce an ENSO signal with significant spatial continuity over large distances. A number of the features are shown to extend into high latitudes. Positive anomalies extend in the Southern Hemisphere (S.H.) from the Pacific southeastward across Chile and Argentina into the south Atlantic Ocean. In the Northern Hemisphere (N.H.) the counterpart feature extends across the southern U.S. and Atlantic Ocean into Europe

  7. Alcohol Measurement Methodology in Epidemiology: Recent Advances and Opportunities

    PubMed Central

    Greenfield, Thomas K.; Kerr, William C.

    2009-01-01

    Aim To review and discuss measurement issues in survey assessment of alcohol consumption for epidemiological studies. Methods The following areas are considered: implications of cognitive studies of question answering like self-referenced schemata of drinking, reference period and retrospective recall, as well as the assets and liabilities of types of current (e.g., food frequency, quantity frequency, graduated frequencies, and heavy drinking indicators) and lifetime drinking measures. Finally we consider units of measurement and improving measurement by detailing the ethanol content of drinks in natural settings. Results and conclusions Cognitive studies suggest inherent limitations in the measurement enterprise, yet diary studies show promise of broadly validating methods that assess a range of drinking amounts per occasion; improvements in survey measures of drinking in the life course are indicated; attending in detail to on and off-premise drink pour sizes and ethanol concentrations of various beverages shows promise of narrowing the coverage gap plaguing survey alcohol measurement. PMID:18422826

  8. Large-scale precipitation estimation using Kalpana-1 IR measurements and its validation using GPCP and GPCC data

    NASA Astrophysics Data System (ADS)

    Prakash, Satya; Mahesh, C.; Gairola, Rakesh M.

    2011-12-01

    Large-scale precipitation estimation is very important for climate science because precipitation is a major component of the earth's water and energy cycles. In the present study, the GOES precipitation index technique has been applied to the Kalpana-1 satellite infrared (IR) images of every three-hourly, i.e., of 0000, 0300, 0600,…., 2100 hours UTC, for rainfall estimation as a preparatory to the INSAT-3D. After the temperatures of all the pixels in a grid are known, they are distributed to generate a three-hourly 24-class histogram of brightness temperatures of IR (10.5-12.5 μm) images for a 1.0° × 1.0° latitude/longitude box. The daily, monthly, and seasonal rainfall have been estimated using these three-hourly rain estimates for the entire south-west monsoon period of 2009 in the present study. To investigate the potential of these rainfall estimates, the validation of monthly and seasonal rainfall estimates has been carried out using the Global Precipitation Climatology Project and Global Precipitation Climatology Centre data. The validation results show that the present technique works very well for the large-scale precipitation estimation qualitatively as well as quantitatively. The results also suggest that the simple IR-based estimation technique can be used to estimate rainfall for tropical areas at a larger temporal scale for climatological applications.

  9. Performance Measurement of Advanced Stirling Convertors (ASC-E3)

    NASA Technical Reports Server (NTRS)

    Oriti, Salvatore M.

    2013-01-01

    NASA Glenn Research Center (GRC) has been supporting development of the Advanced Stirling Radioisotope Generator (ASRG) since 2006. A key element of the ASRG project is providing life, reliability, and performance testing data of the Advanced Stirling Convertor (ASC). The latest version of the ASC (ASC-E3, to represent the third cycle of engineering model test hardware) is of a design identical to the forthcoming flight convertors. For this generation of hardware, a joint Sunpower and GRC effort was initiated to improve and standardize the test support hardware. After this effort was completed, the first pair of ASC-E3 units was produced by Sunpower and then delivered to GRC in December 2012. GRC has begun operation of these units. This process included performance verification, which examined the data from various tests to validate the convertor performance to the product specification. Other tests included detailed performance mapping that encompassed the wide range of operating conditions that will exist during a mission. These convertors were then transferred to Lockheed Martin for controller checkout testing. The results of this latest convertor performance verification activity are summarized here.

  10. Advanced units: quality measures in urgency and emergency care

    PubMed Central

    Viola, Dan Carai Maia; Cordioli, Eduardo; Pedrotti, Carlos Henrique Sartorato; Iervolino, Mauro; Bastos, Antonio da Silva; de Almeida, Luis Roberto Natel; Neves, Henrique Sutton de Sousa; Lottenberg, Claudio Luiz

    2014-01-01

    Objective To evaluate, through care indicators, the quality of services rendered to patients considered urgency and emergency cases at an advanced emergency care unit. Methods We analyzed data from managerial reports of 64,891 medical visits performed in the Emergency Care Unit of the Ibirapuera Unit at Care during the period from June 1st, 2012 through May 31st, 2013. The proposed indicators for the assessment of care were rate of death in the emergency care unit; average length of stay of patients in the unit; rate of unplanned return visits; admission rate for patients screened as level 1 according to the Emergency Severity Index; rate of non-finalized medical consultations; rate of complaints; and door-to-electrocardiogram time. Results The rate of death in the emergency care unit was zero. Five of the 22 patients classified as Emergency Severity Index 1 (22.7%) arrived presenting cardiac arrest. All were treated with cardiopulmonary resuscitation and reestablishment of vital functions. The average length of stay of patients in the unit was 3 hours, 33 minutes, and 7 seconds. The rate of unscheduled return visits at the emergency care unit of the Ibirapuera unit was 13.64%. Rate of complaints was 2.8/1,000 patients seen during the period Conclusion The model of urgency and emergency care in advanced units provides an efficient and efficaious service to patients. Both critically ill patients and those considered less complex can receive proper treatment for their needs. PMID:25628203

  11. Advances in optical property measurements of spacecraft materials

    NASA Technical Reports Server (NTRS)

    Smith, Charles A.; Dever, Joyce A.; Jaworske, Donald A.

    1997-01-01

    Some of the instruments and experimental approaches, used for measuring the optical properties of thermal control systems, are presented. The instruments' use in studies concerning the effects of combined contaminants and space environment on these materials, and in the qualification of hardware for spacecraft, are described. Instruments for measuring the solar absorptance and infrared emittance offer improved speed, accuracy and data handling. A transient method for directly measuring material infrared emittance is described. It is shown that oxygen exposure before measuring the solar absorptance should be avoided.

  12. NASA Dual Precipitation Radar Arrives at Goddard

    NASA Video Gallery

    The Dual-frequency Precipitation Radar (DPR) built by the Japan Aerospace Exploration Agency (JAXA) for the Global Precipitation Measurement (GPM) mission's Core Observatory arrived on Friday, Marc...

  13. Advances in the Measurement of Atomic Transition Probabilities

    NASA Astrophysics Data System (ADS)

    O'Brian, Thomas Raymond

    The technology for measuring absolute atomic transition probabilities is extended. Radiative lifetimes are measured by time-resolved laser-induced fluorescence on a slow atomic beam generated by a versatile hollow cathode discharge source. The radiative lifetimes are free from systematic error at the five percent level. Combined with branching fractions measured with emission or absorption sources, the lifetimes result in absolute transition probabilities usually accurate to 5-10 %. Three new developments in the lifetime and branching fraction technique are reported. Radiative lifetimes for 186 levels in neutral iron are measured, with the energy of the upper levels densely spanning the entire excitation range of neutral iron. Combined with branching fractions measured in emission with Fourier transform spectrophotometry, the level lifetimes directly yield absolute transition probabilities for 1174 transitions. An additional 640 transition probabilities are determined by interpolating level populations in an emission source. The dense energy spacing of the levels with directly measured lifetimes permits accurate population interpolation despite departures from local thermodynamic equilibrium. This technique has the potential to permit accurate absolute transition probability measurements for essentially every classified line in a spectrum. Radiative lifetime measurements are extended into the vacuum ultraviolet with a continuously tunable vacuum ultraviolet laser based on stimulated anti-Stokes Raman scattering. When used with the hollow cathode atomic beam source, accurate lifetimes are measured for 47 levels in neutral silicon and 8 levels in neutral boron, primarily in the vacuum ultraviolet spectral region. Transition probabilities are reported for many lines connected to these upper levels, using previously measured or calculated branching fractions. The hollow cathode beam source is developed for use with refractory non-metals. Intense atomic beams of boron

  14. IMERG Global Precipitation Rates

    NASA Video Gallery

    NASA's Global Precipitation Measurement mission has produced its first global map of rainfall and snowfall. The GPM Core Observatory launched one year ago on Feb. 27, 2014 as a collaboration betwee...

  15. Advances in Raman Lidar Measurements of Water Vapor

    NASA Technical Reports Server (NTRS)

    Whiteman, D. N.; Evans, K.; Demoz, B.; DiGirolamo, P.; Mielke, B.; Stein, B.; Goldsmith, J. E. M.; Tooman, T.; Turner, D.; Starr, David OC. (Technical Monitor)

    2002-01-01

    Recent technology upgrades to the NASA/GSFC Scanning Raman Lidar have permitted significant improvements in the daytime and nighttime measurement of water vapor using Raman lidar. Numerical simulation has been used to study the temperature sensitivity of the narrow spectral band measurements presented here.

  16. Spatial dependences among precipitation maxima over Belgium

    NASA Astrophysics Data System (ADS)

    Vannitsem, S.; Naveau, P.

    2007-09-01

    For a wide range of applications in hydrology, the probability distribution of precipitation maxima represents a fundamental quantity to build dykes, propose flood planning policies, or more generally, to mitigate the impact of precipitation extremes. Classical Extreme Value Theory (EVT) has been applied in this context by usually assuming that precipitation maxima can be considered as Independent and Identically Distributed (IID) events, which approximately follow a Generalized Extreme Value distribution (GEV) at each recording site. In practice, weather stations records can not be considered as independent in space. Assessing the spatial dependences among precipitation maxima provided by two Belgium measurement networks is the main goal of this work. The pairwise dependences are estimated by a variogram of order one, also called madogram, that is specially tailored to be in compliance with spatial EVT and to capture EVT bivariate structures. Our analysis of Belgium precipitation maxima indicates that the degree of dependence varies greatly according to three factors: the distance between two stations, the season (summer or winter) and the precipitation accumulation duration (hourly, daily, monthly, etc.). Increasing the duration (from one hour to 20 days) strengthens the spatial dependence. The full independence is reached after about 50 km (100 km) for summer (winter) for a duration of one hour, while for long durations only after a few hundred kilometers. In addition this dependence is always larger in winter than in summer whatever is the duration. An explanation of these properties in terms of the dynamical processes dominating during the two seasons is advanced.

  17. Comparison of the TRMM Precipitation Radar rainfall estimation with ground-based disdrometer and radar measurements in South Greece

    NASA Astrophysics Data System (ADS)

    Ioannidou, Melina P.; Kalogiros, John A.; Stavrakis, Adrian K.

    2016-11-01

    The performance of the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) rainfall estimation algorithm is assessed, locally, in Crete island, south Greece, using data from a 2D-video disdrometer and a ground-based, X-band, polarimetric radar. A three-parameter, normalized Gamma drop size distribution is fitted to the disdrometer rain spectra; the latter are classified in stratiform and convective rain types characterized by different relations between distribution parameters. The method of moments estimates more accurately the distribution parameters than the best fit technique, which exhibits better agreement with and is more biased by the observed droplet distribution at large diameter values. Power laws between the radar reflectivity factor (Z) and the rainfall rate (R) are derived from the disdrometer data. A significant diversity of the prefactor and the exponent of the estimated power laws is observed, depending on the scattering model and the regression technique. The Z-R relationships derived from the disdrometer data are compared to those obtained from TRMM-PR data. Generally, the power laws estimated from the two datasets are different. Specifically, the greater prefactor found for the disdrometer data suggests an overestimation of rainfall rate by the TRMM-PR algorithm for light and moderate stratiform rain, which was the main rain type in the disdrometer dataset. Finally, contemporary data from the TRMM-PR and a ground-based, X-band, polarimetric radar are analyzed. Comparison of the corresponding surface rain rates for a rain event with convective characteristics indicates a large variability of R in a single TRMM-PR footprint, which typically comprises several hundreds of radar pixels. Thus, the coarse spatial resolution of TRMM-PR may lead to miss of significant high local peaks of convective rain. Also, it was found that the high temporal variability of convective rain may introduce significant errors in the estimation of bias of

  18. Ultra-sensitive transducer advances micro-measurement range

    NASA Technical Reports Server (NTRS)

    Rogallo, V. L.

    1964-01-01

    An ultrasensitive piezoelectric transducer, that converts minute mechanical forces into electrical impulses, measures the impact of micrometeoroids against space vehicles. It has uniform sensitivity over the entire target area and a high degree of stability.

  19. Advances in bioanalytical techniques to measure steroid hormones in serum.

    PubMed

    French, Deborah

    2016-06-01

    Steroid hormones are measured clinically to determine if a patient has a pathological process occurring in the adrenal gland, or other hormone responsive organs. They are very similar in structure making them analytically challenging to measure. Additionally, these hormones have vast concentration differences in human serum adding to the measurement complexity. GC-MS was the gold standard methodology used to measure steroid hormones clinically, followed by radioimmunoassay, but that was replaced by immunoassay due to ease of use. LC-MS/MS has now become a popular alternative owing to simplified sample preparation than for GC-MS and increased specificity and sensitivity over immunoassay. This review will discuss these methodologies and some new developments that could simplify and improve steroid hormone analysis in serum. PMID:27217264

  20. Advances in measuring techniques for turbine cooling test rigs

    NASA Technical Reports Server (NTRS)

    Pollack, F. G.

    1972-01-01

    Surface temperature distribution measurements for turbine vanes and blades were obtained by measuring the infrared energy emitted by the airfoil. The IR distribution can be related to temperature distribution by suitable calibration methods and the data presented in the form of isotherm maps. Both IR photographic and real time electro-optical methods are being investigated. The methods can be adapted to rotating as well as stationary targets, and both methods can utilize computer processing. Pressure measurements on rotating components are made with a rotating system incorporating 10 miniature transducers. A mercury wetted slip ring assembly was used to supply excitation power and as a signal transfer device. The system was successfully tested up to speeds of 9000 rpm and is now being adapted to measure rotating blade airflow quantities in a spin rig and a research engine.

  1. Advances in bioanalytical techniques to measure steroid hormones in serum.

    PubMed

    French, Deborah

    2016-06-01

    Steroid hormones are measured clinically to determine if a patient has a pathological process occurring in the adrenal gland, or other hormone responsive organs. They are very similar in structure making them analytically challenging to measure. Additionally, these hormones have vast concentration differences in human serum adding to the measurement complexity. GC-MS was the gold standard methodology used to measure steroid hormones clinically, followed by radioimmunoassay, but that was replaced by immunoassay due to ease of use. LC-MS/MS has now become a popular alternative owing to simplified sample preparation than for GC-MS and increased specificity and sensitivity over immunoassay. This review will discuss these methodologies and some new developments that could simplify and improve steroid hormone analysis in serum.

  2. Advances in Swept-Wavelength Interferometry for Precision Measurements

    NASA Astrophysics Data System (ADS)

    Moore, Eric D.

    2011-12-01

    Originally developed for radar applications in the 1950s, swept-wavelength interferometry (SWI) at optical wavelengths has been an active area of research for the past thirty years, with applications in fields ranging from fiber optic telecommunications to biomedical imaging. It now forms the basis of several measurement techniques, including optical frequency domain reflectometry (OFDR), swept-source optical coherence tomography (SS-OCT), and frequency-modulated continuous-wave (FMCW) lidar. In this thesis, I present several novel contributions to the field of SWI that include improvements and extensions to the state of the art in SWI for performing precision measurements. The first is a method for accurately monitoring the instantaneous frequency of the tunable source to accommodate nonlinearities in the source tuning characteristics. This work ex- tends the commonly used method incorporating an auxiliary interferometer to the increasingly relevant cases of long interferometer path mismatches and high-speed wavelength tuning. The second contribution enables precision absolute range measurements to within a small fraction of the transform-limited range resolution of the SWI system. This is accomplished through the use of digital filtering in the time domain and phase slope estimation in the frequency domain. Measurements of optical group delay with attosecond-level precision are experimentally demonstrated and applied to measurements of group refractive index and physical thickness. The accuracy of the group refractive index measurement is shown to be on the order of 10-6, while measurements of absolute thicknesses of macroscopic samples are accomplished with accuracy on the order of 10 nm. Furthermore, sub-nanometer uncertainty for relative thickness measurements can be achieved. For the case of crystalline silicon wafers, the achievable uncertainty is on the same order as the Si-Si bond length, opening the door to potential thickness profiling with single atomic

  3. Precise Radio-Telescope Measurements Advance Frontier Gravitational Physics

    NASA Astrophysics Data System (ADS)

    2009-09-01

    Scientists using a continent-wide array of radio telescopes have made an extremely precise measurement of the curvature of space caused by the Sun's gravity, and their technique promises a major contribution to a frontier area of basic physics. "Measuring the curvature of space caused by gravity is one of the most sensitive ways to learn how Einstein's theory of General Relativity relates to quantum physics. Uniting gravity theory with quantum theory is a major goal of 21st-Century physics, and these astronomical measurements are a key to understanding the relationship between the two," said Sergei Kopeikin of the University of Missouri. Kopeikin and his colleagues used the National Science Foundation's Very Long Baseline Array (VLBA) radio-telescope system to measure the bending of light caused by the Sun's gravity to an accuracy of 0.03 percent. With further observations, the scientists say their precision technique can make the most accurate measure ever of this phenomenon. Bending of starlight by gravity was predicted by Albert Einstein when he published his theory of General Relativity in 1916. According to relativity theory, the strong gravity of a massive object such as the Sun produces curvature in the nearby space, which alters the path of light or radio waves passing near the object. The phenomenon was first observed during a solar eclipse in 1919. Though numerous measurements of the effect have been made over the intervening 90 years, the problem of merging General Relativity and quantum theory has required ever more accurate observations. Physicists describe the space curvature and gravitational light-bending as a parameter called "gamma." Einstein's theory holds that gamma should equal exactly 1.0. "Even a value that differs by one part in a million from 1.0 would have major ramifications for the goal of uniting gravity theory and quantum theory, and thus in predicting the phenomena in high-gravity regions near black holes," Kopeikin said. To make

  4. Investigation of differences between field and laboratory pH measurements of national atmospheric deposition program/national trends network precipitation samples

    USGS Publications Warehouse

    Latysh, N.; Gordon, J.

    2004-01-01

    A study was undertaken to investigate differences between laboratory and field pH measurements for precipitation samples collected from 135 weekly precipitation-monitoring sites in the National Trends Network from 12/30/1986 to 12/28/1999. Differences in pH between field and laboratory measurements occurred for 96% of samples collected during this time period. Differences between the two measurements were evaluated for precipitation samples collected before and after January 1994, when modifications to sample-handling protocol and elimination of the contaminating bucket o-ring used in sample shipment occurred. Median hydrogen-ion and pH differences between field and laboratory measurements declined from 3.9 ??eq L-1 or 0.10 pH units before the 1994 protocol change to 1.4 ??eq L-1 or 0.04 pH units after the 1994 protocol change. Hydrogen-ion differences between field and laboratory measurements had a high correlation with the sample pH determined in the field. The largest pH differences between the two measurements occurred for high-pH samples (>5.6), typical of precipitation collected in Western United States; however low- pH samples (<5.0) displayed the highest variability in hydrogen-ion differences between field and laboratory analyses. Properly screened field pH measurements are a useful alternative to laboratory pH values for trend analysis, particularly before 1994 when laboratory pH values were influenced by sample-collection equipment.

  5. Recent Advances in Global Measurement and Application of River Widths

    NASA Astrophysics Data System (ADS)

    Pavelsky, T.; Allen, G. H.

    2015-12-01

    Among variables relevant to river form and discharge that can be observed from space, river width is perhaps the simplest to measure. Width can be extracted directly from optical or radar imagery, and application of remotely sensed widths to problems in hydrology, fluvial geomorphology, and ecology dates back more than two decades. Despite this long heritage, until very recently remotely sensed width measurements have largely been made on an ad-hoc basis for individual studies over relatively small regions. Global studies that required river widths have largely relied on estimates from downstream hydraulic geometry relationships with basin area, which inevitably simplify width variability and may, in practice, underestimate the fraction of wide rivers and the total river surface area in many basins. Over the last two years, multiple new regional- and global-scale, satellite-derived river width datasets have been developed that have substantially improved our global understanding of river form. These datasets include the Global Width Database for Large Rivers (GWD-LR), which provides width measurements for rivers wider than ~180 m, and all rivers wider than ~300 m, based on the SRTM water mask and the Global River Widths from Landsat (GRWL), which provides measurements for rivers as narrow as 30 m and all rivers wider than ~100 m. Several regional-scale datasets have also been developed. These datasets will facilitate improvements to regional and global scale hydrodynamic models, will provide more robust information on global river surface area for gas flux studies, and constitute novel information on global patterns of fluvial geomorphology. These datasets represent the beginning, not the end, of global river width measurements, however, as in the future multitemporal width measurements can be combined with recently developed algorithms to estimate river discharge for many rivers, globally.

  6. Advances in laser-based isotope ratio measurements: selected applications

    NASA Astrophysics Data System (ADS)

    Kerstel, E.; Gianfrani, L.

    2008-09-01

    Small molecules exhibit characteristic ro-vibrational transitions in the near- and mid-infrared spectral regions, which are strongly influenced by isotopic substitution. This gift of nature has made it possible to use laser spectroscopy for the accurate analysis of the isotopic composition of gaseous samples. Nowadays, laser spectroscopy is clearly recognized as a valid alternative to isotope ratio mass spectrometry. Laser-based instruments are leaving the research laboratory stage and are being used by a growing number of isotope researchers for significant advances in their own field of research. In this review article, we discuss the current status and new frontiers of research on high-sensitivity and high-precision laser spectroscopy for isotope ratio analyses. Although many of our comments will be generally applicable to laser isotope ratio analyses in molecules of environmental importance, this paper concerns itself primarily with water and carbon dioxide, two molecules that were studied extensively in our respective laboratories. A complete coverage of the field is practically not feasible in the space constraints of this issue, and in any case doomed to fail, considering the large body of work that has appeared ever since the review by Kerstel in 2004 ( Handbook of Stable Isotope Analytical Techniques, Chapt. 34, pp. 759-787).

  7. Measurement and modeling of advanced coal conversion processes

    SciTech Connect

    Solomon, P.R.; Serio, M.A.; Hamblen, D.G. ); Smoot, L.D.; Brewster, B.S. )

    1992-01-01

    The objectives of this proposed study are to establish the mechanisms and rates of basic steps in coal conversion processes, to integrate and incorporate this information into comprehensive computer models for coal conversion processes, to evaluate these models and to apply them to gasification, mild gasification and combustion in heat engines. This report describes progress during twenty second quarter of the program. Specifically, the paper discusses progress in three task areas: (1) Submodel development and evaluation: coal to char chemistry submodel; fundamental high-pressure reaction rate data; secondary reaction of pyrolysis product and burnout submodels; ash physics and chemistry submodel; large particle submodels; large char particle oxidation at high pressures; and SO[sub x]-NO[sub x] submodel development and evaluation; (2) Comprehensive model development and evaluation: integration of advanced submodels into entrained-flow code, with evaluation and documentation; comprehensive fixed-bed modeling review, development evaluation and implementation; and generalized fuels feedstock submodel; and (3) Application of integrated codes: application of generalized pulverized coal comprehensive code and application of fixed-bed code.

  8. Report calls for measures to advance climate modeling

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2012-09-01

    While climate modeling has made enormous strides over the past several decades, a critical step toward making more rapid, efficient, and coordinated progress in modeling would require “an evolutionary change in U.S. climate modeling institutions away from developing multiple completely independent models toward a collaborative approach,” according to a 7 September report by a committee of the U.S. National Research Council's Board on Atmospheric Sciences and Climate (BASC). “The Committee believes that the best path forward is a strategy centered around the integration of the decentralized U.S. climate modeling enterprise—across modeling efforts, across a hierarchy of model types, across modeling communities focused on different space and timescales, and between model developers and model output users,” the report notes. “A diversity of approaches is necessary for progress in many areas of climate modeling and is vital for addressing the breadth of users needs.” Entitled A National Strategy for Advancing Climate Modeling, the report states that, “If adopted, this strategy of increased unification amidst diversity will allow the United States to more effectively meet the climate information needs of the Nation in the coming decades and beyond.”

  9. CONDENSED MATTER: STRUCTURE, THERMAL AND MECHANICAL PROPERTIES: Three-dimensional size and orientation of the precipitates in AZ91 magnesium alloys measured by TEM techniques

    NASA Astrophysics Data System (ADS)

    Zheng, Ou; Ma, Jia-Yan; Wang, Jian-Bo; Zhou, Jia-Ping; Jin, Lei; Zhao, Dong-Shan; Wang, Ren-Hui

    2009-10-01

    Knowledge of the microscopic structure, including three-dimensional (3-D) size and orientation of the precipitates, is essential to fully understand the mechanical properties of the magnesium alloys and designing the alloys with better performance. Analytical TEM with high spatial resolution offers the simultaneous measurements of 3-D size, structure, orientation, composition of the precipitates from one typical sample along an established crystallographic axis. Besides popular Burgers orientation relationship (OR), other ORs such as Pitsch-Schrader OR, Crawley OR, Potter OR and a new OR with the form of [0001]α 1.0° from [311]γ and (11bar 20)α 2.0°? from (03bar 3)γ between the magnesium matrix and the precipitate γ-Mg17Al12 are identified by TEM imaging and diffraction techniques. As a case study, the thicknesses of the individual precipitates with Burgers OR are further measured to be 100-200 nm through both electron energy-loss spectroscopy and x-ray energy dispersive spectroscopy combining differential x-ray absorption and extrapolation, which are in agreement with the overall 3-D size statistic distribution results obtained through analysing various samples along various directions. Furthermore, the fabricated wedge-shape structure provides a platform on which to study the dependence of the interfacial strain on the variation of the thickness.

  10. Advances in the Conceptualization and Measurement of Critical Consciousness

    ERIC Educational Resources Information Center

    Diemer, Matthew A.; McWhirter, Ellen Hawley; Ozer, Emily J.; Rapa, Luke J.

    2015-01-01

    This article reviews three emergent measures of critical consciousness (CC), which refers to marginalized or oppressed people's critical reflection on oppressive social, economic, or political conditions, the motivation to address perceived injustice, and action taken to counter such injustice in a liberatory manner (Freire in "Education for…

  11. Advances in soil erosion research: processes, measurement, and modeling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil erosion by the environmental agents of water and wind is a continuing global menace that threatens the agricultural base that sustains our civilization. Members of ASABE have been at the forefront of research to understand erosion processes, measure erosion and related processes, and model very...

  12. Advances in Air-Sea Flux Measurement by Eddy Correlation

    NASA Astrophysics Data System (ADS)

    Blomquist, Byron W.; Huebert, Barry J.; Fairall, Christopher W.; Bariteau, Ludovic; Edson, James B.; Hare, Jeffrey E.; McGillis, Wade R.

    2014-09-01

    Eddy-correlation measurements of the oceanic flux are useful for the development and validation of air-sea gas exchange models and for analysis of the marine carbon cycle. Results from more than a decade of published work and from two recent field programs illustrate the principal interferences from water vapour and motion, demonstrating experimental approaches for improving measurement precision and accuracy. Water vapour cross-sensitivity is the greatest source of error for flux measurements using infrared gas analyzers, often leading to a ten-fold bias in the measured flux. Much of this error is not related to optical contamination, as previously supposed. While various correction schemes have been demonstrated, the use of an air dryer and closed-path analyzer is the most effective way to eliminate this interference. This approach also obviates density corrections described by Webb et al. (Q J R Meteorol 106:85-100, 1980). Signal lag and frequency response are a concern with closed-path systems, but periodic gas pulses at the inlet tip provide for precise determination of lag time and frequency attenuation. Flux attenuation corrections are shown to be 5 % for a cavity ring-down analyzer (CRDS) and dryer with a 60-m inlet line. The estimated flux detection limit for the CRDS analyzer and dryer is a factor of ten better than for IRGAs sampling moist air. While ship-motion interference is apparent with all analyzers tested in this study, decorrelation or regression methods are effective in removing most of this bias from IRGA measurements and may also be applicable to the CRDS.

  13. Precipitation Recycling

    NASA Technical Reports Server (NTRS)

    Eltahir, Elfatih A. B.; Bras, Rafael L.

    1996-01-01

    The water cycle regulates and reflects natural variability in climate at the regional and global scales. Large-scale human activities that involve changes in land cover, such as tropical deforestation, are likely to modify climate through changes in the water cycle. In order to understand, and hopefully be able to predict, the extent of these potential global and regional changes, we need first to understand how the water cycle works. In the past, most of the research in hydrology focused on the land branch of the water cycle, with little attention given to the atmospheric branch. The study of precipitation recycling which is defined as the contribution of local evaporation to local precipitation, aims at understanding hydrologic processes in the atmospheric branch of the water cycle. Simply stated, any study on precipitation recycling is about how the atmospheric branch of the water cycle works, namely, what happens to water vapor molecules after they evaporate from the surface, and where will they precipitate?

  14. A Comparative Study on Extreme Precipitation of the Han River Basin using a Bivariate Goodness-of-fit Measure for Regional Frequency Analysis

    NASA Astrophysics Data System (ADS)

    Ahn, Hyunjun; Jung, Younghun; Joo, Kyungwon; Kim, Taereem; Heo, Jun-Haeng

    2016-04-01

    In statistical hydrology, frequency analysis has been widely used for design of water resource systems. The traditional at-site analysis is recommended when the sample size is bigger than twice target return period (2T). However, in reality, the sample size of subject site is usually smaller than the target return periods such as 100- and 200-year ones. To overcome such a weakness, regional frequency analysis has been suggested and performed since 1960. To estimate robust precipitation quantiles in regional frequency analysis, it is important to select an appropriate probability distribution for a given region. Typically, goodness-of-fit measure developed by Hosking and Wallis based on the L-moment ratio diagram is used to select an appropriate probability distribution. Recently, several studies have been carried out on goodness-of-fit test for regional frequency analysis such as a bivariate goodness-of-fit measure to choose more appropriate probability distribution. In this study, regional frequency analysis is conducted for 1-hour maximum rainfall data (1961~2015) of the Han River basin in Korea. In this application, appropriate probability distributions are selected using the traditional goodness-of-fit and a bivariate goodness-of-fit measures, and then extreme precipitation quantiles from both methods are compared to suggest better method. Keywords: regional frequency analysis; goodness-of-fit measure; a bivariate goodness-of-fit measure; extreme precipitation events

  15. STRONTIUM PRECIPITATION

    DOEpatents

    McKenzie, T.R.

    1960-09-13

    A process is given for improving the precipitation of strontium from an aqueous phosphoric-acid-containing solution with nickel or cobalt ferrocyanide by simultaneously precipitating strontium or calcium phosphate. This is accomplished by adding to the ferrocyanide-containing solution calcium or strontium nitrate in a quantity to yield a concentration of from 0.004 to 0.03 and adjusting the pH of the solution to a value of above 8.

  16. Advanced Laser Based Measurements in Porous Media Combustion

    NASA Technical Reports Server (NTRS)

    Tedder, Sarah A.

    2009-01-01

    We present measurements using dual-pump dual-broadband coherent anti-Stokes Raman scattering spectroscopy (DP-DBB-CARS) inside a porous media burner. This work continues our previous measurements in such combustion systems. The existing setup was significantly modified with the aim of providing improved data quality and data rate, reduction of interferences and additional species information. These changes are presented and discussed in detail. The CARS technique was expanded to a dual-pump dual-broadband CARS system which in principle enables acquisition of temperatures together with relative H2/N2- and O2/N2- species concentrations. Experimental complexity was reduced by the use of a modified spectrometer enabling the detection of both signals, vibrational and rotational CARS, with only one detection system.

  17. Advances in Fast Response Acoustically Derived Air Temperature Measurements

    NASA Astrophysics Data System (ADS)

    Bogoev, Ivan; Jacobsen, Larry; Horst, Thomas; Conrad, Benjamin

    2016-04-01

    Fast-response accurate air-temperature measurements are required when estimating turbulent fluxes of heat, water and carbon dioxide by open-path eddy-covariance technique. In comparison with contact thermometers like thermocouples, ultra-sonic thermometers do not suffer from solar radiation loading, water vapor condensation and evaporative cooling effects. Consequently they have the potential to provide more accurate true air temperature measurements. The absolute accuracy of the ultrasonic thermometer is limited by the following parameters: the distance between the transducer pairs, transducer delays associated with the electrical-acoustic signal conversion that vary with temperature, components of the wind vector that are normal to the ultrasonic paths, and humidity. The distance between the transducer pairs is commonly obtained by coordinate measuring machine. Improved accuracy demonstrated in this study results from increased stiffness in the anemometer head to better maintain the ultrasonic path-length distances. To further improve accuracy and account for changes in transducer delays and distance as a function of temperature, these parameters are characterized in a zero-wind chamber over the entire operating temperature range. When the sonic anemometer is combined with a co-located fast-response water vapor analyzer, like in the IRGASON instrument, speed of sound can be compensated for humidity effects on a point-by-point basis resulting in a true fast-response air temperature measurement. Laboratory test results show that when the above steps are implemented in the calibration of the ultrasonic thermometer air-temperature accuracy better than ±0.5 degrees Celsius can be achieved over the entire operating range. The approach is also validated in a field inter-comparison with an aspirated thermistor probe mounted in a radiation shield.

  18. Advanced coordinate measuring machine at Sandia National Laboratories

    NASA Astrophysics Data System (ADS)

    Pilkey, R. D.; Klevgard, P. A.

    1993-03-01

    Sandia National Laboratories/California has acquired a new Moore M-48V CNC five-axis universal coordinate measuring machine (CMM). Site preparation, acceptance testing, and initial performance results are discussed. Unique features of the machine include a ceramic ram and vacuum evacuated laser pathways (VELPS). The implementation of a VELPS system on the machine imposed certain design requirements and entailed certain start-up problems. The machine's projected capabilities, workload, and research possibilities are outlined.

  19. Advanced coordinate measuring machine at Sandia National Laboratories/California

    SciTech Connect

    Pilkey, R.D.; Klevgard, P.A.

    1993-03-01

    Sandia National Laboratories/California has acquired a new Moore M-48V CNC five-axis universal coordinate measuring machine (CMM). Site preparation, acceptance testing, and initial performance results are discussed. Unique features of the machine include a ceramic ram and vacuum evacuated laser pathways (VELPS). The implementation of a VELPS system on the machine imposed certain design requirements and entailed certain start-up problems. The machine's projected capabilities, workload, and research possibilities are outlined.

  20. Advanced coordinate measuring machine at Sandia National Laboratories/California

    SciTech Connect

    Pilkey, R.D.; Klevgard, P.A.

    1993-03-01

    Sandia National Laboratories/California has acquired a new Moore M-48V CNC five-axis universal coordinate measuring machine (CMM). Site preparation, acceptance testing, and initial performance results are discussed. Unique features of the machine include a ceramic ram and vacuum evacuated laser pathways (VELPS). The implementation of a VELPS system on the machine imposed certain design requirements and entailed certain start-up problems. The machine`s projected capabilities, workload, and research possibilities are outlined.

  1. Advanced optical smoke meters for jet engine exhaust measurement

    NASA Technical Reports Server (NTRS)

    Pitz, R. W.

    1986-01-01

    Smoke meters with increased sensitivity, improved accuracy, and rapid response are needed to measure the smoke levels emitted by modern jet engines. The standard soiled tape meter in current use is based on filtering, which yields long term averages and is insensitive to low smoke levels. Two new optical smoke meter techniques that promise to overcome these difficulties have been experimentally evaluated: modulated transmission (MODTRAN) and photothermal deflection spectroscopy (PDS). Both techniques are based on light absorption by smoke, which is closely related to smoke density. They are variations on direct transmission measurements which produce a modulated signal that can be easily measured with phase sensitive detection. The MODTRAN and PDS techniques were tested on low levels of smoke and diluted samples of NO2 in nitrogen, simulating light adsorption due to smoke. The results are evaluated against a set of ideal smoke meter criteria that include a desired smoke measurement range of 0.1 to 12 mg cu.m. (smoke numbers of 1 to 50) and a frequency response of 1 per second. The MODTRAN instrument is found to be inaccurate for smoke levels below 3 mg/cu.m. and is able to make a only about once every 20 seconds because of its large sample cell. The PDS instrument meets nearly all the characteristics of an ideal smoke meter: it has excellent sensitivity over a range of smoke levels from 0.1 to 20 mg/cu.m. (smoke numbers of 1 to 60) and good frequency response (1 per second).

  2. Advances in Patient-Reported Outcomes: The NIH PROMIS® Measures

    PubMed Central

    Broderick, Joan E.; DeWitt, Esi Morgan; Rothrock, Nan; Crane, Paul K.; Forrest, Christopher B.

    2013-01-01

    Patient-reported outcomes (PRO) are questionnaire measures of patients’ symptoms, functioning, and health-related quality of life. They are designed to provide important clinical information that generally cannot be captured with objective medical testing. In 2004, the National Institutes of Health launched a research initiative to improve the clinical research enterprise by developing state-of-the-art PROs. The NIH Patient-Reported Outcomes Measurement System (PROMIS) and Assessment Center are the products of that initiative. Adult, pediatric, and parent-proxy item banks have been developed by using contemporary psychometric methods, yielding rapid, accurate measurements. PROMIS currently provides tools for assessing physical, mental, and social health using short-form and computer-adaptive testing methods. The PROMIS tools are being adopted for use in clinical trials and translational research. They are also being introduced in clinical medicine to assess a broad range of disease outcomes. Recent legislative developments in the United States support greater efforts to include patients’ reports of health experience in order to evaluate treatment outcomes, engage in shared decision-making, and prioritize the focus of treatment. PROs have garnered increased attention by the Food and Drug Administration (FDA) for evaluating drugs and medical devices. Recent calls for comparative effectiveness research favor inclusion of PROs. PROs could also potentially improve quality of care and disease outcomes, provide patient-centered assessment for comparative effectiveness research, and enable a common metric for tracking outcomes across providers and medical systems. PMID:25848562

  3. Advanced wavefront measurement and analysis of laser system modeling

    SciTech Connect

    Wolfe, C.R.; Auerback, J.M.

    1994-11-15

    High spatial resolution measurements of the reflected or transmitted wavefronts of large aperture optical components used in high peak power laser systems is now possible. These measurements are produced by phase shifting interferometry. The wavefront data is in the form of 3-D phase maps that reconstruct the wavefront shape. The emphasis of this work is on the characterization of wavefront features in the mid-spatial wavelength range (from 0.1 to 10.0 mm) and has been accomplished for the first time. Wavefront structure from optical components with spatial wavelengths in this range are of concern because their effects in high peak power laser systems. At high peak power, this phase modulation can convert to large magnitude intensity modulation by non-linear processes. This can lead to optical damage. We have developed software to input the measured phase map data into beam propagation codes in order to model this conversion process. We are analyzing this data to: (1) Characterize the wavefront structure produced by current optical components, (2) Refine our understanding of laser system performance, (3) Develop a database from which future optical component specifications can be derived.

  4. Advanced structural analysis of nanoporous materials by thermal response measurements.

    PubMed

    Oschatz, Martin; Leistner, Matthias; Nickel, Winfried; Kaskel, Stefan

    2015-04-01

    Thermal response measurements based on optical adsorption calorimetry are presented as a versatile tool for the time-saving and profound characterization of the pore structure of porous carbon-based materials. This technique measures the time-resolved temperature change of an adsorbent during adsorption of a test gas. Six carbide and carbon materials with well-defined nanopore architecture including micro- and/or mesopores are characterized by thermal response measurements based on n-butane and carbon dioxide as the test gases. With this tool, the pore systems of the model materials can be clearly distinguished and accurately analyzed. The obtained calorimetric data are correlated with the adsorption/desorption isotherms of the materials. The pore structures can be estimated from a single experiment due to different adsorption enthalpies/temperature increases in micro- and mesopores. Adsorption/desorption cycling of n-butane at 298 K/1 bar with increasing desorption time allows to determine the pore structure of the materials in more detail due to different equilibration times. Adsorption of the organic test gas at selected relative pressures reveals specific contributions of particular pore systems to the increase of the temperature of the samples and different adsorption mechanisms. The use of carbon dioxide as the test gas at 298 K/1 bar provides detailed insights into the ultramicropore structure of the materials because under these conditions the adsorption of this test gas is very sensitive to the presence of pores smaller than 0.7 nm. PMID:25773383

  5. Advancing Performance Measures for Use of Medications in Substance Abuse Treatment

    PubMed Central

    Garnick, Deborah W.; Horgan, Constance M.; McCorry, Frank; Gmyrek, Amanda; Chalk, Mady; Gastfriend, David; Rinaldo, Suzanne Gelber; Albright, Joann; Capoccia, Victor; Harris, Alex; Harwood, Henrick J.; Greenberg, Pamela; Mark, Tami; Un, Huong; Oros, Marla; Stringer, Mark; Thatcher, James

    2010-01-01

    Performance measures have the potential to drive high quality health care. However, technical and policy challenges exist in developing and implementing measures to assess substance use disorder (SUD) pharmacotherapy. Of critical importance in advancing performance measures for use of SUD pharmacotherapy is recognition that different measurement approaches may be needed in the public and private sectors, and will be determined by the availability of different data collection and monitoring systems. In 2009, the Washington Circle convened a panel of nationally recognized insurers, purchasers, providers, policy makers, and researchers to address this topic. The charge of the panel was to identify opportunities and challenges in advancing use of SUD pharmacotherapy performance measures across a range of systems. This paper summarizes those findings by identifying a number of critical themes related to advancing SUD pharmacotherapy performance measures, highlighting examples from the field, and recommending actions for policy makers. PMID:20934836

  6. Two-phase flow measurements with advanced instrumented spool pieces

    SciTech Connect

    Turnage, K.C.

    1980-09-01

    A series of two-phase, air-water and steam-water tests performed with instrumented piping spool pieces is described. The behavior of the three-beam densitometer, turbine meter, and drag flowmeter is discussed in terms of two-phase models. Results from application of some two-phase mass flow models to the recorded spool piece data are shown. Results of the study are used to make recommendations regarding spool piece design, instrument selection, and data reduction methods to obtain more accurate measurements of two-phase flow parameters. 13 refs., 23 figs., 1 tab.

  7. ADVANCES TOWARDS THE MEASUREMENT AND CONTROL LHC TUNE AND CHROMATICITY

    SciTech Connect

    CAMERON, P.; CUPOLO, J.; DEGEN, C.; DELLAPENNA, A.; HOFF, L.; MEAD, J.; SIKORA, R.

    2005-06-06

    Requirements for tune and chromaticity control in most superconducting hadron machines, and in particular the LHC, are stringent. In order to reach nominal operation, the LHC will almost certainly require feedback on both tune and chromaticity. Experience at RHIC has also shown that coupling control is crucial to successful tune feedback. A prototype baseband phase-locked loop (PLL) tune measurement system has recently been brought into operation at RHIC as part of the US LHC Accelerator Research Program (LARP). We report on the performance of that system and compare it with the extensive accumulation of data from the RHIC 245MHz PLL.

  8. Advances in Non-contact Measurement of Creep Properties

    NASA Technical Reports Server (NTRS)

    Hyers, Robert W.; Canepari, Stacy; Rogers, Jan. R.

    2009-01-01

    Our team has developed a novel approach to measuring creep at extremely high temperatures using electrostatic levitation (ESL). This method has been demonstrated on niobium up to 2300 C, while ESL has melted tungsten (3400 C). High-precision machined spheres of the sample are levitated in the NASA MSFC ESL, a national user facility, and heated with a laser. The laser is aligned off-center so that the absorbed photons transfer their momentum to the sample, causing it to rotate at up to 250,000+ RPM. The rapid rotation loads the sample through centripetal acceleration, causing it to deform. The deformation of the sample is captured on high-speed video, which is analyzed by machine-vision software from the University of Massachusetts. The deformations are compared to finite element models to determine the constitutive constants in the creep relation. Furthermore, the noncontact method exploits stress gradients within the sample to determine the stress exponent in a single test. This method was validated in collaboration with the University of Tennessee for niobium at 1985 C, with agreement within the uncertainty of the conventional measurements. A similar method is being employed on Ultra-High-Temperature ZrB2- SiC composites, which may see application in rocket nozzles and sharp leading edges for hypersonic vehicles.

  9. Summer Support of the Advanced Structures and Measurements Group

    NASA Technical Reports Server (NTRS)

    Stuber, Alexander Lee

    2010-01-01

    This presentation is my exit presentation summarizing the work that I did this summer during my 10 week summer internship. It is primarily focused on tensile testing of composite coupons including the use of the ARAMIS optical strain measurement system, but it also includes some discussion of other support that I provided for the Dryden composites working group effort. My main efforts in that area were focused on T-joint design for an upcoming hands-on-workshop as well as design of a fixture to test joint coupons. Finally, there is a brief discussion of the other small projects that I worked on, including support of structurally integrated thermal protection system (STIPS) research and the Global Observer wing loads test.

  10. AN ADVANCED CALIBRATION PROCEDURE FOR COMPLEX IMPEDANCE SPECTRUM MEASUREMENTS OF ADVANCED ENERGY STORAGE DEVICES

    SciTech Connect

    William H. Morrison; Jon P. Christophersen; Patrick Bald; John L. Morrison

    2012-06-01

    With the increasing demand for electric and hybrid electric vehicles and the explosion in popularity of mobile and portable electronic devices such as laptops, cell phones, e-readers, tablet computers and the like, reliance on portable energy storage devices such as batteries has likewise increased. The concern for the availability of critical systems in turn drives the availability of battery systems and thus the need for accurate battery health monitoring has become paramount. Over the past decade the Idaho National Laboratory (INL), Montana Tech of the University of Montana (Tech), and Qualtech Systems, Inc. (QSI) have been developing the Smart Battery Status Monitor (SBSM), an integrated battery management system designed to monitor battery health, performance and degradation and use this knowledge for effective battery management and increased battery life. Key to the success of the SBSM is an in-situ impedance measurement system called the Impedance Measurement Box (IMB). One of the challenges encountered has been development of an accurate, simple, robust calibration process. This paper discusses the successful realization of this process.

  11. Advanced Measurement and Modeling Techniques for Improved SOFC Cathodes

    SciTech Connect

    Stuart Adler; L. Dunyushkina; S. Huff; Y. Lu; J. Wilson

    2006-12-31

    The goal of this project was to develop an improved understanding of factors governing performance and degradation of mixed-conducting SOFC cathodes. Two new diagnostic tools were developed to help achieve this goal: (1) microelectrode half-cells for improved isolation of cathode impedance on thin electrolytes, and (2) nonlinear electrochemical impedance spectroscopy (NLEIS), a variant of traditional impedance that allows workers to probe nonlinear rates as a function of frequency. After reporting on the development and efficacy of these tools, this document reports on the use of these and other tools to better understand performance and degradation of cathodes based on the mixed conductor La{sub 1-x}Sr{sub x}CoO{sub 3-{delta}} (LSC) on gadolinia or samaria-doped ceria (GDC or SDC). We describe the use of NLEIS to measure O{sub 2} exchange on thin-film LSC electrodes, and show that O{sub 2} exchange is most likely governed by dissociative adsorption. We also describe parametric studies of porous LSC electrodes using impedance and NLEIS. Our results suggest that O{sub 2} exchange and ion transport co-limit performance under most relevant conditions, but it is O{sub 2} exchange that is most sensitive to processing, and subject to the greatest degradation and sample-to-sample variation. We recommend further work that focuses on electrodes of well-defined or characterized geometry, and probes the details of surface structure, composition, and impurities. Parallel work on primarily electronic conductors (LSM) would also be of benefit to developers, and to improved understanding of surface vs. bulk diffusion.

  12. Atmospheric Radiation Measurement (ARM) Data from Black Forest Germany for the Convective and Orographically Induced Precipitation Study (COPS)

    DOE Data Explorer

    The primary goal of the ARM Program is to improve the treatment of cloud and radiation physics in global climate models in order to improve the climate simulation capabilities of these models. ARM maintains four major, permanent sites for data collection and deploys the ARM Mobile Facility (AMF) to other sites as determined. In 2007 the AMF operated in the Black Forest region of Germany as part of the Convective and Orographically Induced Precipitation Study (COPS). Scientists studied rainfall resulting from atmospheric uplift (convection) in mountainous terrain, otherwise known as orographic precipitation. This was part of a six -year duration of the German Quantitative Precipitation Forecasting (QPF) Program. COPS was endorsed as a Research and Development Project by the World Weather Research Program. This program was established by the World Meteorological Organization to develop improved and cost-effective forecasting techniques, with an emphasis on high-impact weather. A large collection of data plots based on data streams from specific instruments used at Black Forest are available via a link from ARM's Black Forest site information page. Users will be requested to create a password, but the plots and the data files in the ARM Archive are free for viewing and downloading.

  13. Development of Ground-Based Auroral Photometry Techniques Using In-Situ Electron Precipitation Measurements from the GREECE Mission

    NASA Astrophysics Data System (ADS)

    Grubbs, G. A., II; Samara, M.; Michell, R.; Hampton, D.

    2014-12-01

    The Ground-to-Rocket Electrodynamics-Electrons Correlative Experiment (GREECE) mission successfully launched from Poker Flat, Alaska on 03 March 2014 at 11:09:50 UT and reached an apogee of approximately 335 km during a luminous auroral event. Multiple ground-based electron-multiplying charge-coupled device (EMCCD) imagers were positioned at Venetie, Alaska and aimed along magnetic zenith in order to observe the brightness of different auroral emission lines (427.8, 557.7, and 844.6 nm with a 47 degree field of view) at the magnetic footpoint of the payload, near apogee. Emission line brightness data are presented at the footpoint of the rocket flight and correlated with electron characteristics taken by the Acute Precipitating Electron Spectrometer (APES) on-board instrument. Ratios of different auroral emission lines are also compared to previously published methods and models. This research aims to describe the auroral emissions produced from a known precipitating electron distribution, such that we can more accurately use ground-based imaging and photometry to infer the characteristics of the precipitating electrons. These techniques can then be applied over larger scales and longer times, when only multi-spectral imaging data are available with no corresponding in situ data.

  14. Measurements and Modeling of Stress in Precipitation-Hardened Aluminum Alloy AA2618 during Gleeble Interrupted Quenching and Constrained Cooling

    NASA Astrophysics Data System (ADS)

    Chobaut, Nicolas; Carron, Denis; Saelzle, Peter; Drezet, Jean-Marie

    2016-11-01

    Solutionizing and quenching are the key steps in the fabrication of heat-treatable aluminum parts such as AA2618 compressor impellers for turbochargers as they highly impact the mechanical characteristics of the product. In particular, quenching induces residual stresses that can cause unacceptable distortions during machining and unfavorable stresses in service. Predicting and controlling stress generation during quenching of large AA2618 forgings are therefore of particular interest. Since possible precipitation during quenching may affect the local yield strength of the material and thus impact the level of macroscale residual stresses, consideration of this phenomenon is required. A material model accounting for precipitation in a simple but realistic way is presented. Instead of modeling precipitation that occurs during quenching, the model parameters are identified using a limited number of tensile tests achieved after representative interrupted cooling paths in a Gleeble machine. This material model is presented, calibrated, and validated against constrained coolings in a Gleeble blocked-jaws configuration. Applications of this model are FE computations of stress generation during quenching of large AA2618 forgings for compressor impellers.

  15. Measurements and Modeling of Stress in Precipitation-Hardened Aluminum Alloy AA2618 during Gleeble Interrupted Quenching and Constrained Cooling

    NASA Astrophysics Data System (ADS)

    Chobaut, Nicolas; Carron, Denis; Saelzle, Peter; Drezet, Jean-Marie

    2016-08-01

    Solutionizing and quenching are the key steps in the fabrication of heat-treatable aluminum parts such as AA2618 compressor impellers for turbochargers as they highly impact the mechanical characteristics of the product. In particular, quenching induces residual stresses that can cause unacceptable distortions during machining and unfavorable stresses in service. Predicting and controlling stress generation during quenching of large AA2618 forgings are therefore of particular interest. Since possible precipitation during quenching may affect the local yield strength of the material and thus impact the level of macroscale residual stresses, consideration of this phenomenon is required. A material model accounting for precipitation in a simple but realistic way is presented. Instead of modeling precipitation that occurs during quenching, the model parameters are identified using a limited number of tensile tests achieved after representative interrupted cooling paths in a Gleeble machine. This material model is presented, calibrated, and validated against constrained coolings in a Gleeble blocked-jaws configuration. Applications of this model are FE computations of stress generation during quenching of large AA2618 forgings for compressor impellers.

  16. Fusing enhanced radar precipitation, in-situ hydrometeorological measurements and airborne LIDAR snowpack estimates in a hyper-resolution hydrologic model to improve seasonal water supply forecasts

    NASA Astrophysics Data System (ADS)

    Gochis, D. J.; Busto, J.; Howard, K.; Mickey, J.; Deems, J. S.; Painter, T. H.; Richardson, M.; Dugger, A. L.; Karsten, L. R.; Tang, L.

    2015-12-01

    Scarcity of spatially- and temporally-continuous observations of precipitation and snowpack conditions in remote mountain watersheds results in fundamental limitations in water supply forecasting. These limitationsin observational capabilities can result in strong biases in total snowmelt-driven runoff amount, the elevational distribution of runoff, river basin tributary contributions to total basin runoff and, equally important for water management, the timing of runoff. The Upper Rio Grande River basin in Colorado and New Mexico is one basin where observational deficiencies are hypothesized to have significant adverse impacts on estimates of snowpack melt-out rates and on water supply forecasts. We present findings from a coordinated observational-modeling study within Upper Rio Grande River basin whose aim was to quanitfy the impact enhanced precipitation, meteorological and snowpack measurements on the simulation and prediction of snowmelt driven streamflow. The Rio Grande SNOwpack and streamFLOW (RIO-SNO-FLOW) Prediction Project conducted enhanced observing activities during the 2014-2015 water year. Measurements from a gap-filling, polarimetric radar (NOXP) and in-situ meteorological and snowpack measurement stations were assimilated into the WRF-Hydro modeling framework to provide continuous analyses of snowpack and streamflow conditions. Airborne lidar estimates of snowpack conditions from the NASA Airborne Snow Observatory during mid-April and mid-May were used as additional independent validations against the various model simulations and forecasts of snowpack conditions during the melt-out season. Uncalibrated WRF-Hydro model performance from simulations and forecasts driven by enhanced observational analyses were compared against results driven by currently operational data inputs. Precipitation estimates from the NOXP research radar validate significantly better against independent in situ observations of precipitation and snow-pack increases

  17. Measurement and modeling of advanced coal conversion processes. Annual report, October 1990--September 1991

    SciTech Connect

    Solomon, P.R.; Serio, M.A.; Hamblen, D.G.; Smoot, L.D.; Brewster, B.S. |

    1991-12-31

    The overall objective of this program is the development of predictive capability for the design, scale up, simulation, control and feedstock evaluation in advanced coal conversion devices. This program will merge significant advances made in measuring and quantitatively describing the mechanisms in coal conversion behavior. Comprehensive computer codes for mechanistic modeling of entrained-bed gasification. Additional capabilities in predicting pollutant formation will be implemented and the technology will be expanded to fixed-bed reactors.

  18. Precipitation Matters

    ERIC Educational Resources Information Center

    McDuffie, Thomas

    2007-01-01

    Although weather, including its role in the water cycle, is included in most elementary science programs, any further examination of raindrops and snowflakes is rare. Together rain and snow make up most of the precipitation that replenishes Earth's life-sustaining fresh water supply. When viewed individually, raindrops and snowflakes are quite…

  19. Performance evaluation of interpolation methods for incorporating rain gauge measurements into NEXRAD precipitation data: A case study in the Upper Guadalupe River Basin

    SciTech Connect

    Xie, Hongjie; Zhang, Xuesong; Yu, Beibei; Sharif, Hatim

    2011-04-21

    High spatial and temporal resolution of precipitation data is critical input for hydrological budget estimation and flash flood modeling. This study evaluated four methods (Bias Adjustment (BA), Simple Kriging with varying Local Means (SKlm), Kriging with External Drift (KED), and Regression Kriging (RK)) for their performances in incorporating gauge rainfall measurements into NEXRAD (Next Generation Weather Radar) Multisensor Precipitation Estimator (MPE) (hourly and 4 x 4 km{sup 2}). Measurements from a network of 50 gauges at the Upper Guadalupe River Basin, Central Texas and MPE data for the year 2004 were used in the study. We used three evaluation coefficients Percentage Bias (PB), Coefficient of Determination (R2), and Nash-Sutcliffe efficiency (NSE) to examine the performance of the four methods for preserving regional and local scale characteristics of observed precipitation data. The results show that the two Kriging-based methods (SKlm and RK) are in generally better than BA and KED and that the PB and NSE criteria are better than the R2 criterion in assessing the performance of the four methods. It is also worth noting that the performance of one method at regional scale may be different from its performance at local scale. Critical evaluation of the performance of different methods at local or regional scale should be conducted according to the different purposes. The results obtained in this study are expected to contribute to the development of more accurate spatial rainfall products for hydrologic budget and flash flood modeling.

  20. Advanced Ultrasonic Measurement Methodology for Non-Invasive Interrogation and Identification of Fluids in Sealed Containers

    SciTech Connect

    Tucker, Brian J.; Diaz, Aaron A.; Eckenrode, Brian A.

    2006-03-16

    The Hazardous Materials Response Unit (HMRU) and the Counterterrorism and Forensic Science Research Unit (CTFSRU), Laboratory Division, Federal Bureau of Investigation (FBI) have been mandated to develop and establish a wide range of unprecedented capabilities for providing scientific and technical forensic services to investigations involving hazardous chemical, biological, and radiological materials, including extremely dangerous chemical and biological warfare agents. Pacific Northwest National Laboratory (PNNL) has developed a portable, hand-held, hazardous materials acoustic inspection device (HAZAID) that provides noninvasive container interrogation and material identification capabilities using nondestructive ultrasonic velocity and attenuation measurements. Due to the wide variety of fluids as well as container sizes and materials, the need for high measurement sensitivity and advanced ultrasonic measurement techniques were identified. The HAZAID prototype was developed using a versatile electronics platform, advanced ultrasonic wave propagation methods, and advanced signal processing techniques. This paper primarily focuses on the ultrasonic measurement methods and signal processing techniques incorporated into the HAZAID prototype. High bandwidth ultrasonic transducers combined with the advanced pulse compression technique allowed researchers to 1) impart large amounts of energy, 2) obtain high signal-to-noise ratios, and 3) obtain accurate and consistent time-of-flight (TOF) measurements through a variety of highly attenuative containers and fluid media. Results of this feasibility study demonstrated that the HAZAID experimental measurement technique also provided information regarding container properties, which will be utilized in future container-independent measurements of hidden liquids.

  1. Advanced ultrasonic measurement methodology for non-invasive interrogation and identification of fluids in sealed containers

    NASA Astrophysics Data System (ADS)

    Tucker, Brian J.; Diaz, Aaron A.; Eckenrode, Brian A.

    2006-03-01

    Government agencies and homeland security related organizations have identified the need to develop and establish a wide range of unprecedented capabilities for providing scientific and technical forensic services to investigations involving hazardous chemical, biological, and radiological materials, including extremely dangerous chemical and biological warfare agents. Pacific Northwest National Laboratory (PNNL) has developed a prototype portable, hand-held, hazardous materials acoustic inspection prototype that provides noninvasive container interrogation and material identification capabilities using nondestructive ultrasonic velocity and attenuation measurements. Due to the wide variety of fluids as well as container sizes and materials encountered in various law enforcement inspection activities, the need for high measurement sensitivity and advanced ultrasonic measurement techniques were identified. The prototype was developed using a versatile electronics platform, advanced ultrasonic wave propagation methods, and advanced signal processing techniques. This paper primarily focuses on the ultrasonic measurement methods and signal processing techniques incorporated into the prototype. High bandwidth ultrasonic transducers combined with an advanced pulse compression technique allowed researchers to 1) obtain high signal-to-noise ratios and 2) obtain accurate and consistent time-of-flight (TOF) measurements through a variety of highly attenuative containers and fluid media. Results of work conducted in the laboratory have demonstrated that the prototype experimental measurement technique also provided information regarding container properties, which will be utilized in future container-independent measurements of hidden liquids.

  2. Advanced ultrasonic measurement methodology for non-invasive interrogation and identification of fluids in sealed containers

    SciTech Connect

    Tucker, Brian J.; Diaz, Aaron A.; Eckenrode, Brian A.

    2006-05-01

    Government agencies and homeland security related organizations have identified the need to develop and establish a wide range of unprecedented capabilities for providing scientific and technical forensic services to investigations involving hazardous chemical, biological, and radiological materials, including extremely dangerous chemical and biological warfare agents. Pacific Northwest National Laboratory (PNNL) has developed a prototype portable, hand-held, hazardous materials acoustic inspection prototype that provides noninvasive container interrogation and material identification capabilities using nondestructive ultrasonic velocity and attenuation measurements. Due to the wide variety of fluids as well as container sizes and materials encountered in various law enforcement inspection activities, the need for high measurement sensitivity and advanced ultrasonic measurement techniques were identified. The prototype was developed using a versatile electronics platform, advanced ultrasonic wave propagation methods, and advanced signal processing techniques. This paper primarily focuses on the ultrasonic measurement methods and signal processing techniques incorporated into the prototype. High bandwidth ultrasonic transducers combined with an advanced pulse compression technique allowed researchers to 1) obtain high signal-to-noise ratios and 2) obtain accurate and consistent time-of-flight (TOF) measurements through a variety of highly attenuative containers and fluid media. Results of work conducted in the laboratory have demonstrated that the prototype experimental measurement technique also provided information regarding container properties, which will be utilized in future container-independent measurements of hidden liquids.

  3. On the complex conductivity signatures of calcite precipitation

    SciTech Connect

    Wu, Yuxin; Hubbard, Susan; Williams, Kenneth Hurst; Ajo-Franklin, Jonathan

    2009-11-01

    Calcite is a mineral phase that frequently precipitates during subsurface remediation or geotechnical engineering processes. This precipitation can lead to changes in the overall behavior of the system, such as flow alternation and soil strengthening. Because induced calcite precipitation is typically quite variable in space and time, monitoring its distribution in the subsurface is a challenge. In this research, we conducted a laboratory column experiment to investigate the potential of complex conductivity as a mean to remotely monitor calcite precipitation. Calcite precipitation was induced in a glass bead (3 mm) packed column through abiotic mixing of CaCl{sub 2} and Na{sub 2}CO{sub 3} solutions. The experiment continued for 12 days with a constant precipitation rate of {approx}0.6 milimole/d. Visual observations and scanning electron microscopy imaging revealed two distinct phases of precipitation: an earlier phase dominated by well distributed, discrete precipitates and a later phase characterized by localized precipitate aggregation and associated pore clogging. Complex conductivity measurements exhibited polarization signals that were characteristic of both phases of calcite precipitation, with the precipitation volume and crystal size controlling the overall polarization magnitude and relaxation time constant. We attribute the observed responses to polarization at the electrical double layer surrounding calcite crystals. Our experiment illustrates the potential of electrical methods for characterizing the distribution and aggregation state of nonconductive minerals like calcite. Advancing our ability to quantify geochemical transformations using such noninvasive methods is expected to facilitate our understanding of complex processes associated with natural subsurface systems as well as processes induced through engineered treatments (such as environmental remediation and carbon sequestration).

  4. Application of Gis Technology for the Precipitation Mapping

    NASA Astrophysics Data System (ADS)

    Dyras, I.; Serafin-Rek, D.

    2003-04-01

    Precipitation is one of the most variable meteorological parameters in time and space. The standard surface measurement network provides a very localised information about the precipitation. The satellite, radar observations and Numerical Weather Prediction (NWP) models provide the continuous information on the state of the atmosphere, however, with the much lower resolution. Combining these data into one system allows analysing the data from different sources in order to estimate the precipitation intensity and range. The paper presents the works undertaken for the Central Europe region for the stratiform and convective precipitation. The analysis results are prepared in the form of maps of precipitation intensity and range. The satellite data available from an Advanced Microwave Sounding Unit (AMSU) on board of NOAA-15, 16 and 17 satellites enhanced the possibilities of the new meteorological precipitation related products derivation. The products such as Rain Rate (RR), Scattering Index (SI), Total Precipitation Water (TPW), Precipitation Probability (PP) and Liquid Water Path (LWP) were prepared basing on the regression algorithms. The data from spring and summer seasons in 2001 and 2002 were used. The temperature and precipitation thematic layers are created from the NWP model grid data. Also SYNOP and TEMP data are converted into thematic coverages. The progress in GIS technology application for NOAA/AMSU microwave derived products preparation and visualization in the Satellite Research Department in Poland was accomplished. The developed system allows displaying the rain field forecasted by the NWP model Aladin and the precipitation observed with the satellite data and other ancillary information. The maps of precipitation with additional geographical data and administrative boundaries are available for the weather forecasting units via Intranet. It is planned to make images available on the web for external customers. Radar and lightning data as well as

  5. Electrostatic precipitator with precipitator electrodes

    SciTech Connect

    Junkers, G.

    1980-12-16

    The invention relates to an electrostatic precipitator with collecting electrodes which are arranged in rows adjacent to each other and in respective pairs at equal distances from a respective discharge electrode with which they cooperate. Spring elements are provided between the collecting electrodes and influence the stiffness and oscillating properties of the array of the collecting electrodes.

  6. Acidic precipitation

    SciTech Connect

    Martin, H.C.

    1987-01-01

    At the International Symposium on Acidic Precipitation, over 400 papers were presented, and nearly 200 of them are included here. They provide an overview of the present state of the art of acid rain research. The Conference focused on atmospheric science (monitoring, source-receptor relationships), aquatic effects (marine eutrophication, lake acidification, impacts on plant and fish populations), and terrestrial effects (forest decline, soil acidification, etc.).

  7. ADVANCING THE FUNDAMENTAL UNDERSTANDING AND SCALE-UP OF TRISO FUEL COATERS VIA ADVANCED MEASUREMENT AND COMPUTATIONAL TECHNIQUES

    SciTech Connect

    Biswas, Pratim; Al-Dahhan, Muthanna

    2012-11-01

    to advance the fundamental understanding of the hydrodynamics by systematically investigating the effect of design and operating variables, to evaluate the reported dimensionless groups as scaling factors, and to establish a reliable scale-up methodology for the TRISO fuel particle spouted bed coaters based on hydrodynamic similarity via advanced measurement and computational techniques. An additional objective is to develop an on-line non-invasive measurement technique based on gamma ray densitometry (i.e. Nuclear Gauge Densitometry) that can be installed and used for coater process monitoring to ensure proper performance and operation and to facilitate the developed scale-up methodology. To achieve the objectives set for the project, the work will use optical probes and gamma ray computed tomography (CT) (for the measurements of solids/voidage holdup cross-sectional distribution and radial profiles along the bed height, spouted diameter, and fountain height) and radioactive particle tracking (RPT) (for the measurements of the 3D solids flow field, velocity, turbulent parameters, circulation time, solids lagrangian trajectories, and many other of spouted bed related hydrodynamic parameters). In addition, gas dynamic measurement techniques and pressure transducers will be utilized to complement the obtained information. The measurements obtained by these techniques will be used as benchmark data to evaluate and validate the computational fluid dynamic (CFD) models (two fluid model or discrete particle model) and their closures. The validated CFD models and closures will be used to facilitate the developed methodology for scale-up, design and hydrodynamic similarity. Successful execution of this work and the proposed tasks will advance the fundamental understanding of the coater flow field and quantify it for proper and safe design, scale-up, and performance. Such achievements will overcome the barriers to AGR applications and will help assure that the US maintains

  8. Next Generation High Power Dual-Frequency Transmitter For Space Borne and/or Air Borne Doppler Radar Precipitation Measurements

    NASA Astrophysics Data System (ADS)

    Vasicek, Stephanie; Wintucky, Edwin

    2007-10-01

    Data analysis was performed using a Tektronix RSA 3303A Real-Time Spectrum Analyzer with the objective of demonstrating that an approach using Ka-band Differential Frequency Precipitation Radar (DFPR) works when operating a single Boeing Traveling Wave Tube (TWT) Model 999H to amplify two pulses. This approach is being studied to replace a current model using two separate TWTs at two separate frequencies. Applicability of MATLAB, Tektronix, and Agilent software was explored to investigate and refine pulse analysis techniques. Vector Signal Analysis software used with an Agilent Performance Spectrum Analyzer observed modulated signals at Ka-band in the time domain and is being further investigated to enable more detailed quantitative comparisons. MATLAB Signal Processing Toolbox is being explored as a possible analysis tool. A staggered pulse method of study was determined to be more advantageous than a simultaneous pulse study in that full peak power at each frequency can be viewed and intermodulation products can be avoided.

  9. Advances in Children's Rights and Children's Well-Being Measurement: Implications for School Psychologists

    ERIC Educational Resources Information Center

    Kosher, Hanita; Jiang, Xu; Ben-Arieh, Asher; Huebner, E. Scott

    2014-01-01

    Recent years have brought important changes to the profession of school psychology, influenced by larger social, scientific, and political trends. These trends include the emergence of children's rights agenda and advances in children's well-being measurement. During these years, a growing public attention and commitment to the notion of…

  10. ADVANCED REACTIVITY MEASUREMENT FACILITY, TRA660, INTERIOR. REACTOR INSIDE TANK. METAL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    ADVANCED REACTIVITY MEASUREMENT FACILITY, TRA-660, INTERIOR. REACTOR INSIDE TANK. METAL WORK PLATFORM ABOVE. THE REACTOR WAS IN A SMALL WATER-FILLED POOL. INL NEGATIVE NO. 66-6373. Unknown Photographer, ca. 1966 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  11. Advances in Treatment Integrity Research: Multidisciplinary Perspectives on the Conceptualization, Measurement, and Enhancement of Treatment Integrity

    ERIC Educational Resources Information Center

    Schulte, Ann C.; Easton, Julia E.; Parker, Justin

    2009-01-01

    Documenting treatment integrity is an important issue in research and practice in any discipline concerned with prevention and intervention. However, consensus concerning the dimensions of treatment integrity and how they should be measured has yet to emerge. Advances from three areas in which significant treatment integrity work has taken…

  12. Correlated electron and X ray measurements of quiet time electron precipitation - A comparative study of bremsstrahlung production and transport in the atmosphere

    NASA Astrophysics Data System (ADS)

    Gaines, E. E.; Imhof, W. L.; Francis, W. E.; Walt, M.; Rosenberg, T. J.

    1986-12-01

    Five cases of X-ray observations from balloons, coordinated with measurements of precipitating electrons, were obtained during passes of the polar-orbiting satellite P78-1 near Siple, Antarctica, the launch point of the balloons. The observations, made during a geomagnetically quiet period in late December 1980 to early January 1981, showed small enhancements of the X-ray fluxes (E greater than 25 keV) and moderate trapped electron fluxes (E greater than 68 keV) with pitch angle distributions extending into the edge of the loss cone sufficient to produce the less than about 0.5 dB of cosmic noise absorption recorded by the Siple 30-MHz riometer. Bremsstrahlung production and transport in the atmosphere were calculated using the measured electron fluxes, energy spectra, and pitch angle distributions for the source. The X-ray fluxes and spectra calculated for the balloon altitudes were in good agreement with those measured from the balloons when the total energy deposition from electrons, E greater than 10 keV, exceeded 0.002 erg/sq cm s. The observed electron fluxes show that a significant continuous electron precipitation occurs at the western edge of the South Atlantic magnetic anomaly even at times of low geomagnetic activity.

  13. Correlated electron and X ray measurements of quiet time electron precipitation: a comparative study of Bremsstrahlung production and transport in the atmosphere

    SciTech Connect

    Gaines, E.E.; Imhof, W.L.; Francis, W.E.; Walt, M.; Rosenberg, T.J.

    1986-12-01

    Five cases of X ray observations from balloons coordinated with measurements of precipitating electrons were obtained during passes of the polar-orbiting satellite P78-1 near Siple, Antarctica (L--4.1), the launch point of the balloons. The observations, made during a geomagnetically quiet period in late December 1980 to early January 1981, showed small enhancements of the X ray fluxes (E>25 keV) and moderate trapped electron fluxes (E>68 keV) with pitch angle distributions extending into the edge of the loss cone sufficient to produce the approx. <0.5 dB of cosmic noise absorption recorded by the Siple 30-MHz riometer. Bremsstrahlung production and transport in the atmosphere were calculated using the measured electron fluxes, energy spectra, and pitch angle distributions for the source. The X ray fluxes and spectra calculated for the balloon altitudes were in good agreement with those measured from the balloons when the total energy deposition from electrons, E>10 keV, exceeded 2 x 10/sup -3/ erg/cm/sup 2/ s. The observed electron fluxes show that a significant continuous electron precipitation occurs at the western edge of the South Atlantic magnetic anomaly even at times of low geomagnetic activity.

  14. Performance of current measurement system in poloidal field power supply for Experimental Advanced Superconducting Tokamak

    NASA Astrophysics Data System (ADS)

    Liu, D. M.; Li, J.; Wan, B. N.; Lu, Z.; Wang, L. S.; Jiang, L.; Lu, C. H.; Huang, J.

    2016-11-01

    As one of the core subsystems of the Experimental Advanced Superconducting Tokamak (EAST), the poloidal field power system supplies energy to EAST's superconducting coils. To measure the converter current in the poloidal field power system, a current measurement system has been designed. The proposed measurement system is composed of a Rogowski coil and a newly designed integrator. The results of the resistor-inductor-capacitor discharge test and the converter equal current test show that the current measurement system provides good reliability and stability, and the maximum error of the proposed system is less than 1%.

  15. Electrostatic precipitator

    SciTech Connect

    Hayashi, T.

    1982-08-03

    An electrostatic precipitator comprising a plurality of flat plate dust-collecting electrodes, arranged in substantially equally spaced and parallel relationship with one another and each having a discharge electrode, or electrodes, on and along the edge of one side thereof with the discharge electrodes of the adjacent dust-collecting electrodes alternately facing in opposite directions; the edges having the discharge electrodes are arranged in a setback relation by some distance in relation to the nearby edges of the adjacent dust-collecting plates, where no discharge electrodes are provided, so that uniform and nonuniform electric fields may be produced.

  16. Dynamics of mineral crystallization at inclusion-garnet interface from precipitated slab-derived fluid phase: first in-situ synchrotron x-ray measurements

    NASA Astrophysics Data System (ADS)

    Malaspina, Nadia; Alvaro, Matteo; Campione, Marcello; Nestola, Fabrizio

    2015-04-01

    Remnants of the fluid phase at ultrahigh pressure (UHP) in subduction environments may be preserved as primary multiphase inclusions in UHP minerals. These inclusions are frequently hosted by minerals stable at mantle depths, such as garnet, and show the same textural features as fluid inclusions. The mineral infillings of the solid multiphase inclusions are generally assumed to have crystallized by precipitation from the solute load of dense supercritical fluids equilibrating with the host rock. Notwithstanding the validity of this assumption, the mode of crystallization of daughter minerals during precipitation within the inclusion and/or the mechanism of interaction between the fluid at supercritical conditions and the host mineral are still poorly understood from a crystallographic point of view. A case study is represented by garnet orthopyroxenites from the Maowu Ultramafic Complex (China) deriving from harzburgite precursors metasomatised at ~ 4 GPa, 750 °C by a silica- and incompatible trace element-rich fluid phase. This metasomatism produced poikilitic orthopyroxene and inclusion-rich garnet porphyroblasts. Solid multiphase primary inclusions in garnet display a size within a few tens of micrometers and negative crystal shapes. Infilling minerals (spinel: 10-20 vol.%; amphibole, chlorite, talc, mica: 80- 90 vol.%) occur with constant volume ratios and derive from trapped solute-rich aqueous fluids. To constrain the possible mode of precipitation of daughter minerals, we performed for the first time a single-crystal X-ray diffraction experiment by means of Synchrotron Radiation at DLS-Diamond Light Source. In combination with electron probe microanalyses, this measurement allowed the unique identification of each mineral phase and their reciprocal orientations. We demonstrated the epitaxial relationship between spinel and garnet and between some hydrous minerals. Epitaxy drives a first-stage nucleation of spinel under near-to-equilibrium conditions

  17. NASA Programs in Advanced Sensors and Measurement Technology for Aeronautical Applications

    NASA Technical Reports Server (NTRS)

    Conway, Bruce A.

    2004-01-01

    There are many challenges facing designers and operators of our next-generation aircraft in meeting the demands for efficiency, safety, and reliability which are will be imposed. This paper discusses aeronautical sensor requirements for a number of research and applications areas pertinent to the demands listed above. A brief overview will be given of aeronautical research measurements, along with a discussion of requirements for advanced technology. Also included will be descriptions of emerging sensors and instrumentation technology which may be exploited for enhanced research and operational capabilities. Finally, renewed emphasis of the National Aeronautics and Space Administration in advanced sensor and instrumentation technology development will be discussed, including project of technology advances over the next 5 years. Emphasis on NASA efforts to more actively advance the state-of-the-art in sensors and measurement techniques is timely in light of exciting new opportunities in airspace development and operation. An up-to-date summary of the measurement technology programs being established to respond to these opportunities is provided.

  18. Passive Microwave Precipitation Detection Biases: Relationship to Environment

    NASA Astrophysics Data System (ADS)

    Viramontez, A.; Rapp, A. D.

    2015-12-01

    Accurate satellite precipitation estimates are essential for understanding the long-term variability in the global hydrologic cycle and for constraining global climate models. Spaceborne precipitation estimates depend heavily on passive microwave remote sensors due to the large spatial coverage and long record of observations available from such sensors; however, light precipitation is frequently undetected or underestimated by passive microwave rainfall retrievals. Observations from the CloudSat Profiling Radar (CPR) and the Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E) provide a unique opportunity for long-term collocated precipitation measurements from passive microwave sensors and an active radar with sensitivity to very light precipitation that can be used to assess the precipitation detection biases. For this study, collocated measurements from AMSR-E and CloudSat during 2008 will be used to identify environments where AMSR-E underestimates precipitation. Environmental variables from the ECMWF Reanalysis (ERA-Interim) will be used to understand the characteristics of the large-scale and thermodynamic environments associated with AMSR-E precipitation biases. A preliminary comparison of CPR rain rates and AMSR-E Level-2B rain rates show a large fraction of rain missed by AMSR-E, with nearly 80% of missed light rain in regions with SSTs below 25°C. This is consistent with prior studies showing large detection biases in regions of large-scale subsidence. The relationship between precipitation biases and other factors such as 2 m air temperature, column water vapor, lower tropospheric stability, and vertical velocity will be explored.

  19. Sampling and physico-chemical analysis of precipitation: a review.

    PubMed

    Krupa, Sagar V

    2002-01-01

    Wet deposition is one of two processes governing the transfer of beneficial and toxic chemicals from the atmosphere on to surfaces. Since the early 1970s, numerous investigators have sampled and analyzed precipitation for their chemical constituents, in the context of "acidic rain" and related atmospheric processes. Since then, significant advances have been made in our understanding of how to sample rain, cloud and fog water to preserve their physico-chemical integrity prior to analyses. Since the 1970s large-scale precipitation sampling networks have been in operation to broadly address regional and multi-regional issues. However, in examining the results from such efforts at a site-specific level, concerns have been raised about the accuracy and precision of the information gathered. There is mounting evidence to demonstrate the instability of precipitation samples (e.g. with N species) that have been subjected to prolonged ambient or field conditions. At the present time precipitation sampling procedures allow unrefrigerated or refrigerated collection of wet deposition from individual events, sequential fractions within events, in situ continuous chemical analyses in the field and even sampling of single or individual rain, cloud and fog droplets. Similarly analytical procedures of precipitation composition have advanced from time-consuming methods to rapid and simultaneous analyses of major anions and cations, from bulk samples to single droplets. For example, analytical techniques have evolved from colorimetry to ion chromatography to capillary electrophoresis. Overall, these advances allow a better understanding of heterogeneous reactions and atmospheric pollutant scavenging processes by precipitation. In addition, from an environmental perspective, these advances allow better quantification of semi-labile (e.g. NH4+, frequently its deposition values are underestimated) or labile species [e.g. S (IV)] in precipitation and measurements of toxic chemicals such

  20. The HyMeX Special Observation Period in Central Italy: Precipitation Measurements, Retrieval Techniques and Preliminary Results

    NASA Technical Reports Server (NTRS)

    Gatlin, Patrick; Wingo, Matt; Petersen, Walt; Marzano, Frank Silvio; Baldini, Luca; Picciotti, Errico; Colantonio, Matteo; Barbieri, Stefano; Di Fabio, Saverio; Montopoli, Mario; Roberto, Nicoletta; Adirosi, Elisa; Gorgucci, Eugenio; Anagnostou, Emmanoil N..; Ferretti, Rossella

    2013-01-01

    The Mediterranean area concentrates the major natural risks related to the water cycle, including heavy precipitation and flash-flooding during the fall season. The capability to predict such high-impact events remains weak because of the contribution of very fine-scale processes and their non-linear interactions with the larger scale processes. These societal and science issues motivate the HyMeX (Hydrological cycle in the Mediterranean Experiment, http://www.hymex.orgl) experimental programme. HyMeX aims at a better quantification and understanding of the water cycle in the Mediterranean with emphasis on intense events. The observation strategy of HyMEX is organized in a long-term (4 years) Enhanced Observation Periods (EOP) and short-term (2 months) Special Observation Periods (SOP). HyMEX has identified 3 main Mediterranean target areas: North-West (NW), Adriatic (A) and South-East (SE). Within each target area several hydrometeorological sites for heavy rainfall and flash flooding have been set up. The hydrometeorological sire in Central Italy (CI) is interested by both western and eastern fronts coming from the Atlantic Ocean and Siberia, respectively. Orographic precipitations play an important role due to the central Apennine range, which reaches nearly 3000 m (Gran Sasso peak). Moreover, convective systems commonly develop in CI during late summer and beginning of autumn, often causing localized hailstorms with cluster organized cells. Western fronts may heavily hit the Tiber basin crossing large urban areas (Rome), whereas eastern fronts can cause flash floods along the Adriatic coastline. Two major basins are involved within Cl region: Tiber basin (1000 km long) and its tributary Aniene and the Aterno-Pescara basin (300 km long). The first HyMeX SOP1.1 was carried out from Sept. till Nov. 2012 in the NW target area The Italian SOP1.1 was coordinated by the Centre of Excellence CETEMPS, University of L'Aquila, a city located in the CI heart. The CI area

  1. Analysis of precipitable water vapor from GPS measurements in Chengdu region: Distribution and evolution characteristics in autumn

    NASA Astrophysics Data System (ADS)

    Wang, Hao; Wei, Ming; Li, Guoping; Zhou, Shenghui; Zeng, Qingfeng

    2013-08-01

    The rainfall process of Chengdu region in autumn has obvious regional features. Especially, the night-time rain rate of this region in this season is very high in China. Studying the spatial distribution and temporal variation of regional atmospheric precipitable water vapor (PWV) is important for our understanding of water vapor related processes, such as rainfall, evaporation, convective activity, among others in this area. Since GPS detection technology has the unique characteristics, such as all-weather, high accuracy, high spatial and temporal resolution as well as low cost, tracking and monitoring techniques on water vapor has achieved rapid developments in recent years. With GPS-PWV data at 30-min interval gathered from six GPS observational stations in Chengdu region in two autumns (September 2007-December 2007 and September 2008-December 2008), it is revealed that negative correlations exist between seasonally averaged value of GPS-PWV as well as its variation amplitude and local terrain altitude. The variation of PWV in the upper atmosphere of this region results from the water vapor variation from surface to 850 hPa. With the help of Fast Fourier Transform (FFT), it is found that the autumn PWV in Chengdu region has a multi-scale feature, which includes a seasonal cycle, 22.5 days period (quasi-tri-weekly oscillation). The variation of the GPS-PWV is related to periodical change in the transmitting of the water vapor caused by zonal and meridional wind strengths’ change and to the East Asian monsoon system. According to seasonal variation characteristics, we concluded that the middle October is the critical turning point in PWV content. On a shorter time scale, the relationship between autumn PWV and ground meteorological elements was obtained using the composite analysis approach.

  2. A Novel Microcharacterization Technique in the Measurement of Strain and Orientation Gradient in Advanced Materials

    NASA Technical Reports Server (NTRS)

    Garmestai, H.; Harris, K.; Lourenco, L.

    1997-01-01

    Representation of morphology and evolution of the microstructure during processing and their relation to properties requires proper experimental techniques. Residual strains, lattice distortion, and texture (micro-texture) at the interface and the matrix of a layered structure or a functionally gradient material and their variation are among parameters important in materials characterization but hard to measure with present experimental techniques. Current techniques available to measure changes in interred material parameters (residual stress, micro-texture, microplasticity) produce results which are either qualitative or unreliable. This problem becomes even more complicated in the case of a temperature variation. These parameters affect many of the mechanical properties of advanced materials including stress-strain relation, ductility, creep, and fatigue. A review of some novel experimental techniques using recent advances in electron microscopy is presented here to measure internal stress, (micro)texture, interracial strength and (sub)grain formation and realignment. Two of these techniques are combined in the chamber of an Environmental Scanning Electron Microscope to measure strain and orientation gradients in advanced materials. These techniques which include Backscattered Kikuchi Diffractometry (BKD) and Microscopic Strain Field Analysis are used to characterize metallic and intermetallic matrix composites and superplastic materials. These techniques are compared with the more conventional x-ray diffraction and indentation techniques.

  3. Remote Bridge Deflection Measurement Using an Advanced Video Deflectometer and Actively Illuminated LED Targets.

    PubMed

    Tian, Long; Pan, Bing

    2016-01-01

    An advanced video deflectometer using actively illuminated LED targets is proposed for remote, real-time measurement of bridge deflection. The system configuration, fundamental principles, and measuring procedures of the video deflectometer are first described. To address the challenge of remote and accurate deflection measurement of large engineering structures without being affected by ambient light, the novel idea of active imaging, which combines high-brightness monochromatic LED targets with coupled bandpass filter imaging, is introduced. Then, to examine the measurement accuracy of the proposed advanced video deflectometer in outdoor environments, vertical motions of an LED target with precisely-controlled translations were measured and compared with prescribed values. Finally, by tracking six LED targets mounted on the bridge, the developed video deflectometer was applied for field, remote, and multipoint deflection measurement of the Wuhan Yangtze River Bridge, one of the most prestigious and most publicized constructions in China, during its routine safety evaluation tests. Since the proposed video deflectometer using actively illuminated LED targets offers prominent merits of remote, contactless, real-time, and multipoint deflection measurement with strong robustness against ambient light changes, it has great potential in the routine safety evaluation of various bridges and other large-scale engineering structures. PMID:27563901

  4. Remote Bridge Deflection Measurement Using an Advanced Video Deflectometer and Actively Illuminated LED Targets

    PubMed Central

    Tian, Long; Pan, Bing

    2016-01-01

    An advanced video deflectometer using actively illuminated LED targets is proposed for remote, real-time measurement of bridge deflection. The system configuration, fundamental principles, and measuring procedures of the video deflectometer are first described. To address the challenge of remote and accurate deflection measurement of large engineering structures without being affected by ambient light, the novel idea of active imaging, which combines high-brightness monochromatic LED targets with coupled bandpass filter imaging, is introduced. Then, to examine the measurement accuracy of the proposed advanced video deflectometer in outdoor environments, vertical motions of an LED target with precisely-controlled translations were measured and compared with prescribed values. Finally, by tracking six LED targets mounted on the bridge, the developed video deflectometer was applied for field, remote, and multipoint deflection measurement of the Wuhan Yangtze River Bridge, one of the most prestigious and most publicized constructions in China, during its routine safety evaluation tests. Since the proposed video deflectometer using actively illuminated LED targets offers prominent merits of remote, contactless, real-time, and multipoint deflection measurement with strong robustness against ambient light changes, it has great potential in the routine safety evaluation of various bridges and other large-scale engineering structures. PMID:27563901

  5. Advanced digital speckle correlation method for strain measurement and nondestructive testing

    NASA Astrophysics Data System (ADS)

    Jin, Guan-chang; Bao, Nai-Keng; Chung, Po Sheun

    1997-03-01

    An advanced digital speckle correlation method (DSCM) is presented in this paper. The advantages of this method will not only improve the processing speed but also increase the measuring accuracy. Some mathematics tools are derived and a powerful computing program is developed for further applications. A new feature of the measuring sensitivity of DSCM that can be varied by different amplification of the optical arrangement is first presented. This advantage may be superior to those available in other optical metrology methods like Electronic Speckle Pattern Interferometry (ESPI) in micro-deformation measurements. The applications of strain measurement and nondestructive testing are described and the advantages of DSCM are obvious. Some examples of material behavior measurement and plastic strain measurement are presented. Due to the high sensitivity of DSCM, another potential application in nondestructive testing (NDT) is also described in this paper. From the application examples given, this advanced DSCM proves to be a new and effective optical strain sensing technique especially for small objects or micro-deformation measurements.

  6. Global Precipitation Measurement (GPM) Mission Products and Services at the NASA Goddard Earth Sciences Data and Information Services Center (GES DISC)

    NASA Technical Reports Server (NTRS)

    Ostrenga, D.; Liu, Z.; Vollmer, B.; Teng, W.; Kempler, S.

    2014-01-01

    On February 27, 2014, the NASA Global Precipitation Measurement (GPM) mission was launched to provide the next-generation global observations of rain and snow (http:pmm.nasa.govGPM). The GPM mission consists of an international network of satellites in which a GPM Core Observatory satellite carries both active and passive microwave instruments to measure precipitation and serve as a reference standard, to unify precipitation measurements from a constellation of other research and operational satellites. The NASA Goddard Earth Sciences (GES) Data and Information Services Center (DISC) hosts and distributes GPM data within the NASA Earth Observation System Data Information System (EOSDIS). The GES DISC is home to the data archive for the GPM predecessor, the Tropical Rainfall Measuring Mission (TRMM). Over the past 16 years, the GES DISC has served the scientific as well as other communities with TRMM data and user-friendly services. During the GPM era, the GES DISC will continue to provide user-friendly data services and customer support to users around the world. GPM products currently and to-be available include the following:Level-1 GPM Microwave Imager (GMI) and partner radiometer productsLevel-2 Goddard Profiling Algorithm (GPROF) GMI and partner productsLevel-3 daily and monthly productsIntegrated Multi-satellitE Retrievals for GPM (IMERG) products (early, late, and final) A dedicated Web portal (including user guides, etc.) has been developed for GPM data (http:disc.sci.gsfc.nasa.govgpm). Data services that are currently and to-be available include Google-like Mirador (http:mirador.gsfc.nasa.gov) for data search and access; data access through various Web services (e.g., OPeNDAP, GDS, WMS, WCS); conversion into various formats (e.g., netCDF, HDF, KML (for Google Earth), ASCII); exploration, visualization, and statistical online analysis through Giovanni (http:giovanni.gsfc.nasa.gov); generation of value-added products; parameter and spatial subsetting; time

  7. Global Precipitation Measurement (GPM) Mission Products and Services at the NASA Goddard Earth Sciences (GES) Data and Information Services Center (DISC)

    NASA Technical Reports Server (NTRS)

    Liu, Zhong; Ostrenga, D.; Vollmer, B.; Deshong, B.; Greene, M.; Teng, W.; Kempler, S. J.

    2015-01-01

    On February 27, 2014, the NASA Global Precipitation Measurement (GPM) mission was launched to provide the next-generation global observations of rain and snow (http:pmm.nasa.govGPM). The GPM mission consists of an international network of satellites in which a GPM Core Observatory satellite carries both active and passive microwave instruments to measure precipitation and serve as a reference standard, to unify precipitation measurements from a constellation of other research and operational satellites. The NASA Goddard Earth Sciences (GES) Data and Information Services Center (DISC) hosts and distributes GPM data within the NASA Earth Observation System Data Information System (EOSDIS). The GES DISC is home to the data archive for the GPM predecessor, the Tropical Rainfall Measuring Mission (TRMM). Over the past 16 years, the GES DISC has served the scientific as well as other communities with TRMM data and user-friendly services. During the GPM era, the GES DISC will continue to provide user-friendly data services and customer support to users around the world. GPM products currently and to-be available include the following: 1. Level-1 GPM Microwave Imager (GMI) and partner radiometer products. 2. Goddard Profiling Algorithm (GPROF) GMI and partner products. 3. Integrated Multi-satellitE Retrievals for GPM (IMERG) products. (early, late, and final)A dedicated Web portal (including user guides, etc.) has been developed for GPM data (http:disc.sci.gsfc.nasa.govgpm). Data services that are currently and to-be available include Google-like Mirador (http:mirador.gsfc.nasa.gov) for data search and access; data access through various Web services (e.g., OPeNDAP, GDS, WMS, WCS); conversion into various formats (e.g., netCDF, HDF, KML (for Google Earth), ASCII); exploration, visualization, and statistical online analysis through Giovanni (http:giovanni.gsfc.nasa.gov); generation of value-added products; parameter and spatial subsetting; time aggregation; regridding; data

  8. Global Precipitation Measurement (GPM) Mission Products and Services at the NASA Goddard Earth Sciences (GES) Data and Information Services Center (DISC)

    NASA Astrophysics Data System (ADS)

    Ostrenga, D.; Liu, Z.; Vollmer, B.; Teng, W. L.; Kempler, S. J.

    2014-12-01

    On February 27, 2014, the NASA Global Precipitation Measurement (GPM) mission was launched to provide the next-generation global observations of rain and snow (http://pmm.nasa.gov/GPM). The GPM mission consists of an international network of satellites in which a GPM "Core Observatory" satellite carries both active and passive microwave instruments to measure precipitation and serve as a reference standard, to unify precipitation measurements from a constellation of other research and operational satellites. The NASA Goddard Earth Sciences (GES) Data and Information Services Center (DISC) hosts and distributes GPM data within the NASA Earth Observation System Data Information System (EOSDIS). The GES DISC is home to the data archive for the GPM predecessor, the Tropical Rainfall Measuring Mission (TRMM). Over the past 16 years, the GES DISC has served the scientific as well as other communities with TRMM data and user-friendly services. During the GPM era, the GES DISC will continue to provide user-friendly data services and customer support to users around the world. GPM products currently and to-be available include the following: Level-1 GPM Microwave Imager (GMI) and partner radiometer products Goddard Profiling Algorithm (GPROF) GMI and partner products Integrated Multi-satellitE Retrievals for GPM (IMERG) products (early, late, and final) A dedicated Web portal (including user guides, etc.) has been developed for GPM data (http://disc.sci.gsfc.nasa.gov/gpm). Data services that are currently and to-be available include Google-like Mirador (http://mirador.gsfc.nasa.gov/) for data search and access; data access through various Web services (e.g., OPeNDAP, GDS, WMS, WCS); conversion into various formats (e.g., netCDF, HDF, KML (for Google Earth), ASCII); exploration, visualization, and statistical online analysis through Giovanni (http://giovanni.gsfc.nasa.gov); generation of value-added products; parameter and spatial subsetting; time aggregation; regridding

  9. Field evaluation of a new particle concentrator- electrostatic precipitator system for measuring chemical and toxicological properties of particulate matter

    PubMed Central

    Ning, Zhi; Sillanpää, Markus; Pakbin, Payam; Sioutas, Constantinos

    2008-01-01

    Background A newly designed electrostatic precipitator (ESP) in tandem with Versatile Aerosol Concentration Enrichment System (VACES) was developed by the University of Southern California to collect ambient aerosols on substrates appropriate for chemical and toxicological analysis. The laboratory evaluation of this sampler is described in a previous paper. The main objective of this study was to evaluate the performance of the new VACES-ESP system in the field by comparing the chemical characteristics of the PM collected in the ESP to those of reference samplers operating in parallel. Results The field campaign was carried out in the period from August, 2007 to March, 2008 in a typical urban environment near downtown Los Angeles. Each sampling set was restricted to 2–3 hours to minimize possible sampling artifacts in the ESP. The results showed that particle penetration increases and ozone concentration decreases with increasing sampling flow rate, with highest particle penetration observed between 100 nm and 300 nm. A reference filter sampler was deployed in parallel to the ESP to collect concentration-enriched aerosols, and a MOUDI sampler was used to collect ambient aerosols. Chemical analysis results showed very good agreement between the ESP and MOUDI samplers in the concentrations of trace elements and inorganic ions. The overall organic compound content of PM collected by the ESP, including polycyclic aromatic hydrocarbons (PAHs), hopanes, steranes, and alkanes, was in good agreement with that of the reference sampler, with an average ESP -to -reference concentration ratio of 1.07 (± 0.38). While majority of organic compound ratios were close to 1, some of the semi-volatile organic species had slightly deviated ratios from 1, indicating the possibility of some sampling artifacts in the ESP due to reactions of PM with ozone and radicals generated from corona discharge, although positive and negative sampling artifacts in the reference filter sampler

  10. ER-2 Observations of Precipitation Systems During TRMM-LBA

    NASA Technical Reports Server (NTRS)

    Heymsfield, Gerald; Tian, Lin; Geerts, Bart

    1999-01-01

    The NASA ER-2 performed numerous flights over precipitation systems in Rondonia, Brazil. The ER-2 carried a payload including the ER-2 Doppler Radar (EDOP), the Advanced Microwave Precipitation Radiometer (AMPR), the Lightning Instrument Package, and other instruments. This presentation will overview the types of data sets collected during TRMM-LBA (Tropical Rainfall Measuring Mission Satellite-Large Scale Biosphere Atmosphere Experiment in Amazonia) with particular emphasis on EDOP measurements. Numerous cases of convection ranging from weak to very intense, were overflown by the ER-2. Two TRMM overpasses were coincident with ER-2 flights which allowed for intercomparisons between the Precipitation Radiometer (PR), EDOP, and the S-POL (S-band Polarimetric Radar) and TOGA (Tropical Oceans and Global Atmosphere) ground-based radars. Preliminary results from this comparison will be presented as well as initial selection of case studies and efforts involving vertical motions in convection.

  11. Definition and impact of a quality index for radar-based reference measurements in the H-SAF precipitation product validation

    NASA Astrophysics Data System (ADS)

    Rinollo, A.; Vulpiani, G.; Puca, S.; Pagliara, P.; Kaňák, J.; Lábó, E.; Okon, L'.; Roulin, E.; Baguis, P.; Cattani, E.; Laviola, S.; Levizzani, V.

    2013-10-01

    The EUMETSAT Satellite Application Facility on Support to Operational Hydrology and Water Management (H-SAF) provides rainfall estimations based on infrared and microwave satellite sensors on board polar and geostationary satellites. The validation of these satellite estimations is performed by the H-SAF Precipitation Product Validation Group (PPVG). A common validation methodology has been defined inside the PPVG in order to make validation results from several institutes comparable and understandable. The validation of the PR-OBS-3 (blended infrared-microwave (IR-MW) instantaneous rainfall estimation) product using radar-based rainfall estimations as ground reference is described herein. A network of C-band and Ka-band radars throughout Europe ensures a wide area coverage with different orographic configurations and climatological regimes, but the definition of a quality control protocol for obtaining consistent ground precipitation fields across several countries is required. Among the hydro-meteorological community, the evaluation of the data quality is a quite consolidated practice, even though a unique definition of a common evaluation methodology between different countries and institutions has not been set up yet. Inside H-SAF, the first definition of the quality index of the radar rainfall observations has been introduced at the Italian Civil Protection Department (DPC). In the evaluation of the DPC quality index, several parameters are considered, some measured by the radar itself (static clutter map, range distance, radial velocity, texture of differential reflectivity, texture of co-polar correlation coefficient and texture of differential phase shift) and some obtained by external sources (digital elevation model, freezing layer height). In some cases, corrections were applied for clutter and beam blocking. The DPC quality index was calculated and applied to some relevant meteorological events reported by a radar test site in Italy. The precipitation

  12. An Assessment of Wind Plant Complex Flows Using Advanced Doppler Radar Measurements

    NASA Astrophysics Data System (ADS)

    Gunter, W. S.; Schroeder, J.; Hirth, B.; Duncan, J.; Guynes, J.

    2015-12-01

    As installed wind energy capacity continues to steadily increase, the need for comprehensive measurements of wind plant complex flows to further reduce the cost of wind energy has been well advertised by the industry as a whole. Such measurements serve diverse perspectives including resource assessment, turbine inflow and power curve validation, wake and wind plant layout model verification, operations and maintenance, and the development of future advanced wind plant control schemes. While various measurement devices have been matured for wind energy applications (e.g. meteorological towers, LIDAR, SODAR), this presentation will focus on the use of advanced Doppler radar systems to observe the complex wind flows within and surrounding wind plants. Advanced Doppler radars can provide the combined advantage of a large analysis footprint (tens of square kilometers) with rapid data analysis updates (a few seconds to one minute) using both single- and dual-Doppler data collection methods. This presentation demonstrates the utility of measurements collected by the Texas Tech University Ka-band (TTUKa) radars to identify complex wind flows occurring within and nearby operational wind plants, and provide reliable forecasts of wind speeds and directions at given locations (i.e. turbine or instrumented tower sites) 45+ seconds in advance. Radar-derived wind maps reveal commonly observed features such as turbine wakes and turbine-to-turbine interaction, high momentum wind speed channels between turbine wakes, turbine array edge effects, transient boundary layer flow structures (such as wind streaks, frontal boundaries, etc.), and the impact of local terrain. Operational turbine or instrumented tower data are merged with the radar analysis to link the observed complex flow features to turbine and wind plant performance.

  13. Scenarios and performance measures for advanced ISDN satellite design and experiments

    NASA Technical Reports Server (NTRS)

    Pepin, Gerard R.

    1991-01-01

    Described here are the contemplated input and expected output for the Interim Service Integrated Services Digital Network (ISDN) Satellite (ISIS) and Full Service ISDN Satellite (FSIS) Models. The discrete event simulations of these models are presented with specific scenarios that stress ISDN satellite parameters. Performance measure criteria are presented for evaluating the advanced ISDN communication satellite designs of the NASA Satellite Communications Research (SCAR) Program.

  14. Advanced Placement Results, 2013-14. Measuring Up. D&A Report No.15.01

    ERIC Educational Resources Information Center

    Gilleland, Kevin; Muli, Juliana

    2015-01-01

    Advanced Placement (AP) outcomes for Wake County Public School System (WCPSS) students have continued an upward trend for over 18 years, out-performing the state and the nation in all measures. In 2013-14 there were 13,757 exams taken by 6,955 WCPSS test-takers with almost 76% of the exams resulting in scores at or above 3, outperforming Guilford…

  15. Measuring therapeutic alliance between oncologists and patients with advanced cancer: The Human Connection Scale

    PubMed Central

    Mack, Jennifer W; Block, Susan D.; Nilsson, Matthew; Wright, Alexi; Trice, Elizabeth; Friedlander, Robert; Paulk, Elizabeth; Prigerson, Holly G

    2009-01-01

    Objectives Patients consider having a human connection with a physician to be an important aspect of end-of-life (EOL) care. We sought to develop and validate a measure of therapeutic alliance between advanced cancer patients and their physicians, and to evaluate the effects of therapeutic alliance on EOL experiences and care. Methods We developed The Human Connection (THC) scale to measure the extent to which patients felt a sense of mutual understanding, caring, and trust with their physicians. The scale was administered to 217 advanced cancer patients along with measures of attributes hypothesized to be related to therapeutic alliance, including emotional acceptance of terminal illness. EOL outcomes in 90 patients who died during the study were also examined. Results The 16-item THC questionnaire was internally consistent (Cronbach’s α =.90) and valid, based on its expected positive association with emotional acceptance of the terminal illness (r=.31, P<.0001). THC scores were inversely related to symptom burden (r=−.19, P=.006), functional status (Karnofsky score, r=.22, P=.001), and mental illness (THC score 50.69 for patients with any DSM diagnosis versus 55.22 for those without, P=.03). THC scores were not significantly associated with EOL discussions (P=.68). Among patients who had died, EOL ICU care was inversely associated with therapeutic alliance (THC score 46.5 for those with ICU care versus 55.5 for those without, P=.002), such that patients with higher THC scores were less likely to spend time in the ICU during the last week of life. Conclusion The THC scale is a valid and reliable measure of therapeutic alliance between advanced cancer patients and their physicians. In addition, we found no evidence to suggest that EOL discussions harm patients’ therapeutic alliance. A strong therapeutic alliance is associated with emotional acceptance of a terminal illness and with decreased ICU care at the end of life among patients with advanced cancer

  16. Final Technical Report: Advanced Measurement and Analysis of PV Derate Factors.

    SciTech Connect

    King, Bruce Hardison; Burton, Patrick D.; Hansen, Clifford; Jones, Christian Birk

    2015-12-01

    The Advanced Measurement and Analysis of PV Derate Factors project focuses on improving the accuracy and reducing the uncertainty of PV performance model predictions by addressing a common element of all PV performance models referred to as “derates”. Widespread use of “rules of thumb”, combined with significant uncertainty regarding appropriate values for these factors contribute to uncertainty in projected energy production.

  17. Laser-velocimeter flow-field measurements of an advanced turboprop

    NASA Technical Reports Server (NTRS)

    Serafini, J. S.; Sullivan, J. P.; Neumann, H. E.

    1981-01-01

    Non-intrusive measurements of velocity about a spinner-propeller-nacelle configuration at a Mach number of 0.8 were performed. A laser velocimeter, specifically developed for these measurements in the NASA Lewis 8-foot by 6-foot Supersonic Wind Tunnel, was used to measure the flow-field of the advanced swept SR-3 turboprop. The laser velocimeter uses an argon ion laser and a 2-color optics system to allow simultaneous measurements of 2-components of velocity. The axisymmetric nature of the propeller-nacelle flow-field permits two separate 2 dimensonal measurements to be combined into 3 dimensional velocity data. Presented are data ahead of and behind the prop blades and also a limited set in between the blades. Aspects of the observed flow-field such as the tip vortex are discussed.

  18. Rapid Intelligent Inspection Process Definition for dimensional measurement in advanced manufacturing

    SciTech Connect

    Brown, C.W.

    1993-03-01

    The Rapid Intelligent Inspection Process Definition (RIIPD) project is an industry-led effort to advance computer integrated manufacturing (CIM) systems for the creation and modification of inspection process definitions. The RIIPD project will define, design, develop, and demonstrate an automated tool (i.e., software) to generate inspection process plans and coordinate measuring machine (CMM) inspection programs, as well as produce support information for the dimensional measurement of piece parts. The goal of this project is to make the inspection and part verification function, specifically CMM measurements, a more effective production support tool by reducing inspection process definition flowtime, creating consistent and standard inspections, increasing confidence of measurement results, and capturing inspection expertise. This objective is accomplished through importing STEP geometry definitions, applying solid modeling, incorporating explicit tolerance representations, establishing dimensional inspection,techniques, embedding artificial intelligence techniques, and adhering to the Dimensional Measuring Interface Standard (DMIS) national standard.

  19. The Community Collaborative Rain, Hail and Snow Network (CoCoRaHS): Timely Volunteer Precipitation Measurements to Supplement Existing Hydrometeorological Networks

    NASA Astrophysics Data System (ADS)

    Reges, H. W.; Doesken, N. J.; Cifelli, R. C.; Turner, J. S.

    2005-12-01

    The Community Collaborative Rain, Hail and Snow Network (CoCoRaHS) is a community-based, education-focused high density network of individual and family volunteers of all ages and backgrounds, who take daily measurements of rain, hail and snow at their homes, schools and businesses. Precipitation is measured using low-cost high capacity 4" diameter plastic rain gauges and Styrofoam wrapped in aluminum foil "hail pads". Thanks to the "low-tech/low-cost" approach, thousands of volunteers can afford to participate, giving the end user a large collection of data points that fill in gaps in many existing networks and data sets. Where feasible, CoCoRaHS is striving to achieve a station density approaching one observation per km-squared providing exceptional detail on cumulative storm precipitation over populated areas. These observations are collected and made available on the CoCoRaHS website: www.cocorahs.org in map and table format. The data are already being used daily by federal, state and community organizations and businesses for many resource management and hydrologic monitoring and predication applications. CoCoRaHS "Intense Rain Reports" and "Hail Reports" are used in "real time" by the National Weather Service in the issuing of flash flood warnings and severe thunderstorm warnings. While only providing once-daily and occasional event reports, CoCoRaHS does provide excellent observational consistency and accuracy including snowfall, depth and water content measurements, as well as the only comprehensive hail data currently being gathered in the U.S. The CoCoRaHS network currently engages over 2,000 volunteer observers in communities across six states, and the network continues to grow.

  20. 1/f noise measurements for faster evaluation of electromigration in advanced microelectronics interconnections

    NASA Astrophysics Data System (ADS)

    Beyne, Sofie; Croes, Kristof; De Wolf, Ingrid; Tőkei, Zsolt

    2016-05-01

    The use of 1/f noise measurements is explored for the purpose of finding faster techniques for electromigration (EM) characterization in advanced microelectronic interconnects, which also enable a better understanding of its underlying physical mechanisms. Three different applications of 1/f noise for EM characterization are explored. First, whether 1/f noise measurements during EM stress can serve as an early indicator of EM damage. Second, whether the current dependence of the noise power spectral density (PSD) can be used for a qualitative comparison of the defect concentration of different interconnects and consequently also their EM lifetime t50. Third, whether the activation energies obtained from the temperature dependence of the 1/f noise PSD correspond to the activation energies found by means of classic EM tests. In this paper, the 1/f noise technique has been used to assess and compare the EM properties of various advanced integration schemes and different materials, as they are being explored by the industry to enable advanced interconnect scaling. More concrete, different types of copper interconnects and one type of tungsten interconnect are compared. The 1/f noise measurements confirm the excellent electromigration properties of tungsten and demonstrate a dependence of the EM failure mechanism on copper grain size and distribution, where grain boundary diffusion is found to be a dominant failure mechanism.

  1. Measuring political commitment and opportunities to advance food and nutrition security: piloting a rapid assessment tool.

    PubMed

    Fox, Ashley M; Balarajan, Yarlini; Cheng, Chloe; Reich, Michael R

    2015-06-01

    Lack of political commitment has been identified as a primary reason for the low priority that food and nutrition interventions receive from national governments relative to the high disease burden caused by malnutrition. Researchers have identified a number of factors that contribute to food and nutrition's 'low-priority cycle' on national policy agendas, but few tools exist to rapidly measure political commitment and identify opportunities to advance food and nutrition on the policy agenda. This article presents a theory-based rapid assessment approach to gauging countries' level of political commitment to food and nutrition security and identifying opportunities to advance food and nutrition on the policy agenda. The rapid assessment tool was piloted among food and nutrition policymakers and planners in 10 low- and middle-income countries in April to June 2013. Food and nutrition commitment and policy opportunity scores were calculated for each country and strategies to advance food and nutrition on policy agendas were designed for each country. The article finds that, in a majority of countries, political leaders had verbally and symbolically committed to addressing food and nutrition, but adequate financial resources were not allocated to implement specific programmes. In addition, whereas the low cohesion of the policy community has been viewed a major underlying cause of the low-priority status of food and nutrition, the analysis finds that policy community cohesion and having a well thought-out policy alternative were present in most countries. This tool may be useful to policymakers and planners providing information that can be used to benchmark and/or evaluate advocacy efforts to advance reforms in the food and nutrition sector; furthermore, the results can help identify specific strategies that can be employed to move the food and nutrition agenda forward. This tool complements others that have been recently developed to measure national commitment to

  2. Measuring political commitment and opportunities to advance food and nutrition security: piloting a rapid assessment tool.

    PubMed

    Fox, Ashley M; Balarajan, Yarlini; Cheng, Chloe; Reich, Michael R

    2015-06-01

    Lack of political commitment has been identified as a primary reason for the low priority that food and nutrition interventions receive from national governments relative to the high disease burden caused by malnutrition. Researchers have identified a number of factors that contribute to food and nutrition's 'low-priority cycle' on national policy agendas, but few tools exist to rapidly measure political commitment and identify opportunities to advance food and nutrition on the policy agenda. This article presents a theory-based rapid assessment approach to gauging countries' level of political commitment to food and nutrition security and identifying opportunities to advance food and nutrition on the policy agenda. The rapid assessment tool was piloted among food and nutrition policymakers and planners in 10 low- and middle-income countries in April to June 2013. Food and nutrition commitment and policy opportunity scores were calculated for each country and strategies to advance food and nutrition on policy agendas were designed for each country. The article finds that, in a majority of countries, political leaders had verbally and symbolically committed to addressing food and nutrition, but adequate financial resources were not allocated to implement specific programmes. In addition, whereas the low cohesion of the policy community has been viewed a major underlying cause of the low-priority status of food and nutrition, the analysis finds that policy community cohesion and having a well thought-out policy alternative were present in most countries. This tool may be useful to policymakers and planners providing information that can be used to benchmark and/or evaluate advocacy efforts to advance reforms in the food and nutrition sector; furthermore, the results can help identify specific strategies that can be employed to move the food and nutrition agenda forward. This tool complements others that have been recently developed to measure national commitment to

  3. AISI/DOE Advanced Process Control Program Vol. 6 of 6: Temperature Measurement of Galvanneal Steel

    SciTech Connect

    S.W. Allison; D.L. Beshears; W.W. Manges

    1999-06-30

    This report describes the successful completion of the development of an accurate in-process measurement instrument for galvanneal steel surface temperatures. This achievement results from a joint research effort that is a part of the American Iron and Steel Institute's (AISI) Advanced Process Control Program, a collaboration between the U.S> Department of Energy and fifteen North American Steelmakers. This three-year project entitled ''Temperature Measurement of Galvanneal Steel'' uses phosphor thermography, and outgrowth of Uranium enrichment research at Oak Ridge facilities. Temperature is the controlling factor regarding the distribution of iron and zinc in the galvanneal strip coating, which in turn determines the desired product properties

  4. Advanced near-and mid-infrared laser based instruments for atmospheric measurements

    NASA Astrophysics Data System (ADS)

    Richter, Dirk; Weibring, Petter; Spuler, Scott; Walega, James; Spowart, Mike; Fried, Alan

    2010-05-01

    We present new ground and airborne instruments for atmospheric measurements based on fiber and diode laser sources. This versatile optical technology can be configured to provide high resolution, sensitive, selective, and real-time measurements. In particular we will present current and planned instruments to measure important trace gas species, including isotopes, and 3D wind-speeds from an aircraft platform. All the instruments presented leverage technology advances made in the photonics and optical telecommunication industry. We have developed a set of tools based around these technological building blocks and used them to design a suite of measurement capabilities for use by the atmospheric research community. Optical technologies have been accumulating a proven record of robust performance, and enable one to built more lightweight and compact instrumentation for easy deployment for traditional ground, advanced sea, and airborne measurement platforms. We will present how these enabling optical technologies have served as the foundation for select instruments, and provide a roadmap for future development opportunities.

  5. Measures of Adequacy for Library Collections in Australian Colleges of Advanced Education. Report of a Research Project Conducted in Behalf of the Commission on Advanced Education. Volume 1.

    ERIC Educational Resources Information Center

    Wainwright, E. J.; Dean, J. E.

    This study investigates the bases for constructing quantitative and qualitative measures of Australian Colleges of Advanced Education (CAE) library collection adequacy, and the feasibility of producing specialized and appropriate measures to guide future collection planning. Adequacy is based on the libraries' policies for providing materials to…

  6. Time-dependent Measurements of Dissolution-precipitation Reactions Caused by Caustic Waste Solutions At the Hanford Site Using Synchrotron Computed Microtomography

    NASA Astrophysics Data System (ADS)

    Wang, G.; Jones, K. W.; Um, W.; Rockhold, M. L.; Crandell, L. E.; Peters, C. A.; Lindquist, W. B.

    2012-12-01

    Leaking of caustic (hyper-alkaline) radioactive wastes, generated from plutonium production during the Cold War and stored in underground storage tanks at Hanford Site (Richland, WA), has been detected in the subsurface. The caustic wastes leachate induces primary mineral dissolution (releasing Si) and subsequent secondary precipitation (feldspathoids, such as sodalite and cancrinite) in the sediments. The dissolution-precipitation reactions affect the transport of radioactive elements (90Sr and 137Cs) in the sub-surface through changing the morphology of the sediments. We studied here the changes of the morphology of the sediments caused by exposure of quartz sand or Hanford sediments to simulated tank waste leachates (2 M Na+, 1 M OH-, 1.053 M NO3-, 0.05 M Al3+ and 10-5 M Sr2+) using a series of steady-state-flow saturated column experiments. The 3D structures were determined using synchrotron computed microtomography (CMT) at the National Synchrotron Light Source. Sequential measurements were made at intervals over an exposure time of up to ~620 days with a pixel size of 4 μm in mini columns (ID2.1 mm) packed with quartz sand, or with a pixel size of 11 μm in intermediate size columns (ID19 mm) packed with Hanford sediments. Values for porosity as a function of treatment time were obtained showing major changes. Good agreement was found between the microstructure porosity determinations with results obtained from measurements on the composition of the treatment fluids. The results also show the changes in the three dimensional morphology of the sediment structures as a function of the treatment time. Good agreement was also found between observed and simulated porosity and aqueous chemistry obtained using the reactive transport simulator STOMP. A comparison of the CMT results with complementary high-resolution scanning electron microscopy scans will also be presented.

  7. Environmental Radioactivity, Temperature, and Precipitation.

    ERIC Educational Resources Information Center

    Riland, Carson A.

    1996-01-01

    Reports that environmental radioactivity levels vary with temperature and precipitation and these effects are due to radon. Discusses the measurement of this environmental radioactivity and the theory behind it. (JRH)

  8. The Global Precipitation Mission

    NASA Technical Reports Server (NTRS)

    Braun, Scott; Kummerow, Christian

    2000-01-01

    The Global Precipitation Mission (GPM), expected to begin around 2006, is a follow-up to the Tropical Rainfall Measuring Mission (TRMM). Unlike TRMM, which primarily samples the tropics, GPM will sample both the tropics and mid-latitudes. The primary, or core, satellite will be a single, enhanced TRMM satellite that can quantify the 3-D spatial distributions of precipitation and its associated latent heat release. The core satellite will be complemented by a constellation of very small and inexpensive drones with passive microwave instruments that will sample the rainfall with sufficient frequency to be not only of climate interest, but also have local, short-term impacts by providing global rainfall coverage at approx. 3 h intervals. The data is expected to have substantial impact upon quantitative precipitation estimation/forecasting and data assimilation into global and mesoscale numerical models. Based upon previous studies of rainfall data assimilation, GPM is expected to lead to significant improvements in forecasts of extratropical and tropical cyclones. For example, GPM rainfall data can provide improved initialization of frontal systems over the Pacific and Atlantic Oceans. The purpose of this talk is to provide information about GPM to the USWRP (U.S. Weather Research Program) community and to discuss impacts on quantitative precipitation estimation/forecasting and data assimilation.

  9. Current Development of Global Precipitation Mission (GPM)

    NASA Technical Reports Server (NTRS)

    Smith, Eric A.; Starr, David (Technical Monitor)

    2001-01-01

    The scientific success of the Tropical Rainfall Measuring Mission (TRMM) and additional satellite-focused precipitation retrieval projects, particularly those based on use of passive microwave radiometer measurements, have paved the way for a more advanced global precipitation mission. The new mission is motivated by a number of scientific questions that TRMM research has posed over a range of space-time scales and within a variety of scientific disciplines that are becoming more integrated into earth system science modeling. Added to this success is the realization that satellite rainfall datasets are now a foremost tool in understanding global climate variability out to decadal scales and beyond. This progress has motivated a comprehensive global measuring strategy -- leading to the "Global Precipitation Mission" (GPM). GPM is planning to expand the scope of rainfall measurement through use of a satellite constellation. The intent is to address looming scientific questions arising in the context of global climate-water cycle interactions, hydrometeorology, weather prediction & prediction of fresh water resources, the global carbon budget, and biogeochemical cycles. This talk overviews the status and scientific agenda of this mission currently planned for launch in the 2007-2008 time frame. The GPM notional design involves a 10-member satellite constellation, one of which will be an advanced TRMM-like "core" satellite carrying a dual-frequency Ku-Ka band radar (DFPR) and a TMI-like radiometer. The other nine members of the constellation will be considered daughters of the core satellite, each carrying some type of passive microwave radiometer measuring across the 10.7-85 GHz frequency range -- likely to include a combination of lightweight satellites and co-existing operational/experimental satellites carrying passive microwave radiometers (i.e., 2 DMSP/SSMISs, GCOM-B1/AMSR-J, & Megha Tropiques/MADRAS). The goal behind the constellation is to achieve no worse than

  10. Advances in Mineral Dust Source Composition Measurement with Imaging Spectroscopy at the Salton Sea, CA

    NASA Astrophysics Data System (ADS)

    Green, R. O.; Realmuto, V. J.; Thompson, D. R.; Mahowald, N. M.; Pérez García-Pando, C.; Miller, R. L.; Clark, R. N.; Swayze, G. A.; Okin, G. S.

    2015-12-01

    Mineral dust emitted from the Earth's surface is a principal contributor to direct radiative forcing over the arid regions, where shifts in climate have a significant impact on agriculture, precipitation, and desert encroachment around the globe. Dust particles contribute to both positive and negative forcing, depending on the composition of the particles. Particle composition is a function of the surface mineralogy of dust source regions, but poor knowledge of surface mineralogy on regional to global scales limits the skill of Earth System models to predict shifts in regional climate around the globe. Earth System models include the source, emission, transport and deposition phases of the dust cycle. In addition to direct radiative forcing contributions, mineral dust impacts include indirect radiative forcing, modification of the albedo and melting rates of snow and ice, kinetics of tropospheric photochemistry, formation and deposition of acidic aerosols, supply of nutrients to aquatic and terrestrial ecosystems, and impact on human health and safety. We demonstrate the ability to map mineral dust source composition in the Salton Sea dust source region with imaging spectroscopy measurements acquired as part of the NASA HyspIRI preparatory airborne campaign. These new spectroscopically derived compositional measurements provide a six orders of magnitude improvement over current atlases for this dust source region and provide a pathfinder example for a remote measurement approach to address this critical dust composition gap for global Earth System models.

  11. Development of an integrated energetic neutral particle measurement system on experimental advanced full superconducting tokamak

    SciTech Connect

    Zhu, Y. B. Liu, D.; Heidbrink, W. W.; Zhang, J. Z.; Qi, M. Z.; Xia, S. B.; Wan, B. N.; Li, J. G.

    2014-11-15

    Full function integrated, compact silicon photodiode based solid state neutral particle analyzers (ssNPA) have been developed for energetic particle (EP) relevant studies on the Experimental Advanced Superconducting Tokamak (EAST). The ssNPAs will be mostly operated in advanced current mode with a few channels to be operated in conventional pulse-counting mode, aiming to simultaneously achieve individually proved ultra-fast temporal, spatial, and spectral resolution capabilities. The design details together with considerations on EAST specific engineering realities and physics requirements are presented. The system, including a group of single detectors on two vertical ports and two 16-channel arrays on a horizontal port, can provide both active and passive charge exchange measurements. ssNPA detectors, with variable thickness of ultra thin tungsten dominated foils directly deposited on the front surface, are specially fabricated and utilized to achieve about 22 keV energy resolution for deuterium particle detection.

  12. Development of an integrated energetic neutral particle measurement system on experimental advanced full superconducting tokamak

    NASA Astrophysics Data System (ADS)

    Zhu, Y. B.; Zhang, J. Z.; Qi, M. Z.; Xia, S. B.; Liu, D.; Heidbrink, W. W.; Wan, B. N.; Li, J. G.

    2014-11-01

    Full function integrated, compact silicon photodiode based solid state neutral particle analyzers (ssNPA) have been developed for energetic particle (EP) relevant studies on the Experimental Advanced Superconducting Tokamak (EAST). The ssNPAs will be mostly operated in advanced current mode with a few channels to be operated in conventional pulse-counting mode, aiming to simultaneously achieve individually proved ultra-fast temporal, spatial, and spectral resolution capabilities. The design details together with considerations on EAST specific engineering realities and physics requirements are presented. The system, including a group of single detectors on two vertical ports and two 16-channel arrays on a horizontal port, can provide both active and passive charge exchange measurements. ssNPA detectors, with variable thickness of ultra thin tungsten dominated foils directly deposited on the front surface, are specially fabricated and utilized to achieve about 22 keV energy resolution for deuterium particle detection.

  13. Development of an integrated energetic neutral particle measurement system on experimental advanced full superconducting tokamak.

    PubMed

    Zhu, Y B; Zhang, J Z; Qi, M Z; Xia, S B; Liu, D; Heidbrink, W W; Wan, B N; Li, J G

    2014-11-01

    Full function integrated, compact silicon photodiode based solid state neutral particle analyzers (ssNPA) have been developed for energetic particle (EP) relevant studies on the Experimental Advanced Superconducting Tokamak (EAST). The ssNPAs will be mostly operated in advanced current mode with a few channels to be operated in conventional pulse-counting mode, aiming to simultaneously achieve individually proved ultra-fast temporal, spatial, and spectral resolution capabilities. The design details together with considerations on EAST specific engineering realities and physics requirements are presented. The system, including a group of single detectors on two vertical ports and two 16-channel arrays on a horizontal port, can provide both active and passive charge exchange measurements. ssNPA detectors, with variable thickness of ultra thin tungsten dominated foils directly deposited on the front surface, are specially fabricated and utilized to achieve about 22 keV energy resolution for deuterium particle detection.

  14. The Changing Character of Precipitation.

    NASA Astrophysics Data System (ADS)

    Trenberth, Kevin E.; Dai, Aiguo; Rasmussen, Roy M.; Parsons, David B.

    2003-09-01

    From a societal, weather, and climate perspective, precipitation intensity, duration, frequency, and phase are as much of concern as total amounts, as these factors determine the disposition of precipitation once it hits the ground and how much runs off. At the extremes of precipitation incidence are the events that give rise to floods and droughts, whose changes in occurrence and severity have an enormous impact on the environment and society. Hence, advancing understanding and the ability to model and predict the character of precipitation is vital but requires new approaches to examining data and models. Various mechanisms, storms and so forth, exist to bring about precipitation. Because the rate of precipitation, conditional on when it falls, greatly exceeds the rate of replenishment of moisture by surface evaporation, most precipitation comes from moisture already in the atmosphere at the time the storm begins, and transport of moisture by the storm-scale circulation into the storm is vital. Hence, the intensity of precipitation depends on available moisture, especially for heavy events. As climate warms, the amount of moisture in the atmosphere, which is governed by the Clausius- Clapeyron equation, is expected to rise much faster than the total precipitation amount, which is governed by the surface heat budget through evaporation. This implies that the main changes to be experienced are in the character of precipitation: increases in intensity must be offset by decreases in duration or frequency of events. The timing, duration, and intensity of precipitation can be systematically explored via the diurnal cycle, whose correct simulation in models remains an unsolved challenge of vital importance in global climate change. Typical problems include the premature initiation of convection, and precipitation events that are too light and too frequent. These challenges in observations, modeling, and understanding precipitation changes are being taken up in the NCAR

  15. Spatio-temporal statistical model for the optimal combination of precipitation measured at different time scales for estimating unobserved point values and disaggregating to finer timescales

    NASA Astrophysics Data System (ADS)

    Bàrdossy, Andràs; Pegram, Geoffrey

    2015-04-01

    Precipitation observations are unique in space and time, so if not observed, the values can only be estimated. Many applications, such as the calculation of water balances, calibration of hydrological models or the provision of unbiased ground truth for remote sensing require full datasets. Thus a reliable estimation of the missing observations is of great importance. The problem is exacerbated by the ubiquitous decimation of gauge networks. We consider 2 problems as examples of the methodology: (i) infilling monthly data where some days are missing in the monthly records and (ii) infilling missing hourly values in daily records with the assistance of some nearby pluviometers. The key is that we need estimates of the distributions of the infilled values, not just their expectations, as we have found that the traditional 'best' values bias the spatial estimates. We first performed monthly precipitation interpolation using 311 full records, 31 stations of which were randomly decimated to artificially create incomplete records as inequality constraints. Interpolation was carried out (i) without using these 31 in any way and (ii) using them as inequality constraints, in the sense that we determine a lower limit by aggregating the surviving data in a decimated record. We compare the errors if (i) the 31 stations with incomplete records are not considered against (ii) the errors if the incomplete records are considered as inequalities, and found that the partially decimated data add considerable value, as compared to neglecting them. In a second application we performed a disaggregation in time. We take a set of complete hourly pluviometer data, then aggregate some stations to days. These then have their hourly missing data reconstructed and we evaluate the success of the procedure by cross-validation. In this application the daily sums for a location are considered as a constraint and the disaggregated daily data are compared to their observed hourly precipitation. The

  16. Lidar and radar measurements of the melting layer in the frame of the Convective and Orographically-induced Precipitation Study: observations of dark and bright band phenomena

    NASA Astrophysics Data System (ADS)

    di Girolamo, P.; Summa, D.; Bhawar, R.; di Iorio, T.; Norton, E. G.; Peters, G.; Dufournet, Y.

    2011-11-01

    During the Convective and Orographically-induced Precipitation Study (COPS), lidar dark and bright bands were observed by the University of BASILicata Raman lidar system (BASIL) during several intensive (IOPs) and special (SOPs) observation periods (among others, 23 July, 15 August, and 17 August 2007). Lidar data were supported by measurements from the University of Hamburg cloud radar MIRA 36 (36 GHz), the University of Hamburg dual-polarization micro rain radars (24.1 GHz) and the University of Manchester UHF wind profiler (1.29 GHz). Results from BASIL and the radars for 23 July 2007 are illustrated and discussed to support the comprehension of the microphysical and scattering processes responsible for the appearance of the lidar and radar dark and bright bands. Simulations of the lidar dark and bright band based on the application of concentric/eccentric sphere Lorentz-Mie codes and a melting layer model are also provided. Lidar and radar measurements and model results are also compared with measurements from a disdrometer on ground and a two-dimensional cloud (2DC) probe on-board the ATR42 SAFIRE.

  17. Applications of Advanced Nondestructive Measurement Techniques to Address Safety of Flight Issues on NASA Spacecraft

    NASA Technical Reports Server (NTRS)

    Prosser, Bill

    2016-01-01

    Advanced nondestructive measurement techniques are critical for ensuring the reliability and safety of NASA spacecraft. Techniques such as infrared thermography, THz imaging, X-ray computed tomography and backscatter X-ray are used to detect indications of damage in spacecraft components and structures. Additionally, sensor and measurement systems are integrated into spacecraft to provide structural health monitoring to detect damaging events that occur during flight such as debris impacts during launch and assent or from micrometeoroid and orbital debris, or excessive loading due to anomalous flight conditions. A number of examples will be provided of how these nondestructive measurement techniques have been applied to resolve safety critical inspection concerns for the Space Shuttle, International Space Station (ISS), and a variety of launch vehicles and unmanned spacecraft.

  18. Performance of an Advanced Stirling Convertor Based on Heat Flux Sensor Measurements

    NASA Technical Reports Server (NTRS)

    Wilson, Scott D.

    2012-01-01

    The U.S. Department of Energy (DOE) and Lockheed Martin Space Systems Company (LMSSC) have been developing the Advanced Stirling Radioisotope Generator (ASRG) for use as a power system for space science missions. This generator would use two high-efficiency Advanced Stirling Convertors (ASCs), developed by Sunpower, Inc., and NASA Glenn Research Center. The ASCs convert thermal energy from a radioisotope heat source into electricity. As part of ground testing of these ASCs, different operating conditions are used to simulate expected mission conditions. These conditions require achieving a particular operating frequency, hot-end and cold-end temperatures, and specified electrical power output for a given heat input. It is difficult to measure heat input to Stirling convertors due to the complex geometries of the hot components, temperature limits of sensor materials, and invasive integration of sensors. A thin-film heat flux sensor was used to directly measure heat input to an ASC. The effort succeeded in designing and fabricating unique sensors, which were integrated into a Stirling convertor ground test and exposed to test temperatures exceeding 700 C in air for 10,000 hr. Sensor measurements were used to calculate thermal efficiency for ASC-E (Engineering Unit) #1 and #4. The post-disassembly condition of the sensors is also discussed.

  19. Performance of an Advanced Stirling Convertor Based on Heat Flux Sensor Measurements

    NASA Technical Reports Server (NTRS)

    Wilson, Dcott D.

    2012-01-01

    The U.S. Department of Energy (DOE) and Lockheed Martin Space Systems Company (LMSSC) have been developing the Advanced Stirling Radioisotope Generator (ASRG) for use as a power system for space science missions. This generator would use two highefficiency Advanced Stirling Convertors (ASCs), developed by Sunpower, Inc., and NASA Glenn Research Center. The ASCs convert thermal energy from a radioisotope heat source into electricity. As part of ground testing of these ASCs, different operating conditions are used to simulate expected mission conditions. These conditions require achieving a particular operating frequency, hot-end and cold-end temperatures, and specified electrical power output for a given heat input. It is difficult to measure heat input to Stirling convertors due to the complex geometries of the hot components, temperature limits of sensor materials, and invasive integration of sensors. A thin-film heat flux sensor was used to directly measure heat input to an ASC. The effort succeeded in designing and fabricating unique sensors, which were integrated into a Stirling convertor ground test and exposed to test temperatures exceeding 700 C in air for 10,000 hr. Sensor measurements were used to calculate thermal efficiency for ASC-E (Engineering Unit) #1 and #4. The post-disassembly condition of the sensors is also discussed.

  20. Recent advances in small-scale mechanical property measurement by nanoindentation

    DOE PAGES

    Pharr, George Mathews

    2015-08-25

    Since its initial development in the early 1980’s [1], nanoindentation has matured into one of the premier testing techniques for measuring mechanical properties at the micrometer and sub-micrometer scales and has emerged as a critical tool that has helped to shape the nanotechnology revolution. At the heart of the technique are testing systems with simple but precise force actuators and displacement measuring devices that record the force–displacement record as a diamond indenter, usually the form of a pyramid or a sphere, is pressed into and withdrawn from a small region in the surface of a material of interest. The nano-scalemore » force–displacement data, which can be obtained with a spatial resolution as small as a few nanometers, contains a wealth of information about the local mechanical properties [2], [3] and [4]. This enables the mechanical characterization of very thin films, like those used in the semiconductor, magnetic storage, and hard coatings industries, as well as very small precipitates, particles and second phases, many of which may not exist in bulk form and cannot be characterized by traditional mechanical testing methods. Here, computer automation of nanoindentation testing systems now routinely provides for complete two-dimensional mapping of properties over regions stretching from sub-micron to millimeters in scale.« less

  1. Recent advances in small-scale mechanical property measurement by nanoindentation

    SciTech Connect

    Pharr, George Mathews

    2015-08-25

    Since its initial development in the early 1980’s [1], nanoindentation has matured into one of the premier testing techniques for measuring mechanical properties at the micrometer and sub-micrometer scales and has emerged as a critical tool that has helped to shape the nanotechnology revolution. At the heart of the technique are testing systems with simple but precise force actuators and displacement measuring devices that record the force–displacement record as a diamond indenter, usually the form of a pyramid or a sphere, is pressed into and withdrawn from a small region in the surface of a material of interest. The nano-scale force–displacement data, which can be obtained with a spatial resolution as small as a few nanometers, contains a wealth of information about the local mechanical properties [2], [3] and [4]. This enables the mechanical characterization of very thin films, like those used in the semiconductor, magnetic storage, and hard coatings industries, as well as very small precipitates, particles and second phases, many of which may not exist in bulk form and cannot be characterized by traditional mechanical testing methods. Here, computer automation of nanoindentation testing systems now routinely provides for complete two-dimensional mapping of properties over regions stretching from sub-micron to millimeters in scale.

  2. Techniques for measurement of the thermal expansion of advanced composite materials

    NASA Technical Reports Server (NTRS)

    Tompkins, Stephen S.

    1989-01-01

    Techniques available to measure small thermal displacements in flat laminates and structural tubular elements of advanced composite materials are described. Emphasis is placed on laser interferometry and the laser interferometric dilatometer system used at the National Aeronautics and Space Administration (NASA) Langley Research Center. Thermal expansion data are presented for graphite-fiber reinforced 6061 and 2024 aluminum laminates and for graphite fiber reinforced AZ91 C and QH21 A magnesium laminates before and after processing to minimize or eliminate thermal strain hysteresis. Data are also presented on the effects of reinforcement volume content on thermal expansion of silicon-carbide whisker and particulate reinforced aluminum.

  3. Advanced Communications Technology Satellite (ACTS): Design and on-orbit performance measurements

    NASA Technical Reports Server (NTRS)

    Gargione, F.; Acosta, R.; Coney, T.; Krawczyk, R.

    1995-01-01

    The Advanced Communications Technology Satellite (ACTS), developed and built by Lockheed Martin Astro space for the NASA Lewis Research Center, was launched in September 1993 on the shuttle STS 51 mission. ACTS is a digital experimental communications test bed that incorporates gigahertz bandwidth transponders operating at Ka band, hopping spot beams, on-board storage and switching, and dynamic rain fade compensation. This paper describes the ACTS enabling technologies, the design of the communications payload, the constraints imposed on the spacecraft bus, and the measurements conducted to verify the performance of the system in orbit.

  4. Precision bone and muscle loss measurements by advanced, multiple projection DEXA (AMPDXA) techniques for spaceflight applications

    NASA Technical Reports Server (NTRS)

    Charles, H. K. Jr; Beck, T. J.; Feldmesser, H. S.; Magee, T. C.; Spisz, T. S.; Pisacane, V. L.

    2001-01-01

    An advanced, multiple projection, dual energy x-ray absorptiometry (AMPDXA) scanner system is under development. The AMPDXA is designed to make precision bone and muscle loss measurements necessary to determine the deleterious effects of microgravity on astronauts as well as develop countermeasures to stem their bone and muscle loss. To date, a full size test system has been developed to verify principles and the results of computer simulations. Results indicate that accurate predictions of bone mechanical properties can be determined from as few as three projections, while more projections are needed for a complete, three-dimensional reconstruction. c 2001. Elsevier Science Ltd. All rights reserved.

  5. The investigation of advanced remote sensing techniques for the measurement of aerosol characteristics

    NASA Technical Reports Server (NTRS)

    Deepak, A.; Becher, J.

    1979-01-01

    Advanced remote sensing techniques and inversion methods for the measurement of characteristics of aerosol and gaseous species in the atmosphere were investigated. Of particular interest were the physical and chemical properties of aerosols, such as their size distribution, number concentration, and complex refractive index, and the vertical distribution of these properties on a local as well as global scale. Remote sensing techniques for monitoring of tropospheric aerosols were developed as well as satellite monitoring of upper tropospheric and stratospheric aerosols. Computer programs were developed for solving multiple scattering and radiative transfer problems, as well as inversion/retrieval problems. A necessary aspect of these efforts was to develop models of aerosol properties.

  6. Measurements of wind, aeolian sand transport, and precipitation in the Colorado River corridor, Grand Canyon, Arizona; January 2005 to January 2006

    USGS Publications Warehouse

    Draut, Amy E.; Rubin, David M.

    2006-01-01

    This report presents measurements of aeolian sediment-transport rates, wind speed and direction, and precipitation records from six locations that contain aeolian deposits in the Colorado River corridor through Grand Canyon, Grand Canyon National Park, Arizona. Aeolian deposits, many of which contain and preserve archaeological material, are an important part of the Grand Canyon ecosystem. This report contains data collected between January 2005 and January 2006, and is the second in a series; the first contained data that were collected between November 2003 and December 2004 (Draut and Rubin, 2005; http://pubs.usgs.gov/of/2005/1309/). Analysis of data collected in 2005 shows great spatial and seasonal variation in wind and precipitation patterns. Total annual rainfall can vary by more than a factor of two over distances ~ 10 km. Western Grand Canyon received substantially more precipitation than the eastern canyon during the abnormally wet winter of 2005. Great spatial variability in precipitation indicates that future sedimentary and geomorphic studies would benefit substantially from continued or expanded data collection at multiple locations along the river corridor, because rainfall records collected by NPS at Phantom Ranch (near river-mile 88) cannot be assumed to apply to other areas of the canyon. Wind velocities and sand transport in 2005 were greatest during May and June, with maximum winds locally as high as ~25 m s-1, and transport rates locally >100 g cm-1 d-1. This represents a later peak in seasonal aeolian sand transport compared to the previous year, in which transport rates were greatest in April and May 2004. Dominant wind direction varies with location, but during the spring windy season the greatest transport potential was directed upstream in Marble Canyon (eastern Grand Canyon). At all locations, rates of sand transport during the spring windy season were 5–15 times higher than at other times of year. This information has been used to

  7. Accuracy Advances in Measuring Earth Emission Spectra for Weather and Climate

    NASA Astrophysics Data System (ADS)

    Revercomb, H. E.; Best, F. A.; Tobin, D. C.; Knuteson, R. O.; Taylor, J. K.; Gero, P.; Adler, D. P.; Pettersen, C.; Mulligan, M.

    2011-12-01

    Launch of the first component of the Joint Polar Satellite System (JPSS) in late October is expected to initiate a new series of US afternoon satellites to complement the EUMETSAT MetOp EPS morning observations. A key component is the Cross-track Infrared Sounder (CrIS) designed for advanced temperature and water vapor profiling for weather and climate applications. We have worked on getting this operational capability in space ever since conducting a Phase A instrument design in 1990, and will report on what is expected to be its highly accurate radiometric and spectral performance post launch. The expectation from thermal/vacuum testing is that the accuracy will exceed 0.2 K (k=3) brightness temperature at scene temperature for all three bands in the region from 3.5 to 15 microns. CrIS is expected to offer further confirmation of techniques that have proven to offer significant accuracy improvements for the new family of advanced sounding instruments including AIRS on NASA Aqua platform and IASI on MetOp A and that are needed in the new IR Decadal Survey measurements. CrIS and these other advanced sounders help set the stage for a new era in establishing spectrally resolved IR climate benchmark measurements from space. Here we report on being able to achieve even higher accuracy with instruments designed specifically for climate missions similar to the Decadal Survey Climate Absolute Radiance and Refractivity Observatory (CLARREO). Results will be presented from our NASA Instrument Incubator Program (IIP) effort for which a new concept for on-orbit verification and test has been developed. This system is capable of performing fundamental radiometric calibration, spectral characterization and calibration, and other key performance tests that are normally only performed prior to launch in thermal/vacuum testing. By verifying accuracy directly on-orbit, this capability should provide the ultra-high confidence in data sets needed for societal decision making.

  8. Advanced Nuclear Measurements - Sensitivity Analysis Emerging Safeguards, Problems and Proliferation Risk

    SciTech Connect

    Dreicer, J.S.

    1999-07-15

    During the past year this component of the Advanced Nuclear Measurements LDRD-DR has focused on emerging safeguards problems and proliferation risk by investigating problems in two domains. The first is related to the analysis, quantification, and characterization of existing inventories of fissile materials, in particular, the minor actinides (MA) formed in the commercial fuel cycle. Understanding material forms and quantities helps identify and define future measurement problems, instrument requirements, and assists in prioritizing safeguards technology development. The second problem (dissertation research) has focused on the development of a theoretical foundation for sensor array anomaly detection. Remote and unattended monitoring or verification of safeguards activities is becoming a necessity due to domestic and international budgetary constraints. However, the ability to assess the trustworthiness of a sensor array has not been investigated. This research is developing an anomaly detection methodology to assess the sensor array.

  9. Application of visible bremsstrahlung to Z{sub eff} measurement on the Experimental Advanced Superconducting Tokamak

    SciTech Connect

    Chen, Yingjie; Wu, Zhenwei; Gao, Wei; Ti, Ang; Zhang, Ling; Jie, Yinxian; Zhang, Jizong; Huang, Juan; Xu, Zong; Zhao, Junyu

    2015-02-15

    The multi-channel visible bremsstrahlung measurement system has been developed on Experimental Advanced Superconducting Tokamak (EAST). In addition to providing effective ion charge Z{sub eff} as a routine diagnostic, this diagnostic can also be used to estimate other parameters. With the assumption that Z{sub eff} can be seen as constant across the radius and does not change significantly during steady state discharges, central electron temperature, averaged electron density, electron density profile, and plasma current density profile have been obtained based on the scaling of Z{sub eff} with electron density and the relations between Z{sub eff} and these parameters. The estimated results are in good coincidence with measured values, providing an effective and convenient method to estimate other plasma parameters.

  10. Application of visible bremsstrahlung to Z(eff) measurement on the Experimental Advanced Superconducting Tokamak.

    PubMed

    Chen, Yingjie; Wu, Zhenwei; Gao, Wei; Ti, Ang; Zhang, Ling; Jie, Yinxian; Zhang, Jizong; Huang, Juan; Xu, Zong; Zhao, Junyu

    2015-02-01

    The multi-channel visible bremsstrahlung measurement system has been developed on Experimental Advanced Superconducting Tokamak (EAST). In addition to providing effective ion charge Zeff as a routine diagnostic, this diagnostic can also be used to estimate other parameters. With the assumption that Zeff can be seen as constant across the radius and does not change significantly during steady state discharges, central electron temperature, averaged electron density, electron density profile, and plasma current density profile have been obtained based on the scaling of Zeff with electron density and the relations between Zeff and these parameters. The estimated results are in good coincidence with measured values, providing an effective and convenient method to estimate other plasma parameters.

  11. Badhwar-O'Neil 2007 Galactic Cosmic Ray (GCR) Model Using Advanced Composition Explorer (ACE) Measurements for Solar Cycle 23

    NASA Technical Reports Server (NTRS)

    ONeill, P. M.

    2007-01-01

    Advanced Composition Explorer (ACE) satellite measurements of the galactic cosmic ray flux and correlation with the Climax Neutron Monitor count over Solar Cycle 23 are used to update the Badhwar O'Neill Galactic Cosmic Ray (GCR) model.

  12. Measures of Adequacy for Library Collections in Australian Colleges of Advanced Education. Report of a Research Project Conducted on Behalf of the Commission on Advanced Education. Volume 2.

    ERIC Educational Resources Information Center

    Wainwright, E. J.; Dean, J. E.

    This volume presents an extensive review of the literature relating to collection development in tertiary institution libraries, a bibliography, and appendices for the main report of "Measures of Adequacy for Library Collections in Australian Colleges of Advanced Education" (IR 004 761). The literature review includes sections on principles of…

  13. Measured and predicted rotor performance for the SERI advanced wind turbine blades

    NASA Astrophysics Data System (ADS)

    Tangler, J.; Smith, B.; Kelley, N.; Jager, D.

    1992-02-01

    Measured and predicted rotor performance for the Solar Energy Research Institute (SERI) advanced wind turbine blades were compared to assess the accuracy of predictions and to identify the sources of error affecting both predictions and measurements. An awareness of these sources of error contributes to improved prediction and measurement methods that will ultimately benefit future rotor design efforts. Propeller/vane anemometers were found to underestimate the wind speed in turbulent environments such as the San Gorgonio Pass wind farm area. Using sonic or cup anemometers, good agreement was achieved between predicted and measured power output for wind speeds up to 8 m/sec. At higher wind speeds an optimistic predicted power output and the occurrence of peak power at wind speeds lower than measurements resulted from the omission of turbulence and yaw error. In addition, accurate two-dimensional (2-D) airfoil data prior to stall and a post stall airfoil data synthesization method that reflects three-dimensional (3-D) effects were found to be essential for accurate performance prediction.

  14. Measurements of the subcriticality using advanced technique of shooting source during operation of NPP reactors

    SciTech Connect

    Lebedev, G. V. Petrov, V. V.; Bobylyov, V. T.; Butov, R. I.; Zhukov, A. M.; Sladkov, A. A.

    2014-12-15

    According to the rules of nuclear safety, the measurements of the subcriticality of reactors should be carried out in the process of performing nuclear hazardous operations. An advanced technique of shooting source of neutrons is proposed to meet this requirement. As such a source, a pulsed neutron source (PNS) is used. In order to realize this technique, it is recommended to enable a PNS with a frequency of 1–20 Hz. The PNS is stopped after achieving a steady-state (on average) number of neutrons in the reactor volume. The change in the number of neutrons in the reactor volume is measured in time with an interval of discreteness of ∼0.1 s. The results of these measurements with the application of a system of point-kinetics equations are used in order to calculate the sought subcriticality. The basic idea of the proposed technique used to measure the subcriticality is elaborated in a series of experiments on the Kvant assembly. The conditions which should be implemented in order to obtain a positive result of measurements are formulated. A block diagram of the basic version of the experimental setup is presented, whose main element is a pulsed neutron generator.

  15. Measurements of the subcriticality using advanced technique of shooting source during operation of NPP reactors

    NASA Astrophysics Data System (ADS)

    Lebedev, G. V.; Petrov, V. V.; Bobylyov, V. T.; Butov, R. I.; Zhukov, A. M.; Sladkov, A. A.

    2014-12-01

    According to the rules of nuclear safety, the measurements of the subcriticality of reactors should be carried out in the process of performing nuclear hazardous operations. An advanced technique of shooting source of neutrons is proposed to meet this requirement. As such a source, a pulsed neutron source (PNS) is used. In order to realize this technique, it is recommended to enable a PNS with a frequency of 1-20 Hz. The PNS is stopped after achieving a steady-state (on average) number of neutrons in the reactor volume. The change in the number of neutrons in the reactor volume is measured in time with an interval of discreteness of ˜0.1 s. The results of these measurements with the application of a system of point-kinetics equations are used in order to calculate the sought subcriticality. The basic idea of the proposed technique used to measure the subcriticality is elaborated in a series of experiments on the Kvant assembly. The conditions which should be implemented in order to obtain a positive result of measurements are formulated. A block diagram of the basic version of the experimental setup is presented, whose main element is a pulsed neutron generator.

  16. The aerosol impact on ice clouds and precipitation

    NASA Astrophysics Data System (ADS)

    Jiang, Jonathan; Su, Hui; Schoeberl, Mark; Massie, Steven; Colarco, Peter; Platnick, Steven

    Aerosol-cloud-precipitation interactions are a very challenging problem in climate research and model predictions. The magnitude and mechanisms of aerosol impacts on cloud properties (e.g. particle radii), and the resulting influence on precipitation are poorly known, primarily due to the lack of accurate global scale observations. The aerosol impact on ice clouds is especially lacking. New data from NASA's satellites, particularly from the "A-train constellation", create a new opportunity to advance understanding of aerosol-cloud-precipitation interactions. In this study we analyze nearly-simultaneous measurements of clouds and pollutants along A- train tracks. In particular, Aura MLS measured CO at 215 hPa is used together with ice water content(IWC) observed by MLS to classify cirrus clouds as "clean" or "polluted". We analyze Aqua MODIS cloud particle radii and TRMM precipitation to investigate how pollution may change precipitation, cloud ice and their correlations. Aerosol optical depth data from MODIS and CALIPSO are also used in our study. Analysis results for South America are presented. We find evidence of suppressed precipitation and reduced ice particle radii associated with the polluted clouds during the dry bio-mass burning season, in which there is a strong correlation between the observed CO and aerosol, indicating microphysical influence of aerosols on ice clouds. In contrast, there is neither significant changes in precipitation nor in ice particle size associated with the CO-polluted clouds during the wet rainy season, in which the observed CO is not well-correlated with aerosol.

  17. Passive microwave precipitation detection biases: Relationship to cloud morphology

    NASA Astrophysics Data System (ADS)

    Marter, R. E.; Rapp, A. D.

    2015-12-01

    Accurate measurement of the Earth's hydrologic cycle requires a more precise understanding of precipitation accumulation and intensity on a global scale. While there is a long record of passive microwave satellite measurements, passive microwave rainfall retrievals often fail to detect light precipitation or have light rain intensity biases because they cannot differentiate between emission from cloud and rain water. Previous studies have shown that AMSR-E significantly underestimates rainfall occurrence and volume compared to CloudSat. This underestimation totals just below 0.6 mm/day quasi-globally (60S-60N), but there are larger regional variations related to the dominant cloud regime. This study aims to use Moderate Resolution Imaging Spectroradiometer (MODIS) and the 94-GHz CloudSat Cloud Profiling Radar (CPR), which has a high sensitivity to light rain, with the Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E) observations, to help better characterize the properties of clouds that lead to passive microwave rainfall detection biases. CPR cloud and precipitation retrievals. AMSR-E Level-2B Goddard Profiling 2010 Algorithm (GPROF 2010) rainfall retrievals, and MODIS cloud properties were collocated and analyzed for 2008. Results are consistent with past studies and show large passive microwave precipitation detection biases compared to CloudSat in stratocumulus and shallow cumulus regimes. A preliminary examination of cases where AMSR-E failed to detect precipitation detected by CloudSat shows that over 50% of missed warm precipitation occurs in clouds with top heights below 2 km. MODIS cloud microphysical and macrophysical properties, such as optical thickness, particle effective radius, and liquid water path will be analyzed when precipitation is detected by CloudSat and missed by AMSR-E. The overall goal is to understand how cloud morphology relates to detection biases.

  18. Precipitation Indices Low Countries

    NASA Astrophysics Data System (ADS)

    van Engelen, A. F. V.; Ynsen, F.; Buisman, J.; van der Schrier, G.

    2009-09-01

    Since 1995, KNMI published a series of books(1), presenting an annual reconstruction of weather and climate in the Low Countries, covering the period AD 763-present, or roughly, the last millennium. The reconstructions are based on the interpretation of documentary sources predominantly and comparison with other proxies and instrumental observations. The series also comprises a number of classifications. Amongst them annual classifications for winter and summer temperature and for winter and summer dryness-wetness. The classification of temperature have been reworked into peer reviewed (2) series (AD 1000-present) of seasonal temperatures and temperature indices, the so called LCT (Low Countries Temperature) series, now incorporated in the Millennium databases. Recently we started a study to convert the dryness-wetness classifications into a series of precipitation; the so called LCP (Low Countries Precipitation) series. A brief outline is given here of the applied methodology and preliminary results. The WMO definition for meteorological drought has been followed being that a period is called wet respectively dry when the amount of precipitation is considerable more respectively less than usual (normal). To gain a more quantitative insight for four locations, geographically spread over the Low Countries area (De Bilt, Vlissingen, Maastricht and Uccle), we analysed the statistics of daily precipitation series, covering the period 1900-present. This brought us to the following definition, valid for the Low Countries: A period is considered as (very) dry respectively (very) wet if over a continuous period of at least 60 days (~two months) cq 90 days (~three months) on at least two out of the four locations 50% less resp. 50% more than the normal amount for the location (based on the 1961-1990 normal period) has been measured. This results into the following classification into five drought classes hat could be applied to non instrumental observations: Very wet period

  19. Advancing the science of measurement of diagnostic errors in healthcare: the Safer Dx framework

    PubMed Central

    Singh, Hardeep; Sittig, Dean F

    2015-01-01

    Diagnostic errors are major contributors to harmful patient outcomes, yet they remain a relatively understudied and unmeasured area of patient safety. Although they are estimated to affect about 12 million Americans each year in ambulatory care settings alone, both the conceptual and pragmatic scientific foundation for their measurement is under-developed. Health care organizations do not have the tools and strategies to measure diagnostic safety and most have not integrated diagnostic error into their existing patient safety programs. Further progress toward reducing diagnostic errors will hinge on our ability to overcome measurement-related challenges. In order to lay a robust groundwork for measurement and monitoring techniques to ensure diagnostic safety, we recently developed a multifaceted framework to advance the science of measuring diagnostic errors (The Safer Dx framework). In this paper, we describe how the framework serves as a conceptual foundation for system-wide safety measurement, monitoring and improvement of diagnostic error. The framework accounts for the complex adaptive sociotechnical system in which diagnosis takes place (the structure), the distributed process dimensions in which diagnoses evolve beyond the doctor's visit (the process) and the outcomes of a correct and timely “safe diagnosis” as well as patient and health care outcomes (the outcomes). We posit that the Safer Dx framework can be used by a variety of stakeholders including researchers, clinicians, health care organizations and policymakers, to stimulate both retrospective and more proactive measurement of diagnostic errors. The feedback and learning that would result will help develop subsequent interventions that lead to safer diagnosis, improved value of health care delivery and improved patient outcomes. PMID:25589094

  20. Evaluation of precipitation from the ERA-40, NCEP-1, and NCEP-2 Reanalyses and CMAP-1, CMAP-2, and GPCP-2 with ground-based measurements in China

    NASA Astrophysics Data System (ADS)

    Ma, Lijuan; Zhang, Tingjun; Frauenfeld, Oliver W.; Ye, Baisheng; Yang, Daqing; Qin, Dahe

    2009-05-01

    We assess the correspondence between precipitation products from atmospheric reanalyses (ERA-40, NCEP-1, and NCEP-2), the Climate Prediction Center (CPC) Merged Analyses of Precipitation (CMAP-1 and CMAP-2), and the Global Precipitation Climatology Project Version 2 (GPCP-2) with adjusted observational precipitation (AOP) from China for 1979-2001 and also for ERA-40 and NCEP-1 over 1958-1978. In general, we conclude that CMAP-1 and GPCP-2 agree more closely with AOP than the reanalysis products do, although ERA-40 data agree more closely with AOP than NCEP data. The percentages of precipitation differences (PPDs) across China between annual ERA-40, NCEP-1, NCEP-2, CMAP-1, CMAP-2, and GPCP-2 data and AOP are -12, 22, 14, -8, -7, and -15%, respectively, for 1979-2001. Although relatively small biases are evident for China as a whole, maximum PPDs, usually occurring around the Qinghai-Tibetan Plateau, can exceed 1000%, indicating a strong terrain dependence of gridded precipitation data. GPCP-2, although characterized by greater underestimation for most of China compared with CMAP-1, exhibits a smaller biases range and hence may be better than CMAP-1. Compared with the NCEP-1 system, NCEP-2 represents an improvement as NCEP-2 precipitation agrees more closely with AOP than NCEP-1 data. However, the coherence of NCEP-2 precipitation needs further improvement. In addition, we find worse consistency and accuracy and larger positive biases in some parts of China for CMAP-2 versus CMAP-1, illustrating an advantage of including reanalysis data in CMAP, as CMAP-1 does. CMAP-1 could be further improved if they used the more skillful ERA-40 precipitation instead of the NCEP/NCAR data.

  1. Advances in High-Frequency Liquid Water Isotope Analyzer for Hydrological Measurements in the Field

    NASA Astrophysics Data System (ADS)

    Owano, T. G.; Berman, E. S.; Leen, J.; Baer, D. S.

    2010-12-01

    Measurements of the stable isotope ratios of liquid water (δ2H and δ18O) allow determination of water flowpaths, residence times in catchments, and groundwater migration. In the past, discrete water samples have been collected and transported to an IRMS lab for isotope characterization. Due to the expense and labor associated with such sampling, isotope studies have thus been generally limited in scope and in temporal resolution. We report on the recent development of an improved field-portable Liquid Water Isotope Analyzer (LWIA) that accurately quantifies δ2H and δ18O of different natural water sources (e.g., rain, snow, streams and groundwater) at the unprecedented rate of over 1000 injections per day, which yields 166 total unknown and reference samples per day (132 unknown samples per day), or 1 measurement of an unknown sample every 10 minutes (with 6 injections per measurement). This fast time response provides isotope hydrologists with the capability to study dynamic changes in δ values quickly (minutes) and over long time scales (weeks, months), thus enabling studies of mixing dynamics in snowmelt, canopy throughfall, stream mixing, and allows for individual precipitation events to be independently studied. In addition, the new LWIA includes post-analysis software that significantly accelerates data processing and provides data visualization and diagnostics. This software automatically processes sample measurements recorded by the LWIA to calibrated delta values. In addition, new software tools allow post-processing of every injected sample to generate a spectral interference metric, which quantifies the likelihood of interferences from contaminants and can then generate a flag to notify the user when interfering contamination is likely. This technology detects both narrow and broadband absorption spectral interferences that may be generated by water samples containing contaminants such as methanol, ethanol, and others. The ability of the LWIA to

  2. Advanced turboprop wing installation effects measured by unsteady blade pressure and noise

    NASA Technical Reports Server (NTRS)

    Heidelberg, Laurence J.; Woodward, Richard P.

    1987-01-01

    A single rotation model propeller (SR-7A) was tested at simulated takeoff/approach conditions (Mach 0.2), in the NASA Lewis 9- by 15-Ft Anechoic Wind Tunnel. Both unsteady blade surface pressures and noise measurements were made for a tractor configuration with propeller/straight wing and propeller alone configurations. The angle between the wing chord and propeller axis (droop angle) was varied along with the wing angle of attack to determine the effects on noise and unsteady loading. A method was developed that uses unsteady blade pressure measurements to provide a quantitative indication of propeller inflow conditions, at least for a uniform (across the propeller disk) inflow angle. The wing installation caused a nearly uniform upwash at the propeller inlet as evidenced by the domination of the pressure spectra by the first shaft order. This inflow angle increased at a rate of almost 150 percent of that of the wing angle-of-attack for a propeller-wing spacing of 0.54 wing chords at a constant droop angle. The flyover noise, as measured by the maximum blade passing frequency level, correlates closely with the propeller inflow angle (approx. 0.6 dB per degree of inflow angle) for all droop angles and wing angles of attack tested, including the propeller alone data. Large changes in the unsteady pressure responses on the suction surface of the blade were observed as the advance ratio was varied. The presence of a leading edge vortex may explain this behavior since changes in the location of this vortex would change with loading (advance ratio).

  3. MPACT FY2011 Advanced Time-Correlated Measurement Research at INL

    SciTech Connect

    D. L. Chichester; S. A. Pozzi; J. L. Dolan; M. Flaska; S. M. Watson

    2011-09-01

    Simulations and experiments have been carried out to investigate advanced time-correlated measurement methods for characterizing and assaying nuclear material for safeguarding the nuclear fuel cycle. These activities are part of a project studying advanced instrumentation techniques in support of the U.S. Department of Energy's Fuel Cycle Research and Development program and its Materials Protection, Accounting, and Control Technologies (MPACT) program. For fiscal year 2011 work focused on examining the practical experimental aspects of using a time-tagged, associated-particle electronic neutron generator for interrogating low-enrichment uranium in combination with steady-state interrogation using a moderated 241Am-Li neutron source. Simulation work for the project involved the use of the MCNP-PoliMi Monte Carlo simulation tool to determine the relative strength and the time-of-flight energy spectra of different sample materials under irradiation. Work also took place to develop a post-processor parser code to extract comparable data from the MCNP5&6 codes. Experiments took place using a commercial deuterium-tritium associated-particle electronic neutron generator to irradiate a number of uranium-bearing material samples. Time-correlated measurements of neutron and photon signatures of these measurements were made using five liquid scintillator detectors in a novel array, using high-speed waveform digitizers for data collection. This report summarizes the experiments that took place in FY2011, presents preliminary analyses that have been carried out to date for a subpart of these experiments, and describes future activities planned in this area. The report also describes support Idaho National Laboratory gave to Oak Ridge National Laboratory in 2011 to facilitate 2-dimensional imagery of mixed-oxide fuel pins for safeguards applications as a part of the MPACT program.

  4. Robust quantitative parameter estimation by advanced CMP measurements for vadose zone hydrological studies

    NASA Astrophysics Data System (ADS)

    Koyama, C.; Wang, H.; Khuut, T.; Kawai, T.; Sato, M.

    2015-12-01

    Soil moisture plays a crucial role in the understanding of processes in the vadose zone hydrology. In the last two decades ground penetrating radar (GPR) has been widely discussed has nondestructive measurement technique for soil moisture data. Especially the common mid-point (CMP) technique, which has been used in both seismic and GPR surveys to investigate the vertical velocity profiles, has a very high potential for quantitaive obervsations from the root zone to the ground water aquifer. However, the use is still rather limited today and algorithms for robust quantitative paramter estimation are lacking. In this study we develop an advanced processing scheme for operational soil moisture reetrieval at various depth. Using improved signal processing, together with a semblance - non-normalized cross-correlation sum combined stacking approach and the Dix formula, the interval velocities for multiple soil layers are obtained from the RMS velocities allowing for more accurate estimation of the permittivity at the reflecting point. Where the presence of a water saturated layer, like a groundwater aquifer, can be easily identified by its RMS velocity due to the high contrast compared to the unsaturated zone. By using a new semi-automated measurement technique the acquisition time for a full CMP gather with 1 cm intervals along a 10 m profile can be reduced significantly to under 2 minutes. The method is tested and validated under laboratory conditions in a sand-pit as well as on agricultural fields and beach sand in the Sendai city area. Comparison between CMP estimates and TDR measurements yield a very good agreement with RMSE of 1.5 Vol.-%. The accuracy of depth estimation is validated with errors smaller than 2%. Finally, we demonstrate application of the method in a test site in semi-arid Mongolia, namely the Orkhon River catchment in Bulgan, using commercial 100 MHz and 500 MHz RAMAC GPR antennas. The results demonstrate the suitability of the proposed method for

  5. Advancements in Root Growth Measurement Technologies and Observation Capabilities for Container-Grown Plants.

    PubMed

    Judd, Lesley A; Jackson, Brian E; Fonteno, William C

    2015-07-03

    The study, characterization, observation, and quantification of plant root growth and root systems (Rhizometrics) has been and remains an important area of research in all disciplines of plant science. In the horticultural industry, a large portion of the crops grown annually are grown in pot culture. Root growth is a critical component in overall plant performance during production in containers, and therefore it is important to understand the factors that influence and/or possible enhance it. Quantifying root growth has varied over the last several decades with each method of quantification changing in its reliability of measurement and variation among the results. Methods such as root drawings, pin boards, rhizotrons, and minirhizotrons initiated the aptitude to measure roots with field crops, and have been expanded to container-grown plants. However, many of the published research methods are monotonous and time-consuming. More recently, computer programs have increased in use as technology advances and measuring characteristics of root growth becomes easier. These programs are instrumental in analyzing various root growth characteristics, from root diameter and length of individual roots to branching angle and topological depth of the root architecture. This review delves into the expanding technologies involved with expertly measuring root growth of plants in containers, and the advantages and disadvantages that remain.

  6. Advancements in Root Growth Measurement Technologies and Observation Capabilities for Container-Grown Plants

    PubMed Central

    Judd, Lesley A.; Jackson, Brian E.; Fonteno, William C.

    2015-01-01

    The study, characterization, observation, and quantification of plant root growth and root systems (Rhizometrics) has been and remains an important area of research in all disciplines of plant science. In the horticultural industry, a large portion of the crops grown annually are grown in pot culture. Root growth is a critical component in overall plant performance during production in containers, and therefore it is important to understand the factors that influence and/or possible enhance it. Quantifying root growth has varied over the last several decades with each method of quantification changing in its reliability of measurement and variation among the results. Methods such as root drawings, pin boards, rhizotrons, and minirhizotrons initiated the aptitude to measure roots with field crops, and have been expanded to container-grown plants. However, many of the published research methods are monotonous and time-consuming. More recently, computer programs have increased in use as technology advances and measuring characteristics of root growth becomes easier. These programs are instrumental in analyzing various root growth characteristics, from root diameter and length of individual roots to branching angle and topological depth of the root architecture. This review delves into the expanding technologies involved with expertly measuring root growth of plants in containers, and the advantages and disadvantages that remain. PMID:27135334

  7. Reflectivity and scattering measurements of an Advanced X-ray Astrophysics Facility test coating sample

    NASA Astrophysics Data System (ADS)

    Bixler, J. V.; Mauche, C. W.; Hailey, C. J.; Madison, L.

    1995-10-01

    Reflectivity and scattering profile measurements were made on a gold-coated witness sample produced to evaluate mirror coatings for the Advanced X-ray Astrophysics Facility program. Reflectivity measurements were made at Al K, Ti K, and Cu K energies as a function of incident graze angle. The results are fit to a model that includes the effects of roughness, particulate and organic contamination layers, and gold-coating density. Reflectivities are close to theoretical, with the difference being well accounted for by 4.1 A of roughness at spatial frequencies above 4 mu m-1, a gold-coating density equal to 0.98 bulk, and a surface contaminant layer 27 A thick. Scattering measurements extending to +/-35 arcmin of the line center were obtained by the use of Al K x rays and incidence angles from 0.75 deg to 3 deg The scattering profiles imply a power spectral density of surface-scattering frequencies that follows a power law with an index of -1.0 and a total surface roughness for the spatial frequency band between 0.05 mu m-1 and 4 mu m -1 of 3.3 A. Combining the roughnesses derived from both the reflectivity and scattering measurements yields a total roughness of 5.3 A for scattering frequencies between 0.05 mu m-1 and 15,000 mu m-1.

  8. PRECIPITATION OF PLUTONOUS PEROXIDE

    DOEpatents

    Barrick, J.G.; Manion, J.P.

    1961-08-15

    A precipitat