Science.gov

Sample records for impact instrument calibration

  1. Invited Article: Deep Impact instrument calibration.

    PubMed

    Klaasen, Kenneth P; A'Hearn, Michael F; Baca, Michael; Delamere, Alan; Desnoyer, Mark; Farnham, Tony; Groussin, Olivier; Hampton, Donald; Ipatov, Sergei; Li, Jianyang; Lisse, Carey; Mastrodemos, Nickolaos; McLaughlin, Stephanie; Sunshine, Jessica; Thomas, Peter; Wellnitz, Dennis

    2008-09-01

    Calibration of NASA's Deep Impact spacecraft instruments allows reliable scientific interpretation of the images and spectra returned from comet Tempel 1. Calibrations of the four onboard remote sensing imaging instruments have been performed in the areas of geometric calibration, spatial resolution, spectral resolution, and radiometric response. Error sources such as noise (random, coherent, encoding, data compression), detector readout artifacts, scattered light, and radiation interactions have been quantified. The point spread functions (PSFs) of the medium resolution instrument and its twin impactor targeting sensor are near the theoretical minimum [ approximately 1.7 pixels full width at half maximum (FWHM)]. However, the high resolution instrument camera was found to be out of focus with a PSF FWHM of approximately 9 pixels. The charge coupled device (CCD) read noise is approximately 1 DN. Electrical cross-talk between the CCD detector quadrants is correctable to <2 DN. The IR spectrometer response nonlinearity is correctable to approximately 1%. Spectrometer read noise is approximately 2 DN. The variation in zero-exposure signal level with time and spectrometer temperature is not fully characterized; currently corrections are good to approximately 10 DN at best. Wavelength mapping onto the detector is known within 1 pixel; spectral lines have a FWHM of approximately 2 pixels. About 1% of the IR detector pixels behave badly and remain uncalibrated. The spectrometer exhibits a faint ghost image from reflection off a beamsplitter. Instrument absolute radiometric calibration accuracies were determined generally to <10% using star imaging. Flat-field calibration reduces pixel-to-pixel response differences to approximately 0.5% for the cameras and <2% for the spectrometer. A standard calibration image processing pipeline is used to produce archival image files for analysis by researchers.

  2. Rotary mode system initial instrument calibration

    SciTech Connect

    Johns, B.R.

    1994-10-01

    The attached report contains the vendor calibration procedures used for the initial instrument calibration of the rotary core sampling equipment. The procedures are from approved vendor information files.

  3. Calibration facility for environment dosimetry instruments

    NASA Astrophysics Data System (ADS)

    Bercea, Sorin; Celarel, Aurelia; Cenusa, Constantin

    2013-12-01

    In the last ten years, the nuclear activities, as well as the major nuclear events (see Fukushima accident) had an increasing impact on the environment, merely by contamination with radioactive materials. The most conferment way to quickly identify the presence of some radioactive elements in the environment, is to measure the dose-equivalent rate H. In this situation, information concerning the values of H due only to the natural radiation background must exist. Usually, the values of H due to the natural radiation background, are very low (˜10-9 - 10-8 Sv/h). A correct measurement of H in this range involve a performing calibration of the measuring instruments in the measuring range corresponding to the natural radiation background lead to important problems due to the presence of the natural background itself the best way to overlap this difficulty is to set up the calibration stand in an area with very low natural radiation background. In Romania, we identified an area with such special conditions at 200 m dept, in a salt mine. This paper deals with the necessary requirements for such a calibration facility, as well as with the calibration stand itself. The paper includes also, a description of the calibration stand (and images) as well as the radiological and metrological parameters. This calibration facilities for environment dosimetry is one of the few laboratories in this field in Europe.

  4. Spacecraft instrument calibration and stability

    NASA Technical Reports Server (NTRS)

    Gille, J. C.; Feldman, P.; Hudson, R.; Lean, J.; Madden, R.; Mcmaster, L.; Mount, G.; Rottman, G.; Simon, P. C.

    1989-01-01

    The following topics are covered: instrument degradation; the Solar Backscatter Ultraviolet (SBUV) Experiment; the Total Ozone Mapping Spectrometer (TOMS); the Stratospheric Aerosol and Gas Experiment 1 (SAGE-1) and SAGE-2 instruments; the Solar Mesosphere Explorer (SME) UV ozone and near infrared airglow instruments; and the Limb Infrared Monitor of the Stratosphere (LIMS).

  5. Calibration Changes in EUV Solar Satellite Instruments.

    PubMed

    Reeves, E M; Parkinson, W H

    1970-05-01

    This paper reviews the problem of absolute photometric calibration in the extreme uv range with particular reference to a solar satellite instrument. EUV transfer standards, the use of predispersing spectrometers, and polarization effects at near normal incidence are discussed. Changes in preflight calibration associated with the general problems of contamination are given as the background to the main discussion relating to changes in photometric calibration during orbital operation. Conclusions relating to adequate photometric measurements in orbit are drawn, with a short list of the "best" solar flux measurements for reference. Finally, the importance of rocket flights for photometric calibration of satellite instruments is indicated.

  6. Instrument Calibration and Certification Procedure

    SciTech Connect

    Davis, R. Wesley

    2016-05-31

    The Amptec 640SL-2 is a 4-wire Kelvin failsafe resistance meter, designed to reliably use very low-test currents for its resistance measurements. The 640SL-1 is a 2-wire version, designed to support customers using the Reynolds Industries type 311 connector. For both versions, a passive (analog) dual function DC Milliameter/Voltmeter allows the user to verify the actual 640SL output current level and the open circuit voltage on the test leads. This procedure includes tests of essential performance parameters. Any malfunction noticed during calibration, whether specifically tested for or not, shall be corrected before calibration continues or is completed.

  7. MODIS Instrument Operation and Calibration Improvements

    NASA Technical Reports Server (NTRS)

    Xiong, X.; Angal, A.; Madhavan, S.; Link, D.; Geng, X.; Wenny, B.; Wu, A.; Chen, H.; Salomonson, V.

    2014-01-01

    Terra and Aqua MODIS have successfully operated for over 14 and 12 years since their respective launches in 1999 and 2002. The MODIS on-orbit calibration is performed using a set of on-board calibrators, which include a solar diffuser for calibrating the reflective solar bands (RSB) and a blackbody for the thermal emissive bands (TEB). On-orbit changes in the sensor responses as well as key performance parameters are monitored using the measurements of these on-board calibrators. This paper provides an overview of MODIS on-orbit operation and calibration activities, and instrument long-term performance. It presents a brief summary of the calibration enhancements made in the latest MODIS data collection 6 (C6). Future improvements in the MODIS calibration and their potential applications to the S-NPP VIIRS are also discussed.

  8. Calibration of the COBE FIRAS instrument

    NASA Technical Reports Server (NTRS)

    Fixsen, D. J.; Cheng, E. S.; Cottingham, D. A.; Eplee, R. E., Jr.; Hewagama, T.; Isaacman, R. B.; Jensen, K. A.; Mather, J. C.; Massa, D. L.; Meyer, S. S.

    1994-01-01

    The Far-Infrared Absolute Spectrophotometer (FIRAS) instrument on the Cosmic Background Explorer (COBE) satellite was designed to accurately measure the spectrum of the cosmic microwave background radiation (CMBR) in the frequency range 1-95/cm with an angular resolution of 7 deg. We describe the calibration of this instrument, including the method of obtaining calibration data, reduction of data, the instrument model, fitting the model to the calibration data, and application of the resulting model solution to sky observations. The instrument model fits well for calibration data that resemble sky condition. The method of propagating detector noise through the calibration process to yield a covariance matrix of the calibrated sky data is described. The final uncertainties are variable both in frequency and position, but for a typical calibrated sky 2.6 deg square pixel and 0.7/cm spectral element the random detector noise limit is of order of a few times 10(exp -7) ergs/sq cm/s/sr cm for 2-20/cm, and the difference between the sky and the best-fit cosmic blackbody can be measured with a gain uncertainty of less than 3%.

  9. HPS instrument calibration laboratory accreditation program

    SciTech Connect

    Masse, F.X; Eisenhower, E.H.; Swinth, K.L.

    1993-12-31

    The purpose of this paper is to provide an accurate overview of the development and structure of the program established by the Health Physics Society (HPS) for accrediting instrument calibration laboratories relative to their ability to accurately calibrate portable health physics instrumentation. The purpose of the program is to provide radiation protection professionals more meaningful direct and indirect access to the National Institute of Standards and Technology (NIST) national standards, thus introducing a means for improving the uniformity, accuracy, and quality of ionizing radiation field measurements. The process is designed to recognize and document the continuing capability of each accredited laboratory to accurately perform instrument calibration. There is no intent to monitor the laboratory to the extent that each calibration can be guaranteed by the program; this responsibility rests solely with the accredited laboratory.

  10. Uncertainty Analysis of Instrument Calibration and Application

    NASA Technical Reports Server (NTRS)

    Tripp, John S.; Tcheng, Ping

    1999-01-01

    Experimental aerodynamic researchers require estimated precision and bias uncertainties of measured physical quantities, typically at 95 percent confidence levels. Uncertainties of final computed aerodynamic parameters are obtained by propagation of individual measurement uncertainties through the defining functional expressions. In this paper, rigorous mathematical techniques are extended to determine precision and bias uncertainties of any instrument-sensor system. Through this analysis, instrument uncertainties determined through calibration are now expressed as functions of the corresponding measurement for linear and nonlinear univariate and multivariate processes. Treatment of correlated measurement precision error is developed. During laboratory calibration, calibration standard uncertainties are assumed to be an order of magnitude less than those of the instrument being calibrated. Often calibration standards do not satisfy this assumption. This paper applies rigorous statistical methods for inclusion of calibration standard uncertainty and covariance due to the order of their application. The effects of mathematical modeling error on calibration bias uncertainty are quantified. The effects of experimental design on uncertainty are analyzed. The importance of replication is emphasized, techniques for estimation of both bias and precision uncertainties using replication are developed. Statistical tests for stationarity of calibration parameters over time are obtained.

  11. 10 CFR 35.61 - Calibration of survey instruments.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Calibration of survey instruments. 35.61 Section 35.61... § 35.61 Calibration of survey instruments. (a) A licensee shall calibrate the survey instruments used... of calibration. (b) A licensee may not use survey instruments if the difference between the...

  12. Postlaunch calibration of spacecraft attitude instruments

    NASA Technical Reports Server (NTRS)

    Davis, W.; Hashmall, J.; Garrick, J.; Harman, R.

    1993-01-01

    The accuracy of both onboard and ground attitude determination can be significantly enhanced by calibrating spacecraft attitude instruments (sensors) after launch. Although attitude sensors are accurately calibrated before launch, the stresses of launch and the space environment inevitably cause changes in sensor parameters. During the mission, these parameters may continue to drift requiring repeated on-orbit calibrations. The goal of attitude sensor calibration is to reduce the systematic errors in the measurement models. There are two stages at which systematic errors may enter. The first occurs in the conversion of sensor output into an observation vector in the sensor frame. The second occurs in the transformation of the vector from the sensor frame to the spacecraft attitude reference frame. This paper presents postlaunch alignment and transfer function calibration of the attitude sensors for the Compton Gamma Ray Observatory (GRO), the Upper Atmosphere Research Satellite (UARS), and the Extreme Ultraviolet Explorer (EUVE).

  13. USE OF THE SDO POINTING CONTROLLERS FOR INSTRUMENT CALIBRATION MANEUVERS

    NASA Technical Reports Server (NTRS)

    Vess, Melissa F.; Starin, Scott R.; Morgenstern, Wendy M.

    2005-01-01

    During the science phase of the Solar Dynamics Observatory mission, the three science instruments require periodic instrument calibration maneuvers with a frequency of up to once per month. The command sequences for these maneuvers vary in length from a handful of steps to over 200 steps, and individual steps vary in size from 5 arcsec per step to 22.5 degrees per step. Early in the calibration maneuver development, it was determined that the original attitude sensor complement could not meet the knowledge requirements for the instrument calibration maneuvers in the event of a sensor failure. Because the mission must be single fault tolerant, an attitude determination trade study was undertaken to determine the impact of adding an additional attitude sensor versus developing alternative, potentially complex, methods of performing the maneuvers in the event of a sensor failure. To limit the impact to the science data capture budget, these instrument calibration maneuvers must be performed as quickly as possible while maintaining the tight pointing and knowledge required to obtain valid data during the calibration. To this end, the decision was made to adapt a linear pointing controller by adjusting gains and adding an attitude limiter so that it would be able to slew quickly and still achieve steady pointing once on target. During the analysis of this controller, questions arose about the stability of the controller during slewing maneuvers due to the combination of the integral gain, attitude limit, and actuator saturation. Analysis was performed and a method for disabling the integral action while slewing was incorporated to ensure stability. A high fidelity simulation is used to simulate the various instrument calibration maneuvers.

  14. Portable calibration instrument of hemodialysis unit

    NASA Astrophysics Data System (ADS)

    Jin, Liang-bing; Li, Dong-sheng; Chen, Ai-jun

    2013-01-01

    For the purpose of meeting the rapid development of blood purification in China, improve the level of blood purification treatment, and get rid of the plight of the foreign technology monopolization to promise patients' medical safety, a parameter-calibrator for the hemodialysis unit, which can detect simultaneously multi-parameter, is designed. The instrument includes a loop, which connects to the hemodialysis unit. Sensors are in the loop in series, so that the dialysis can flow through this loop and the sensors can acquisitive data of various parameters. In order to facilitate detection and carrying, the integrated circuit part modularly based on the ultralow-power microcontrollers,TI MSP430 is designed. High-performance and small-packaged components are used to establish a modular, high-precision, multi-functional, portable system. The functions and the key technical indexes of the instrument have reached the level of products abroad.

  15. New instrument calibration facility for the DOE Savannah River Site

    SciTech Connect

    Wilkie, W.H.; Polz, E.J.

    1993-12-31

    A new laboratory facility is being designed, constructed, and equipped at the Savannah River Site (SRS) as a fiscal year 1992 line item project. This facility will provide space and equipment for test, evaluation, repair, maintenance, and calibration of radiation monitoring instrumentation. The project will replace an obsolete facility and will allow implementation of program upgrades necessary to meet ANSI N323 requirements and National Voluntary Laboratory Accreditation Program (NVLAP) criteria for accreditation of federally owned secondary calibration laboratories. An outline of the project is presented including description, scope, cost, management organization, chronology, and current status. Selected design criteria and their impacts on the project are discussed. The upgraded SRS calibration program is described, and important features of the new facility and equipment that will accommodate this program are listed. The floor plan for the facility is shown, and equipment summaries and functional descriptions for each area are provided.

  16. Comparison of Two Methodologies for Calibrating Satellite Instruments in the Visible and Near Infrared

    NASA Technical Reports Server (NTRS)

    Barnes, Robert A.; Brown, Steven W.; Lykke, Keith R.; Guenther, Bruce; Xiong, Xiaoxiong (Jack); Butler, James J.

    2010-01-01

    Traditionally, satellite instruments that measure Earth-reflected solar radiation in the visible and near infrared wavelength regions have been calibrated for radiance response in a two-step method. In the first step, the spectral response of the instrument is determined using a nearly monochromatic light source, such a lamp-illuminated monochromator. Such sources only provide a relative spectral response (RSR) for the instrument, since they do not act as calibrated sources of light nor do they typically fill the field-of-view of the instrument. In the second step, the instrument views a calibrated source of broadband light, such as lamp-illuminated integrating sphere. In the traditional method, the RSR and the sphere spectral radiance are combined and, with the instrument's response, determine the absolute spectral radiance responsivity of the instrument. More recently, an absolute calibration system using widely tunable monochromatic laser systems has been developed, Using these sources, the absolute spectral responsivity (ASR) of an instrument can be determined on a wavelength-hy-wavelength basis. From these monochromatic ASRs. the responses of the instrument bands to broadband radiance sources can be calculated directly, eliminating the need for calibrated broadband light sources such as integrating spheres. Here we describe the laser-based calibration and the traditional broad-band source-based calibration of the NPP VIIRS sensor, and compare the derived calibration coefficients for the instrument. Finally, we evaluate the impact of the new calibration approach on the on-orbit performance of the sensor.

  17. Gaia astrometric instrument calibration and image processing

    NASA Astrophysics Data System (ADS)

    Castaneda, J.; Fabricius, C.; Portell, J.; Garralda, N.; González-Vidal, J. J.; Clotet, M.; Torra, J.

    2017-03-01

    The astrometric instrument calibration and image processing is an integral and critical part of the Gaia mission. The data processing starts with a preliminary treatment on daily basis of the most recent data received and continues with the execution of several processing chains included in a cyclic reduction system. The cyclic processing chains are reprocessing all the accumulated data again in each iteration, thus adding the latest measurements and recomputing the outputs to obtain better quality on their results. This cyclic processing lasts until the convergence of the results is achieved and the catalogue is consolidated and published periodically. In this paper we describe the core of the data processing which has made possible the first catalogue release from the Gaia mission.

  18. Instrument calibration architecture of Radar Imaging Satellite (RISAT-1)

    NASA Astrophysics Data System (ADS)

    Misra, T.; Bhan, R.; Putrevu, D.; Mehrotra, P.; Nandy, P. S.; Shukla, S. D.; Rao, C. V. N.; Dave, D. B.; Desai, N. M.

    2016-05-01

    Radar Imaging Satellite (RISAT-1) payload system is configured to perform self-calibration of transmit and receive paths before and after imaging sessions through a special instrument calibration technique. Instrument calibration architecture of RISAT-1 supported ground verification and validation of payload including active array antenna. During on-ground validation of 126 beams of active array antenna which needed precise calibration of boresight pointing, a unique method called "collimation coefficient error estimation" was utilized. This method of antenna calibration was supported by special hardware and software calibration architecture of RISAT-1. This paper concentrates on RISAT-1 hardware and software architecture which supports in-orbit and on-ground instrument calibration. Efforts are also put here to highlight use of special calibration scheme of RISAT-1 instrument to evaluate system response during ground verification and validation.

  19. Calibration and postlaunch performance of the Meteor 3/TOMS instrument

    SciTech Connect

    Jaross, G.; Krueger, A.; Cebula, R.P.; Seftor, C.; Hartmann, U.; Haring, R.; Burchfield, D. ||

    1995-02-01

    Prelaunch and postlaunch calibration results for the Meteor 3/total ozone mapping spectrometer (TOMS) instrument are presented here. Ozone amounts are retrieved from measurements of Earth albedo in the 312- to 380-nm range. The accuracy of albedo measurements is primarily tied to knowledge of the reflective properties of diffusers used in the calibrations and to the instrument`s wavelength selection. These and other important prelaunch calibrations are presented. Their estimated accuracies are within the bounds necessary to determine column ozone to better than 1%. However, postlaunch validation results indicate some prelaunch calibration uncertainties may be larger than originally estimated. Instrument calibrations have been maintained postlaunch to within a corresponding 1% error in retrieved ozone. Onboard calibrations, including wavelength monitoring and a three-diffuser solar measurement system, are described and specific results are presented. Other issues, such as the effects of orbital precession on calibration and recent chopper wheel malfunctions, are also discussed.

  20. Calibrating coastal GNSS-R instrumentation

    NASA Astrophysics Data System (ADS)

    Löfgren, Johan; Haas, Rüdiger; Hobiger, Thomas

    2015-04-01

    Since 2011, a GNSS-R (Global Navigation Satellite System - Reflectometry) instrument for local sea level observations is operated at the Onsala Space Observatory (Löfgren et al., 2011). The Onsala Space Observatory is the Swedish geodetic fundamental station, located at the Swedish West Coast, and contributes to the Global Geodetic Observing System (GGOS) by a variety of geodetic and geophysical observations. The Onsala GNSS-R instrumentation consists of two GNSS antennas that are mounted back-to-back on a bar at the coastline extending over the open sea in southward direction. One of the antennas is upward oriented and receives the direct satellite signals, while the other antenna is downward oriented and receives the satellite signals that reflect off the sea surface. The antennas are connected to a commercial GNSS receiver each and data are recorded with sampling rate of up to 20 Hz. Satellite signals of several GNSS are received and are analysed with various different analysis strategies to provide sea level results with different temporal resolution and precision (Larson et al., 2013; Löfgren and Haas, 2014). Since the instrumentation uses GNSS signals, it is possible to derive both local sea level, i.e. relative to the coast, and absolute sea level, i.e. relative to the geocentre as realised by the GNSS. The bar carrying the two antennas can be placed in 10 different vertical positions covering a height difference of 2.5 m between the highest and lowest position. We present results from a calibration campaign of the Onsala GNSS-R instrumentation performed in 2014. During this several weeks long campaign the antennas were placed at different vertical positions for several days at each position. The recorded data are analysed with the different analysis strategies, and the results are compared to the results derived from the co-located tide gauge equipment. References - Löfgren J, Haas R, Scherneck H-G (2011). Three months of local sea-level derived from

  1. Brookhaven National Laboratory meteorological services instrument calibration plan and procedures

    SciTech Connect

    Heiser .

    2013-02-16

    This document describes the Meteorological Services (Met Services) Calibration and Maintenance Schedule and Procedures, The purpose is to establish the frequency and mechanism for the calibration and maintenance of the network of meteorological instrumentation operated by Met Services. The goal is to maintain the network in a manner that will result in accurate, precise and reliable readings from the instrumentation.

  2. Geometric calibration of rotational kaleidoscopic instrument

    NASA Astrophysics Data System (ADS)

    Havran, Vlastimil; Němcová, Šárka; Čáp, Jiří; Hošek, Jan; Bittner, Jiří; Macúchová, Karolina

    2016-11-01

    The measurement of spatially varying surface reflectance is required for faithful reproduction of real world to allow for predictive look of computer generated images. One such proposed method uses a rotational kaleidoscopic imaging, where illumination and imaging paths are realized by subimages on kaleidoscopic mirrors and illumination is carried out by a DLP projector. We describe a novel geometric calibration method for a rotational kaleidoscope that is necessary to get aligned and accurate data from measurement. The calibration has two stages. The first stage mechanically adjusts the camera, the projector, and the autocollimator against the kaleidoscope mirrors. The second stage is based on the software. By random perturbation of camera and projector in corresponding mathematical model of the kaleidoscope we estimate better real positions of camera and projector in a physical setup, comparing the computed images from the software simulator and the acquired images from the physical setup.

  3. Proceedings of the workshop on radiation survey instruments and calibrations

    SciTech Connect

    Selby, J.M.; Swinth, K.L.; Vallario, E.J.; Murphy, B.L.

    1985-11-01

    The workshop was held to discuss two topics: first, a performance standard for radiation survey instruments and the potential for a testing program based on that standard; and second, a system of secondary standards laboratories to provide instrument calibrations and related services. Separate abstracts have been prepared for the individual presentations. (ACR)

  4. Comparison of two methodologies for calibrating satellite instruments in the visible and near infrared

    PubMed Central

    Barnes, Robert A.; Brown, Steven W.; Lykke, Keith R.; Guenther, Bruce; Butler, James J.; Schwarting, Thomas; Moyer, David; Turpie, Kevin; DeLuccia, Frank; Moeller, Christopher

    2016-01-01

    Traditionally, satellite instruments that measure Earth-reflected solar radiation in the visible and near infrared wavelength regions have been calibrated for radiance responsivity in a two-step method. In the first step, the relative spectral response (RSR) of the instrument is determined using a nearly monochromatic light source such as a lamp-illuminated monochromator. These sources do not typically fill the field-of-view of the instrument nor act as calibrated sources of light. Consequently, they only provide a relative (not absolute) spectral response for the instrument. In the second step, the instrument views a calibrated source of broadband light, such as a lamp-illuminated integrating sphere. The RSR and the sphere absolute spectral radiance are combined to determine the absolute spectral radiance responsivity (ASR) of the instrument. More recently, a full-aperture absolute calibration approach using widely tunable monochromatic lasers has been developed. Using these sources, the ASR of an instrument can be determined in a single step on a wavelength-by-wavelength basis. From these monochromatic ASRs, the responses of the instrument bands to broadband radiance sources can be calculated directly, eliminating the need for calibrated broadband light sources such as integrating spheres. In this work, the traditional broadband source-based calibration of the Suomi National Preparatory Project (SNPP) Visible Infrared Imaging Radiometer Suite (VIIRS) sensor is compared with the laser-based calibration of the sensor. Finally, the impact of the new full-aperture laser-based calibration approach on the on-orbit performance of the sensor is considered. PMID:26836861

  5. Comparison of Two Methodologies for Calibrating Satellite Instruments in the Visible and Near-Infrared

    NASA Technical Reports Server (NTRS)

    Barnes, Robert A.; Brown, Steven W.; Lykke, Keith R.; Guenther, Bruce; Butler, James J.; Schwarting, Thomas; Turpie, Kevin; Moyer, David; DeLuccia, Frank; Moeller, Christopher

    2015-01-01

    Traditionally, satellite instruments that measure Earth-reflected solar radiation in the visible and near infrared wavelength regions have been calibrated for radiance responsivity in a two-step method. In the first step, the relative spectral response (RSR) of the instrument is determined using a nearly monochromatic light source such as a lamp-illuminated monochromator. These sources do not typically fill the field-of-view of the instrument nor act as calibrated sources of light. Consequently, they only provide a relative (not absolute) spectral response for the instrument. In the second step, the instrument views a calibrated source of broadband light, such as a lamp-illuminated integrating sphere. The RSR and the sphere absolute spectral radiance are combined to determine the absolute spectral radiance responsivity (ASR) of the instrument. More recently, a full-aperture absolute calibration approach using widely tunable monochromatic lasers has been developed. Using these sources, the ASR of an instrument can be determined in a single step on a wavelength-by-wavelength basis. From these monochromatic ASRs, the responses of the instrument bands to broadband radiance sources can be calculated directly, eliminating the need for calibrated broadband light sources such as lamp-illuminated integrating spheres. In this work, the traditional broadband source-based calibration of the Suomi National Preparatory Project (SNPP) Visible Infrared Imaging Radiometer Suite (VIIRS) sensor is compared with the laser-based calibration of the sensor. Finally, the impact of the new full-aperture laser-based calibration approach on the on-orbit performance of the sensor is considered.

  6. Comparison of two methodologies for calibrating satellite instruments in the visible and near-infrared.

    PubMed

    Barnes, Robert A; Brown, Steven W; Lykke, Keith R; Guenther, Bruce; Butler, James J; Schwarting, Thomas; Turpie, Kevin; Moyer, David; DeLuccia, Frank; Moeller, Christopher

    2015-12-10

    Traditionally, satellite instruments that measure Earth-reflected solar radiation in the visible and near infrared wavelength regions have been calibrated for radiance responsivity in a two-step method. In the first step, the relative spectral response (RSR) of the instrument is determined using a nearly monochromatic light source such as a lamp-illuminated monochromator. These sources do not typically fill the field of view of the instrument nor act as calibrated sources of light. Consequently, they only provide a relative (not absolute) spectral response for the instrument. In the second step, the instrument views a calibrated source of broadband light, such as a lamp-illuminated integrating sphere. The RSR and the sphere's absolute spectral radiance are combined to determine the absolute spectral radiance responsivity (ASR) of the instrument. More recently, a full-aperture absolute calibration approach using widely tunable monochromatic lasers has been developed. Using these sources, the ASR of an instrument can be determined in a single step on a wavelength-by-wavelength basis. From these monochromatic ASRs, the responses of the instrument bands to broadband radiance sources can be calculated directly, eliminating the need for calibrated broadband light sources such as lamp-illuminated integrating spheres. In this work, the traditional broadband source-based calibration of the Suomi National Preparatory Project Visible Infrared Imaging Radiometer Suite sensor is compared with the laser-based calibration of the sensor. Finally, the impact of the new full-aperture laser-based calibration approach on the on-orbit performance of the sensor is considered.

  7. A calibration service for biomedical instrumentation maintenance laboratories.

    PubMed

    Barnes, A; Evans, A L; Job, H M; Laing, R; Smith, D C

    1999-01-01

    An in-house calibration laboratory for the Biomedical Instrumentation Maintenance Services of the hospitals in the West of Scotland was established in 1993. This paper describes the development of this calibration service in the context of an overall quality system and also estimates its costs. Not only does the in-house service have many advantages but it is shown to be cost effective for workloads exceeding 260 items per annum.

  8. Evaluation of two gas-dilution methods for instrument calibration

    NASA Technical Reports Server (NTRS)

    Evans, A., Jr.

    1977-01-01

    Two gas dilution methods were evaluated for use in the calibration of analytical instruments used in air pollution studies. A dual isotope fluorescence carbon monoxide analyzer was used as the transfer standard. The methods are not new but some modifications are described. The rotary injection gas dilution method was found to be more accurate than the closed loop method. Results by the two methods differed by 5 percent. This could not be accounted for by the random errors in the measurements. The methods avoid the problems associated with pressurized cylinders. Both methods have merit and have found a place in instrument calibration work.

  9. 10 CFR 35.61 - Calibration of survey instruments.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Calibration of survey instruments. 35.61 Section 35.61 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL General Technical Requirements... to show compliance with this part and 10 CFR Part 20 before first use, annually, and following...

  10. Instrument calibration plan of the Technical Support Section

    SciTech Connect

    Allison, K.L.; Davis, B.C.; Smith, H.E.; Hylton, J.O.; Robbins, W.L.

    1997-06-01

    This document describes the Calibration Program for the Instrumentation and Controls Division`s Technical Support Section (TSS). The implementation of the program is the responsibility of TSS; however, determining whether or not equipment is to be calibrated is the responsibility of the equipment`s custodian or user. The Calibration Program is a planned, systematic schedule of actions necessary to provide confidence that equipment used to make measurements or quality judgments meets established technical requirements and that its performance is traceable to nationally recognized standards. It is imperative that all parties maintain timely and effective dialogue to ensure that the process is adequate to meet the needs of Oak Ridge National Laboratory (ORNL). It is especially important to place this guidance in the proper context. ORNL instrumentation support at the shop and facility level is the primary application. Lockheed Martin Energy Research Corporation (LMER) and site policy provide the umbrella guidance for overall measuring and test equipment support.

  11. Impact Damage to Instruments

    NASA Astrophysics Data System (ADS)

    Maag, C. R.; Hansen, P. A.

    2002-05-01

    Today measured impacts of orbiting manmade debris on spacecraft presents one of the more serious space environmental threats to space missions. Post-flight data from recently returned hardware have provided very interesting and alarming results. The data suggests that mathematical models are conservative for predicting the number of impacts (flux) a spacecraft will receive from small particles (less than 0.8 mm diameter), while the models predict a flux nearly a factor of 10 less than that measured for particles above 1.0 mm. The data observed at the larger sizes is well above the predicted values. In the future, as the population of debris grows with increasing space traffic, the likelihood of debris impacts will become a critical problem. Data on population growth of larger sized particles have implications concerning the constellations of satellites that will support the information super highway. It is clear that the solutions to the exacerbation of the space debris environment in constellation orbits are a combination of operations and design. For those spacecraft not in constellation orbits, it is imperative that they prevent penetrations into their interior volumes. This paper presents the problems and solutions associated with surviving the debris environment, and eliminating the penetration potential to subsystems for three (3) current NASA science missions. These innovative concepts, while simplistic in nature, of stopping hypervelocity particles have unique applications for all space systems.

  12. Lunar Crater Observation and Sensing Satellite (LCROSS) Instrument Calibration Summary. Version 1

    NASA Technical Reports Server (NTRS)

    Smith, Kimberly Ennico; Colaprete, Anthony; Shirley, Mark H.; Wooden, Diane H.

    2010-01-01

    This document describes the calibration of the LCROSS instruments. It will be released to the public via the Planetary Data System. We need a quick review, if possible, because the data has been delivered to the PDS, and this document is needed to interpret the LCROSS impact data fully. [My mistake [shirley) in not realizing this needed to be treated as a normal publication.] The LCROSS instruments are commercially available units except for one designed and built at Ames. The commercially available instruments don't seem to me to present ITAR issues (Sony video camera, thermal camera from England, and so on.) Also, the internal design details of the instruments are not included in this report, only the process of calibrating them against standard targets. Only very high-level descriptions of the spacecraft are included, comparable to the level of detail included in the public web pages on nasa.gov.

  13. The Gemini Planet Imager Calibration Wavefront Sensor Instrument

    NASA Technical Reports Server (NTRS)

    Wallace, J. Kent; Burruss, Rick S.; Bartos, Randall D.; Trinh, Thang Q.; Pueyo, Laurent A.; Fregoso, Santos F.; Angione, John R.; Shelton, J. Chris

    2010-01-01

    The Gemini Planet Imager is an extreme adaptive optics system that will employ an apodized-pupil coronagraph to make direct detections of faint companions of nearby stars to a contrast level of the 10(exp -7) within a few lambda/D of the parent star. Such high contrasts from the ground require exquisite wavefront sensing and control both for the AO system as well as for the coronagraph. Un-sensed non-common path phase and amplitude errors after the wavefront sensor dichroic but before the coronagraph would lead to speckles which would ultimately limit the contrast. The calibration wavefront system for GPI will measure the complex wavefront at the system pupil before the apodizer and provide slow phase corrections to the AO system to mitigate errors that would cause a loss in contrast. The calibration wavefront sensor instrument for GPI has been built. We will describe the instrument and its performance.

  14. Instrument Calibration plan of the Technical Support Department

    SciTech Connect

    Allison, K.L.; Duncan, D.M.; McIntyre, T.J.; Millet, A.J.; Swabe, T.E.; Vines, R.A.

    1993-11-01

    This document describes the management of the Calibration Program of the Instrumentation and Controls Division`s Technical Support Department (ISD). The implementation of the program is the responsibility of ISD; however, the decision as to whether or not equipment is calibrated is the responsibility of the end user. It is imperative that all parties maintain timely and effective dialogue to ensure that the process is adequate to meet the needs of Oak Ridge National Laboratory (ORNL). The program is a planned, systematic schedule of actions necessary to provide confidence that equipment used to make measurements or quality judgments conforms to established technical requirements and is traceable to nationally recognized standards. It is especially important to place this guidance in the context for which it is intended. ORNL instrumentation support at the shop and facility level is the primary application. Energy Systems and site policy provide the umbrella guidance needed for overall measuring and test equipment support.

  15. Xenon arc lamp spectral radiance modelling for satellite instrument calibration

    NASA Astrophysics Data System (ADS)

    Rolt, Stephen; Clark, Paul; Schmoll, Jürgen; Shaw, Benjamin J. R.

    2016-07-01

    Precise radiometric measurements play a central role in many areas of astronomical and terrestrial observation. We focus on the use of continuum light sources in the absolute radiometric calibration of detectors in an imaging spectrometer for space applications. The application, in this instance, revolves around the ground based calibration of the Sentinel-4/UVN instrument. This imaging spectrometer instrument is expected to be deployed in 2019 and will make spatially resolved spectroscopic measurements of atmospheric chemistry. The instrument, which operates across the UV/VIS and NIR spectrum from 305-775 nm, is designed to measure the absolute spectral radiance of the Earth and compare it with the absolute spectral irradiance of the Sun. Of key importance to the fidelity of these absolute measurements is the ground based calibration campaign. Continuum lamp sources that are temporally stable and are spatially well defined are central to this process. Xenon short arc lamps provide highly intense and efficient continuum illumination in a range extending from the ultra-violet to the infra-red and their spectrum is well matched to this specific application. Despite their widespread commercial use, certain aspects of their performance are not well documented in the literature. One of the important requirements in this calibration application is the delivery of highly uniform, collimated illumination at high radiance. In this process, it cannot be assumed that the xenon arc is a point source; the spatial distribution of the radiance must be characterised accurately. We present here careful measurements that thoroughly characterise the spatial distribution of the spectral radiance of a 1000W xenon lamp. A mathematical model is presented describing the spatial distribution. Temporal stability is another exceptionally important requirement in the calibration process. As such, the paper also describes strategies to re-inforce the temporal stability of the lamp output by

  16. Precision Spectrophotometric Calibration System for Dark Energy Instruments

    SciTech Connect

    Schubnell, Michael S.

    2015-06-30

    For this research we build a precision calibration system and carried out measurements to demonstrate the precision that can be achieved with a high precision spectrometric calibration system. It was shown that the system is capable of providing a complete spectrophotometric calibration at the sub-pixel level. The calibration system uses a fast, high precision monochromator that can quickly and efficiently scan over an instrument’s entire spectral range with a spectral line width of less than 0.01 nm corresponding to a fraction of a pixel on the CCD. The system was extensively evaluated in the laboratory. Our research showed that a complete spectrophotometric calibration standard for spectroscopic survey instruments such as DESI is possible. The monochromator precision and repeatability to a small fraction of the DESI spectrograph LSF was demonstrated with re-initialization on every scan and thermal drift compensation by locking to multiple external line sources. A projector system that mimics telescope aperture for point source at infinity was demonstrated.

  17. The CHEOPS instrument on-ground calibration system

    NASA Astrophysics Data System (ADS)

    Wildi, F. P.; Chazelas, B.; Deline, A.; Sordet, M.; Sarajlic, M.

    2015-09-01

    The CHaracterising ExOPlanet Satellite (CHEOPS) is a joint ESA-Switzerland space mission dedicated to the search for exoplanet photometric transits. Its launch readiness is expected at the end of 2017. The CHEOPS instrument will be the first space telescope dedicated to search for transits on bright stars already known to host planets. By being able to point at nearly any location on the sky, it will provide the unique capability of determining accurate radii for a subset of those planets for which the mass has already been estimated from ground-based spectroscopic surveys. To reach its goals CHEOPS will measure photometric signals with a precision of 20 ppm in 6 hours of integration time for a 9th magnitude star. This corresponds to a signal-to-noise ratio of 5 for a transit of an Earth-sized planet orbiting a solar-sized star. Achieving the precision goal requires thorough post-processing of the data acquired by the CHEOPS' instrument system (CIS) in order to remove as much as possible the instrument's signature. To this purpose, a rigorous calibration campaign will be conducted after the CIS tests in order to measure, its behavior under the different environmental conditions. The main tool of this calibration campaign is a custom-made calibration system that will inject a stimulus beam in the CIS and measure its response to the variation of electrical and environmental parameters. These variations will be compiled in a correction model. Ultimately, the CIS photometric performance will be measured on an artificial star, applying the correction model This paper addresses the requirements applicable to the calibration system, its design and its design performance.

  18. 10 CFR 35.2061 - Records of radiation survey instrument calibrations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Records of radiation survey instrument calibrations. 35... § 35.2061 Records of radiation survey instrument calibrations. A licensee shall maintain a record of radiation survey instrument calibrations required by § 35.61 for 3 years. The record must include the...

  19. 10 CFR 35.2061 - Records of radiation survey instrument calibrations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Records of radiation survey instrument calibrations. 35... § 35.2061 Records of radiation survey instrument calibrations. A licensee shall maintain a record of radiation survey instrument calibrations required by § 35.61 for 3 years. The record must include the...

  20. 10 CFR 35.2061 - Records of radiation survey instrument calibrations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Records of radiation survey instrument calibrations. 35... § 35.2061 Records of radiation survey instrument calibrations. A licensee shall maintain a record of radiation survey instrument calibrations required by § 35.61 for 3 years. The record must include the...

  1. 10 CFR 35.2061 - Records of radiation survey instrument calibrations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Records of radiation survey instrument calibrations. 35... § 35.2061 Records of radiation survey instrument calibrations. A licensee shall maintain a record of radiation survey instrument calibrations required by § 35.61 for 3 years. The record must include the...

  2. 10 CFR 35.2061 - Records of radiation survey instrument calibrations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Records of radiation survey instrument calibrations. 35... § 35.2061 Records of radiation survey instrument calibrations. A licensee shall maintain a record of radiation survey instrument calibrations required by § 35.61 for 3 years. The record must include the...

  3. Aquarius Instrument Science Calibration During the Risk Reduction Phase

    NASA Technical Reports Server (NTRS)

    Ruf, Christopher S.

    2004-01-01

    This final report presents the results of work performed under NASA Grant NAG512726 during the period 15 January 2003 through 30 June 2004. An analysis was performed of a possible vicarious calibration method for use by Aquarius to monitor and stabilize the absolute and relative calibration of its microwave radiometer. Stationary statistical properties of the brightness temperature (T(sub B)) measured by a low Earth orbiting radiometer operating at 1.4135 GHz are considered as a means of validating its absolute calibration. The global minimum, maximum, and average T(sub B) are considered, together with a vicarious cold reference method that detects the presence of a sharp lower bound on naturally occurring values for T(sub B). Of particular interest is the reliability with which these statistics can be extracted from a realistic distribution of T(sub B) measurements that would be observed by a typical sensor. Simulations of measurements are performed that include the effects of instrument noise and variable environmental factors such as the global water vapor and ocean surface temperature, salinity and wind distributions. Global minima can vary widely due to instrument noise and are not a reliable calibration reference. Global maxima are strongly influenced by several environmental factors as well as instrument noise and are even less stationary. Global averages are largely insensitive to instrument noise and, in most cases, to environmental conditions as well. The global average T(sub B) varies at only the 0.1 K RMS level except in cases of anomalously high winds, when it can increase considerably more. The vicarious cold reference is similarly insensitive to instrument effects and most environmental factors. It is not significantly affected by high wind conditions. The stability of the vicarious reference is, however, found to be somewhat sensitive (at the several tenths of Kelvins level) to variations in the background cold space brightness, T(sub c). The global

  4. Integrated development facility for the calibration of low-energy charged particle flight instrumentation

    NASA Technical Reports Server (NTRS)

    Biddle, A. P.; Reynolds, J. M.

    1986-01-01

    The design of a low-energy ion facility for development and calibration of thermal ion instrumentation is examined. A directly heated cathode provides the electrons used to produce ions by impact ionization and an applied magnetic field increases the path length followed by the electrons. The electrostatic and variable geometry magnetic mirror configuration in the ion source is studied. The procedures for the charge neutralization of the beam and the configuration and function of the 1.4-m drift tube are analyzed. A microcomputer is utilized to control and monitor the beam energy and composition, and the mass- and angle-dependent response of the instrument under testing. The facility produces a high-quality ion beam with an adjustable range of energies up to 150 eV; the angular divergence and uniformity of the beam is obtained from two independent retarding potential analyzers. The procedures for calibrating the instrument being developed are described.

  5. The THEMIS ESA Plasma Instrument and In-flight Calibration

    NASA Astrophysics Data System (ADS)

    McFadden, J. P.; Carlson, C. W.; Larson, D.; Ludlam, M.; Abiad, R.; Elliott, B.; Turin, P.; Marckwordt, M.; Angelopoulos, V.

    2008-12-01

    The THEMIS plasma instrument is designed to measure the ion and electron distribution functions over the energy range from a few eV up to 30 keV for electrons and 25 keV for ions. The instrument consists of a pair of “top hat” electrostatic analyzers with common 180°×6° fields-of-view that sweep out 4 π steradians each 3 s spin period. Particles are detected by microchannel plate detectors and binned into six distributions whose energy, angle, and time resolution depend upon instrument mode. On-board moments are calculated, and processing includes corrections for spacecraft potential. This paper focuses on the ground and in-flight calibrations of the 10 sensors on five spacecraft. Cross-calibrations were facilitated by having all the plasma measurements available with the same resolution and format, along with spacecraft potential and magnetic field measurements in the same data set. Lessons learned from this effort should be useful for future multi-satellite missions.

  6. SMOS Instrument Performance and Calibration after 3 Years in Orbit

    NASA Astrophysics Data System (ADS)

    Martin-Neira, Manuel; Corbella, Ignasi; Torres, Francesc; Kainulainen, Juha; Oliva, Roger; Closa, Josep; Cabot, François; Castro, Rita; Barbosa, Jose; Gutierrez, Antonio; Anterrieu, Eric; Tenerelli, Joe; Martin-Porqueras, Fernando; Buenadicha, Guillermo; Delwart, Steven; Crapolicchio, Raffaele; Suess, Martin

    2013-04-01

    ESA's Soil Moisture and Ocean Salinity (SMOS) mission has been in orbit for already over 3 years which has allowed the calibration and data processing team consolidating both the calibration strategy and the Level-1 processor which transforms the raw visibility samples into polarimetric brightness temperature images. The payload on board SMOS, MIRAS, is quite unique in that it is the first microwave radiometer in space ever capable to generate wide field of view images at every snapshot measurement. This means that most of the calibration as well as image processing techniques are being developed for the first time with little heritage from any previous space mission. Issues intrinsically attached to its wide field of view such as spatial ripples across the snapshot images are particular to MIRAS and to no other earlier radiometer. Even the fundamental theory behind the instrument was put at test, first on ground inside an electromagnetic compatibility chamber, and now in orbit when imaging the Cosmic Microwave Background Radiation of the cold sky. A groundbreaking effort is being carried out by the SMOS project team to understand and master all calibration and image reconstruction issues of this novel microwave interferometer payload. MIRAS in-orbit performance is driven by the amplitude of spatial ripples across the image and orbital and seasonal radiometer stability. Spatial ripples are unique to interferometric radiometers and are produced by (a) a limited knowledge of the antenna patterns and, in general, of the model of the instrument, (b) some fundamental limitations related to the inverse problem of image reconstruction in undetermined conditions and (c) subtle data processing inconsistencies which are discovered and corrected. To reduce the spatial ripples sea surface salinity retrievals are performed by first removing the brightness temperature spatial errors using a uniform region of the Pacific Ocean. However soil moisture retrievals cannot benefit of

  7. GMI Instrument Spin Balance Method, Optimization, Calibration, and Test

    NASA Technical Reports Server (NTRS)

    Ayari, Laoucet; Kubitschek, Michael; Ashton, Gunnar; Johnston, Steve; Debevec, Dave; Newell, David; Pellicciotti, Joseph

    2014-01-01

    The Global Microwave Imager (GMI) instrument must spin at a constant rate of 32 rpm continuously for the 3 year mission life. Therefore, GMI must be very precisely balanced about the spin axis and CG to maintain stable scan pointing and to minimize disturbances imparted to the spacecraft and attitude control on-orbit. The GMI instrument is part of the core Global Precipitation Measurement (GPM) spacecraft and is used to make calibrated radiometric measurements at multiple microwave frequencies and polarizations. The GPM mission is an international effort managed by the National Aeronautics and Space Administration (NASA) to improve climate, weather, and hydro-meteorological predictions through more accurate and frequent precipitation measurements. Ball Aerospace and Technologies Corporation (BATC) was selected by NASA Goddard Space Flight Center to design, build, and test the GMI instrument. The GMI design has to meet a challenging set of spin balance requirements and had to be brought into simultaneous static and dynamic spin balance after the entire instrument was already assembled and before environmental tests began. The focus of this contribution is on the analytical and test activities undertaken to meet the challenging spin balance requirements of the GMI instrument. The novel process of measuring the residual static and dynamic imbalances with a very high level of accuracy and precision is presented together with the prediction of the optimal balance masses and their locations.

  8. GMI Instrument Spin Balance Method, Optimization, Calibration and Test

    NASA Technical Reports Server (NTRS)

    Ayari, Laoucet; Kubitschek, Michael; Ashton, Gunnar; Johnston, Steve; Debevec, Dave; Newell, David; Pellicciotti, Joseph

    2014-01-01

    The Global Microwave Imager (GMI) instrument must spin at a constant rate of 32 rpm continuously for the 3-year mission life. Therefore, GMI must be very precisely balanced about the spin axis and center of gravity (CG) to maintain stable scan pointing and to minimize disturbances imparted to the spacecraft and attitude control on-orbit. The GMI instrument is part of the core Global Precipitation Measurement (GPM) spacecraft and is used to make calibrated radiometric measurements at multiple microwave frequencies and polarizations. The GPM mission is an international effort managed by the National Aeronautics and Space Administration (NASA) to improve climate, weather, and hydro-meteorological predictions through more accurate and frequent precipitation measurements. Ball Aerospace and Technologies Corporation (BATC) was selected by NASA Goddard Space Flight Center to design, build, and test the GMI instrument. The GMI design has to meet a challenging set of spin balance requirements and had to be brought into simultaneous static and dynamic spin balance after the entire instrument was already assembled and before environmental tests began. The focus of this contribution is on the analytical and test activities undertaken to meet the challenging spin balance requirements of the GMI instrument. The novel process of measuring the residual static and dynamic imbalances with a very high level of accuracy and precision is presented together with the prediction of the optimal balance masses and their locations.

  9. Instrument calibration plan of the Maintenance Management Department

    SciTech Connect

    Blanton, J.D.; Cooper, M.H.; Millet, A.J.; Vines, R.A.

    1990-10-01

    This document describes the methods and procedures for management of the Instrumentation and Controls I C Division Maintenance Management Department Calibration Program. The implementation of the Program rests primarily with the I C Division Maintenance shops and the services supplied by the I C Division Metrology Research and Development Laboratory. An important aspect of the overall program is the user or customer interface. Support activities are initiated and maintained through an active participation of operations and research organizations. It is imperative that all parties involved in the process maintain timely and effective dialogue to ensure that the process is adequate for the needs of the Laboratory. 1 ref., 6 figs.

  10. Monocrystalline test structures, and use for calibrating instruments

    DOEpatents

    Cresswell, Michael W.; Ghoshtagore, R. N.; Linholm, Loren W.; Allen, Richard A.; Sniegowski, Jeffry J.

    1997-01-01

    An improved test structure for measurement of width of conductive lines formed on substrates as performed in semiconductor fabrication, and for calibrating instruments for such measurements, is formed from a monocrystalline starting material, having an insulative layer formed beneath its surface by ion implantation or the equivalent, leaving a monocrystalline layer on the surface. The monocrystalline surface layer is then processed by preferential etching to accurately define components of the test structure. The substrate can be removed from the rear side of the insulative layer to form a transparent window, such that the test structure can be inspected by transmissive-optical techniques. Measurements made using electrical and optical techniques can be correlated with other measurements, including measurements made using scanning probe microscopy.

  11. 10 CFR 35.61 - Calibration of survey instruments.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... repair that affects the calibration. A licensee shall— (1) Calibrate all scales with readings up to 10 mSv (1000 mrem) per hour with a radiation source; (2) Calibrate two separated readings on each...

  12. 10 CFR 35.61 - Calibration of survey instruments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... repair that affects the calibration. A licensee shall— (1) Calibrate all scales with readings up to 10 mSv (1000 mrem) per hour with a radiation source; (2) Calibrate two separated readings on each...

  13. 10 CFR 35.61 - Calibration of survey instruments.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... repair that affects the calibration. A licensee shall— (1) Calibrate all scales with readings up to 10 mSv (1000 mrem) per hour with a radiation source; (2) Calibrate two separated readings on each...

  14. Calibration of LSST Instrumental and Atmospheric Photometric Passbands

    SciTech Connect

    Burke, David L.; Axelrod, T.; Barrau, Aurelien; Baumont, Sylvain; Blondin, Stephane; Claver, Chuck; Gorecki, Alexia; Ivezic, Zeljko; Jones, Lynne; Krabbendam, Victor; Liang, Ming; Saha, Abhijit; Smith, Allyn; Smith, R.Chris; Stubbs, Christopher W.; /Harvard-Smithsonian Ctr. Astrophys.

    2011-07-06

    The Large Synoptic Survey Telescope (LSST) will continuously image the entire sky visible from Cerro Pachon in northern Chile every 3-4 nights throughout the year. The LSST will provide data for a broad range of science investigations that require better than 1% photometric precision across the sky (repeatability and uniformity) and a similar accuracy of measured broadband color. The fast and persistent cadence of the LSST survey will significantly improve the temporal sampling rate with which celestial events and motions are tracked. To achieve these goals, and to optimally utilize the observing calendar, it will be necessary to obtain excellent photometric calibration of data taken over a wide range of observing conditions - even those not normally considered 'photometric'. To achieve this it will be necessary to routinely and accurately measure the full optical passband that includes the atmosphere as well as the instrumental telescope and camera system. The LSST mountain facility will include a new monochromatic dome illumination projector system to measure the detailed wavelength dependence of the instrumental passband for each channel in the system. The facility will also include an auxiliary spectroscopic telescope dedicated to measurement of atmospheric transparency at all locations in the sky during LSST observing. In this paper, we describe these systems and present laboratory and observational data that illustrate their performance.

  15. Comparison of Spectral Radiance Calibration Techniques Used for Backscatter Ultraviolet Satellite Instruments

    NASA Technical Reports Server (NTRS)

    Kowalewski, Matthew G.; Janz, Scott

    2014-01-01

    Methods for determining the absolute radiometric calibration sensitivities of backscatter ultraviolet (BUV) satellite instruments are compared as part of an effort to minimize pre-launch calibration errors. An internally illuminated integrating sphere source has been used for the Shuttle Solar BUV (SSBUV), Total Ozone Mapping Spectrometer (TOMS), Ozone Mapping Instrument (OMI), and Global Ozone Monitoring Experiment 2 (GOME-2) using standardized procedures traceable to national standards. These sphere-based sensitivities agree to within three percent [k equals 2] relative to calibrations performed using an external diffuser illuminated by standard irradiance sources, the customary radiance calibration method for BUV instruments. The uncertainty for these calibration techniques as implemented at the NASA Goddard Space Flight Centers Radiometric Calibration and Development Laboratory is shown to be 4 percent at 250nm [k equals 2] when using a single traceable calibration standard. Significant reduction in the uncertainty of nearly 1 percent is demonstrated when multiple calibration standards are used.

  16. Statistical self-calibration of SPOT satellite imaging instrument

    NASA Astrophysics Data System (ADS)

    Carfantan, H.; Idier, J.; Beghin, B.; Meygret, A.; Rougé, B.

    2001-05-01

    SPOT satellites imaging instruments acquire rows of up to 6000 elements using a CCD linear array. The other dimension is obtained by the column-wise scanning resulting from the motion of the satellite. In practice, the responses of the detectors are not strictly identical along the array, which generates a stripe effect in the direction of columns. Our aim is to perform the calibration of the detectors response from the observed image, without supervision, in the restricted case of perfectly linear responses. In a Bayesian framework, we rely on a first-order Markov model for the image and on a Gaussian model for the gains of the detector. The MAP estimate minimizes a criterion, quadratic, convex, or nonconvex according to the chosen Markov model. In the quadratic case, MAP computation amounts to solving a tridiagonal linear system. In the other cases, we take advantage of introducing an equivalent augmented half-quadratic criterion, which can be minimized by iterately solving tridiagonal linear systems. Minimizing nonconvex criteria provides the best results, although convergence towards the global minimizer is not ensured in this case. .

  17. Direct Reading Particle Counters: Calibration Verification and Multiple Instrument Agreement via Bump Testing

    SciTech Connect

    Jankovic, John; Zontek, Tracy L.; Ogle, Burton R.; Hollenbeck, Scott

    2015-01-27

    We examined the calibration records of two direct reading instruments designated as condensation particle counters in order to determine the number of times they were found to be out of tolerance at annual manufacturer's recalibration. For both instruments were found to be out of tolerance more times than within tolerance. And, it was concluded that annual calibration alone was insufficient to provide operational confidence in an instrument's response. Thus, a method based on subsequent agreement with data gathered from a newly calibrated instrument was developed to confirm operational readiness between annual calibrations, hereafter referred to as bump testing. The method consists of measuring source particles produced by a gas grille spark igniter in a gallon-size jar. Sampling from this chamber with a newly calibrated instrument to determine the calibrated response over the particle concentration range of interest serves as a reference. Agreement between this reference response and subsequent responses at later dates implies that the instrument is performing as it was at the time of calibration. Side-by-side sampling allows the level of agreement between two or more instruments to be determined. This is useful when simultaneously collected data are compared for differences, i.e., background with process aerosol concentrations. A reference set of data was obtained using the spark igniter. The generation system was found to be reproducible and suitable to form the basis of calibration verification. Finally, the bump test is simple enough to be performed periodically throughout the calibration year or prior to field monitoring.

  18. Direct Reading Particle Counters: Calibration Verification and Multiple Instrument Agreement via Bump Testing.

    PubMed

    Jankovic, John; Zontek, Tracy L; Ogle, Burton R; Hollenbeck, Scott

    2015-01-01

    The calibration records of two direct reading instruments designated as condensation particle counters were examined to determine the number of times they were found to be out of tolerance at annual manufacturer's recalibration. Both instruments were found to be out of tolerance more times than within tolerance. And, it was concluded that annual calibration alone was insufficient to provide operational confidence in an instrument's response. Therefore, a method based on subsequent agreement with data gathered from a newly calibrated instrument was developed to confirm operational readiness between annual calibrations, hereafter referred to as bump testing. The method consists of measuring source particles produced by a gas grille spark igniter in a gallon-size jar. Sampling from this chamber with a newly calibrated instrument to determine the calibrated response over the particle concentration range of interest serves as a reference. Agreement between this reference response and subsequent responses at later dates implies that the instrument is performing as it was at the time of calibration. Side-by-side sampling allows the level of agreement between two or more instruments to be determined. This is useful when simultaneously collected data are compared for differences, i.e., background with process aerosol concentrations. A reference set of data was obtained using the spark igniter. The generation system was found to be reproducible and suitable to form the basis of calibration verification. The bump test is simple enough to be performed periodically throughout the calibration year or prior to field monitoring.

  19. Validation of smart sensor technologies for instrument calibration reduction in nuclear power plants

    SciTech Connect

    Hashemian, H M; Mitchell, D W; Petersen, K M; Shell, C S

    1993-01-01

    This report presents the preliminary results of a research and development project on the validation of new techniques for on-line testing of calibration drift of process instrumentation channels in nuclear power plants. These techniques generally involve a computer-based data acquisition and data analysis system to trend the output of a large number of instrument channels and identify the channels that have drifted out of tolerance. This helps limit the calibration effort to those channels which need the calibration, as opposed to the current nuclear industry practice of calibrating essentially all the safety-related instrument channels at every refueling outage.

  20. Comparison of spectral radiance responsivity calibration techniques used for backscatter ultraviolet satellite instruments

    NASA Astrophysics Data System (ADS)

    Kowalewski, M. G.; Janz, S. J.

    2015-02-01

    Methods of absolute radiometric calibration of backscatter ultraviolet (BUV) satellite instruments are compared as part of an effort to minimize pre-launch calibration uncertainties. An internally illuminated integrating sphere source has been used for the Shuttle Solar BUV, Total Ozone Mapping Spectrometer, Ozone Mapping Instrument, and Global Ozone Monitoring Experiment 2 using standardized procedures traceable to national standards. These sphere-based spectral responsivities agree to within the derived combined standard uncertainty of 1.87% relative to calibrations performed using an external diffuser illuminated by standard irradiance sources, the customary spectral radiance responsivity calibration method for BUV instruments. The combined standard uncertainty for these calibration techniques as implemented at the NASA Goddard Space Flight Center’s Radiometric Calibration and Development Laboratory is shown to less than 2% at 250 nm when using a single traceable calibration standard.

  1. Generic System for Remote Testing and Calibration of Measuring Instruments: Security Architecture

    NASA Astrophysics Data System (ADS)

    Jurčević, M.; Hegeduš, H.; Golub, M.

    2010-01-01

    Testing and calibration of laboratory instruments and reference standards is a routine activity and is a resource and time consuming process. Since many of the modern instruments include some communication interfaces, it is possible to create a remote calibration system. This approach addresses a wide range of possible applications and permits to drive a number of different devices. On the other hand, remote calibration process involves a number of security issues due to recommendations specified in standard ISO/IEC 17025, since it is not under total control of the calibration laboratory personnel who will sign the calibration certificate. This approach implies that the traceability and integrity of the calibration process directly depends on the collected measurement data. The reliable and secure remote control and monitoring of instruments is a crucial aspect of internet-enabled calibration procedure.

  2. A new method for monitoring long term calibration of the SBUV and TOMS instruments

    NASA Technical Reports Server (NTRS)

    Ahmad, Z.; Seftor, C.; Wellemeyer, C.

    1994-01-01

    A new method has been developed to monitor the long-term calibration of the Solar Backscatter Ultraviolet (SBUV) and Total Ozone Mapping Spectrometer (TOMS) instruments. It is based on the fact that the radiance in one channel can be expressed as a linear sum of the radiances in neighboring channels. Using simulated radiances for the SBUV and TOMS instruments, various scenarios of changes in instrument calibration are investigated. Results from sample processing of SBUV data are also presented.

  3. Radiometric calibration stability and inter-calibration of solar-band instruments in orbit using the moon

    USGS Publications Warehouse

    Stone, T.C.

    2008-01-01

    With the increased emphasis on monitoring the Earth's climate from space, more stringent calibration requirements are being placed on the data products from remote sensing satellite instruments. Among these are stability over decade-length time scales and consistency across sensors and platforms. For radiometer instruments in the solar reflectance wavelength range (visible to shortwave infrared), maintaining calibration on orbit is difficult due to the lack of absolute radiometric standards suitable for flight use. The Moon presents a luminous source that can be viewed by all instruments in Earth orbit. Considered as a solar diffuser, the lunar surface is exceedingly stable. The chief difficulty with using the Moon is the strong variations in the Moon's brightness with illumination and viewing geometry. This mandates the use of a photometric model to compare lunar observations, either over time by the same instrument or between instruments. The U.S. Geological Survey in Flagstaff, Arizona, under NASA sponsorship, has developed a model for the lunar spectral irradiance that explicitly accounts for the effects of phase, the lunar librations, and the lunar surface reflectance properties. The model predicts variations in the Moon's brightness with precision ???1% over a continuous phase range from eclipse to the quarter lunar phases. Given a time series of Moon observations taken by an instrument, the geometric prediction capability of the lunar irradiance model enables sensor calibration stability with sub-percent per year precision. Cross-calibration of instruments with similar passbands can be achieved with precision comparable to the model precision. Although the Moon observations used for intercomparison can be widely separated in phase angle and/or time, SeaWiFS and MODIS have acquired lunar views closely spaced in time. These data provide an example to assess inter-calibration biases between these two instruments.

  4. Positioning system for single or multi-axis sensitive instrument calibration and calibration system for use therewith

    NASA Technical Reports Server (NTRS)

    Finley, Tom D. (Inventor); Parker, Peter A. (Inventor)

    2008-01-01

    A positioning and calibration system are provided for use in calibrating a single or multi axis sensitive instrument, such as an inclinometer. The positioning system includes a positioner that defines six planes of tangential contact. A mounting region within the six planes is adapted to have an inclinometer coupled thereto. The positioning system also includes means for defining first and second flat surfaces that are approximately perpendicular to one another with the first surface adapted to be oriented relative to a local or induced reference field of interest to the instrument being calibrated, such as a gravitational vector. The positioner is positioned such that one of its six planes tangentially rests on the first flat surface and another of its six planes tangentially contacts the second flat surface. A calibration system is formed when the positioning system is used with a data collector and processor.

  5. A virtual instrument to standardise the calibration of atomic force microscope cantilevers

    NASA Astrophysics Data System (ADS)

    Sader, John E.; Borgani, Riccardo; Gibson, Christopher T.; Haviland, David B.; Higgins, Michael J.; Kilpatrick, Jason I.; Lu, Jianing; Mulvaney, Paul; Shearer, Cameron J.; Slattery, Ashley D.; Thorén, Per-Anders; Tran, Jim; Zhang, Heyou; Zhang, Hongrui; Zheng, Tian

    2016-09-01

    Atomic force microscope (AFM) users often calibrate the spring constants of cantilevers using functionality built into individual instruments. This calibration is performed without reference to a global standard, hindering the robust comparison of force measurements reported by different laboratories. Here, we describe a virtual instrument (an internet-based initiative) whereby users from all laboratories can instantly and quantitatively compare their calibration measurements to those of others—standardising AFM force measurements—and simultaneously enabling non-invasive calibration of AFM cantilevers of any geometry. This global calibration initiative requires no additional instrumentation or data processing on the part of the user. It utilises a single website where users upload currently available data. A proof-of-principle demonstration of this initiative is presented using measured data from five independent laboratories across three countries, which also allows for an assessment of current calibration.

  6. A virtual instrument to standardise the calibration of atomic force microscope cantilevers.

    PubMed

    Sader, John E; Borgani, Riccardo; Gibson, Christopher T; Haviland, David B; Higgins, Michael J; Kilpatrick, Jason I; Lu, Jianing; Mulvaney, Paul; Shearer, Cameron J; Slattery, Ashley D; Thorén, Per-Anders; Tran, Jim; Zhang, Heyou; Zhang, Hongrui; Zheng, Tian

    2016-09-01

    Atomic force microscope (AFM) users often calibrate the spring constants of cantilevers using functionality built into individual instruments. This calibration is performed without reference to a global standard, hindering the robust comparison of force measurements reported by different laboratories. Here, we describe a virtual instrument (an internet-based initiative) whereby users from all laboratories can instantly and quantitatively compare their calibration measurements to those of others-standardising AFM force measurements-and simultaneously enabling non-invasive calibration of AFM cantilevers of any geometry. This global calibration initiative requires no additional instrumentation or data processing on the part of the user. It utilises a single website where users upload currently available data. A proof-of-principle demonstration of this initiative is presented using measured data from five independent laboratories across three countries, which also allows for an assessment of current calibration.

  7. Post-launch calibration and testing of space weather instruments on GOES-R satellite

    NASA Astrophysics Data System (ADS)

    Tadikonda, Sivakumara S. K.; Merrow, Cynthia S.; Kronenwetter, Jeffrey A.; Comeyne, Gustave J.; Flanagan, Daniel G.; Todirita, Monica

    2016-05-01

    The Geostationary Operational Environmental Satellite - R (GOES-R) is the first of a series of satellites to be launched, with the first launch scheduled for October 2016. The three instruments -- Solar UltraViolet Imager (SUVI), Extreme ultraviolet and X-ray Irradiance Sensor (EXIS), and Space Environment In-Situ Suite (SEISS) provide the data needed as inputs for the product updates National Oceanic and Atmospheric Administration (NOAA) provides to the public. SUVI is a full-disk extreme ultraviolet imager enabling Active Region characterization, filament eruption, and flare detection. EXIS provides inputs to solar backgrounds/events impacting climate models. SEISS provides particle measurements over a wide energy-and-flux range that varies by several orders of magnitude and these data enable updates to spacecraft charge models for electrostatic discharge. EXIS and SEISS have been tested and calibrated end-to-end in ground test facilities around the United States. Due to the complexity of the SUVI design, data from component tests were used in a model to predict on-orbit performance. The ground tests and model updates provided inputs for designing the on-orbit calibration tests. A series of such tests have been planned for the Post-Launch Testing (PLT) of each of these instruments, and specific parameters have been identified that will be updated in the Ground Processing Algorithms, on-orbit parameter tables, or both. Some of SUVI and EXIS calibrations require slewing them off the Sun, while no such maneuvers are needed for SEISS. After a six-month PLT period the GOES-R is expected to be operational. The calibration details are presented in this paper.

  8. Post-Launch Calibration and Testing of Space Weather Instruments on GOES-R Satellite

    NASA Technical Reports Server (NTRS)

    Tadikonda, S. K.; Merrow, Cynthia S.; Kronenwetter, Jeffrey A.; Comeyne, Gustave J.; Flanagan, Daniel G.; Todrita, Monica

    2016-01-01

    The Geostationary Operational Environmental Satellite - R (GOES-R) is the first of a series of satellites to be launched, with the first launch scheduled for October 2016. The three instruments Solar UltraViolet Imager (SUVI), Extreme ultraviolet and X-ray Irradiance Sensor (EXIS), and Space Environment In-Situ Suite (SEISS) provide the data needed as inputs for the product updates National Oceanic and Atmospheric Administration (NOAA) provides to the public. SUVI is a full-disk extreme ultraviolet imager enabling Active Region characterization, filament eruption, and flare detection. EXIS provides inputs to solar back-ground-sevents impacting climate models. SEISS provides particle measurements over a wide energy-and-flux range that varies by several orders of magnitude and these data enable updates to spacecraft charge models for electrostatic discharge. EXIS and SEISS have been tested and calibrated end-to-end in ground test facilities around the United States. Due to the complexity of the SUVI design, data from component tests were used in a model to predict on-orbit performance. The ground tests and model updates provided inputs for designing the on-orbit calibration tests. A series of such tests have been planned for the Post-Launch Testing (PLT) of each of these instruments, and specific parameters have been identified that will be updated in the Ground Processing Algorithms, on-orbit parameter tables, or both. Some of SUVI and EXIS calibrations require slewing them off the Sun, while no such maneuvers are needed for SEISS. After a six-month PLT period the GOES-R is expected to be operational. The calibration details are presented in this paper.

  9. Post-Launch Calibration and Testing of Space Weather Instruments on GOES-R Satellite

    NASA Technical Reports Server (NTRS)

    Tadikonda, Sivakumara S. K.; Merrow, Cynthia S.; Kronenwetter, Jeffrey A.; Comeyne, Gustave J.; Flanagan, Daniel G.; Todirita, Monica

    2016-01-01

    The Geostationary Operational Environmental Satellite - R (GOES-R) is the first of a series of satellites to be launched, with the first launch scheduled for October 2016. The three instruments - Solar Ultra Violet Imager (SUVI), Extreme ultraviolet and X-ray Irradiance Sensor (EXIS), and Space Environment In-Situ Suite (SEISS) provide the data needed as inputs for the product updates National Oceanic and Atmospheric Administration (NOAA) provides to the public. SUVI is a full-disk extreme ultraviolet imager enabling Active Region characterization, filament eruption, and flare detection. EXIS provides inputs to solar backgrounds/events impacting climate models. SEISS provides particle measurements over a wide energy-and-flux range that varies by several orders of magnitude and these data enable updates to spacecraft charge models for electrostatic discharge. EXIS and SEISS have been tested and calibrated end-to-end in ground test facilities around the United States. Due to the complexity of the SUVI design, data from component tests were used in a model to predict on-orbit performance. The ground tests and model updates provided inputs for designing the on-orbit calibration tests. A series of such tests have been planned for the Post-Launch Testing (PLT) of each of these instruments, and specific parameters have been identified that will be updated in the Ground Processing Algorithms, on-orbit parameter tables, or both. Some of SUVI and EXIS calibrations require slewing them off the Sun, while no such maneuvers are needed for SEISS. After a six-month PLT period the GOES-R is expected to be operational. The calibration details are presented in this paper.

  10. Instrumented impact testing at high velocities

    SciTech Connect

    Delfosse, D.; Pageau, G.; Bennett, R.; Poursartip, A. Defence Research Establishment Valcartier, Courcelette )

    1993-01-01

    Impact loading of carbon fiber-reinforced plastic (CFRP) aircraft parts is a major concern. Birds or hailstones striking an aircraft generally have a low mass and a high velocity, whereas typically instrumented impact experiments are performed with a high mass and a low velocity. Our aim has been to build an instrumented impact facility with a low-mass projectile capable of simulating these impact events, since there is evidence that a low-velocity impact will not always result in the same amount or even type of damage as a high-velocity impact. This paper provides a detailed description of the instrumented low-mass impact facility at The University of British Columbia (UBC). A gas gun is used to accelerate the instrumented projectile to impact velocities as high as 50 m/s, corresponding to an energy level of 350 J. The contact force during the impact event is measured by an incorporated load cell. The necessary mathematical operations to determine the real load-displacement curves are outlined, and the results of some impact events at different velocities are shown. 23 refs.

  11. Instrumented Pneumatic-Impact Tester

    NASA Technical Reports Server (NTRS)

    Shelley, Richard M.; Armendariz, Norman

    1993-01-01

    Pneumatic-impact tester is small pressure chamber equipped with specimen holder and optical port. Device designed to test susceptibility of polymeric material to ignition by "pneumatic impact" in high-pressure gaseous oxygen. Used to determine differences among susceptibilities to ignition of different materials and of different batches of nominally same material proposed for use in systems containing pressurized oxygen. Also used to show characteristics of ignition and combustion.

  12. Soot Reference Materials for instrument calibration and intercomparisons: a workshop summary with recommendations

    NASA Astrophysics Data System (ADS)

    Baumgardner, D.; Popovicheva, O.; Allan, J.; Bernardoni, V.; Cao, J.; Cavalli, F.; Cozic, J.; Diapouli, E.; Eleftheriadis, K.; Genberg, P. J.; Gonzalez, C.; Gysel, M.; John, A.; Kirchstetter, T. W.; Kuhlbusch, T. A. J.; Laborde, M.; Lack, D.; Müller, T.; Niessner, R.; Petzold, A.; Piazzalunga, A.; Putaud, J. P.; Schwarz, J.; Sheridan, P.; Subramanian, R.; Swietlicki, E.; Valli, G.; Vecchi, R.; Viana, M.

    2012-03-01

    Soot, which is produced from biomass burning and the incomplete combustion of fossil and biomass fuels, has been linked to regional and global climate change and to negative health problems. Scientists measure soot using a variety of methods in order to quantify source emissions and understand its atmospheric chemistry, reactivity under emission conditions, interaction with solar radiation, influence on clouds, and health impacts. A major obstacle currently limiting progress is the absence of established standards or reference materials for calibrating the many instruments used to measure the various properties of soot. The current state of availability and practicability of soot standard reference materials (SRMs) was reviewed by a group of 50 international experts during a workshop in June of 2011. The workshop was convened to summarize the current knowledge on soot measurement techniques, identify the measurement uncertainties and limitations related to the lack of SRMs, and identify attributes of SRMs that, if developed, would reduce measurement uncertainties. The workshop established that suitable SRMs are available for calibrating some, but not all, measurement methods. The community of single-particle sootphotometer (SP2) users identified a suitable SRM, fullerene soot, but users of instruments that measure light absorption by soot collected on filters did not. Similarly, those who use thermal optical analysis (TOA) to analyze the organic and elemental carbon components of soot were not satisfied with current SRMs. The workshop produced recommendations for the development of new SRMs that would be suitable for the different soot measurement methods.

  13. Source-based calibration of space instruments using calculable synchrotron radiation

    NASA Astrophysics Data System (ADS)

    Klein, Roman; Fliegauf, Rolf; Kroth, Simone; Paustian, Wolfgang; Reichel, Thomas; Richter, Mathias; Thornagel, Reiner

    2016-10-01

    Physikalisch-Technische Bundesanstalt (PTB) has more than 20 years of experience in the calibration of space-based instruments using synchrotron radiation to cover the ultraviolet (UV), vacuum UV (VUV), and x-ray spectral range. Over the past decades, PTB has performed calibrations for numerous space missions within scientific collaborations and has become an important partner for activities in this field. New instrumentation at the electron storage ring, metrology light source, creates additional calibration possibilities within this framework. A new facility for the calibration of radiation transfer source standards with a considerably extended spectral range has been put into operation. The commissioning of a large vacuum vessel that can accommodate entire space instruments opens up new prospects. Finally, an existing VUV transfer calibration source was upgraded to increase the spectral range coverage to a band from 15 to 350 nm.

  14. The Impact of Indoor and Outdoor Radiometer Calibration on Solar Measurements: Preprint

    SciTech Connect

    Habte, Aron; Sengupta, Manajit; Andreas, Afshin; Reda, Ibrahim; Robinson, Justin

    2016-07-01

    Accurate solar radiation data sets are critical to reducing the expenses associated with mitigating performance risk for solar energy conversion systems, and they help utility planners and grid system operators understand the impacts of solar resource variability. The accuracy of solar radiation measured by radiometers depends on the instrument performance specification, installation method, calibration procedure, measurement conditions, maintenance practices, location, and environmental conditions. This study addresses the effect of calibration methodologies and the resulting calibration responsivities provided by radiometric calibration service providers such as the National Renewable Energy Laboratory (NREL) and manufacturers of radiometers. Some of these radiometers are calibrated indoors, and some are calibrated outdoors. To establish or understand the differences in calibration methodology, we processed and analyzed field-measured data from these radiometers. This study investigates calibration responsivities provided by NREL's broadband outdoor radiometer calibration (BORCAL) and a few prominent manufacturers. The reference radiometer calibrations are traceable to the World Radiometric Reference. These different methods of calibration demonstrated 1% to 2% differences in solar irradiance measurement. Analyzing these values will ultimately assist in determining the uncertainties of the radiometer data and will assist in developing consensus on a standard for calibration.

  15. Calibration of Instruments for Measuring Wind Velocity and Direction

    NASA Technical Reports Server (NTRS)

    Vogler, Raymond D.; Pilny, Miroslav J.

    1950-01-01

    Signal Corps wind equipment AN/GMQ-1 consisting of a 3-cup anemometer and wind vane was calibrated for wind velocities from 1 to 200 miles per hour. Cup-shaft failure prevented calibration at higher wind velocities. The action of the wind vane was checked and found to have very poor directional accuracy below a velocity of 8 miles per hour. After shaft failure was reported to the Signal Corps, the cup rotors were redesigned by strengthening the shafts for better operation at high velocities. The anemometer with the redesigned cup rotors was recalibrated, but cup-shaft failure occurred again at a wind velocity of approximately 220 miles per hour. In the course of this calibration two standard generators were checked for signal output variation, and a wind-speed meter was calibrated for use with each of the redesigned cup rotors. The variation of pressure coefficient with air-flow direction at four orifices on a disk-shaped pitot head was obtained for wind velocities of 37.79 53.6, and 98.9 miles per hour. A pitot-static tube mounted in the nose of a vane was calibrated up to a dynamic pressure of 155 pounds per square foot, or approximately 256 miles per hour,

  16. Direct Reading Particle Counters: Calibration Verification and Multiple Instrument Agreement via Bump Testing

    DOE PAGES

    Jankovic, John; Zontek, Tracy L.; Ogle, Burton R.; ...

    2015-01-27

    We examined the calibration records of two direct reading instruments designated as condensation particle counters in order to determine the number of times they were found to be out of tolerance at annual manufacturer's recalibration. For both instruments were found to be out of tolerance more times than within tolerance. And, it was concluded that annual calibration alone was insufficient to provide operational confidence in an instrument's response. Thus, a method based on subsequent agreement with data gathered from a newly calibrated instrument was developed to confirm operational readiness between annual calibrations, hereafter referred to as bump testing. The methodmore » consists of measuring source particles produced by a gas grille spark igniter in a gallon-size jar. Sampling from this chamber with a newly calibrated instrument to determine the calibrated response over the particle concentration range of interest serves as a reference. Agreement between this reference response and subsequent responses at later dates implies that the instrument is performing as it was at the time of calibration. Side-by-side sampling allows the level of agreement between two or more instruments to be determined. This is useful when simultaneously collected data are compared for differences, i.e., background with process aerosol concentrations. A reference set of data was obtained using the spark igniter. The generation system was found to be reproducible and suitable to form the basis of calibration verification. Finally, the bump test is simple enough to be performed periodically throughout the calibration year or prior to field monitoring.« less

  17. Dust Impact Monitor DIM onboard Rosetta/Philae: Laboratory Calibration with Impact Experiments

    NASA Astrophysics Data System (ADS)

    Krüger, H.; Ossowski, T.; Seidensticker, K.; Apathy, I.; Fischer, H.-H.; Hirn, A.; Jünemann, M.; Loose, A.; Peter, A.; Sperl, M.

    2011-10-01

    The Rosetta lander spacecraft Philae, which will land on the surface of comet 67P/Churyumov- Gerasimenko in late 2014, is equipped with the Dust Impact Monitor instrument (DIM). The DIM sensor, which is part of the SESAME instrument package [Seidensticker et al., 2007], consists of three piezoelectric detectors, each one mounted on the outer side of a cube facing in three orthogonal directions. The total sensor area is approximately 70 cm2. DIM will measure impacts of sub-millimeter and millimeter sized ice and dust particles that are emitted from the nucleus and transported into the cometary coma by the escaping gas flow. A grain-size dependent fraction of the emitted grains is expected to fall back to the nucleus surface due to gravity. DIM will be able to detect both these components, the backfalling particles as well as the grains hitting the detector on direct trajectories from the surface. With DIM we will be able to measure fluxes, impact directions as well as the speed and size of the impacting cometary particles. Two particle acceleration devices for impact calibration experiments are presently available at Max- Planck-Institut für Sonnensystemforschung (MPS), Katlenburg-Lindau: With (a) a dedicated dropping device and (b) a small air gun we can simulate impacts with particles of different materials (steel, glass, ruby, polyethylen, etc.), radii between 0.2 and 1mm and impact speeds up to 2msec-1. We have performed a large number of impact experiments with two flight spare units of the DIM sensor at MPS. We present the results from our impact experiments and discuss their implications for the calibration of the DIM flight instrument.

  18. Instrumentation for calibration and control of a continuous-flow cryogenic tunnel

    NASA Technical Reports Server (NTRS)

    Ladson, C. L.; Kilgore, R. A.

    1980-01-01

    Those aspects of selection and application of calibration and control instrumentation that are influenced by the extremes in the temperature environment to be found in cryogenic tunnels are described with emphasis on the instrumentation and data acquisition system used in the Langley 0.3 m transonic cryogenic tunnel. Typical calibration results obtained in a 20 by 60 cm two dimensional test section are included.

  19. Report on the ''2017 ESO Calibration Workshop: The Second-Generation VLT Instruments and Friends''

    NASA Astrophysics Data System (ADS)

    Smette, A.; Kerber, F.; Kaufer, A.

    2017-03-01

    The participants at the 2017 ESO Calibration Workshop shared their experiences and the challenges encountered in calibrating VLT second-generation instruments and the upgraded first-generation instruments, and discussed improvements in the characterisation of the atmosphere and data reduction. A small group of ESO participants held a follow-up retreat and identified possible game changers in the future operations of the La Silla Paranal Observatory: feedback on the proposals is encouraged.

  20. Specifying and calibrating instrumentations for wideband electronic power measurements. [in switching circuits

    NASA Technical Reports Server (NTRS)

    Lesco, D. J.; Weikle, D. H.

    1980-01-01

    The wideband electric power measurement related topics of electronic wattmeter calibration and specification are discussed. Tested calibration techniques are described in detail. Analytical methods used to determine the bandwidth requirements of instrumentation for switching circuit waveforms are presented and illustrated with examples from electric vehicle type applications. Analog multiplier wattmeters, digital wattmeters and calculating digital oscilloscopes are compared. The instrumentation characteristics which are critical to accurate wideband power measurement are described.

  1. NASA-6 atmospheric measuring station. [calibration, functional checks, and operation of measuring instruments

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Information required to calibrate, functionally check, and operate the Instrumentation Branch equipment on the NASA-6 aircraft is provided. All procedures required for preflight checks and in-flight operation of the NASA-6 atmospheric measuring station are given. The calibration section is intended for only that portion of the system maintained and calibrated by IN-MSD-12 Systems Operation contractor personnel. Maintenance is not included.

  2. 40 CFR 92.117 - Gas meter or flow instrumentation calibration, particulate measurement.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... ENGINES Test Procedures § 92.117 Gas meter or flow instrumentation calibration, particulate measurement... practice. (2) Flow air through the calibration system at the sample flow rate used for particulate testing... standard device. (4) Calculate air flow at standard conditions as measured by both the standard device...

  3. 40 CFR 92.117 - Gas meter or flow instrumentation calibration, particulate measurement.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... ENGINES Test Procedures § 92.117 Gas meter or flow instrumentation calibration, particulate measurement... practice. (2) Flow air through the calibration system at the sample flow rate used for particulate testing... standard device. (4) Calculate air flow at standard conditions as measured by both the standard device...

  4. 40 CFR 92.117 - Gas meter or flow instrumentation calibration, particulate measurement.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... ENGINES Test Procedures § 92.117 Gas meter or flow instrumentation calibration, particulate measurement... practice. (2) Flow air through the calibration system at the sample flow rate used for particulate testing... standard device. (4) Calculate air flow at standard conditions as measured by both the standard device...

  5. 40 CFR 92.117 - Gas meter or flow instrumentation calibration, particulate measurement.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... ENGINES Test Procedures § 92.117 Gas meter or flow instrumentation calibration, particulate measurement... practice. (2) Flow air through the calibration system at the sample flow rate used for particulate testing... standard device. (4) Calculate air flow at standard conditions as measured by both the standard device...

  6. 40 CFR 92.117 - Gas meter or flow instrumentation calibration, particulate measurement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... ENGINES Test Procedures § 92.117 Gas meter or flow instrumentation calibration, particulate measurement... practice. (2) Flow air through the calibration system at the sample flow rate used for particulate testing... standard device. (4) Calculate air flow at standard conditions as measured by both the standard device...

  7. On-line calibration of process instrumentation channels in nuclear power plants

    SciTech Connect

    Hashemian, H.M.; Farmer, J.P.

    1995-04-01

    An on-line instrumentation monitoring system was developed and validated for use in nuclear power plants. This system continuously monitors the calibration status of instrument channels and determines whether or not they require manual calibrations. This is accomplished by comparing the output of each instrument channel to an estimate of the process it is monitoring. If the deviation of the instrument channel from the process estimate is greater than an allowable limit, then the instrument is said to be {open_quotes}out of calibration{close_quotes} and manual adjustments are made to correct the calibration. The success of the on-line monitoring system depends on the accuracy of the process estimation. The system described in this paper incorporates both simple intercomparison techniques as well as analytical approaches in the form of data-driven empirical modeling to estimate the process. On-line testing of the calibration of process instrumentation channels will reduce the number of manual calibrations currently performed, thereby reducing both costs to utilities and radiation exposure to plant personnel.

  8. Laser Calibration of an Impact Disdrometer

    NASA Technical Reports Server (NTRS)

    Lane, John E.; Kasparis, Takis; Metzger, Philip T.; Jones, W. Linwood

    2014-01-01

    A practical approach to developing an operational low-cost disdrometer hinges on implementing an effective in situ adaptive calibration strategy. This calibration strategy lowers the cost of the device and provides a method to guarantee continued automatic calibration. In previous work, a collocated tipping bucket rain gauge was utilized to provide a calibration signal to the disdrometer's digital signal processing software. Rainfall rate is proportional to the 11/3 moment of the drop size distribution (a 7/2 moment can also be assumed, depending on the choice of terminal velocity relationship). In the previous case, the disdrometer calibration was characterized and weighted to the 11/3 moment of the drop size distribution (DSD). Optical extinction by rainfall is proportional to the 2nd moment of the DSD. Using visible laser light as a means to focus and generate an auxiliary calibration signal, the adaptive calibration processing is significantly improved.

  9. SMOS Instrument Performance and Calibration After 6 Years in Orbit

    NASA Astrophysics Data System (ADS)

    Oliva, R.

    2015-12-01

    ESA's Soil Moisture and Ocean Salinity (SMOS) mission has been in orbit for over 6 years, and its Microwave Imaging Radiometer with Aperture Synthesis (MIRAS) in two dimensions keeps working well. The data for this whole period has been recently reprocessed with the new fully polarimetric version (v620) of the Level-1 processor which also includes refined calibration schema for the antenna losses. This reprocessing has allowed the assessment of an improved performance benchmark. The long term drift exhibited by the previous processor version has been significantly mitigated thanks to a better calibration of the antenna losses and the use of only the most accurate Noise Injection Radiometer. These improvements have also reduced the orbital and seasonal variations, although residual drifts still remain, in particular during the satellite eclipse season. The spatial tilt existing in the images produced with the previous version of the Level-1 processor has been considerably decreased, removing the negative trend at low incidence angles and reducing the overall standard deviation of the spatial ripples. The expected improvement in the 3rd and 4th Stokes, after correcting the use of the cross-polar antenna patterns, has been confirmed, enabling accurate retrieval of the Faraday rotation angle. Finally, a better Sun and RFI flagging strategy has been implemented, allowing for the removal of the corrupted data. A problem which still persist in the new Level-1 data is the land-sea contamination. However, recent progress in the calibration investigations has shed new light on the origin of the land-sea contamination, linking it to visibility amplitude calibration errors. Thus, future versions of the Level-1 processor will have very much reduced land-sea contamination. An overview of the results and the progress achieved in both calibration and image reconstruction will be presented in this contribution.

  10. Soot reference materials for instrument calibration and intercomparisons: a workshop summary with recommendations

    NASA Astrophysics Data System (ADS)

    Baumgardner, D.; Popovicheva, O.; Allan, J.; Bernardoni, V.; Cao, J.; Cavalli, F.; Cozic, J.; Diapouli, E.; Eleftheriadis, K.; Genberg, P. J.; Gonzalez, C.; Gysel, M.; John, A.; Kirchstetter, T. W.; Kuhlbusch, T. A. J.; Laborde, M.; Lack, D.; Müller, T.; Niessner, R.; Petzold, A.; Piazzalunga, A.; Putaud, J. P.; Schwarz, J.; Sheridan, P.; Subramanian, R.; Swietlicki, E.; Valli, G.; Vecchi, R.; Viana, M.

    2012-08-01

    Soot, which is produced from biomass burning and the incomplete combustion of fossil and biomass fuels, has been linked to regional and global climate change and to negative health problems. Scientists measure the properties of soot using a variety of methods in order to quantify source emissions and understand its atmospheric chemistry, reactivity under emission conditions, interaction with solar radiation, influence on clouds, and health impacts. A major obstacle currently limiting progress is the absence of established standards or reference materials for calibrating the many instruments used to measure the various properties of soot. The current state of availability and practicability of soot standard reference materials (SRMs) was reviewed by a group of 50 international experts during a workshop in June of 2011. The workshop was convened to summarize the current knowledge on soot measurement techniques, identify the measurement uncertainties and limitations related to the lack of soot SRMs, and identify attributes of SRMs that, if developed, would reduce measurement uncertainties. The workshop established that suitable SRMs are available for calibrating some, but not all, measurement methods. The community of users of the single-particle soot-photometer (SP2), an instrument using laser-induced incandescence, identified a suitable SRM, fullerene soot, but users of instruments that measure light absorption by soot collected on filters did not. Similarly, those who use thermal optical analysis (TOA) to analyze the organic and elemental carbon components of soot were not satisfied with current SRMs. The workshop, and subsequent, interactive discussions, produced a number of recommendations for the development of new SRMs, and their implementation, that would be suitable for the different soot measurement methods.

  11. A Sr-90/Y-90 field calibrator for performance testing of beta-gamma survey instruments

    SciTech Connect

    Olsher, R.H.; Haynie, J.S.

    1988-01-01

    ANSI and regulatory agency guidelines prescribe periodic performance tests for radiation protection instrumentation. Reference readings should be obtained for one point on each scale or decade normally used. A small and lightweight calibrator has been developed that facilitates field testing of beta-gamma survey instruments. The calibrator uses a 45 microcurie Sr-90/Y-90 beta source with a filter wheel to generate variable dose rates in the range from 4 to 400 mrad/hr. Thus, several ranges may be checked by dialing in appropriate filters. The design, use, and typical applications of the calibrator are described.

  12. Application of six sigma and AHP in analysis of variable lead time calibration process instrumentation

    NASA Astrophysics Data System (ADS)

    Rimantho, Dino; Rahman, Tomy Abdul; Cahyadi, Bambang; Tina Hernawati, S.

    2017-02-01

    Calibration of instrumentation equipment in the pharmaceutical industry is an important activity to determine the true value of a measurement. Preliminary studies indicated that occur lead-time calibration resulted in disruption of production and laboratory activities. This study aimed to analyze the causes of lead-time calibration. Several methods used in this study such as, Six Sigma in order to determine the capability process of the calibration instrumentation of equipment. Furthermore, the method of brainstorming, Pareto diagrams, and Fishbone diagrams were used to identify and analyze the problems. Then, the method of Hierarchy Analytical Process (AHP) was used to create a hierarchical structure and prioritize problems. The results showed that the value of DPMO around 40769.23 which was equivalent to the level of sigma in calibration equipment approximately 3,24σ. This indicated the need for improvements in the calibration process. Furthermore, the determination of problem-solving strategies Lead Time Calibration such as, shortens the schedule preventive maintenance, increase the number of instrument Calibrators, and train personnel. Test results on the consistency of the whole matrix of pairwise comparisons and consistency test showed the value of hierarchy the CR below 0.1.

  13. Design and realization of photoelectric instrument binocular optical axis parallelism calibration system

    NASA Astrophysics Data System (ADS)

    Ying, Jia-ju; Chen, Yu-dan; Liu, Jie; Wu, Dong-sheng; Lu, Jun

    2016-10-01

    The maladjustment of photoelectric instrument binocular optical axis parallelism will affect the observe effect directly. A binocular optical axis parallelism digital calibration system is designed. On the basis of the principle of optical axis binocular photoelectric instrument calibration, the scheme of system is designed, and the binocular optical axis parallelism digital calibration system is realized, which include four modules: multiband parallel light tube, optical axis translation, image acquisition system and software system. According to the different characteristics of thermal infrared imager and low-light-level night viewer, different algorithms is used to localize the center of the cross reticle. And the binocular optical axis parallelism calibration is realized for calibrating low-light-level night viewer and thermal infrared imager.

  14. An Altitude Chamber for the Study and Calibration of Aeronautical Instruments

    NASA Technical Reports Server (NTRS)

    Reid, J E; Kirchner, Otto E

    1925-01-01

    The design and construction of an altitude chamber, in which both pressure and temperature can be varied independently, was carried out by the NACA at the Langley Memorial Aeronautical Laboratory for the purpose of studying the effects of temperature and pressure on aeronautical research instruments. Temperatures from +20c to -50c are obtained by the expansion of CO2from standard containers. The chamber can be used for the calibration of research instruments under altitude conditions simulating those up to 45,000 feet. Results obtained with this chamber have a direct application in the design and calibration of instruments used in free flight research.

  15. Preparation of a new autonomous instrumented radiometric calibration site: Gobabeb, Namib Desert

    NASA Astrophysics Data System (ADS)

    Greenwell, Claire; Bialek, Agnieszka; Marks, Amelia; Woolliams, Emma; Berthelot, Béatrice; Meygret, Aimé; Marcq, Sébastien; Bouvet, Marc; Fox, Nigel

    2015-10-01

    A new permanently instrumented radiometric calibration site for high/medium resolution imaging satellite sensors is currently under development, focussing on the visible and near infra-red parts of the spectrum. The site will become a European contribution to the Committee on Earth Observation Satellites (CEOS) initiative RadCalNet (Radiometric Calibration Network). The exact location of the permanent monitoring instrumentation will be defined following the initial site characterisation. The new ESA/CNES RadCalNet site will have a robust uncertainty budget and its data fully SI traceable through detailed characterisation and calibration by NPL of the instruments and artefacts to be used on the site. This includes a CIMEL sun photometer (the permanent instrumentation) an ASD FieldSpec spectroradiometer, Gonio Radiometric Spectrometer System (GRASS), and reference reflectance standards.

  16. 40 CFR 1066.130 - Measurement instrument calibrations and verifications.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... air flow; the linearity verification described in § 1066.135 applies for the following measurements... (CONTINUED) AIR POLLUTION CONTROLS VEHICLE-TESTING PROCEDURES Equipment, Measurement Instruments, Fuel, and... apply for engine speed, torque, fuel rate, or intake air flow. (b) The linearity verification...

  17. Instrumental and Calibration Advancements for the Dark Ages Radio Explorer (DARE)

    NASA Astrophysics Data System (ADS)

    Monsalve, Raul A.; Burns, Jack O.; Bradley, Richard F.; Tauscher, Keith; Nhan, Bang; Bowman, Judd D.; Purcell, William R.; Newell, David; Draper, David

    2017-01-01

    The Dark Ages Radio Explorer (DARE) is a space mission concept proposed to NASA to measure with high precision the monopole component of the redshifted 21-cm signal from neutral hydrogen originated during cosmic dawn at redshifts 35 > z > 11. For the 21-cm line, these high redshifts correspond to the frequency range 40-120 MHz. Through its spectral features, this signal will provide a wealth of information about the large-scale physics of the first stars, galaxies and black holes. The signal is expected to have an absolute amplitude below 200 mK, which is five orders of magnitude smaller than the diffuse foregrounds dominated by Galactic synchrotron radiation. In order to avoid the impact of the Earth’s ionosphere, which corrupts low-frequency radio waves through refraction, absorption, and emission, this measurement is conducted from orbit above the far side of the Moon. This location is ideal because it enables the Moon to shield the spacecraft from Solar radiation and terrestrial radio-frequency interference. The DARE instrument is designed around a dual-polarization, widefield, wideband, biconical antenna, which provides full-Stokes capabilities in order to measure and remove the low-level polarized component of the foregrounds. The spacecraft is rotated about its boresight axis at 1 RPM to modulate the foregrounds and separate them from the spatially uniform cosmological signal. The instrument requires exquisite calibration to reach a sensitivity of a few mK in the presence of strong foregrounds. For this purpose, the frequency-dependent antenna beam is characterized to 20 ppm. This is accomplished through a combination of electromagnetic simulations, anechoic chamber measurements, and on-orbit mapping using a calibrated high-power ground-based source. The DARE front-end receiver is characterized on the ground in terms of its input impedance, gain, noise properties, and stability. Its performance is verified when operating on-orbit at a fixed temperature

  18. S-NPP VIIRS instrument telemetry and calibration data trend study

    NASA Astrophysics Data System (ADS)

    Sun, ZiPing; De Luccia, Frank J.; Cardema, Jason C.; Moy, Gabriel

    2015-09-01

    The Suomi National Polar Orbiting Partnership (S-NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) employs a large number of temperature and voltage sensors (telemetry points) to monitor instrument health and performance. We have collected data and built tools to study telemetry and calibration parameters trends. The telemetry points are organized into groups based on locations and functionalities. Examples of the groups are: telescope motor, focal plane array (FPA), scan cavity bulkhead, radiators, solar diffuser and Solar Diffuser Stability Monitor (SDSM). We have performed daily monitoring and long-term trending studies. Daily monitoring processes are automated with alarms built into the software to indicate if pre-defined limits are exceeded. Long-term trending studies focus on instrument performance and sensitivities of Sensor Data Record (SDR) products and calibration look-up tables (LUTs) to instrument temperature and voltage variations. VIIRS uses a DC Restore (DCR) process to periodically correct the analog offsets of each detector of each spectral band to ensure that the FPA output signals are always within the dynamic range of the Analog to Digital Converter (ADC). The offset values are updated based on observations of the On-Board Calibrator Blackbody source. We have performed a long-term trend study of DCR offsets and calibration parameters to explore connections of the DCR offsets with onboard calibrators. The study also shows how the instrument and calibration parameters respond to the VIIRS Petulant Mode, spacecraft (SC) anomalies and flight software (FSW) updates. We have also shown that trending studies of telemetry and calibration parameters may help to improve the instrument calibration processes and SDR Quality Flags.

  19. CheMin Instrument Performance and Calibration on Mars

    NASA Technical Reports Server (NTRS)

    Vaniman, D. T.; Blake, D. F.; Morookian, J. M.; Yen, A. S.; Ming, D. W.; Morris, R. V.; Achilles, C. N.; Bish, D. L.; Chipera, S. J.; Morrison, S. M.; Downs, R. T.; Rampe, E. B.; Sarrazin, P. C.; Treiman, A. H.; Anderson, R. C.; Bristow, T. F.; Crisp, J. A.; Des Marais, D. J.; Spanovich, N.; Wilson, M. A.

    2013-01-01

    The CheMin (Chemistry and Mineralogy) instrument on the Mars Science Laboratory rover Curiosity uses a CCD detector and a Co-anode X-ray tube source to acquire both mineralogy (from the pattern of Co diffraction) and chemical information (from energies of fluoresced X-rays). A key component of the CheMin instrument is the ability to move grains within sample cells during analysis, providing multiple, random grain orientations that disperse diffracted X-ray photons along Debye rings rather than producing discrete Laue spots. This movement is accomplished by piezoelectric vibration of the sample cells. A cryocooler is used to maintain the CCD at a temperature at about -50 C in order to obtain energy resolution better than 250 eV, allowing discrimination of diffracted Co K X-rays from Fe K and other fluorescent X-rays. A detailed description of CheMin is provided in [1]. The CheMin flight model (FM) is mounted within the body of Curiosity and has been operating on Mars since August 6, 2012. An essentially identical sister instrument, the CheMin demonstration model (DM), is operated in a Mars environment chamber at JPL.

  20. Photometric and Thermal Cross-calibration of Solar EUV Instruments

    NASA Astrophysics Data System (ADS)

    Boerner, P. F.; Testa, P.; Warren, H.; Weber, M. A.; Schrijver, C. J.

    2014-06-01

    We present an assessment of the accuracy of the calibration measurements and atomic physics models that go into calculating the SDO/AIA response as a function of wavelength and temperature. The wavelength response is tested by convolving SDO/EVE and Hinode/EIS spectral data with the AIA effective area functions and by comparing the predictions with AIA observations. For most channels, the AIA intensities summed over the disk agree with the corresponding measurements derived from the current version (V2) of the EVE data to within the estimated 25 % calibration error. This agreement indicates that the AIA effective areas are generally stable in time. The AIA 304 Å channel, however, does show degradation by a factor of almost 3 from May 2010 through September 2011, when the throughput apparently reached a minimum. We also found some inconsistencies in the 335 Å passband, possibly due to higher-order contamination of the EVE data. The intensities in the AIA 193 Å channel agree to within the uncertainties with the corresponding measurements from EIS full CCD observations. Analysis of high-resolution X-ray spectra of the solar-like corona of Procyon and of EVE spectra allowed us to investigate the accuracy and completeness of the CHIANTI database in the AIA shorter wavelength passbands. We found that in the 94 Å channel, the spectral model significantly underestimates the plasma emission owing to a multitude of missing lines. We derived an empirical correction for the AIA temperature responses by performing differential emission measure (DEM) inversion on a broad set of EVE spectra and adjusting the AIA response functions so that the count rates predicted by the full-disk DEMs match the observations.

  1. Calibration of the GNU and HSREM neutron survey instruments

    NASA Astrophysics Data System (ADS)

    Eakins, J. S.; Hager, L. G.; Leake, J. W.; Mason, R. S.; Tanner, R. J.

    2017-04-01

    Two innovative designs of neutron survey instrument have recently been developed to estimate ambient dose equivalent in the workplace: the GNU has an improved energy-independence of response in the meV to TeV range; the HSREM is a comparatively lightweight device covering the meV to 10 MeV range. Both designs offer good detection sensitivity, allowing measurements to be made efficiently and thereby minimizing the exposure to their users. Prototypes of both devices have been constructed and exposed to sets of well-characterized reference fields: the resulting measured responses are presented and discussed here, compared against comprehensive Monte Carlo data.

  2. Long-term analysis of GOME in-flight calibration parameters and instrument degradation.

    PubMed

    Coldewey-Egbers, Melanie; Slijkhuis, Sander; Aberle, Bernd; Loyola, Diego

    2008-09-10

    Since 1995, the Global Ozone Monitoring Experiment (GOME) has measured solar and backscattered spectra in the ultraviolet and visible wavelength range. Now, the extensive data set of the most important calibration parameters has been investigated thoroughly in order to analyze the long-term stability and performance of the instrument. This study focuses on GOME in-flight calibration and degradation for the solar path. Monitoring the sensor degradation yields an intensity decrease of 70% to 90% in 240-316 nm and 35% to 65% in 311-415 nm. The spectral calibration is very stable over the whole period, although a very complex interaction between predisperser temperature and wavelength was found. The leakage current and the pixel-to-pixel gain increased significantly during the mission, which requires an accurate correction of the measured radiance and irradiance signals using proper calibration parameters. Finally, several outliers in the data sets can be directly assigned to instrument and satellite anomalies.

  3. Software System for the Calibration of X-Ray Measuring Instruments

    NASA Astrophysics Data System (ADS)

    Gaytán-Gallardo, E.; Tovar-Muñoz, V. M.; Cruz-Estrada, P.; Vergara-Martínez, F. J.; Rivero-Gutiérrez, T.

    2006-09-01

    A software system that facilities the calibration of X-ray measuring instruments used in medical applications is presented. The Secondary Standard Dosimetry Laboratory (SSDL) of the Nuclear Research National Institute in México (ININ in Spanish), supports activities concerning with ionizing radiations in medical area. One of these activities is the calibration of X-ray measuring instruments, in terms of air kerma or exposure by substitution method in an X-ray beam at a point where the rate has been determined by means of a standard ionization chamber. To automatize this process, a software system has been developed, the calibration system is composed by an X-ray unit, a Dynalizer IIIU X-ray meter by RADCAL, a commercial data acquisition card, the software system and the units to be tested and calibrated. A quality control plan has been applied in the development of the software system, ensuring that quality assurance procedures and standards are being followed.

  4. Design Through Integration of On-Board Calibration Device with Imaging Spectroscopy Instruments

    NASA Technical Reports Server (NTRS)

    Stange, Michael

    2012-01-01

    The main purpose of the Airborne Visible and Infrared Imaging Spectroscopy (AVIRIS) project is to "identify, measure, and monitor constituents of the Earth's surface and atmosphere based on molecular absorption and particle scattering signatures." The project designs, builds, and tests various imaging spectroscopy instruments that use On-Board Calibration devices (OBC) to check the accuracy of the data collected by the spectrometers. The imaging instrument records the spectral signatures of light collected during flight. To verify the data is correct, the OBC shines light which is collected by the imaging spectrometer and compared against previous calibration data to track spectral response changes in the instrument. The spectral data has the calibration applied to it based on the readings from the OBC data in order to ensure accuracy.

  5. Droplet sizing instrumentation used for icing research: Operation, calibration, and accuracy

    NASA Technical Reports Server (NTRS)

    Hovenac, Edward A.

    1989-01-01

    The accuracy of the Forward Scattering Spectrometer Probe (FSSP) is determined using laboratory tests, wind tunnel comparisons, and computer simulations. Operation in an icing environment is discussed and a new calibration device for the FSSP (the rotating pinhole) is demonstrated to be a valuable tool. Operation of the Optical Array Probe is also presented along with a calibration device (the rotating reticle) which is suitable for performing detailed analysis of that instrument.

  6. Multivariate calibration and instrument standardization for the rapid detection of diethylene glycol in glycerin by Raman spectroscopy.

    PubMed

    Gryniewicz-Ruzicka, Connie M; Arzhantsev, Sergey; Pelster, Lindsey N; Westenberger, Benjamin J; Buhse, Lucinda F; Kauffman, John F

    2011-03-01

    The transfer of a multivariate calibration model for quantitative determination of diethylene glycol (DEG) contaminant in pharmaceutical-grade glycerin between five portable Raman spectrometers was accomplished using piecewise direct standardization (PDS). The calibration set was developed using a multi-range ternary mixture design with successively reduced impurity concentration ranges. It was found that optimal selection of calibration transfer standards using the Kennard-Stone algorithm also required application of the algorithm to multiple successively reduced impurity concentration ranges. Partial least squares (PLS) calibration models were developed using the calibration set measured independently on each of the five spectrometers. The performance of the models was evaluated based on the root mean square error of prediction (RMSEP), calculated using independent validation samples. An F-test showed that no statistical differences in the variances were observed between models developed on different instruments. Direct cross-instrument prediction without standardization was performed between a single primary instrument and each of the four secondary instruments to evaluate the robustness of the primary instrument calibration model. Significant increases in the RMSEP values for the secondary instruments were observed due to instrument variability. Application of piecewise direct standardization using the optimal calibration transfer subset resulted in the lowest values of RMSEP for the secondary instruments. Using the optimal calibration transfer subset, an optimized calibration model was developed using a subset of the original calibration set, resulting in a DEG detection limit of 0.32% across all five instruments.

  7. Suborbital Reusable Launch Vehicles as an Opportunity to Consolidate and Calibrate Ground Based and Satellite Instruments

    NASA Astrophysics Data System (ADS)

    Papadopoulos, K.

    2014-12-01

    XCOR Aerospace, a commercial space company, is planning to provide frequent, low cost access to near-Earth space on the Lynx suborbital Reusable Launch Vehicle (sRLV). Measurements in the external vacuum environment can be made and can launch from most runways on a limited lead time. Lynx can operate as a platform to perform suborbital in situ measurements and remote sensing to supplement models and simulations with new data points. These measurements can serve as a quantitative link to existing instruments and be used as a basis to calibrate detectors on spacecraft. Easier access to suborbital data can improve the longevity and cohesiveness of spacecraft and ground-based resources. A study of how these measurements can be made on Lynx sRLV will be presented. At the boundary between terrestrial and space weather, measurements from instruments on Lynx can help develop algorithms to optimize the consolidation of ground and satellite based data as well as assimilate global models with new data points. For example, current tides and the equatorial electrojet, essential to understanding the Thermosphere-Ionosphere system, can be measured in situ frequently and on short notice. Furthermore, a negative-ion spectrometer and a Faraday cup, can take measurements of the D-region ion composition. A differential GPS receiver can infer the spatial gradient of ionospheric electron density. Instruments and optics on spacecraft degrade over time, leading to calibration drift. Lynx can be a cost effective platform for deploying a reference instrument to calibrate satellites with a frequent and fast turnaround and a successful return of the instrument. A calibrated reference instrument on Lynx can make collocated observations as another instrument and corrections are made for the latter, thus ensuring data consistency and mission longevity. Aboard a sRLV, atmospheric conditions that distort remotely sensed data (ground and spacecraft based) can be measured in situ. Moreover, an

  8. Inter-calibration and validation of observations from SAPHIR and ATMS instruments

    NASA Astrophysics Data System (ADS)

    Moradi, I.; Ferraro, R. R.

    2015-12-01

    We present the results of evaluating observations from microwave instruments aboard the Suomi National Polar-orbiting Partnership (NPP, ATMS instrument) and Megha-Tropiques (SAPHIR instrument) satellites. The study includes inter-comparison and inter-calibration of observations of similar channels from the two instruments, evaluation of the satellite data using high-quality radiosonde data from Atmospheric Radiation Measurement Program and GPS Radio Occultaion Observations from COSMIC mission, as well as geolocation error correction. The results of this study are valuable for generating climate data records from these instruments as well as for extending current climate data records from similar instruments such as AMSU-B and MHS to the ATMS and SAPHIR instruments. Reference: Moradi et al., Intercalibration and Validation of Observations From ATMS and SAPHIR Microwave Sounders. IEEE Transactions on Geoscience and Remote Sensing. 01/2015; DOI: 10.1109/TGRS.2015.2427165

  9. Calibration and intercomparison of water vapor instrumentation used on the NSF/NCAR HIAPER aircraft

    NASA Astrophysics Data System (ADS)

    Kraemer, D.; Campos, T.; Flocke, F.; Jensen, J.; Wang, J.; Cole, H.; Korn, E.; Lauritsen, D.; Kraemer, M.

    2007-12-01

    Subject of the study is the characterization of a Kahn DCS-80 water vapor calibration system and the calibration of two water vapor sensors used on research aircraft, namely a Buck Instruments B-1001 chilled mirror sensor and a MayComm Tunable Diode Laser Absorption Hygrometer. A series of Vaisala drop sondes were also characterized and compared to the aircraft instruments. In an effort to assess the precision of the water vapor sensors that are being used on board the NSF/NACR GV aircraft (HIAPER), the instruments were tested at ambient pressure (800 mbar) inside an environmental chamber to simulate temperature conditions during flight. Tested dewpoints ranged from -70 to +20 degrees Celsius. The TDL - hygrometer was calibrated in preparation for an international water vapor measurement intercomparison campaign at the Forschungszentrum Karlsruhe, Germany. We will present the detailed calibration and characterization procedure, the laboratory setup for the different sensors, results from the calibrations of all instruments, assess their precision and useful operating range, and present some preliminary results from the international intercomparison campaign.

  10. Updated Global Data from the Guvi Instrument: New Products, Updated Calibration, and a New Web Interface

    NASA Astrophysics Data System (ADS)

    Schaefer, R. K.; Paxton, L. J.; Romeo, G.; Wolven, B. C.; Zhang, Y.; Comberiate, J.

    2014-12-01

    With it's high inclination orbit, GUVI provides global coverage of the ionosphere/thermosphere system, revisiting each polar region 15 times a day. The GUVI instrument has long been a resource for the ITM community with a panoply of data products available from the GUVI website (http://guvi.jhuapl.edu). GUVI is in a high inclination orbit and so provides coverage of both hemispheres. With the release last year of the data products from the DMSO/SSUSI instrument, particularly more detailed auroral zone products (Q, E0, Hemispheric Power, discrete auroral arcs, proton precipitation regions), new equatorial ionospheric products (3D electron densities, bubbles), a whole new set of UV data products has become available. SSUSI are available from http://ssusi.jhuapl.edu. To leverage the experience and knowledge gained from running all of these instruments we have adapted the SSUSI products so they can be made from GUVI telemetry. There are now updated versions of GUVI legacy products as well as brand new products. In addition, better on-orbit calibration techniques developed for SSUSI have now been applied to the GUVI instrument calibration - there is now a common set of software for calibrating both instruments. With a common data format, calibration, and product definition, the data from all SSUSI and GUVI instruments can now be easily combined to get multiple instruments to cover the hemispheres to do a variety of global studies. In addition, the GUVI spectrographic mode data provides great detail about spectrographic features (e.g. O/N2 ratios, NO band emission) that are important for understanding dynamical processes in the thermosphere. A new version of the GUVI website (with the same interface as the SSUSI website) has been launched from guvi.jhuapl.edu to showcase the legacy products made with the new calibration and also highlight the newly developed products for the GUVI imaging and spectrographic modes.

  11. Windowless Far-Ultraviolet Electron Impact Calibration Lamp

    NASA Astrophysics Data System (ADS)

    France, K.; McCandliss, S. R.; Pelton, R.

    2002-12-01

    We present preliminary results from a windowless calibration lamp for determining wavelength solutions and detector flat-fielding at far-ultraviolet wavelengths. This lamp produces free electrons from a filament, accelerating them toward a tungsten target by an applied voltage ( 200 - 2000 V). An emission line spectrum is produced by electrons impacting the residual gas molecules present and continuous emission is produced by bremsstrahlung as the electrons collide with the target. The emission line spectrum can be modified to provide a rich wavelength coverage by introducing different species, and spectra of H2, N2, O2, CO2, HD, and Ar have been measured at modest spectral resolution (1 Å) across the far-UV bandpass (900 - 1400 Å). The long wavelength tail of the x-ray bremsstrahlung continuum falling in this bandpass can be used to make detector flat-field measurements. The lamp is robust and compact, housed in a mini-conflat cube and operates at the ambient vacuum compatible with microchannel plate operation. It is scheduled to be tested on an upcoming sounding rocket flight. We present initial results of both electron impact and bremsstrahlung spectra and adaptability to space-based instrumentation. This work is supported by NASA grant NAG5-5315 to The Johns Hopkins University.

  12. Development and Calibration of Space Flight Instruments at the University of Bern

    NASA Astrophysics Data System (ADS)

    Scheer, Jürgen A.; Wurz, Peter

    2014-05-01

    Since more than 40 years the division for Space Research and Planetary Sciences of the Physical Institute of the University of Bern develops space flight instruments, such as mass spectrometers, pressure gauges, laser altimeters, and more. Consequently, space flight instruments developed in Bern or with Bernese participation were flown on multiple space missions, for example GEOS, GIOTTO, ULYSSES, SOHO, ROSETTA, and IBEX. All these instruments need to be tested for functionality upon their different development stages (prototypes and engineering units) and the flight units need to be calibrated. Furthermore, these instruments do also need to be tested for survival regarding vibration, shock and thermal loads. Over the years different facilities have been set up at the Physical Institute of the University of Bern to do such work. This report will present these facilities with special respect to the aspect of calibration.

  13. Neutron monitoring systems including gamma thermometers and methods of calibrating nuclear instruments using gamma thermometers

    DOEpatents

    Moen, Stephan Craig; Meyers, Craig Glenn; Petzen, John Alexander; Foard, Adam Muhling

    2012-08-07

    A method of calibrating a nuclear instrument using a gamma thermometer may include: measuring, in the instrument, local neutron flux; generating, from the instrument, a first signal proportional to the neutron flux; measuring, in the gamma thermometer, local gamma flux; generating, from the gamma thermometer, a second signal proportional to the gamma flux; compensating the second signal; and calibrating a gain of the instrument based on the compensated second signal. Compensating the second signal may include: calculating selected yield fractions for specific groups of delayed gamma sources; calculating time constants for the specific groups; calculating a third signal that corresponds to delayed local gamma flux based on the selected yield fractions and time constants; and calculating the compensated second signal by subtracting the third signal from the second signal. The specific groups may have decay time constants greater than 5.times.10.sup.-1 seconds and less than 5.times.10.sup.5 seconds.

  14. Status of Aqua MODIS Instrument On-Orbit Operation and Calibration

    NASA Technical Reports Server (NTRS)

    Xiong, Jack; Angal, Amit; Madhaven, Sri; Choi, Jason; Wenny, Brian; Sun, Junqiang; Wu, Aisheng; Chen, Hongda; Salomonson, Vincent; Barnes, William

    2011-01-01

    The Aqua MOderate resolution Imaging Spectroradiometer (MODIS) has successfully operated for nearly a decade, since its launch in May 2002. MODIS was developed and designed with improvements over its heritage sensors in terms of its overall spectral, spatial, and temporal characteristics, and with more stringent calibration requirements. MODIS carries a set of on-board calibrators that can be used to track and monitor its on-orbit radiometric, spectral, and spatial performance. Since launch, extensive instrument calibration and characterization activities have been scheduled and executed by the MODIS Characterization Support Team (MCST). These efforts are made to assure the quality of instrument calibration and L 1B data products, as well as support all science disciplines (land, ocean, and atmospheric) for continuous improvements of science data product quality. MODIS observations from both Terra and Aqua have significantly contributed to the science and user community over a wide range of research activities and applications. This paper provides an overview of Aqua MODIS on-orbit operation and calibration activities, instrument health status, and on-board calibrators (OBC) performance. On-orbit changes of key sensor parameters, such as spectral band radiometric responses, center wavelengths, and bandwidth, are illustrated and compared with those derived from its predecessor, Terra MODIS. Lessons and challenges identified from Aqua MODIS performance are also discussed in this paper. These lessons are not only critical to future improvements of Aqua MODIS on-orbit operation and calibration but also beneficial to its follow-on instrument, the Visible Infrared Imager Radiometer Suite (VIIRS) to be launched on NPOESS Preparatory Project (NPP) spacecraft.

  15. A New Automatic System for Angular Measurement and Calibration in Radiometric Instruments

    PubMed Central

    Marquez, Jose Manuel Andujar; Bohórquez, Miguel Ángel Martínez; Garcia, Jonathan Medina; Nieto, Francisco Jose Aguilar

    2010-01-01

    This paper puts forward the design, construction and testing of a new automatic system for angular-response measurement and calibration in radiometric instruments. Its main characteristics include precision, speed, resolution, noise immunity, easy programming and operation. The developed system calculates the cosine error of the radiometer under test by means of a virtual instrument, from the measures it takes and through a mathematical procedure, thus allowing correcting the radiometer with the aim of preventing cosine error in its measurements. PMID:22319320

  16. A new automatic system for angular measurement and calibration in radiometric instruments.

    PubMed

    Marquez, Jose Manuel Andujar; Bohórquez, Miguel Ángel Martínez; Garcia, Jonathan Medina; Nieto, Francisco Jose Aguilar

    2010-01-01

    This paper puts forward the design, construction and testing of a new automatic system for angular-response measurement and calibration in radiometric instruments. Its main characteristics include precision, speed, resolution, noise immunity, easy programming and operation. The developed system calculates the cosine error of the radiometer under test by means of a virtual instrument, from the measures it takes and through a mathematical procedure, thus allowing correcting the radiometer with the aim of preventing cosine error in its measurements.

  17. Across-subject calibration of an instrumented glove to measure hand movement for clinical purposes.

    PubMed

    Gracia-Ibáñez, Verónica; Vergara, Margarita; Buffi, James H; Murray, Wendy M; Sancho-Bru, Joaquín L

    2017-05-01

    Motion capture of all degrees of freedom of the hand collected during performance of daily living activities remains challenging. Instrumented gloves are an attractive option because of their higher ease of use. However, subject-specific calibration of gloves is lengthy and has limitations for individuals with disabilities. Here, a calibration procedure is presented, consisting in the recording of just a simple hand position so as to allow capture of the kinematics of 16 hand joints during daily life activities even in case of severe injured hands. 'across-subject gains' were obtained by averaging the gains obtained from a detailed subject-specific calibration involving 44 registrations that was repeated three times on multiple days to 6 subjects. In additional 4 subjects, joint angles that resulted from applying the 'across-subject calibration' or the subject-specific calibration were compared. Global errors associated with the 'across-subject calibration' relative to the detailed, subject-specific protocol were small (bias: 0.49°; precision: 4.45°) and comparable to those that resulted from repeating the detailed protocol with the same subject on multiple days (0.36°; 3.50°). Furthermore, in one subject, performance of the 'across-subject calibration' was directly compared to another fast calibration method, expressed relative to a videogrammetric protocol as a gold-standard, yielding better results.

  18. Impact of calibration on estimates of central blood pressures.

    PubMed

    Soender, T K; Van Bortel, L M; Møller, J E; Lambrechtsen, J; Hangaard, J; Egstrup, K

    2012-12-01

    Using the Sphygmocor device it is recommended that the radial pressure wave is calibrated for brachial systolic blood pressure (SBP) and diastolic blood pressure (DBP). However it has been suggested that brachial-to-radial pressure amplification causes underestimation of central blood pressures (BPs) using this calibration. In the present study we examined if different calibrations had an impact on estimates of central BPs and on the clinical interpretation of our results. On the basis of ambulatory BP measurements, patients were categorized into patients with controlled, uncontrolled or resistant hypertension. We first calibrated the radial pressure wave as recommended and afterwards recalibrated the same pressure wave using brachial DBP and calculated mean arterial pressure. Recalibration of the pressure wave generated significantly higher estimates of central SBP (P=0.0003 and P<0.0001 at baseline and P=0.0001 and P=0.0002 after 6 months). Using recommended calibration we found a significant change in central SBP in both treatment groups (P=0.05 and P=0.01), however, after recalibrating significance was lost in patients with resistant hypertension (P=0.15). We conclude that calibration with DBP and mean arterial pressure produces higher estimates of central BPs than recommended calibration. The present study also shows that this difference between the two calibration methods can produce more than a systematic error and has an impact on interpretation of clinical results.

  19. Calibration of the Quadrupole Mass Spectrometer of the Sample Analysis at Mars Instrument Suite

    NASA Technical Reports Server (NTRS)

    Mahaffy, P. R.; Trainer, M. G.; Eigenbrode, J. L.; Franz, H. B.; Stern, J. C.; Harpold, D.; Conrad, P. G.; Raaen, E.; Lyness, E.

    2011-01-01

    The SAM suite of instruments on the "Curiosity" Rover of the Mars Science Laboratory (MSL) is designed to provide chemical and isotopic analysis of organic and inorganic volatiles for both atmospheric and solid samples. The mission of the MSL investigations is to advance beyond the successful search for aqueous transformation in surface environments at Mars toward a quantitative assessment of habitability and preservation through a series of chemical and geological measurements. The SAM suite was delivered in December 2010 (Figure 1) to the Jet Propulsion Laboratory for integration into the Curiosity Rover. We previously outlined the range of SAM solid and gas calibrations implemented or planned and here we discuss a specific set of calibration experiments to establish the response of the SAM Quadrupole Mass Spectrometer (QMS) to the four most abundant gases in the Martian atmosphere CO2, N2, Ar, and O2, A full SAM instrument description and calibration report is presently in preparation.

  20. Inter-calibrating, Multi-instrument Microwave Ocean Data Records over Three Decades

    NASA Astrophysics Data System (ADS)

    Smith, D. K.; Wentz, F. J.

    2015-12-01

    Satellite microwave radiometers have been in continuous operation since 1987. When inter-calibrated and consistently processed, the data from a series of DMSP SSM/I and SSMIS sensors, TRMM TMI, Coriolis WindSat, Aqua AMSR-E, GCOM-W1 AMSR2, and GPM GMI collectively result in a long-term high-quality ocean data set of surface winds, atmospheric water vapor, cloud liquid water content, rain rate, and for some instruments, sea surface temperature and wind direction. Slight variations in frequencies, design and satellite orbits stress the need for carefully implementing an inter-calibration method, so as not to introduce trends or jumps when new instruments begin or when old instruments drift and/or die. The authors have developed a robust inter-calibration method using a published, well-developed and validated radiative transfer model (RTM) as the calibration standard. Most of the sensor data for this nearly 30-year period are available as the Version-7 RTM standard. The GMI sensor, recently launched in 2014, has strict calibration accuracy requirements and was built to have greater precision than any previous microwave sensor. We have utilized the dual calibration and non-linearity-measurement systems built into GMI to improve the RTM, which is now Version-8. In this talk we will present an overview of our calibration procedures and outline the steps required to produce climate quality earth data records. We also intend to present the latest validation results and provide information on recent changes in distribution, format, and availability for these already-popular data products.

  1. Calibration of the Reflected Solar Instrument for the Climate Absolute Radiance and Refractivity Observatory

    NASA Technical Reports Server (NTRS)

    Thome, Kurtis; Barnes, Robert; Baize, Rosemary; O'Connell, Joseph; Hair, Jason

    2010-01-01

    The Climate Absolute Radiance and Refractivity Observatory (CLARREO) plans to observe climate change trends over decadal time scales to determine the accuracy of climate projections. The project relies on spaceborne earth observations of SI-traceable variables sensitive to key decadal change parameters. The mission includes a reflected solar instrument retrieving at-sensor reflectance over the 320 to 2300 nm spectral range with 500-m spatial resolution and 100-km swath. Reflectance is obtained from the ratio of measurements of the earth s surface to those while viewing the sun relying on a calibration approach that retrieves reflectance with uncertainties less than 0.3%. The calibration is predicated on heritage hardware, reduction of sensor complexity, adherence to detector-based calibration standards, and an ability to simulate in the laboratory on-orbit sources in both size and brightness to provide the basis of a transfer to orbit of the laboratory calibration including a link to absolute solar irradiance measurements.

  2. Polarimetric calibrations and astronomical polarimetry in the V-band with Solar Orbiter/METIS instrument

    NASA Astrophysics Data System (ADS)

    Capobianco, Gerardo; Fineschi, Silvano; Focardi, Mauro; Andretta, Vincenzo; Massone, Giuseppe; Bemporad, Alessandro; Romoli, Marco; Antonucci, Ester; Naletto, Giampiero; Nicolini, Gianalfredo; Nicolosi, Piergiorgio; Spadaro, Daniele

    2014-08-01

    METIS is one of the remote sensing instruments on board the ESA- Solar Orbiter mission, that will be launched in July 2017. The Visible Light Channel (VLC) of the instrument is composed by an achromatic LC-based polarimeter for the study of the linearly polarized solar K-corona in the 580-640 nm bandpass. The laboratory calibrations with spectropolarimetric techniques and the in-flight calibrations of this channel, using some well knows linearly polarized stars in the FoV of the instrument with a degree of linear polarization DOLP > 10% are here discussed. The selection of the stars and the use of other astronomical targets (i.e. planets, comets,…) and the opportunity of measurements of the degree of linear polarization in the visible bandpass of some astronomical objects (i.e. Earth, comets,…) are also objects of this paper.

  3. GIADA - Grain Impact Analyzer and Dust Accumulator - Onboard Rosetta spacecraft: Extended calibrations

    NASA Astrophysics Data System (ADS)

    Della Corte, V.; Sordini, R.; Accolla, M.; Ferrari, M.; Ivanovski, S.; Rotundi, A.; Rietmeijer, F. J. M.; Fulle, M.; Mazzotta-Epifani, E.; Palumbo, P.; Colangeli, L.; Lopez-Moreno, J. J.; Rodriguez, J.; Morales, R.; Cosi, M.

    2016-09-01

    Despite a long tradition of dust instruments flown on-board space mission, the largest number of these can be considered unique as they used different detection techniques. GIADA (Grain Impact Analyzer and Dust Accumulator), is one of the dust instruments on-board the Rosetta spacecraft and is devoted to measure the dust dynamical parameters in the coma of comet 67P/Churyumov-Gerasimenko. It couples two different techniques to measure the mass and speed of individual dust particles. We report here the results of an extended calibration activity carried-out, during the hibernation phase of the Rosetta mission, on the GIADA Proto Flight Model (PFM) operative in a clean room in our laboratory. The main aims of an additional calibration campaign are: to verify the algorithms and procedures for data calibration developed before Rosetta launch; to improve the comprehension of GIADA response after the increased knowledge on cometary dust, e.g. the composition of dust particles after Stardust mission. These calibration improvements implied a final step, which consisted in defining transfer functions to correlate the new calibration curves obtained for the GIADA PFM to those to be used for GIADA onboard the Rosetta spacecraft. The extended calibration activity allowed us to analyze GIADA data acquired in the 67P/C-G coma permitting to infer additional information on cometary dust particles, e.g. density and tensile strength.

  4. Millipol, a millimeter/submillimeter wavelength polarimeter - Instrument, operation, and calibration

    NASA Technical Reports Server (NTRS)

    Clemens, Dan P.; Kane, Brian D.; Leach, Robert W.; Barvainis, Richard

    1990-01-01

    An instrument capable of measuring the polarization characteristics of weakly polarized, cold dust at millimeter and submillimeter wavelengths is presented in detail. The operation and calibration of this polarimeter at a wavelength of 1300 microns, configured for the NRAO 12-meter telescope, are discussed. Deep observations of Jupiter using this instrument revealed a main-beam instrumental polarization at, or below, the 0.2 percent level. Lunar limb observations revealed a sidelobe polarization sensitivity, in the range 0.25 percent - 1.0 percent. Further, through these efforts the nonthermal polarized flux from Jupiter at a level of about 0.04 percent of the thermal flux has been detected. Astronomical polarization measurements to 0.03 percent are possible, limited by the uncertainties in the instrumental polarization. This instrument has been primarily employed to measure and map magnetic-field directions in the very optically opaque cores of massive molecular clouds.

  5. 10 CFR 35.60 - Possession, use, and calibration of instruments used to measure the activity of unsealed...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Possession, use, and calibration of instruments used to measure the activity of unsealed byproduct material. 35.60 Section 35.60 Energy NUCLEAR REGULATORY... calibration of instruments used to measure the activity of unsealed byproduct material. (a) For...

  6. 10 CFR 35.2060 - Records of calibrations of instruments used to measure the activity of unsealed byproduct material.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Records of calibrations of instruments used to measure the activity of unsealed byproduct material. 35.2060 Section 35.2060 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL Records § 35.2060 Records of calibrations of instruments used to...

  7. 10 CFR 35.2060 - Records of calibrations of instruments used to measure the activity of unsealed byproduct material.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Records of calibrations of instruments used to measure the activity of unsealed byproduct material. 35.2060 Section 35.2060 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL Records § 35.2060 Records of calibrations of instruments used to...

  8. 10 CFR 35.2060 - Records of calibrations of instruments used to measure the activity of unsealed byproduct material.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Records of calibrations of instruments used to measure the activity of unsealed byproduct material. 35.2060 Section 35.2060 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL Records § 35.2060 Records of calibrations of instruments used to...

  9. Calibration of high resolution remote sensing instruments in the visible and near infrared

    NASA Astrophysics Data System (ADS)

    Schüller, L.; Fischer, J.; Armbruster, W.; Bartsch, B.

    1997-05-01

    Measurements of the reflected solar radiation with high spectral resolution airborne instruments are usually used to develop new remote sensing techniques. The observed spectral features in the signals provide the possibility to define useful band settings for future satellite instruments. A precise wavelength and radiometric calibration is a prerequisite for such tasks. In this paper, a calibration procedure for the airborne spectrometer OVID is presented. The Optical Visible and near Infrared Detector consists of two similar detector systems, (600 - 1100 nm = VIS and 900 - 1700 nm = NIR). The spectral resolution is ~1.7 nm for the VIS-system and ~6 nm for the IR-system. This instrument is applied for the retrieval of water vapour content, aerosol and cloud properties. Besides the spectral and intensity calibration, also corrections for the dark current signals and for defective pixels have been performed. An indirect verification of the calibration procedure by the comparison of OVID measurements in cloudy and cloud free atmospheres with radiative transfer simulations is discussed in this paper. The used radiation transfer model MOMO is based on the matrix operator method.

  10. The GOME-2 instrument on the Metop series of satellites: instrument design, calibration, and level 1 data processing - an overview

    NASA Astrophysics Data System (ADS)

    Munro, R.; Lang, R.; Klaes, D.; Poli, G.; Retscher, C.; Lindstrot, R.; Huckle, R.; Lacan, A.; Grzegorski, M.; Holdak, A.; Kokhanovsky, A.; Livschitz, J.; Eisinger, M.

    2015-08-01

    The Global Ozone Monitoring Experiment-2 (GOME-2) flies on the Metop series of satellites, the space component of the EUMETSAT Polar System. In this paper we will provide an overview of the instrument design, the on-ground calibration and characterisation activities, in-flight calibration, and level 0 to 1 data processing. The quality of the level 1 data is presented and points of specific relevance to users are highlighted. Long-term level 1 data consistency is also discussed and plans for future work are outlined. The information contained in this paper summarises a large number of technical reports and related documents containing information that is not currently available in the published literature. These reports and documents are however made available on the EUMETSAT web pages (http://www.eumetsat.int) and readers requiring more details than can be provided in this overview paper will find appropriate references at relevant points in the text.

  11. The GOME-2 instrument on the Metop series of satellites: instrument design, calibration, and level 1 data processing - an overview

    NASA Astrophysics Data System (ADS)

    Munro, Rosemary; Lang, Rüdiger; Klaes, Dieter; Poli, Gabriele; Retscher, Christian; Lindstrot, Rasmus; Huckle, Roger; Lacan, Antoine; Grzegorski, Michael; Holdak, Andriy; Kokhanovsky, Alexander; Livschitz, Jakob; Eisinger, Michael

    2016-03-01

    The Global Ozone Monitoring Experiment-2 (GOME-2) flies on the Metop series of satellites, the space component of the EUMETSAT Polar System. In this paper we will provide an overview of the instrument design, the on-ground calibration and characterization activities, in-flight calibration, and level 0 to 1 data processing. The current status of the level 1 data is presented and points of specific relevance to users are highlighted. Long-term level 1 data consistency is also discussed and plans for future work are outlined. The information contained in this paper summarizes a large number of technical reports and related documents containing information that is not currently available in the published literature. These reports and documents are however made available on the EUMETSAT web pages and readers requiring more details than can be provided in this overview paper will find appropriate references at relevant points in the text.

  12. An instrument for gravimetric calibration of flow devices with corrosive gases

    NASA Astrophysics Data System (ADS)

    Remenyik, Carl J.; Hylton, James O.

    An instrument was developed for the calibration of mass flow controllers primarily used in the production of semiconductor wafers. Almost all other types of such calibrators require measurement of temperature, pressure, and volume. This instrument measures the weight of gas collected in a container and makes measuring those thermodynamic variables unnecessary. The need to measure the weight of the gas container is eliminated by submerging it in a liquid (presently water) and balancing its weight with the force of buoyancy. The accuracy of this gravimetric calibrator is unaffected by the pressure and temperature of the gas. The calibrator can also measure reactive, corrosive, and nonideal gases. The container remains connected to the process by a torsion capillary, and a load cell measures the changing gas weight continuously throughout the measuring process. A prototype was designed for gas flows ranging from 1 sccm of hydrogen to 10,000 sccm of tungsten hexafluoride, constructed, tested, and used to calibrate flow devices. Experience with the prototype and results are presented, and plans for further developments are discussed. Design of a version for the flow range from 0.1 sccm to 100 sccm is in progress.

  13. An instrument for gravimetric calibration of flow devices with corrosive gases

    SciTech Connect

    Remenyik, C.J.; Hylton, J.O.

    1995-04-01

    An instrument was developed for the calibration of mass flow controllers primarily used in the production of semiconductor wafers. Almost all other types of such calibrators require measurement of temperature, pressure and volume. This instrument measures the weight of gas collected in a container and makes measuring those thermodynamic variables unnecessary. The need to measure the weight of the gas container is eliminated by submerging it in a liquid (presently water) and balancing its weight with the force of buoyancy. The accuracy of this Gravimetric Calibrator is unaffected by the pressure and temperature of the gas. The Calibrator can also measure reactive, corrosive, and non-ideal gases. The container remains connected to the process by a torsion capillary, and a load cell measures the changing gas weight continuously throughout the measuring process. A prototype was designed for gas flows ranging from 1 sccm of hydrogen to 10,000 sccm of tungsten hexafluoride, constructed, tested, and used to calibrate flow devices. Experience with the prototype and results are presented, and plans for further developments are discussed. Design of a version for the flow range from 0.1 sccm to 100 sccm is in progress.

  14. Preparation of high purity plutonium oxide for radiochemistry instrument calibration standards and working standards

    SciTech Connect

    Wong, A.S.; Stalnaker, N.D.

    1997-04-01

    Due to the lack of suitable high level National Institute of Standards and Technology (NIST) traceable plutonium solution standards from the NIST or commercial vendors, the CST-8 Radiochemistry team at Los Alamos National Laboratory (LANL) has prepared instrument calibration standards and working standards from a well-characterized plutonium oxide. All the aliquoting steps were performed gravimetrically. When a {sup 241}Am standardized solution obtained from a commercial vendor was compared to these calibration solutions, the results agreed to within 0.04% for the total alpha activity. The aliquots of the plutonium standard solutions and dilutions were sealed in glass ampules for long term storage.

  15. On-line testing of calibration of process instrumentation channels in nuclear power plants. Phase 2, Final report

    SciTech Connect

    Hashemian, H.M.

    1995-11-01

    The nuclear industry is interested in automating the calibration of process instrumentation channels; this report provides key results of one of the sponsored projects to determine the validity of automated calibrations. Conclusion is that the normal outputs of instrument channels in nuclear plants can be monitored over a fuel cycle while the plant is operating to determine calibration drift in the field sensors and associated signal conversion and signal conditioning equipment. The procedure for on-line calibration tests involving calculating the deviation of each instrument channel from the best estimate of the process parameter that the instrument is measuring. Methods were evaluated for determining the best estimate. Deviation of each signal from the best estimate is updated frequently while the plant is operating and plotted vs time for entire fuel cycle, thereby providing time history plots that can reveal channel drift and other anomalies. Any instrument channel that exceeds allowable drift or channel accuracy band is then scheduled for calibration during a refueling outage or sooner. This provides calibration test results at the process operating point, one of the most critical points of the channel operation. This should suffice for most narrow-range instruments, although the calibration of some instruments can be verified at other points throughout their range. It should be pointed out that the calibration of some process signals such as the high pressure coolant injection flow in BWRs, which are normally off- scale during plant operation, can not be tested on-line.

  16. Instrumentation report 1: specification, design, calibration, and installation of instrumentation for an experimental, high-level, nuclear waste storage facility

    SciTech Connect

    Brough, W.G.; Patrick, W.C.

    1982-01-01

    The Spent Fuel Test-Climax (SFT-C) is being conducted 420 m underground at the Nevada Test Site under the auspices of the US Department of Energy. The test facility houses 11 spent fuel assemblies from an operating commercial nuclear reactor and numerous other thermal sources used to simulate the near-field effects of a large repository. We developed a large-scale instrumentation plan to ensure that a sufficient quality and quantity of data were acquired during the three- to five-year test. These data help satisfy scientific, operational, and radiation safety objectives. Over 800 data channels are being scanned to measure temperature, electrical power, radiation, air flow, dew point, stress, displacement, and equipment operation status (on/off). This document details the criteria, design, specifications, installation, calibration, and current performance of the entire instrumentation package.

  17. The on-orbit performance of the Orbiting Carbon Observatory-2 (OCO-2) instrument and its radiometrically calibrated products

    NASA Astrophysics Data System (ADS)

    Crisp, David; Pollock, Harold R.; Rosenberg, Robert; Chapsky, Lars; Lee, Richard A. M.; Oyafuso, Fabiano A.; Frankenberg, Christian; O'Dell, Christopher W.; Bruegge, Carol J.; Doran, Gary B.; Eldering, Annmarie; Fisher, Brendan M.; Fu, Dejian; Gunson, Michael R.; Mandrake, Lukas; Osterman, Gregory B.; Schwandner, Florian M.; Sun, Kang; Taylor, Tommy E.; Wennberg, Paul O.; Wunch, Debra

    2017-01-01

    the yield and quality of the OCO-2 data products. These issues include increased numbers of bad pixels, transient artifacts introduced by cosmic rays, radiance discontinuities for spatially non-uniform scenes, a misunderstanding of the instrument polarization orientation, and time-dependent changes in the throughput of the oxygen A-band channel. Here, we describe the OCO-2 instrument, its data products, and its on-orbit performance. We then summarize calibration challenges encountered during its first 18 months in orbit and the methods used to mitigate their impact on the calibrated radiance spectra distributed to the science community.

  18. Inter-Calibration and Concatenation of Climate Quality Infrared Cloudy Radiances from Multiple Instruments

    NASA Technical Reports Server (NTRS)

    Behrangi, Ali; Aumann, Hartmut H.

    2013-01-01

    A change in climate is not likely captured from any single instrument, since no single instrument can span decades of time. Therefore, to detect signals of global climate change, observations from many instruments on different platforms have to be concatenated. This requires careful and detailed consideration of instrumental differences such as footprint size, diurnal cycle of observations, and relative biases in the spectral brightness temperatures. Furthermore, a common basic assumption is that the data quality is independent of the observed scene and therefore can be determined using clear scene data. However, as will be demonstrated, this is not necessarily a valid assumption as the globe is mostly cloudy. In this study we highlight challenges in inter-calibration and concatenation of infrared radiances from multiple instruments by focusing on the analysis of deep convective or anvil clouds. TRMM/VIRS is potentially useful instrument to make correction for observational differences in the local time and foot print sizes, and thus could be applied retroactively to vintage instruments such as AIRS, IASI, IRIS, AVHRR, and HIRS. As the first step, in this study, we investigate and discuss to what extent AIRS and VIRS agree in capturing deep cloudy radiances at the same local time. The analysis also includes comparisons with one year observations from CrIS. It was found that the instruments show calibration differences of about 1K under deep cloudy scenes that can vary as a function of land type and local time of observation. The sensitivity of footprint size, view angle, and spectral band-pass differences cannot fully explain the observed differences. The observed discrepancies can be considered as a measure of the magnitude of issues which will arise in the comparison of legacy data with current data.

  19. On-Orbit Cross-Calibration of AM Satellite Remote Sensing Instruments using the Moon

    NASA Technical Reports Server (NTRS)

    Butler, James J.; Kieffer, Hugh H.; Barnes, Robert A.; Stone, Thomas C.

    2003-01-01

    On April 14,2003, three Earth remote sensing spacecraft were maneuvered enabling six satellite instruments operating in the visible through shortwave infrared wavelength region to view the Moon for purposes of on-orbit cross-calibration. These instruments included the Moderate Resolution Imaging Spectroradiometer (MODIS), the Multi-angle Imaging SpectroRadiometer (MISR), the Advanced Spaceborne Thermal Emission and Reflection (ASTER) radiometer on the Earth Observing System (EOS) Terra spacecraft, the Advanced Land Imager (ALI) and Hyperion instrument on Earth Observing-1 (EO-1) spacecraft, and the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) on the SeaStar spacecraft. Observations of the Moon were compared using a spectral photometric mode for lunar irradiance developed by the Robotic Lunar Observatory (ROLO) project located at the United States Geological Survey in Flagstaff, Arizona. The ROLO model effectively accounts for variations in lunar irradiance corresponding to lunar phase and libration angles, allowing intercomparison of observations made by instruments on different spacecraft under different time and location conditions. The spacecraft maneuvers necessary to view the Moon are briefly described and results of using the lunar irradiance model in comparing the radiometric calibration scales of the six satellite instruments are presented here.

  20. The 1997 HST Calibration Workshop with a New Generation of Instruments

    NASA Technical Reports Server (NTRS)

    Casertano, S. (Editor); Jedrzejewski, R. (Editor); Keyes, T. (Editor); Stevens, M. (Editor)

    1997-01-01

    The Second Servicing mission in early 1997 has brought major changes to the Hubble Space Telescope (HST). Two of the original instruments, Faint Object Spectrograph (FOS) and Goddard High Resolution Spectrograph (GHRS), were taken out, and replaced by completely new instruments, the Space Telescope Imaging Spectrograph (STIS) and the Near Infrared Camera Multi-Object Spectrograph (NICMOS). Two new types of detectors were installed, and for the first time, HST gained infrared capabilities. A new Fine Guidance Sensor (FGS) was installed, with an alignment mechanism that could improve substantially both guiding and astrometric capabilities. With all these changes come new challenges. The characterization of the new instruments has required a major effort, both by their respective Investigation Definition Teams and at the Space Telescope Science Institute. All necessary final calibrations for the retired spectrographs needed to be carried out, and their properties definitively characterized. At the same time, work has continued to improve our understanding of the instruments that have remained on board. The results of these activities were discussed in the 1997 HST (Hubble Space Telescope) Calibration Workshop. The main focus of the Workshop was to provide users with the tools and the understanding they need to use HST's instruments and archival data to the best of their possibilities. This book contains the written record of the Workshop. As such, it should provide a valuable tool to all interested in using existing HST data or in proposing for new observations.

  1. A method for automating calibration and records management for instrumentation and dosimetry

    SciTech Connect

    O`Brien, J.M. Jr.; Rushton, R.O.; Burns, R.E. Jr.

    1993-12-31

    Current industry requirements are becoming more stringent on quality assurance records and documentation for calibration of instruments and dosimetry. A novel method is presented here that will allow a progressive automation scheme to be used in pursuit of that goal. This concept is based on computer-controlled irradiators that can act as stand-alone devices or be interfaced to other components via a computer local area network. In this way, complete systems can be built with modules to create a records management system to meet the needs of small laboratories or large multi-building calibration groups. Different database engines or formats can be used simply by replacing a module. Modules for temperature and pressure monitoring or shipping and receiving can be added, as well as equipment modules for direct IEEE-488 interface to electrometers and other instrumentation.

  2. Stokes imaging polarimetry using image restoration: a calibration strategy for Fabry-Pérot based instruments

    NASA Astrophysics Data System (ADS)

    Schnerr, R. S.; de La Cruz Rodríguez, J.; van Noort, M.

    2011-10-01

    Context. The combination of image restoration and a Fabry-Pérot interferometer (FPI) based instrument in solar observations results in specific calibration issues. FPIs generally show variations over the field-of-view, while in the image restoration process, the 1-to-1 relation between pixel space and image space is lost, thus complicating any correcting for such variations. Aims: We develop a data reduction method that takes these issues into account and minimizes the resulting errors. Methods: By accounting for the time variations in the telescope's Mueller matrix and using separate calibration data optimized for the wavefront sensing in the MOMFBD image restoration process and for the final deconvolution of the data, we have removed most of the calibration artifacts from the resulting data. Results: Using this method to reduce full Stokes data from CRISP at the SST, we find that it drastically reduces the instrumental and image restoration artifacts resulting from cavity errors, reflectivity variations, and the polarization dependence of flatfields. The results allow for useful scientific interpretation. Inversions of restored data from the δ sunspot AR11029 using the Nicole inversion code, reveal strong (~10 km s-1) downflows near the disk center side of the umbra. Conclusions: The use of image restoration in combination with an FPI-based instrument leads to complications in the calibrations and intrinsic limitations to the accuracy that can be achieved. We find that for CRISP, the resulting errors can be kept mostly below the polarimetric accuracy of ~10-3. Similar instruments aiming for higher polarimetric and high spectroscopic accuracy, will, however, need to take these problems into account.

  3. An Instrument for Gravimetric Calibration of Flow Devices with Corrosive Gases

    SciTech Connect

    Hylton, J.O.; Remenyik, C.J.

    1999-06-27

    An instrument was developed for the direct mass flow calibration of gas flowmeters that does not require measurement of temperature, pressure, or specific volume. This instrument measures the weight of gas collected in a container and makes measuring those thermodynamic variables unnecessary. The need to measure the weight of the gas container is eliminated by submerging it in a liquid (presently water) and balancing its weight with the force of buoyancy. The accuracy of this Gravimetric Calibrator is unaffected by the pressure and temperature of the gas. The Calibrator can also measure reactive, corrosive, and non-ideal gases. The container remains connected to the process by a torsion capillary, and a load cell measures the changing gas weight continuously throughout the measuring process. A prototype was designed for gas flows ranging from 1 sccm of hydrogen to 10,000 sccm of tungsten hexafluoride, constructed, tested, and used to calibrate flow devices. Experience with the prototype and results are presented, and plans for further developments are discussed.

  4. Optical Comb from a Whispering Gallery Mode Resonator for Spectroscopy and Astronomy Instruments Calibration

    NASA Technical Reports Server (NTRS)

    Strekalov, Dmitry V.; Yu, Nam; Thompson, Robert J.

    2012-01-01

    The most accurate astronomical data is available from space-based observations that are not impeded by the Earth's atmosphere. Such measurements may require spectral samples taken as long as decades apart, with the 1 cm/s velocity precision integrated over a broad wavelength range. This raises the requirements specifically for instruments used in astrophysics research missions -- their stringent wavelength resolution and accuracy must be maintained over years and possibly decades. Therefore, a stable and broadband optical calibration technique compatible with spaceflights becomes essential. The space-based spectroscopic instruments need to be calibrated in situ, which puts forth specific requirements to the calibration sources, mainly concerned with their mass, power consumption, and reliability. A high-precision, high-resolution reference wavelength comb source for astronomical and astrophysics spectroscopic observations has been developed that is deployable in space. The optical comb will be used for wavelength calibrations of spectrographs and will enable Doppler measurements to better than 10 cm/s precision, one hundred times better than the current state-of-the- art.

  5. Best practice for pre-launch characterization and calibration of instruments for remote sensing

    NASA Astrophysics Data System (ADS)

    Datla, Raju

    2008-08-01

    The pre-launch characterization and calibration of remote sensing instruments should be planned and carried out in conjunction with their design and development to meet the mission requirements. In the case of infrared instruments, the onboard calibrators such as blackbodies and the sensors such as spectral radiometers should be characterized and calibrated using SI traceable standards. In the case of earth remote sensing, this allows intercomparison and intercalibration of different sensors in space to create global time series of climate records of high accuracy where some inevitable data gaps can be easily bridged. In the case of ballistic missile defense, this provides sensor quality assurance based on SI traceable measurements. The recommended best practice for this pre-launch effort is presented based on experience gained at National Institute of Standards and Technology (NIST) working with National Aeronautics and Space Administration (NASA), National Oceanic and Atmospheric Administration (NOAA) and Department of Defense (DoD) programs in the past two decades. Examples of infrared standards and calibration facilities at NIST for serving the remote sensing community will be discussed.

  6. 40 CFR 86.120-94 - Gas meter or flow instrumentation calibration; particulate, methanol and formaldehyde measurement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Gas meter or flow instrumentation... Procedures § 86.120-94 Gas meter or flow instrumentation calibration; particulate, methanol and formaldehyde... or flow instrumentation to determine flow through the particulate filters, methanol impingers...

  7. Preparation of calibrated test packages for particle impact noise detection

    NASA Technical Reports Server (NTRS)

    1977-01-01

    A standard calibration method for any particle impact noise detection (PIND) test system used to detect loose particles responsible for failures in hybrid circuits was developed along with a procedure for preparing PIND standard test devices. Hybrid packages were seeded with a single gold ball, hermetically sealed, leak tested, and PIND tested. Conclusions are presented.

  8. Multi-Dimensional Calibration of Impact Dynamic Models

    NASA Technical Reports Server (NTRS)

    Horta, Lucas G.; Reaves, Mercedes C.; Annett, Martin S.; Jackson, Karen E.

    2011-01-01

    NASA Langley, under the Subsonic Rotary Wing Program, recently completed two helicopter tests in support of an in-house effort to study crashworthiness. As part of this effort, work is on-going to investigate model calibration approaches and calibration metrics for impact dynamics models. Model calibration of impact dynamics problems has traditionally assessed model adequacy by comparing time histories from analytical predictions to test at only a few critical locations. Although this approach provides for a direct measure of the model predictive capability, overall system behavior is only qualitatively assessed using full vehicle animations. In order to understand the spatial and temporal relationships of impact loads as they migrate throughout the structure, a more quantitative approach is needed. In this work impact shapes derived from simulated time history data are used to recommend sensor placement and to assess model adequacy using time based metrics and orthogonality multi-dimensional metrics. An approach for model calibration is presented that includes metric definitions, uncertainty bounds, parameter sensitivity, and numerical optimization to estimate parameters to reconcile test with analysis. The process is illustrated using simulated experiment data.

  9. Assessment of variation in Elekta plastic spherical-calibration phantom and its impact on the Leksell Gamma Knife calibration

    SciTech Connect

    Novotny, Josef Jr.; Bhatnagar, Jagdish P.; Chung, Hyun-Tai; Johansson, Jonas; Bednarz, Greg; Ma, Lijun; Saiful Huq, M.

    2010-09-15

    Purpose: Traditionally, the dose-rate calibration (output) of the Leksell Gamma Knife (LGK) unit is performed using a 160 mm diameter plastic spherical phantom provided by the vendor of the LGK, Elekta Instrument AB. The purpose of this study was to evaluate variations in the Elekta spherical phantom and to assess its impact and use for the LGK calibration. Methods: Altogether, 13 phantoms from six different centers were acquired, 10 of these phantoms were manufactured within the past 10 years and the last 3 approximately 15-20 years ago. To assess variation in phantoms, the diameter and mass densities were measured. To assess the impact on LGK calibration, the output of two models of LGK (LGK Perfexion and LGK 4C) were measured under identical irradiation conditions using all 13 phantoms for each LGK model. Results: The mean measured deviation in diameter from expected nominal 160 mm for 13 phantoms was 0.51 mm (range of 0.09-1.51 mm). The mean measured phantom mass density for 13 phantoms was 1.066{+-}0.019 g/cm{sup 3} (range of 1.046-1.102 g/cm{sup 3}). The percentage deviation of output for individual phantom from mean of 13 phantom outputs ranged from -0.37% to 0.55% for LGK Perfexion. Similarly, the percentage deviation of output for individual phantom from mean of 13 phantom outputs ranged from -0.72% to 0.47% for LGK 4C. Conclusions: This study demonstrated that small variations in terms of phantom size and mass density of the phantom material do not have a significant impact on dose-rate measurements of the Leksell Gamma Knife. Also, date of manufacture of the phantom did not show up to be a significant factor in this study.

  10. Impact of data quality and quantity and the calibration procedure on crop growth model calibration

    NASA Astrophysics Data System (ADS)

    Seidel, Sabine J.; Werisch, Stefan

    2014-05-01

    Crop growth models are a commonly used tool for impact assessment of climate variability and climate change on crop yields and water use. Process-based crop models rely on algorithms that approximate the main physiological plant processes by a set of equations containing several calibration parameters as well as basic underlying assumptions. It is well recognized that model calibration is essential to improve the accuracy and reliability of model predictions. However, model calibration and validation is often hindered by a limited quantity and quality of available data. Recent studies suggest that crop model parameters can only be derived from field experiments in which plant growth and development processes have been measured. To be able to achieve a reliable prediction of crop growth under irrigation or drought stress, the correct characterization of the whole soil-plant-atmosphere system is essential. In this context is the accurate simulation of crop development, yield and the soil water dynamics plays an important role. In this study we aim to investigate the importance of a site and cultivar-specific model calibration based on experimental data using the SVAT model Daisy. We investigate to which extent different data sets and different parameter estimation procedures affect particularly yield estimates, irrigation water demand and the soil water dynamics. The comprehensive experimental data has been derived from an experiment conducted in Germany where five irrigation regimes were imposed on cabbage. Data collection included continuous measurements of soil tension and soil water content in two plots at three depths, weekly measurements of LAI, plant heights, leaf-N-content, stomatal conductivity, biomass partitioning, rooting depth as well as harvested yields and duration of growing period. Three crop growth calibration strategies were compared: (1) manual calibration based on yield and duration of growing period, (2) manual calibration based on yield

  11. Analysis of the Cyclotron Facility Calibration and Aircraft Results Obtained by LIULIN-3M Instrument

    NASA Technical Reports Server (NTRS)

    Dachev, T. P.; Stassinopoulos, E. G.; Tomov, B. T.; Dimitrov, P. G.; Matviichuk, Y. N.; Shurshakov, V. A.; Petrov, V. M.

    1998-01-01

    The LIULIN-3M instrument is a further development of the LIULIN dosimeter-radiometer, which has been used on the NffR space station in the 1988-1994 time period, The LIULIN-3M is designed for continuous monitoring of the radiation environment during the BION-12 satellite flight in 1999. A semiconductor detector with 1 mm thickness and 1 cm(exp 2) area is used in the instrument. Pulse high analysis technique is used for measurement of the energy losses in the detector. The final data sets from the instrument are the flux and the dose rate for the exposition time and 256 channels of LET spectra if a non-nal coincidence of the particles to the detector is considered. The LIULIN-3M instrument was calibrated by proton fluxes with different energies at the Indiana University Cyclotron Facility in June 1997 and was used for space radiation measurements during commercial aircraft flights. Obtained calibration and flight results are analyzed in the paper.

  12. Environmental Assessment for the Health Protection Instrument Calibration Facility at the Savannah River Site

    SciTech Connect

    Not Available

    1993-08-01

    The purpose of this Environmental Assessment (EA) is to review the possible environmental consequences associated with the construction and operation of a Health Protection Instrument Calibration Facility on the Savannah River Site (SRS). The proposed replacement calibration facility would be located in B Area of SRS and would replace an inadequate existing facility currently located within A Area of SRS (Building 736-A). The new facility would provide laboratories, offices, test equipment and the support space necessary for the SRS Radiation Monitoring Instrument Calibration Program to comply with DOE Orders 5480.4 (Environmental Protection, Safety and Health Protection Standards) and 5480.11 (Radiation Protection for Occupational Workers). The proposed facility would serve as the central site source for the evaluation, selection, inspection, testing, calibration, and maintenance of all SRS radiation monitoring instrumentation. The proposed facility would be constructed on a currently undeveloped portion in B Area of SRS. The exact plot associated with the proposed action is a 1.2 hectare (3 acre) tract of land located on the west side of SRS Road No. 2. The proposed facility would lie approximately 4.4 km (2.75 mi) from the nearest SRS site boundary. The proposed facility would also lie within the confines of the existing B Area, and SRS safeguards and security systems. Archaeological, ecological, and land use reviews have been conducted in connection with the use of this proposed plot of land, and a detailed discussion of these reviews is contained herein. Socioeconomic, operational, and accident analyses were also examined in relation to the proposed project and the findings from these reviews are also contained in this EA.

  13. Application of new techniques in the calibration of the TROPOMI-SWIR instrument (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Tol, Paul; van Hees, Richard; van Kempen, Tim; Krijger, Matthijs; Cadot, Sidney; Aben, Ilse; Ludewig, Antje; Dingjan, Jos; Persijn, Stefan; Hoogeveen, Ruud

    2016-10-01

    The Tropospheric Monitoring Instrument (TROPOMI) on-board the Sentinel-5 Precursor satellite is an Earth-observing spectrometer with bands in the ultraviolet, visible, near infrared and short-wave infrared (SWIR). It provides daily global coverage of atmospheric trace gases relevant for tropospheric air quality and climate research. Three new techniques will be presented that are unique for the TROPOMI-SWIR spectrometer. The retrieval of methane and CO columns from the data of the SWIR band requires for each detector pixel an accurate instrument spectral response function (ISRF), i.e. the normalized signal as a function of wavelength. A new determination method for Earth-observing instruments has been used in the on-ground calibration, based on measurements with a SWIR optical parametric oscillator (OPO) that was scanned over the whole TROPOMI-SWIR spectral range. The calibration algorithm derives the ISRF without needing the absolute wavelength during the measurement. The same OPO has also been used to determine the two-dimensional stray-light distribution for each SWIR pixel with a dynamic range of 7 orders. This was achieved by combining measurements at several exposure times and taking saturation into account. The correction algorithm and data are designed to remove the mean stray-light distribution and a reflection that moves relative to the direct image, within the strict constraints of the available time for the L01b processing. A third new technique is an alternative calibration of the SWIR absolute radiance and irradiance using a black body at the temperature of melting silver. Unlike a standard FEL lamp, this source does not have to be calibrated itself, because the temperature is very stable and well known. Measurement methods, data analyses, correction algorithms and limitations of the new techniques will be presented.

  14. Development and Calibration of Space Flight Instruments at the University of Bern

    NASA Astrophysics Data System (ADS)

    Scheer, Jürgen; Wurz, Peter

    2013-04-01

    For more than 40 years the Physical Institute of the University of Bern is active in space flight instrumentation. What started in the late 60ies with foil experiments to collect solar wind particles on Apollo missions grew quickly into development of mass spectrometers for different space missions, such as GEOS (1976), GIOTTO (1985), and more. Nowadays, the division for Space Research and Planetary Sciences of the Physical Institute develops in addition to mass spectrometers as well other instruments, such as pressure gauges, laser altimeters, etc. All these instruments need to be tested and eventually calibrated. Over the years different facilities have been set up at the Physical Institute to do such work. This report will present these facilities with special respect to their unique properties and previous, current and future use.

  15. Planck 2015 results. VIII. High Frequency Instrument data processing: Calibration and maps

    NASA Astrophysics Data System (ADS)

    Planck Collaboration; Adam, R.; Ade, P. A. R.; Aghanim, N.; Arnaud, M.; Ashdown, M.; Aumont, J.; Baccigalupi, C.; Banday, A. J.; Barreiro, R. B.; Bartolo, N.; Battaner, E.; Benabed, K.; Benoît, A.; Benoit-Lévy, A.; Bernard, J.-P.; Bersanelli, M.; Bertincourt, B.; Bielewicz, P.; Bock, J. J.; Bonavera, L.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Boulanger, F.; Bucher, M.; Burigana, C.; Calabrese, E.; Cardoso, J.-F.; Catalano, A.; Challinor, A.; Chamballu, A.; Chiang, H. C.; Christensen, P. R.; Clements, D. L.; Colombi, S.; Colombo, L. P. L.; Combet, C.; Couchot, F.; Coulais, A.; Crill, B. P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R. D.; Davis, R. J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Delouis, J.-M.; Désert, F.-X.; Diego, J. M.; Dole, H.; Donzelli, S.; Doré, O.; Douspis, M.; Ducout, A.; Dupac, X.; Efstathiou, G.; Elsner, F.; Enßlin, T. A.; Eriksen, H. K.; Falgarone, E.; Fergusson, J.; Finelli, F.; Forni, O.; Frailis, M.; Fraisse, A. A.; Franceschi, E.; Frejsel, A.; Galeotta, S.; Galli, S.; Ganga, K.; Ghosh, T.; Giard, M.; Giraud-Héraud, Y.; Gjerløw, E.; González-Nuevo, J.; Górski, K. M.; Gratton, S.; Gruppuso, A.; Gudmundsson, J. E.; Hansen, F. K.; Hanson, D.; Harrison, D. L.; Henrot-Versillé, S.; Herranz, D.; Hildebrandt, S. R.; Hivon, E.; Hobson, M.; Holmes, W. A.; Hornstrup, A.; Hovest, W.; Huffenberger, K. M.; Hurier, G.; Jaffe, A. H.; Jaffe, T. R.; Jones, W. C.; Juvela, M.; Keihänen, E.; Keskitalo, R.; Kisner, T. S.; Kneissl, R.; Knoche, J.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lamarre, J.-M.; Lasenby, A.; Lattanzi, M.; Lawrence, C. R.; Le Jeune, M.; Leahy, J. P.; Lellouch, E.; Leonardi, R.; Lesgourgues, J.; Levrier, F.; Liguori, M.; Lilje, P. B.; Linden-Vørnle, M.; López-Caniego, M.; Lubin, P. M.; Macías-Pérez, J. F.; Maggio, G.; Maino, D.; Mandolesi, N.; Mangilli, A.; Maris, M.; Martin, P. G.; Martínez-González, E.; Masi, S.; Matarrese, S.; McGehee, P.; Melchiorri, A.; Mendes, L.; Mennella, A.; Migliaccio, M.; Mitra, S.; Miville-Deschênes, M.-A.; Moneti, A.; Montier, L.; Moreno, R.; Morgante, G.; Mortlock, D.; Moss, A.; Mottet, S.; Munshi, D.; Murphy, J. A.; Naselsky, P.; Nati, F.; Natoli, P.; Netterfield, C. B.; Nørgaard-Nielsen, H. U.; Noviello, F.; Novikov, D.; Novikov, I.; Oxborrow, C. A.; Paci, F.; Pagano, L.; Pajot, F.; Paoletti, D.; Pasian, F.; Patanchon, G.; Pearson, T. J.; Perdereau, O.; Perotto, L.; Perrotta, F.; Pettorino, V.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Pratt, G. W.; Prézeau, G.; Prunet, S.; Puget, J.-L.; Rachen, J. P.; Reinecke, M.; Remazeilles, M.; Renault, C.; Renzi, A.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Rossetti, M.; Roudier, G.; Rusholme, B.; Sandri, M.; Santos, D.; Sauvé, A.; Savelainen, M.; Savini, G.; Scott, D.; Seiffert, M. D.; Shellard, E. P. S.; Spencer, L. D.; Stolyarov, V.; Stompor, R.; Sudiwala, R.; Sutton, D.; Suur-Uski, A.-S.; Sygnet, J.-F.; Tauber, J. A.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Tuovinen, J.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Vibert, L.; Vielva, P.; Villa, F.; Wade, L. A.; Wandelt, B. D.; Watson, R.; Wehus, I. K.; Yvon, D.; Zacchei, A.; Zonca, A.

    2016-09-01

    This paper describes the processing applied to the cleaned, time-ordered information obtained from the Planck High Frequency Instrument (HFI) with the aim of producing photometrically calibrated maps in temperature and (for the first time) in polarization. The data from the entire 2.5-year HFI mission include almost five full-sky surveys. HFI observes the sky over a broad range of frequencies, from 100 to 857 GHz. To obtain the best accuracy on the calibration over such a large range, two different photometric calibration schemes have been used. The 545 and 857 GHz data are calibrated using models of planetary atmospheric emission. The lower frequencies (from 100 to 353 GHz) are calibrated using the time-variable cosmological microwave background dipole, which we call the orbital dipole. This source of calibration only depends on the satellite velocity with respect to the solar system. Using a CMB temperature of TCMB = 2.7255 ± 0.0006 K, it permits an independent measurement of the amplitude of the CMB solar dipole (3364.3 ± 1.5 μK), which is approximatively 1σ higher than the WMAP measurement with a direction that is consistent between the two experiments. We describe the pipeline used to produce the maps ofintensity and linear polarization from the HFI timelines, and the scheme used to set the zero level of the maps a posteriori. We also summarize the noise characteristics of the HFI maps in the 2015 Planck data release and present some null tests to assess their quality. Finally, we discuss the major systematic effects and in particular the leakage induced by flux mismatch between the detectors that leads to spurious polarization signal.

  16. Interferometric 30 m bench for calibrations of 1D scales and optical distance measuring instruments

    NASA Astrophysics Data System (ADS)

    Unkuri, J.; Rantanen, A.; Manninen, J.; Esala, V.-P.; Lassila, A.

    2012-09-01

    During construction of a new metrology building for MIKES, a 30 m interferometric bench was designed. The objective was to implement a straight, stable, adjustable and multifunctional 30 m measuring bench for calibrations. Special attention was paid to eliminating the effects of thermal expansion and inevitable concrete shrinkage. The linear guide, situated on top of a monolithic concrete beam, comprises two parallel round shafts with adjustable fixtures every 1 m. A carriage is moved along the rail and its position is followed by a reference interferometer. Depending on the measurement task, one or two retro-reflectors are fixed on the carriage. A microscope with a CCD camera and a monitor can be used to detect line mark positions on different line standards. When calibrating optical distance measuring instruments, various targets can be fixed to the carriage. For the most accurate measurements an online Abbe-error correction based on simultaneous carriage pitch measurement by a separate laser interferometer is applied. The bench is used for calibrations of machinist scales, tapes, circometers, electronic distance meters, total stations and laser trackers. The estimated expanded uncertainty for 30 m displacement for highest accuracy calibrations is 2.6 µm.

  17. Laboratory calibrations of the PP-SESAME instrument on Philae for measuring the cometary surface permittivity

    NASA Astrophysics Data System (ADS)

    Hamelin, M.; Le Gall, A.; Caujolle-Bert, S.; Schmidt, W.; Grard, R.; Laasko, H.; Ciarletti, V.; Seidensticker, K.

    2013-09-01

    The complex permittivity of terrestrial and planetary grounds can be derived from Mutual Impedance (MI) measurements using a four-electrode array [1]; the system is working at a fixed frequency with the electrodes not necessarily in contact with the ground and with a dedicated electronic system. This concept was used to build the Permittivity Probe (PP) as part of the SESAME experiment of the Philae Rosetta cometary lander. However severe constraints due to the payload facilities and to the particular environment lead to the actual design of the instrument. Unfortunately it was not possible to perform calibrations of the full system before lauch and the ground model consists of several parts used by various instruments. Here we report the results of basic calibration tests performed with a model of the Philae Landing Gear built in DLR. These tests involve only the three feet electrodes and a mockup of the the Philae body with very simple and well defined targets for characterizing the instrument. Further measurements on natural targets would be the next step.

  18. The Microscope Space Mission and the In-Orbit Calibration Plan for its Instrument

    NASA Astrophysics Data System (ADS)

    Levy, Agnès Touboul, Pierre; Rodrigues, Manuel; Onera, Émilie Hardy; Métris, Gilles; Robert, Alain

    2015-01-01

    The MICROSCOPE space mission aims at testing the Equivalence Principle (EP) with an accuracy of 10-15. This principle is one of the basis of the General Relativity theory; it states the equivalence between gravitational and inertial mass. The test is based on the precise measurement of a gravitational signal by a differential electrostatic accelerometer which includes two cylindrical test masses made of different materials. The accelerometers constitute the payload accommodated on board a drag-free micro-satellite which is controlled inertial or rotating about the normal to the orbital plane. The acceleration estimates used for the EP test are disturbed by the instruments physical parameters and by the instrument environment conditions on-board the satellite. These parameters are partially measured with ground tests or during the integration of the instrument in the satellite (alignment). Nevertheless, the ground evaluations are not sufficient with respect to the EP test accuracy objectives. An in-orbit calibration is therefore needed to characterize them finely. The calibration process for each parameter has been defined.

  19. Impact of Nuclear Data Uncertainties on Calculated Spent Fuel Nuclide Inventories and Advanced NDA Instrument Response

    DOE PAGES

    Hu, Jianwei; Gauld, Ian C.

    2014-12-01

    The U.S. Department of Energy’s Next Generation Safeguards Initiative Spent Fuel (NGSI-SF) project is nearing the final phase of developing several advanced nondestructive assay (NDA) instruments designed to measure spent nuclear fuel assemblies for the purpose of improving nuclear safeguards. Current efforts are focusing on calibrating several of these instruments with spent fuel assemblies at two international spent fuel facilities. Modelling and simulation is expected to play an important role in predicting nuclide compositions, neutron and gamma source terms, and instrument responses in order to inform the instrument calibration procedures. As part of NGSI-SF project, this work was carried outmore » to assess the impacts of uncertainties in the nuclear data used in the calculations of spent fuel content, radiation emissions and instrument responses. Nuclear data is an essential part of nuclear fuel burnup and decay codes and nuclear transport codes. Such codes are routinely used for analysis of spent fuel and NDA safeguards instruments. Hence, the uncertainties existing in the nuclear data used in these codes affect the accuracies of such analysis. In addition, nuclear data uncertainties represent the limiting (smallest) uncertainties that can be expected from nuclear code predictions, and therefore define the highest attainable accuracy of the NDA instrument. This work studies the impacts of nuclear data uncertainties on calculated spent fuel nuclide inventories and the associated NDA instrument response. Recently developed methods within the SCALE code system are applied in this study. The Californium Interrogation with Prompt Neutron instrument was selected to illustrate the impact of these uncertainties on NDA instrument response.« less

  20. Impact of Nuclear Data Uncertainties on Calculated Spent Fuel Nuclide Inventories and Advanced NDA Instrument Response

    SciTech Connect

    Hu, Jianwei; Gauld, Ian C.

    2014-12-01

    The U.S. Department of Energy’s Next Generation Safeguards Initiative Spent Fuel (NGSI-SF) project is nearing the final phase of developing several advanced nondestructive assay (NDA) instruments designed to measure spent nuclear fuel assemblies for the purpose of improving nuclear safeguards. Current efforts are focusing on calibrating several of these instruments with spent fuel assemblies at two international spent fuel facilities. Modelling and simulation is expected to play an important role in predicting nuclide compositions, neutron and gamma source terms, and instrument responses in order to inform the instrument calibration procedures. As part of NGSI-SF project, this work was carried out to assess the impacts of uncertainties in the nuclear data used in the calculations of spent fuel content, radiation emissions and instrument responses. Nuclear data is an essential part of nuclear fuel burnup and decay codes and nuclear transport codes. Such codes are routinely used for analysis of spent fuel and NDA safeguards instruments. Hence, the uncertainties existing in the nuclear data used in these codes affect the accuracies of such analysis. In addition, nuclear data uncertainties represent the limiting (smallest) uncertainties that can be expected from nuclear code predictions, and therefore define the highest attainable accuracy of the NDA instrument. This work studies the impacts of nuclear data uncertainties on calculated spent fuel nuclide inventories and the associated NDA instrument response. Recently developed methods within the SCALE code system are applied in this study. The Californium Interrogation with Prompt Neutron instrument was selected to illustrate the impact of these uncertainties on NDA instrument response.

  1. Improvements in Clouds and the Earth's Radiant Energy System (CERES) Products Based on Instrument Calibrations

    NASA Astrophysics Data System (ADS)

    Smith, N. M.; Priestley, K.; Loeb, N. G.; Thomas, S.; Shankar, M.; Walikainen, D.

    2014-12-01

    The Clouds and the Earth's Radiant Energy System (CERES) mission is instrumental in providing highly accurate radiance measurements that are critical for monitoring the Earth's radiation budget. Two identical CERES instruments are deployed aboard NASA's Earth Observing System (EOS) satellites Terra and Aqua. Each CERES instrument consists of scanning thermistor bolometer sensors that measure broadband radiances in the shortwave (0.3 to 5 micron), total (0.3 to < 100 micron) and water vapor window (8 to 12 micron) regions. CERES instruments have the capability of scanning in either the cross-track or rotating azimuth plane (RAP) scan mode. Cross-track scanning, the primary mode of CERES operation, allows for the geographical mapping of the radiation fields while RAP scanning enables the acquisition of data over a more extensive combination of viewing configurations, needed for developing vastly improved angular distribution models used in radiance to flux conversion. To evaluate, achieve and maintain radiometric stability, a rigorous and comprehensive radiometric calibration and validation protocol is implemented. Calibrations and validation studies have indicated spectral changes in the reflected solar spectral regions of the shortwave and total sensors. Spectral darkening is detected in the shortwave channel optics, which is more prominent while the instrument operates in RAP mode. In the absence of a climatological explanation for this darkening, this likely occurs during part of the RAP scan cycle when the scan plane is aligned with the direction of motion, making the optics more susceptible to increased UV exposure and molecular contamination. Additionally, systematic daytime-nighttime longwave top-of-atmosphere (TOA) flux inconsistency was also detected during validation, which highlights the changes in the shortwave region of the total sensor. This paper briefly describes the strategy to correct for the sensor response changes and presents the improvements in

  2. The Multispectral Atmospheric Mapping Sensor (MAMS): Instrument description, calibration and data quality

    NASA Technical Reports Server (NTRS)

    Jedlovec, G. J.; Menzel, W. P.; Atkinson, R.; Wilson, G. S.; Arvesen, J.

    1986-01-01

    A new instrument has been developed to produce high resolution imagery in eight visible and three infared spectral bands from an aircraft platform. An analysis of the data and calibration procedures has shown that useful data can be obtained at up to 50 m resolution with a 2.5 milliradian aperture. Single sample standard errors for the measurements are 0.5, 0.2, and 0.9 K for the 6.5, 11.1, and 12.3 micron spectral bands, respectively. These errors are halved when a 5.0 milliradian aperture is used to obtain 100 m resolution data. Intercomparisons with VAS and AVHRR measurements show good relative calibration. MAMS development is part of a larger program to develop multispectral Earth imaging capabilities from space platforms during the 1990s.

  3. 40 CFR 86.1320-90 - Gas meter or flow instrumentation calibration; particulate, methanol, and formaldehyde measurement.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... part of the system, using good engineering practice. (2) Flow air through the calibration system at the... range. (6) If the air flow at standard conditions measured by the instrument differs by ±1.0 percent of... agrees with the calibration measurement at the specified flow rates using the criteria of paragraph...

  4. 40 CFR 86.1320-90 - Gas meter or flow instrumentation calibration; particulate, methanol, and formaldehyde measurement.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... part of the system, using good engineering practice. (2) Flow air through the calibration system at the... range. (6) If the air flow at standard conditions measured by the instrument differs by ±1.0 percent of... agrees with the calibration measurement at the specified flow rates using the criteria of paragraph...

  5. 40 CFR 86.1320-90 - Gas meter or flow instrumentation calibration; particulate, methanol, and formaldehyde measurement.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... part of the system, using good engineering practice. (2) Flow air through the calibration system at the... range. (6) If the air flow at standard conditions measured by the instrument differs by ±1.0 percent of... agrees with the calibration measurement at the specified flow rates using the criteria of paragraph...

  6. 40 CFR 86.1320-90 - Gas meter or flow instrumentation calibration; particulate, methanol, and formaldehyde measurement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... part of the system, using good engineering practice. (2) Flow air through the calibration system at the... range. (6) If the air flow at standard conditions measured by the instrument differs by ±1.0 percent of... agrees with the calibration measurement at the specified flow rates using the criteria of paragraph...

  7. The Harvard experiment on OSO-6 - Instrumentation, calibration, operation, and description of observations.

    NASA Technical Reports Server (NTRS)

    Huber, M. C. E.; Dupree, A. K.; Goldberg, L.; Parkinson, W. H.; Reeves, E. M.; Withbroe, G. L.; Noyes, R. W.

    1973-01-01

    The Harvard experiment carried by OSO-6 was an extreme-ultraviolet (EUV) spectrometer-spectroheliometer with a wavelength range of 285 to 1385 A, a spatial and spectral bandwidth of 35 x 35(arc sec) squared and 3 A, respectively. The instrument acquired data that have been deposited with the National Space Science Data Center and World Data Center A at the Goddard Space Flight Center in Greenbelt, Maryland, and are now available in their entirety to the scientific community. Aspects of the experiment that are relevant to potential users of the data are described - namely, instrument configuration and parameters, laboratory and inflight calibrations, as well as operational capabilities and procedures. The observations obtained are reported, and the nature, number, and dates of observation, where relevant, are listed.

  8. The Calibration of a Large Number of Scientific Instruments for the Auroral Spatial Structures Probe Sub-Orbital Mission.

    NASA Astrophysics Data System (ADS)

    Swenson, A.; Miller, J.; Neilsen, T. L.; Fish, C. S.; Swenson, C.

    2014-12-01

    The Auroral Spatial Structures Probe (ASSP) is a NASA sounding rocket mission to be launched in the early January 2015 time frame from the Poker Flat Research Range. The primary scientific objective of this mission is to determine the contribution of small spatial and temporal scale fluctuations of the electric fields to the larger-scale processes during active aurora. This will be accomplished through the use of a constellation of six small payloads ejected at high velocity from a sounding rocket. The multiple baseline observations of the electric and magnetic fields will be used to observe variability of both the E-field and the Poynting flux. These observations will be placed in the context of available data, including winds, large scale E-fields, and proxy conductivity (airglow images) observations.Each sub-payload will carry a crossed pair of electric field double-probe sensors, a three-axis magnetometer, and a Langmuir probe. In total there are eight of each instrument type requireing calibration. Since the instruments need to be calibrated over temperature a full calibration of a single instrument is very time-consuming. The decision was made to automate the calibration process. Measurements were taken using a relay switch-box connecting the instruments to test sources. Calibration data were saved into a database. Using post-processing scripts on these databases a calibration for each instrument at each temperature point was made. This approach is a prototype process that might be used for calibrating a large constellation of CubeSats with similar instruments. In this poster we review the ASSP science and mission, and the results of the pre-flight calibration of the science instruments.

  9. A Comparison of Radiometric Calibration Techniques for Lunar Impact Flashes

    NASA Technical Reports Server (NTRS)

    Suggs, R.

    2016-01-01

    Video observations of lunar impact flashes have been made by a number of researchers since the late 1990's and the problem of determination of the impact energies has been approached in different ways (Bellot Rubio, et al., 2000 [1], Bouley, et al., 2012.[2], Suggs, et al. 2014 [3], Rembold and Ryan 2015 [4], Ortiz, et al. 2015 [5]). The wide spectral response of the unfiltered video cameras in use for all published measurements necessitates color correction for the standard filter magnitudes available for the comparison stars. An estimate of the color of the impact flash is also needed to correct it to the chosen passband. Magnitudes corrected to standard filters are then used to determine the luminous energy in the filter passband according to the stellar atmosphere calibrations of Bessell et al., 1998 [6]. Figure 1 illustrates the problem. The camera pass band is the wide black curve and the blue, green, red, and magenta curves show the band passes of the Johnson-Cousins B, V, R, and I filters for which we have calibration star magnitudes. The blackbody curve of an impact flash of temperature 2800K (Nemtchinov, et al., 1998 [7]) is the dashed line. This paper compares the various photometric calibration techniques and how they address the color corrections necessary for the calculation of luminous energy (radiometry) of impact flashes. This issue has significant implications for determination of luminous efficiency, predictions of impact crater sizes for observed flashes, and the flux of meteoroids in the 10s of grams to kilogram size range.

  10. 40 CFR 86.120-94 - Gas meter or flow instrumentation calibration; particulate, methanol and formaldehyde measurement.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 18 2011-07-01 2011-07-01 false Gas meter or flow instrumentation... Procedures § 86.120-94 Gas meter or flow instrumentation calibration; particulate, methanol and formaldehyde measurement. (a) Sampling for particulate, methanol and formaldehyde emissions requires the use of gas...

  11. Astrobiology Sample Analysis Program (ASAP) for Advanced Life Detection Instrumentation Development and Calibration

    NASA Technical Reports Server (NTRS)

    Glavin, Daniel; Brinkerhoff, Will; Dworkin, Jason; Eigenbrode, Jennifer; Franz, Heather; Mahaffy, Paul; Stern, Jen; Blake, Daid; Sandford, Scott; Fries, marc; Steele, Andrew; Amashukeli, Xenia; Fisher, Anita; Grunthaner, Frank; Aubrey, Andrew; Bada, Jeff; Chiesl, Tom; Stockton, Amanda; Mathies, Rich

    2008-01-01

    Scientific ground-truth measurements for near-term Mars missions, such as the 2009 Mars Science Laboratory (MSL) mission, are essential for validating current in situ flight instrumentation and for the development of advanced instrumentation technologies for life-detection missions over the next decade. The NASA Astrobiology Institute (NAI) has recently funded a consortium of researchers called the Astrobiology Sample Analysis Program (ASAP) to analyze an identical set of homogenized martian analog materials in a "round-robin" style using both state-of-the-art laboratory techniques as well as in-situ flight instrumentation including the SAM gas chromatograph mass spectrometer and CHEMIN X-ray diffraction/fluorescence instruments on MSL and the Urey and MOMA organic analyzer instruments under development for the 2013 ExoMars missions. The analog samples studied included an Atacama Desert soil from Chile, the Murchison meteorite, a gypsum sample from the 2007 AMASE Mars analog site, jarosite from Panoche Valley, CA, a hydrothermal sample from Rio Tinto, Spain, and a "blind" sample collected during the 2007 MSL slow-motion field test in New Mexico. Each sample was distributed to the team for analysis to: (1) determine the nature and inventory of organic compounds, (2) measure the bulk carbon and nitrogen isotopic composition, (3) investigate elemental abundances, mineralogy and matrix, and (4) search for biological activity. The experimental results obtained from the ASAP Mars analog research consortium will be used to build a framework for understanding the biogeochemistry of martian analogs, help calibrate current spaceflight instrumentation, and enhance the scientific return from upcoming missions.

  12. Characterization and Calibration of the CheMin Mineralogical Instrument on Mars Science Laboratory

    NASA Astrophysics Data System (ADS)

    Blake, David; Vaniman, David; Achilles, Cherie; Anderson, Robert; Bish, David; Bristow, Tom; Chen, Curtis; Chipera, Steve; Crisp, Joy; Des Marais, David; Downs, Robert T.; Farmer, Jack; Feldman, Sabrina; Fonda, Mark; Gailhanou, Marc; Ma, Hongwei; Ming, Doug W.; Morris, Richard V.; Sarrazin, Philippe; Stolper, Ed; Treiman, Allan; Yen, Albert

    2012-09-01

    A principal goal of the Mars Science Laboratory (MSL) rover Curiosity is to identify and characterize past habitable environments on Mars. Determination of the mineralogical and chemical composition of Martian rocks and soils constrains their formation and alteration pathways, providing information on climate and habitability through time. The CheMin X-ray diffraction (XRD) and X-ray fluorescence (XRF) instrument on MSL will return accurate mineralogical identifications and quantitative phase abundances for scooped soil samples and drilled rock powders collected at Gale Crater during Curiosity's 1-Mars-year nominal mission. The instrument has a Co X-ray source and a cooled charge-coupled device (CCD) detector arranged in transmission geometry with the sample. CheMin's angular range of 5∘ to 50∘ 2 θ with <0.35∘ 2 θ resolution is sufficient to identify and quantify virtually all minerals. CheMin's XRF requirement was descoped for technical and budgetary reasons. However, X-ray energy discrimination is still required to separate Co K α from Co K β and Fe K α photons. The X-ray energy-dispersive histograms (EDH) returned along with XRD for instrument evaluation should be useful in identifying elements Z>13 that are contained in the sample. The CheMin XRD is equipped with internal chemical and mineralogical standards and 27 reusable sample cells with either Mylar® or Kapton® windows to accommodate acidic-to-basic environmental conditions. The CheMin flight model (FM) instrument will be calibrated utilizing analyses of common samples against a demonstration-model (DM) instrument and CheMin-like laboratory instruments. The samples include phyllosilicate and sulfate minerals that are expected at Gale crater on the basis of remote sensing observations.

  13. The pre-flight calibration setup of the instrument SIMBIO-SYS onboard the mission BepiColombo

    NASA Astrophysics Data System (ADS)

    Poulet, F.; Rodriguez-Ferreira, J.; Arondel, A.; Dassas, K.; Eng, P.; Lami, P.; Langevin, Y.; Longval, Y.; Pradel, P.; Dami, M.

    2015-11-01

    BepiColombo, an European Space Agency (ESA) mission being conducted in cooperation with the Japan space agency, will explore Mercury with a set of eleven instruments onboard the spacecraft Mercury Planetary Orbiter (MPO). Among them, SIMBIO-SYS (Spectrometers and Imagers for MPO BepiColombo Integrated Observatory SYStem) is a complex instrument that will provide images and spectra in the 400-2000 nm wavelength range of the entire surface of Mercury. Pre-flight calibration of the SYMBIO-SYS instrument is mandatory for reliable scientific interpretation of images and spectra returned from the planet Mercury. This paper presents the calibration device designed and implemented for the specific requirements of this instrument. It mainly consists of a thermal vacuum chamber simulating the space environment, an optical bench collecting calibration sources and optical elements that simulate the conditions of Mercury observations, mechanical interfaces used for positioning the three channels inside the vacuum chamber, thermal interfaces to explore the operating temperatures, computer interfaces that allow to communicate with both the instrument and the calibration elements and synchronize the calibrations sequences with the status of the calibration device. As the major goal is the characterization of the radiometric performances of the three channels of SIMBIO-SYS, radiometric performances of the test setup evaluated by simulations and measurements are emphasized.

  14. Digitally Calibrated TR Modules Enabling Real-Time Beamforming SweepSAR Architectures for DESDynI-Class Radar Instruments

    NASA Technical Reports Server (NTRS)

    Hoffman, James Patrick; Peral, Eva; Veilluex, Louise; Perkovic, Dragana; Shaffer, Scott

    2011-01-01

    Real-time digital beamforming, combined with lightweight, large aperture reflectors, enable SweepSAR architectures such as that of the proposed DESDynI [Deformation, Ecosystem Structure, and Dynamics of Ice] SAR [Synthetic Aperture Radar] Instrument (or DSI). SweepSAR promises significant increases in instrument capability for solid earth and biomass remote sensing, while reducing mission mass and cost. This new instrument concept requires new methods for calibrating the multiple channels, which must be combined on-board, in real-time. We are developing new methods for digitally calibrating digital beamforming arrays to reduce development time, risk and cost of precision calibrated TR modules for array architectures by accurately tracking modules' characteristics through closed-loop Digital Calibration, thus tracking systematic changes regardless of temperature

  15. Evaluation applications of instrument calibration research findings in psychology for very small samples

    NASA Astrophysics Data System (ADS)

    Fisher, W. P., Jr.; Petry, P.

    2016-11-01

    Many published research studies document item calibration invariance across samples using Rasch's probabilistic models for measurement. A new approach to outcomes evaluation for very small samples was employed for two workshop series focused on stress reduction and joyful living conducted for health system employees and caregivers since 2012. Rasch-calibrated self-report instruments measuring depression, anxiety and stress, and the joyful living effects of mindfulness behaviors were identified in peer-reviewed journal articles. Items from one instrument were modified for use with a US population, other items were simplified, and some new items were written. Participants provided ratings of their depression, anxiety and stress, and the effects of their mindfulness behaviors before and after each workshop series. The numbers of participants providing both pre- and post-workshop data were low (16 and 14). Analysis of these small data sets produce results showing that, with some exceptions, the item hierarchies defining the constructs retained the same invariant profiles they had exhibited in the published research (correlations (not disattenuated) range from 0.85 to 0.96). In addition, comparisons of the pre- and post-workshop measures for the three constructs showed substantively and statistically significant changes. Implications for program evaluation comparisons, quality improvement efforts, and the organization of communications concerning outcomes in clinical fields are explored.

  16. TOPEX/Poseidon Microwave Radiometer (TMR): 1. Instrument Description and Antenna Temperature Calibration

    NASA Technical Reports Server (NTRS)

    Ruf, C. S.; Keihm, S. J.; Janssen, M. A.

    1993-01-01

    The TOPEX/Poseidon Microwave Radiometer (TMR) is a 3-frequency radiometer flown on the TOPEX/Poseidon (T/P) satellite in low Earth orbit. It operates at 18, 21 and 37 GHz in a nadir only viewing direction which is co-aligned with the T/P radar altimeters. TMR monitors and corrects for the electrical path delay of the altimeter radar signal due to water vapor and non-precipitating liquid water in the atmosphere. This paper describes the TMR instrument and the radiometric instrument calibration required to derive antenna temperature (T_A) from the raw digital data. T_A precision of 0.4 K is predicted on orbit in all expected thermal environments. T_A accuracy of 0.5-0.6 K is expected following a post-launch field calibration campaign. When uncertainties related to antenna sidelobe corrections are included, this T_A accuracy yields a brightness temperature accuracy of 0.7- 0.8 K...

  17. Infrared calibration for climate: a perspective on present and future high-spectral resolution instruments

    NASA Astrophysics Data System (ADS)

    Revercomb, Henry E.; Anderson, James G.; Best, Fred A.; Tobin, David C.; Knuteson, Robert O.; LaPorte, Daniel D.; Taylor, Joe K.

    2006-12-01

    The new era of high spectral resolution infrared instruments for atmospheric sounding offers great opportunities for climate change applications. A major issue with most of our existing IR observations from space is spectral sampling uncertainty and the lack of standardization in spectral sampling. The new ultra resolution observing capabilities from the AIRS grating spectrometer on the NASA Aqua platform and from new operational FTS instruments (IASI on Metop, CrIS for NPP/NPOESS, and the GIFTS for a GOES demonstration) will go a long way toward improving this situation. These new observations offer the following improvements: 1. Absolute accuracy, moving from issues of order 1 K to <0.2-0.4 K brightness temperature, 2. More complete spectral coverage, with Nyquist sampling for scale standardization, and 3. Capabilities for unifying IR calibration among different instruments and platforms. However, more needs to be done to meet the immediate needs for climate and to effectively leverage these new operational weather systems, including 1. Place special emphasis on making new instruments as accurate as they can be to realize the potential of technological investments already made, 2. Maintain a careful validation program for establishing the best possible direct radiance check of long-term accuracy--specifically, continuing to use aircraft-or balloon-borne instruments that are periodically checked directly with NIST, and 3. Commit to a simple, new IR mission that will provide an ongoing backbone for the climate observing system. The new mission would make use of Fourier Transform Spectrometer measurements to fill in spectral and diurnal sampling gaps of the operational systems and provide a benchmark with better than 0.1K 3-sigma accuracy based on standards that are verifiable in-flight.

  18. Application of Allan Deviation to Assessing Uncertainties of Continuous-measurement Instruments, and Optimizing Calibration Schemes

    NASA Astrophysics Data System (ADS)

    Jacobson, Gloria; Rella, Chris; Farinas, Alejandro

    2014-05-01

    Technological advancement of instrumentation in atmospheric and other geoscience disciplines over the past decade has lead to a shift from discrete sample analysis to continuous, in-situ monitoring. Standard error analysis used for discrete measurements is not sufficient to assess and compare the error contribution of noise and drift from continuous-measurement instruments, and a different statistical analysis approach should be applied. The Allan standard deviation analysis technique developed for atomic clock stability assessment by David W. Allan [1] can be effectively and gainfully applied to continuous measurement instruments. As an example, P. Werle et al has applied these techniques to look at signal averaging for atmospheric monitoring by Tunable Diode-Laser Absorption Spectroscopy (TDLAS) [2]. This presentation will build on, and translate prior foundational publications to provide contextual definitions and guidelines for the practical application of this analysis technique to continuous scientific measurements. The specific example of a Picarro G2401 Cavity Ringdown Spectroscopy (CRDS) analyzer used for continuous, atmospheric monitoring of CO2, CH4 and CO will be used to define the basics features the Allan deviation, assess factors affecting the analysis, and explore the time-series to Allan deviation plot translation for different types of instrument noise (white noise, linear drift, and interpolated data). In addition, the useful application of using an Allan deviation to optimize and predict the performance of different calibration schemes will be presented. Even though this presentation will use the specific example of the Picarro G2401 CRDS Analyzer for atmospheric monitoring, the objective is to present the information such that it can be successfully applied to other instrument sets and disciplines. [1] D.W. Allan, "Statistics of Atomic Frequency Standards," Proc, IEEE, vol. 54, pp 221-230, Feb 1966 [2] P. Werle, R. Miicke, F. Slemr, "The Limits

  19. Calibration results using highly aberrated images for aligning the JWST instruments to the telescope

    NASA Astrophysics Data System (ADS)

    Smith, Koby Z.; Acton, D. Scott; Gallagher, Ben B.; Knight, J. Scott; Dean, Bruce H.; Jurling, Alden S.; Zielinski, Thomas P.

    2016-07-01

    mostly of 3rd-order astigmatism and coma. This is because the elliptical tertiary mirror of the AOS is used off of its ideal foci locations without the compensating wavefront effects of the JWST primary and secondary mirrors. Therefore, the PSFs created are highly asymmetric with relatively complex structure and the centroid and encircled energy analyses traditionally used to locate images are not sufficient for ensuring the AOS to ISIM alignment. A novel approach combining phase retrieval and spatial metrology was developed to both locate the images with respect to the AOS and provide calibration information for eventual AOS to ISIM alignment verification. During final JWST OTE and ISIM (OTIS) testing, only a single thru-focus image will be collected by the instruments. Therefore, tools and processes were developed to perform single-image phase retrieval on these highly aberrated images such that any single image of the ASPA source can provide calibrated knowledge of the instruments' position relative to the AOS. This paper discusses the results of the methodology, hardware, and calibration performed to ensure that the AOS and ISIM are aligned within their respective tolerances at JWST OTIS testing.

  20. Far-infrared spectroscopy of the troposphere: instrument description and calibration performance.

    PubMed

    Latvakoski, Harri; Mlynczak, Martin G; Johnson, David G; Cageao, Richard P; Kratz, David P; Johnson, Kendall

    2013-01-10

    The far-infrared spectroscopy of the troposphere (FIRST) instrument is a Fourier transform spectrometer developed to measure the Earth's thermal emission spectrum with a particular emphasis on far-infrared (far-IR) wavelengths greater than 15 μm. FIRST was developed under NASA's Instrument Incubator Program to demonstrate technology for providing measurements from 10 to 100 μm (1000 to 100 cm(-1)) on a single focal plane with a spectral resolution finer than 1 cm(-1). Presently no spectrometers in orbit are capable of directly observing the Earth's far-IR spectrum. This fact, coupled with the fundamental importance of the far-IR to Earth's climate system, provided the impetus for the development of FIRST. In this paper the FIRST instrument is described and results of a detailed absolute laboratory calibration are presented. Specific channels in FIRST are shown to be accurate in the far-IR to better than 0.3 K at 270 K scene temperature, 0.5 K at 247 K, and 1 K at 225 K.

  1. On-orbit radiometric validation and field-of-view calibration of spaceborne microwave sounding instruments

    NASA Astrophysics Data System (ADS)

    Blackwell, William J.; Bickmeier, Laura J.; Jairam, Laura G.; Leslie, R. Vincent

    2008-12-01

    Two calibration/validation efforts planned for current and future spaceborne microwave sounding instruments will be presented. First, the NPOESS Aircraft Sounder Testbed-Microwave (NAST-M) airborne sensor is used to directly validate the microwave radiometers (AMSU and MHS) on several operational satellites. Comparison results for underflights of the Aqua, NOAA, and MetOp-A satellites will be shown. Second, a potential approach will be presented for on-orbit field-of-view (FOV) calibration of the Advanced Technology Microwave Sounder (ATMS). A variety of proposed spacecraft maneuvers that could facilitate the characterization of the radiometric boresight of all 22 ATMS channels will be discussed. Radiance observations from the NAST-M airborne sensor can be used to directly validate the radiometric performance of spaceborne sensors. NAST-M includes a total of four spectrometers, with three operating near the oxygen lines at 50-57, 118.75, and 424.76 GHz, and a fourth spectrometer centered on the water vapor absorption line at 183.31 GHz. All four feedhorns are co-located, have 3-dB (full-width at half-maximum) beamwidths of 7.5° (translating to 2.5-km nominal pixel diameter at nadir incidence), and are directed at a single mirror that scans cross-track beneath the aircraft with a nominal swath width of 100 km. We will present results for two recent validation efforts: 1) the Pacific THORpex (THe Observing-system Research and predictability experiment) Observing System Test (PTOST 2003, Honolulu, HI) and 2) the Joint Airborne IASI Validation Experiment (JAIVEx 2007, Houston, TX). Radiance differences between the NAST-M sensor and the Advanced Microwave Sounding Unit (AMSU) and the Microwave Humidity Sensor (MHS) were found to be less than 1K for most channels. Comparison results for ocean underflights of the Aqua, NOAA, and MetOp-A satellites are shown. We also present an approach for on-orbit FOV calibration of the ATMS satellite instrument using vicarious

  2. Using Lunar Observations to Validate In-Flight Calibrations of Clouds and Earth Radiant Energy System Instruments

    NASA Technical Reports Server (NTRS)

    Daniels, Janet L.; Smith, G. Louis; Priestley, Kory J.; Thomas, Susan

    2014-01-01

    The validation of in-orbit instrument performance requires stability in both instrument and calibration source. This paper describes a method of validation using lunar observations scanning near full moon by the Clouds and Earth Radiant Energy System (CERES) instruments. Unlike internal calibrations, the Moon offers an external source whose signal variance is predictable and non-degrading. From 2006 to present, in-orbit observations have become standardized and compiled for the Flight Models-1 and -2 aboard the Terra satellite, for Flight Models-3 and -4 aboard the Aqua satellite, and beginning 2012, for Flight Model-5 aboard Suomi-NPP. Instrument performance parameters which can be gleaned are detector gain, pointing accuracy and static detector point response function validation. Lunar observations are used to examine the stability of all three detectors on each of these instruments from 2006 to present. This validation method has yielded results showing trends per CERES data channel of 1.2% per decade or less.

  3. Application of the Langley plot method to the calibration of the solar backscattered ultraviolet instrument on the Nimbus 7 satellite

    NASA Technical Reports Server (NTRS)

    Bhartia, P. K.; Taylor, S.; Mcpeters, R. D.; Wellemeyer, C.

    1995-01-01

    The concept of the well-known Langley plot technique, used for the calibration of ground-based instruments, has been generalized for application to satellite instruments. In polar regions, near summer solstice, the solar backscattered ultraviolet (SBUV) instrument on the Nimbus 7 satellite samples the same ozone field at widely different solar zenith angles. These measurements are compared to assess the long-term drift in the instrument calibration. Although the technique provides only a relative wavelength-to-wavelength calibration, it can be combined with existing techniques to determine the drift of the instrument at any wavelength. Using this technique, we have generated a 12-year data set of ozone vertical profiles from SBUV with an estimated accuracy of +/- 5% at 1 mbar and +/- 2% at 10 mbar (95% confidence) over 12 years. Since the method is insensitive to true changes in the atmospheric ozone profile, it can also be used to compare the calibrations of similar SBUV instruments launched without temporal overlap.

  4. ON-LINE SELF-CALIBRATING SINGLE CRYSTAL SAPPHIRE OPTICAL SENSOR INSTRUMENTATION FOR ACCURATE AND RELIABLE COAL GASIFIER TEMPERATURE MEASUREMENT

    SciTech Connect

    Kristie Cooper; Gary Pickrell; Anbo Wang

    2003-04-01

    This report summarizes technical progress over the first six months of the Phase II program ''On-Line Self-Calibrating Single Crystal Sapphire Optical Sensor Instrumentation for Accurate and Reliable Coal Gasifier Temperature Measurement'', funded by the Federal Energy Technology Center of the U.S. Department of Energy, and performed by the Center for Photonics Technology of the Bradley Department of Electrical and Computer Engineering at Virginia Tech. The outcome of the first phase of this program was the selection of broadband polarimetric differential interferometry (BPDI) for further prototype instrumentation development. This approach is based on the measurement of the optical path difference (OPD) between two orthogonally polarized light beams in a single-crystal sapphire disk. The objective of this program is to bring the BPDI sensor technology, which has already been demonstrated in the laboratory, to a level where the sensor can be deployed in the harsh industrial environments and will become commercially viable. Research efforts were focused on analyzing and testing factors that impact performance degradation of the initially designed sensor prototype, including sensing element movement within the sensing probe and optical signal quality degradation. Based these results, a new version of the sensing system was designed by combining the sapphire disk sensing element and the single crystal zirconia right angle light reflector into one novel single crystal sapphire right angle prism. The new sensor prototype was tested up to 1650 C.

  5. Instrumentation for one-way satellite PTTI applications. [calibration and synchronization of clocks from navigation satellite

    NASA Technical Reports Server (NTRS)

    Osborne, A. E.

    1973-01-01

    A review of general principles and operational procedures illustrates how the typical passive user and omni receiving antenna can recover Precise Time and Time Interval (PTTI) information from a low altitude navigation satellite system for clock calibration and synchronization. Detailed discussions of concepts and theory of the receiver design are presented. The importance of RF correlation of the received and local PN encoded sequences is emphasized as a means of reducing delay uncertainties of the instrumentation to values compatible with nanosecond to submicrosecond PTTI objectives. Two receiver configurations were fabricated for use in satellite-to-laboratory experiments. In one receiver the delay-locked loop for PN signals synchronization used a dithered amplitude detection process while the second receiver used a complex sums phase detection method for measurement of delay error. The necessity for compensation of Doppler shift is discussed. Differences in theoretical signal acquisition and tracking performance of the design concepts are noted.

  6. An automated calibration laboratory for flight research instrumentation: Requirements and a proposed design approach

    NASA Technical Reports Server (NTRS)

    Oneill-Rood, Nora; Glover, Richard D.

    1990-01-01

    NASA's Dryden Flight Research Facility (Ames-Dryden), operates a diverse fleet of research aircraft which are heavily instrumented to provide both real time data for in-flight monitoring and recorded data for postflight analysis. Ames-Dryden's existing automated calibration (AUTOCAL) laboratory is a computerized facility which tests aircraft sensors to certify accuracy for anticipated harsh flight environments. Recently, a major AUTOCAL lab upgrade was initiated; the goal of this modernization is to enhance productivity and improve configuration management for both software and test data. The new system will have multiple testing stations employing distributed processing linked by a local area network to a centralized database. The baseline requirements for the new AUTOCAL lab and the design approach being taken for its mechanization are described.

  7. Contributions of the SDR Task Network tool to Calibration and Validation of the NPOESS Preparatory Project instruments

    NASA Astrophysics Data System (ADS)

    Feeley, J.; Zajic, J.; Metcalf, A.; Baucom, T.

    2009-12-01

    The National Polar-orbiting Operational Environmental Satellite System (NPOESS) Preparatory Project (NPP) Calibration and Validation (Cal/Val) team is planning post-launch activities to calibrate the NPP sensors and validate Sensor Data Records (SDRs). The IPO has developed a web-based data collection and visualization tool in order to effectively collect, coordinate, and manage the calibration and validation tasks for the OMPS, ATMS, CrIS, and VIIRS instruments. This tool is accessible to the multi-institutional Cal/Val teams consisting of the Prime Contractor and Government Cal/Val leads along with the NASA NPP Mission team, and is used for mission planning and identification/resolution of conflicts between sensor activities. Visualization techniques aid in displaying task dependencies, including prerequisites and exit criteria, allowing for the identification of a critical path. This presentation will highlight how the information is collected, displayed, and used to coordinate the diverse instrument calibration/validation teams.

  8. Design, calibration and error analysis of instrumentation for heat transfer measurements in internal combustion engines

    NASA Technical Reports Server (NTRS)

    Ferguson, C. R.; Tree, D. R.; Dewitt, D. P.; Wahiduzzaman, S. A. H.

    1987-01-01

    The paper reports the methodology and uncertainty analyses of instrumentation for heat transfer measurements in internal combustion engines. Results are presented for determining the local wall heat flux in an internal combustion engine (using a surface thermocouple-type heat flux gage) and the apparent flame-temperature and soot volume fraction path length product in a diesel engine (using two-color pyrometry). It is shown that a surface thermocouple heat transfer gage suitably constructed and calibrated will have an accuracy of 5 to 10 percent. It is also shown that, when applying two-color pyrometry to measure the apparent flame temperature and soot volume fraction-path length, it is important to choose at least one of the two wavelengths to lie in the range of 1.3 to 2.3 micrometers. Carefully calibrated two-color pyrometer can ensure that random errors in the apparent flame temperature and in the soot volume fraction path length will remain small (within about 1 percent and 10-percent, respectively).

  9. Scientific calibration and analysis of calibration data for the CaSSIS instrument of the ExoMars Trace Gas Orbiter

    NASA Astrophysics Data System (ADS)

    Roloff, V.; Gambicorti, L.; Pommerol, A.; Thomas, N.

    2015-10-01

    The Colour and Stereo Surface Imaging System (CaSSIS) is a camera, the development of which is led by the University of Bern (CH), with hardware contributions from the University of Padova (I) and the Space Research Center of Warsaw (Pl). It will take high resolution stereo images in 4 colours of the Martian surface, from on board the ExoMars Trace Gas Orbiter. Our calibration facility stands ready to perform the required measurements. We are currently testing the procedures on a dummy system and we will report on calibration results of the CaSSIS instrument.

  10. Impact of radiance variations on satellite sensor calibration

    NASA Astrophysics Data System (ADS)

    Duggin, Michael J.

    1987-04-01

    The intercalibration of digital data from different sensors depends on systematic and random variations in factors controlling recorded radiance. Theoretical expressions are presented which describe the impact of random variations in those factors which control radiance incident on the sensor. Means of measuring or estimating the impact of random variations on intercalibration factors are discussed. Means of detecting and calibrating for systematic effects are also discussed. The optical-reflective, middle-infrared, and thermal infrared regions of the spectrum are considered. An example is presented whereby NOAA-7 and NOAA-8 advanced very high resolution radiometer (AVHRR) radiance data, obtained over the same test fields, are shown to depend on the differences in view angles used by the two satellites.

  11. Post calibration of the two-dimensional electron cyclotron emission imaging instrument with electron temperature characteristics of the magnetohydrodynamic instabilities

    NASA Astrophysics Data System (ADS)

    Choi, M. J.; Park, H. K.; Yun, G. S.; Nam, Y. B.; Choe, G. H.; Lee, W.; Jardin, S.

    2016-01-01

    The electron cyclotron emission imaging (ECEI) instrument is widely used to study the local electron temperature (Te) fluctuations by measuring the ECE intensity IECE ∝ Te in tokamak plasmas. The ECEI measurement is often processed in a normalized fluctuation quantity against the time averaged value due to complication in absolute calibration. In this paper, the ECEI channels are relatively calibrated using the flat Te assumption of the sawtooth crash or the tearing mode island and a proper extrapolation. The 2-D relatively calibrated electron temperature (Te,rel) images are reconstructed and the displacement amplitude of the magnetohydrodynamic modes can be measured for the accurate quantitative growth analysis.

  12. SI traceable calibration of an instrumented indentation sensor spring constant using electrostatic force.

    PubMed

    Chung, Koo-Hyun; Scholz, Stefan; Shaw, Gordon A; Kramar, John A; Pratt, Jon R

    2008-09-01

    We present a measurement scheme for creating reference electrostatic forces that are traceable to the International System of Units. This scheme yields reference forces suitable for calibrating the force sensitivity of instrumented indentation machines and atomic force microscopes. Forces between 10 and 200 muN were created and expressed in terms of the voltage, length, and capacitance between a pair of interacting electrodes. The electrodes comprised an electrically conductive sphere mounted as a tip on an instrumented indentation sensor, and a planar counterelectrode fixed to a sample stage in close proximity to the sphere. For comparison, we applied mechanical forces of similar magnitudes, first using deadweights and then using a reference force sensor. The deflection of the sensor due to the various applied forces was measured using an interferometer. A spring constant for the sensor was computed from the observed records of force versus displacement. Each procedure yielded a relative standard uncertainty of approximately 1%; however, the electrostatic technique is scalable and could provide traceable reference forces as small as a few hundred piconewtons, a range far below anything yet achieved using deadweights.

  13. SI traceable calibration of an instrumented indentation sensor spring constant using electrostatic force

    SciTech Connect

    Chung, Koo-Hyun; Scholz, Stefan; Shaw, Gordon A.; Kramar, John A.; Pratt, Jon R.

    2008-09-15

    We present a measurement scheme for creating reference electrostatic forces that are traceable to the International System of Units. This scheme yields reference forces suitable for calibrating the force sensitivity of instrumented indentation machines and atomic force microscopes. Forces between 10 and 200 {mu}N were created and expressed in terms of the voltage, length, and capacitance between a pair of interacting electrodes. The electrodes comprised an electrically conductive sphere mounted as a tip on an instrumented indentation sensor, and a planar counterelectrode fixed to a sample stage in close proximity to the sphere. For comparison, we applied mechanical forces of similar magnitudes, first using deadweights and then using a reference force sensor. The deflection of the sensor due to the various applied forces was measured using an interferometer. A spring constant for the sensor was computed from the observed records of force versus displacement. Each procedure yielded a relative standard uncertainty of approximately 1%; however, the electrostatic technique is scalable and could provide traceable reference forces as small as a few hundred piconewtons, a range far below anything yet achieved using deadweights.

  14. Overview of Suomi National Polar-Orbiting Partnership (NPP) Satellite Instrument Calibration and Validation

    NASA Astrophysics Data System (ADS)

    Weng, F.

    2015-12-01

    The Suomi National Polar-Orbiting Partnership (SNPP) satellite carries five instruments on board including ATMS, CrIS, VIIRS, OMPS and CERES. During the SNPP intensive calval, ATMS was pitched over to observe the cold space radiation. This unique data set was used for diagnostics of the ATMS scan-angle dependent bias and a scan-to-scan variation. A new algorithm is proposed to correct the ATMS scan angle dependent bias related to the reflector emission. ATMS radiometric calibration is also revised in IDPS with the full radiance processing (FRP). CrIS is the first Fourier transform Michelson interferometer and measures three infrared spectral bands from 650 to 1095, 1210 to 1750 and 2155 to 2550 cm-1 with spectral resolutions of 0.625 cm-1, respectively. Its spectral calibration is with an accuracy of better than 2 ppm and its noise is also well characterized with the Allan variance. Since CrIS was switched to the transmission of full spectral resolution (FSR) of RDR data to the ground in January 2015. The CrIS FSR SDR data are also produced offline at NOAA STAR. VIIRS has 22 spectral bands covering the spectrum between 0.412 μm and 12.01 μm, including 16 moderate resolution bands (M-bands) with a spatial resolution of 750 m at nadir, five imaging resolution bands (I-bands) with a spatial resolution of 375 m at nadir, and one day-night band (DNB) with a nearly-constant 750 m spatial resolution throughout the scan. The calibration of VIIRS reflective solar bands (RSB) requires a solar diffuser (SD) and a solar diffuser stability monitor (SDSM). Using the SNPP yaw maneuver data, SDSM screen transmission function can be updated to better capture the fine structures of the vignetting function. For OMPS nadir mapper (NM) and nadir profiler (NP), the detector signal-to-noise ratio, and sensor signal-to-noise ratio meet the system requirement. Detector gain and bias performance trends are generally stable. System linearity performance is stable and highly consistent with

  15. The Calibration of the DSCOVR EPIC Multiple Visible Channel Instrument Using MODIS and VIIRS as a Reference

    NASA Technical Reports Server (NTRS)

    Haney, Conor; Doeling, David; Minnis, Patrick; Bhatt, Rajendra; Scarino, Benjamin; Gopalan, Arun

    2016-01-01

    The Deep Space Climate Observatory (DSCOVR), launched on 11 February 2015, is a satellite positioned near the Lagrange-1 (L1) point, carrying several instruments that monitor space weather, and Earth-view sensors designed for climate studies. The Earth Polychromatic Imaging Camera (EPIC) onboard DSCOVR continuously views the sun-illuminated portion of the Earth with spectral coverage in the UV, VIS, and NIR bands. Although the EPIC instrument does not have any onboard calibration abilities, its constant view of the sunlit Earth disk provides a unique opportunity for simultaneous viewing with several other satellite instruments. This arrangement allows the EPIC sensor to be inter-calibrated using other well-characterized satellite instrument reference standards. Two such instruments with onboard calibration are MODIS, flown on Aqua and Terra, and VIIRS, onboard Suomi-NPP. The MODIS and VIIRS reference calibrations will be transferred to the EPIC instrument using both all-sky ocean and deep convective clouds (DCC) ray-matched EPIC and MODIS/VIIRS radiance pairs. An automated navigation correction routine was developed to more accurately align the EPIC and MODIS/VIIRS granules. The automated navigation correction routine dramatically reduced the uncertainty of the resulting calibration gain based on the EPIC and MODIS/VIIRS radiance pairs. The SCIAMACHY-based spectral band adjustment factors (SBAF) applied to the MODIS/ VIIRS radiances were found to successfully adjust the reference radiances to the spectral response of the specific EPIC channel for over-lapping spectral channels. The SBAF was also found to be effective for the non-overlapping EPIC channel 10. Lastly, both ray-matching techniques found no discernable trends for EPIC channel 7 over the year of publically released EPIC data.

  16. Roller compaction process development and scale up using Johanson model calibrated with instrumented roll data.

    PubMed

    Nesarikar, Vishwas V; Patel, Chandrakant; Early, William; Vatsaraj, Nipa; Sprockel, Omar; Jerzweski, Robert

    2012-10-15

    and calibrated using a subset of placebo run data obtained on WP120. The roll force values were calculated using vendor supplied equation. The nip angle was expressed as a function of gap and RFU. The nip angle, gap and RFU were used in a new roll force equation to estimate normal stress P2 at the center of the ribbon. Using ratios P1/P2 and P3/P2 from the calibration data set, P1 and P2 were estimated. The ribbon width over which P1, P2, and P3 are effective was determined by minimizing sum square error between the model predicted vs. experimental ribbon densities of the calibration set. The model predicted ribbon densities of the placebo runs compared well with the experimental data. The placebo model also predicted with reasonable accuracy the ribbon densities of active A, B, and C blends prepared at various combinations of process parameters. The placebo model was then used to calculate scale up parameters from WP120 to WP200 roller compactor. While WP120 has a single screw speed, WP200 is equipped with a twin feed screw system. A limited number of roller compaction runs on WP200 was used as a calibration set to determine normal stress profile across ribbon width. The nip angle equation derived from instrumented roll data collected on WP120 was applied to estimate nip angles on WP200 at various processing conditions. The roll force values calculated from vendor supplied equation and the nip angle values were used in roll force equation to estimate normal stress P2 at the tip of the feed screws. Based on feed screw design, it was assumed that the normal stress at the center of the ribbon was equal to those calculated at the tip of the feed screws. The ratio of normal stress at the edge of the ribbon Pe to the normal stress P2 at the feed screw tip was optimized to minimize sum square error between model predicted vs. experimental ribbon densities of the calibration set. The model predicted ribbon densities of the batches prepared on WP200 compared well with the

  17. 10 CFR 35.60 - Possession, use, and calibration of instruments used to measure the activity of unsealed...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Possession, use, and calibration of instruments used to measure the activity of unsealed byproduct material. 35.60 Section 35.60 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL General Technical Requirements § 35.60 Possession, use,...

  18. 10 CFR 35.60 - Possession, use, and calibration of instruments used to measure the activity of unsealed...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Possession, use, and calibration of instruments used to measure the activity of unsealed byproduct material. 35.60 Section 35.60 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL General Technical Requirements § 35.60 Possession, use,...

  19. 10 CFR 35.60 - Possession, use, and calibration of instruments used to measure the activity of unsealed...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Possession, use, and calibration of instruments used to measure the activity of unsealed byproduct material. 35.60 Section 35.60 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL General Technical Requirements § 35.60 Possession, use,...

  20. 10 CFR 35.60 - Possession, use, and calibration of instruments used to measure the activity of unsealed...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Possession, use, and calibration of instruments used to measure the activity of unsealed byproduct material. 35.60 Section 35.60 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL General Technical Requirements § 35.60 Possession, use,...

  1. 40 CFR 86.120-94 - Gas meter or flow instrumentation calibration; particulate, methanol and formaldehyde measurement.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... pumps that may be part of the system, using good engineering practice. (2) Flow air through the... range. (6) If the air flow at standard conditions measured by the instrument differs by ±1.0 percent of... agrees with the calibration measurement at the specified flow rates using the criteria of paragraph...

  2. 40 CFR 86.120-94 - Gas meter or flow instrumentation calibration; particulate, methanol and formaldehyde measurement.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... pumps that may be part of the system, using good engineering practice. (2) Flow air through the... range. (6) If the air flow at standard conditions measured by the instrument differs by ±1.0 percent of... agrees with the calibration measurement at the specified flow rates using the criteria of paragraph...

  3. 40 CFR 86.120-94 - Gas meter or flow instrumentation calibration; particulate, methanol and formaldehyde measurement.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... pumps that may be part of the system, using good engineering practice. (2) Flow air through the... range. (6) If the air flow at standard conditions measured by the instrument differs by ±1.0 percent of... agrees with the calibration measurement at the specified flow rates using the criteria of paragraph...

  4. Best Practice Guidelines for Pre-Launch Characterization and Calibration of Instruments for Passive Optical Remote Sensing1

    PubMed Central

    Datla, R. U.; Rice, J. P.; Lykke, K. R.; Johnson, B. C.; Butler, J. J.; Xiong, X.

    2011-01-01

    The pre-launch characterization and calibration of remote sensing instruments should be planned and carried out in conjunction with their design and development to meet the mission requirements. The onboard calibrators such as blackbodies and the sensors such as spectral radiometers should be characterized and calibrated using SI traceable standards. In the case of earth remote sensing, this allows inter-comparison and intercalibration of different sensors in space to create global time series of climate records of high accuracy where some inevitable data gaps can be easily bridged. The recommended best practice guidelines for this pre-launch effort is presented based on experience gained at National Institute of Standards and Technology (NIST), National Aeronautics and Space Administration (NASA) and National Oceanic and Atmospheric Administration (NOAA) programs over the past two decades. The currently available radiometric standards and calibration facilities at NIST serving the remote sensing community are described. Examples of best practice calibrations and intercomparisons to build SI (international System of Units) traceable uncertainty budget in the instrumentation used for preflight satellite sensor calibration and validation are presented. PMID:26989588

  5. Portable near-infrared instruments: Application for quality control of polymorphs in pharmaceutical raw materials and calibration transfer.

    PubMed

    da Silva, Vitor Hugo; da Silva, Jailson José; Pereira, Claudete Fernandes

    2017-02-05

    This work presents an evaluation of the analytical performance of three different portable near-infrared (NIR) instruments (denominated Port.1, Port.2 and Port.3) for quantifying mebendazole polymorphs (A, B and C) in pharmaceutical raw materials using multivariate calibration models. The performance of the portable instruments was compared with a benchtop one (FT-NIR Frontier spectrometer). In addition, calibration transfer between the benchtop and one of the portable instruments was also performed. For polymorph A, the Port.1 presented the lowest RMSEP value (1.01% w/w) even when compared to the FT-NIR instrument. For polymorphs B and C, the same Port.1 instrument presented RMSEP values of 2.09% w/w and 2.41% w/w, respectively, which were statistically similar to those obtained with the benchtop instrument. The LOD ranges (3.9-5.5 for polymorph A, 3.6-5.1 for polymorph B and 5.7-7.7 for polymorph C) obtained with the Port.1 was higher than those achieved with the benchtop NIR instrument, with high spectral resolution, signal-to-noise ratio and better wavelength reproducibility. Calibration transfer was performed between the benchtop NIR and Port.1 instruments. According to the results, the transferability of models is possible. The results obtained for complete recalibration of the portable instrument and those for the benchtop are comparable. The methods developed demonstrated a flexible, easy, cheap and fast way for quality control of MBZ polymorphs in incoming material, mainly in pharmaceutical laboratory chains.

  6. Calibration of the MSL/ChemCam/LIBS Remote Sensing Composition Instrument

    NASA Technical Reports Server (NTRS)

    Wiens, R. C.; Maurice S.; Bender, S.; Barraclough, B. L.; Cousin, A.; Forni, O.; Ollila, A.; Newsom, H.; Vaniman, D.; Clegg, S.; Lasue, J. A.; Blaney, D.; DeFlores, L.; Morris, R. V.

    2011-01-01

    The ChemCam instrument suite on board the 2011 Mars Science Laboratory (MSL) Rover, Curiosity, will provide remote-sensing composition information for rock and soil samples within seven meters of the rover using a laser-induced breakdown spectroscopy (LIBS) system, and will provide context imaging with a resolution of 0.10 mradians using the remote micro-imager (RMI) camera. The high resolution is needed to image the small analysis footprint of the LIBS system, at 0.2-0.6 mm diameter. This fine scale analytical capability will enable remote probing of stratigraphic layers or other small features the size of "blueberries" or smaller. ChemCam is intended for rapid survey analyses within 7 m of the rover, with each measurement taking less than 6 minutes. Repeated laser pulses remove dust coatings and provide depth profiles through weathering layers, allowing detailed investigation of rock varnish features as well as analysis of the underlying pristine rock composition. The LIBS technique uses brief laser pulses greater than 10 MW/square mm to ablate and electrically excite material from the sample of interest. The plasma emits photons with wavelengths characteristic of the elements present in the material, permitting detection and quantification of nearly all elements, including the light elements H, Li, Be, B, C, N, O. ChemCam LIBS projects 14 mJ of 1067 nm photons on target and covers a spectral range of 240-850 nm with resolutions between 0.15 and 0.60 nm FWHM. The Nd:KGW laser is passively cooled and is tuned to provide maximum power output from -10 to 0 C, though it can operate at 20% degraded energy output at room temperature. Preliminary calibrations were carried out on the flight model (FM) in 2008. However, the detectors were replaced in 2009, and final calibrations occurred in April-June, 2010. This presentation describes the LIBS calibration and characterization procedures and results, and details plans for final analyses during rover system thermal testing

  7. Addressing the Photometric Calibration Challenge: Explicit Determination of the Instrumental Response and Atmospheric Response Functions, and Tying it All Together.

    NASA Astrophysics Data System (ADS)

    Stubbs, C. W.; Tonry, J. L.

    2016-05-01

    Photometric calibration is currently the dominant source of systematic uncertainty in exploiting type Ia supernovae to determine the nature of the dark energy. We review our ongoing program to address this calibration challenge by performing measurements of both the instrumental response function and the optical transmission function of the atmosphere. A key aspect of this approach is to complement standard star observations by using NIST-calibrated photodiodes as a metrology foundation for optical flux measurements. We present our first attempt to assess photometric consistency between synthetic photometry and observations, by comparing predictions based on a NIST-diode-based determination of the PanSTARRS-1 instrumental response and empirical atmospheric transmission measurements, with fluxes we obtained from observing spectrophotometric standards.

  8. The calibration of flight mirror modules for the ART-XC instrument on board the SRG mission

    NASA Astrophysics Data System (ADS)

    Gubarev, M.; Ramsey, B.; Kolodziejczak, J. J.; O'Dell, S. L.; Elsner, R.; Zavlin, V.; Swartz, D.; Pavlinsky, M.; Tkachenko, A.; Lapshov, I.

    2014-07-01

    MSFC is fabricating x-ray optics for the Astronomical Roentgen Telescope - X-Ray Concentrator (ART-XC or ART for short) instrument under agreements with the Russian Space Research Institute (IKI). ART-XC is one of two instruments that will be launched on the Russian-German Spectrum-Roentgen-Gamma (SRG) Mission to be launched in 20161. Delivery of the flight optics for ART-XC (7 mirror modules) is currently scheduled for summer/fall of 20142. MSFC has to date completed assembly of four modules and has performed extensive calibration on two of these. These calibrations show that the modules meet effective area requirements and greatly exceed the angular resolution requirements. Details of the calibration procedure and an overview of the results obtained to date are presented here.

  9. The Calibration Target for the Mars 2020 SHERLOC Instrument: Multiple Science Roles for Future Manned and Unmanned Mars Exploration

    NASA Technical Reports Server (NTRS)

    Fries, M.; Bhartia, R.; Beegle, L.; Burton, A.; Ross, A.; Shahar, A.

    2014-01-01

    The Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals (SHERLOC) instrument is a deep ultraviolet (UV) Raman/fluorescence instrument selected as part of the Mars 2020 rover instrument suite. SHERLOC will be mounted on the rover arm and its primary role is to identify carbonaceous species in martian samples, which may be selected for inclusion into a returnable sample cache. The SHERLOC instrument will require the use of a calibration target, and by design, multiple science roles will be addressed in the design of the target. Samples of materials used in NASA Extravehicular Mobility unit (EMU, or "space suit") manufacture have been included in the target to serve as both solid polymer calibration targets for SHERLOC instrument function, as well as for testing the resiliency of those materials under martian ambient conditions. A martian meteorite will also be included in the target to serve as a well-characterized example of a martian rock that contains trace carbonaceous material. This rock will be the first rock that we know of that has completed a round trip between planets and will therefore serve an EPO role to attract public attention to science and planetary exploration. The SHERLOC calibration target will address a wide range of NASA goals to include basic science of interest to both the Science Mission Directorate (SMD) and Human Exploration and Operations Mission Directorate (HEOMD).

  10. RADBALL TECHNOLOGY TESTING IN THE SAVANNAH RIVER SITE HEALTH PHYSICS INSTRUMENT CALIBRATION LABORATORY

    SciTech Connect

    Farfan, E.

    2010-07-08

    The United Kingdom's National Nuclear Laboratory (NNL) has developed a radiation-mapping device that can locate and quantify radioactive hazards within contaminated areas of the nuclear industry. The device, known as RadBall{trademark}, consists of a colander-like outer collimator that houses a radiation-sensitive polymer sphere. The collimator has over two hundred small holes; thus, specific areas of the polymer sphere are exposed to radiation becoming increasingly more opaque in proportion to the absorbed dose. The polymer sphere is imaged in an optical-CT scanner that produces a high resolution 3D map of optical attenuation coefficients. Subsequent analysis of the optical attenuation data provides information on the spatial distribution of sources in a given area forming a 3D characterization of the area of interest. The RadBallTM technology has been deployed in a number of technology trials in nuclear waste reprocessing plants at Sellafield in the United Kingdom and facilities of the Savannah River National Laboratory (SRNL). This paper summarizes the tests completed at SRNL Health Physics Instrument Calibration Laboratory (HPICL).

  11. James Webb Space Telescope Integrated Science Instrument Module Calibration and Verification of High-Accuracy Instrumentation to Measure Heat Flow in Cryogenic Testing

    NASA Technical Reports Server (NTRS)

    Comber, Brian; Glazer, Stuart

    2012-01-01

    The James Webb Space Telescope (JWST) is an upcoming flagship observatory mission scheduled to be launched in 2018. Three of the four science instruments are passively cooled to their operational temperature range of 36K to 40K, and the fourth instrument is actively cooled to its operational temperature of approximately 6K. The requirement for multiple thermal zoned results in the instruments being thermally connected to five external radiators via individual high purity aluminum heat straps. Thermal-vacuum and thermal balance testing of the flight instruments at the Integrated Science Instrument Module (ISIM) element level will take place within a newly constructed shroud cooled by gaseous helium inside Goddard Space Flight Center's (GSFC) Space environment Simulator (SES). The flight external radiators are not available during ISIM-level thermal vacuum/thermal testing, so they will be replaced in test with stable and adjustable thermal boundaries with identical physical interfaces to the flight radiators. Those boundaries are provided by specially designed test hardware which also measures the heat flow within each of the five heat straps to an accuracy of less than 2 mW, which is less than 5% of the minimum predicted heat flow values. Measurement of the heat loads to this accuracy is essential to ISIM thermal model correlation, since thermal models are more accurately correlated when temperature data is supplemented by accurate knowledge of heat flows. It also provides direct verification by test of several high-level thermal requirements. Devices that measure heat flow in this manner have historically been referred to a "Q-meters". Perhaps the most important feature of the design of the JWST Q-meters is that it does not depend on the absolute accuracy of its temperature sensors, but rather on knowledge of precise heater power required to maintain a constant temperature difference between sensors on two stages, for which a table is empirically developed during a

  12. The calibration of the DSCOVR EPIC multiple visible channel instrument using MODIS and VIIRS as a reference

    NASA Astrophysics Data System (ADS)

    Haney, Conor; Doelling, David; Minnis, Patrick; Bhatt, Rajendra; Scarino, Benjamin; Gopalan, Arun

    2016-09-01

    The Deep Space Climate Observatory (DSCOVR), launched on 11 February 2015, is a satellite positioned near the Lagrange-1 (L1) point, carrying several instruments that monitor space weather, and Earth-view sensors designed for climate studies. The Earth Polychromatic Imaging Camera (EPIC) onboard DSCOVR continuously views the sun illuminated portion of the Earth with spectral coverage in the UV, VIS, and NIR bands. Although the EPIC instrument does not have any onboard calibration abilities, its constant view of the sunlit Earth disk provides a unique opportunity for simultaneous viewing with several other satellite instruments. This arrangement allows the EPIC sensor to be intercalibrated using other well-characterized satellite instrument reference standards. Two such instruments with onboard calibration are MODIS, flown on Aqua and Terra, and VIIRS, onboard Suomi-NPP. The MODIS and VIIRS reference calibrations will be transferred to the EPIC instrument using both all-sky ocean and deep convective clouds (DCC) ray-matched EPIC and MODIS/VIIRS radiance pairs. An automated navigation correction routine was developed to more accurately align the EPIC and MODIS/VIIRS granules. The automated navigation correction routine dramatically reduced the uncertainty of the resulting calibration gain based on the EPIC and MODIS/VIIRS radiance pairs. The SCIAMACHY-based spectral band adjustment factors (SBAF) applied to the MODIS/ VIIRS radiances were found to successfully adjust the reference radiances to the spectral response of the specific EPIC channel for over-lapping spectral channels. The SBAF was also found to be effective for the non overlapping EPIC channel 10. Lastly, both ray-matching techniques found no discernable trends for EPIC channel 7 over the year of publically released EPIC data.

  13. On accuracy of radiometric calibration of hyperspectral visible/NIR satellite remote sensing instruments using test sites of different altitudes

    NASA Astrophysics Data System (ADS)

    Borovski, Alexander; Ivanov, Victor; Pankratova, Natalia; Postylyakov, Oleg

    2016-04-01

    To provide accurate data the regular on-board absolute radiometric calibration of a satellite hyperspectral instrument is required. Together with the internal calibration the external calibration using comparison of radiance measurements above special ground test sites and calculated radiances is performed. The top of the atmosphere radiances are calculated using a radiative transfer model basing on atmospheric and surface characteristics measured at the test sites. The paper presents preliminary results of the comparative theoretical analysis of the errors of a satellite hyperspectral instrument radiometric calibration using test sites located at 200 m.a.s.l. and 2000 m.a.s.l. with the atmospheric composition and surface reflectance measurements. The analysis is performed for an instrument with the spectral resolution of 1-8 nm which is typical for special regime of payload GSA of Russian satellite Resurs-P. The errors related with the atmospheric composition and albedo measurement errors and scenarios of the aerosol vertical distribution were theoretically examined. The error is less than 4% in all the cases at all the wavelengths between 400 nm and 1000 nm with the exception of the absorption bands of water vapor. In the absorption bands of water vapor about 720 nm and 820 nm the errors reach 5% at the mountain site and 10% at the downcountry site. In the absorption band of 950 nm the errors reach 15% in mountains and 35% in downcountry.

  14. Nitrogen dioxide and kerosene-flame soot calibration of photoacoustic instruments for measurement of light absorption by aerosols

    SciTech Connect

    Arnott, W. Patrick; Moosmu''ller, Hans; Walker, John W.

    2000-12-01

    A nitrogen dioxide calibration method is developed to evaluate the theoretical calibration for a photoacoustic instrument used to measure light absorption by atmospheric aerosols at a laser wavelength of 532.0 nm. This method uses high concentrations of nitrogen dioxide so that both a simple extinction and the photoacoustically obtained absorption measurement may be performed simultaneously. Since Rayleigh scattering is much less than absorption for the gas, the agreement between the extinction and absorption coefficients can be used to evaluate the theoretical calibration, so that the laser gas spectra are not needed. Photoacoustic theory is developed to account for strong absorption of the laser beam power in passage through the resonator. Findings are that the photoacoustic absorption based on heat-balance theory for the instrument compares well with absorption inferred from the extinction measurement, and that both are well within values represented by published spectra of nitrogen dioxide. Photodissociation of nitrogen dioxide limits the calibration method to wavelengths longer than 398 nm. Extinction and absorption at 532 and 1047 nm were measured for kerosene-flame soot to evaluate the calibration method, and the single scattering albedo was found to be 0.31 and 0.20 at these wavelengths, respectively.

  15. Laboratory Simulation of Impacts upon Aluminum Foils of the Stardust Spacecraft: Calibration of Dust Particle Size from Comet Wild 2

    NASA Technical Reports Server (NTRS)

    Kearsley, A. T.; Burchell, M. J.; Horz, F.; Cole, M. J.; Schwandt, C. S.

    2006-01-01

    Metallic aluminium alloy foils exposed on the forward, comet-facing surface of the aerogel tray on the Stardust spacecraft are likely to have been impacted by the same cometary particle population as the dedicated impact sensors and the aerogel collector. The ability of soft aluminium alloy to record hypervelocity impacts as bowl-shaped craters offers an opportunistic substrate for recognition of impacts by particles of a wide potential size range. In contrast to impact surveys conducted on samples from low Earth orbit, the simple encounter geometry for Stardust and Wild 2, with a known and constant spacecraft-particle relative velocity and effective surface-perpendicular impact trajectories, permits closely comparable simulation in laboratory experiments. For a detailed calibration programme we have selected a suite of spherical glass projectiles of uniform density and hardness characteristics, with well-documented particle size range from 10 microns to nearly 100 microns. Light gas gun buckshot firings of these particles at approximately 6km s)exp -1) onto samples of the same foil as employed on Stardust have yielded large numbers of craters. Scanning electron microscopy of both projectiles and impact features has allowed construction of a calibration plot, showing a linear relationship between impacting particle size and impact crater diameter. The close match between our experimental conditions and the Stardust mission encounter parameters should provide another opportunity to measure particle size distributions and fluxes close to the nucleus of Wild 2, independent of the active impact detector instruments aboard the Stardust spacecraft.

  16. Capabilities, Calibration, and Impact of the ISS-RAD Fast Neutron Detector

    NASA Technical Reports Server (NTRS)

    Leitgab, Martin

    2015-01-01

    In the current NASA crew radiation health risk assessment framework, estimates for the neutron contributions to crew radiation exposure largely rely on simulated data with sizeable uncertainties due to the lack of experimental measurements inside the ISS. Integrated in the ISS-RAD instrument, the ISS-RAD Fast Neutron Detector (FND) will deploy to the ISS on one of the next cargo supply missions. Together with the ISS-RAD Charged Particle Detector, the FND will perform, for the first time, routine and precise direct neutron measurements inside the ISS between 0.5 and 80 MeV. The measurements will close the NASA Medical Operations Requirement to monitor neutrons inside the ISS and impact crew radiation health risk assessments by reducing uncertainties on the neutron contribution to crew exposure, enabling more efficient mission planning. The presentation will focus on the FND detection mechanism, calibration results and expectations about the FND's interaction with the mixed radiation field inside the ISS.

  17. Apparatus for in-situ calibration of instruments that measure fluid depth

    DOEpatents

    Campbell, Melvin D.

    1994-01-01

    The present invention provides a method and apparatus for in-situ calibration of distance measuring equipment. The method comprises obtaining a first distance measurement in a first location, then obtaining at least one other distance measurement in at least one other location of a precisely known distance from the first location, and calculating a calibration constant. The method is applied specifically to calculating a calibration constant for obtaining fluid level and embodied in an apparatus using a pressure transducer and a spacer of precisely known length. The calibration constant is used to calculate the depth of a fluid from subsequent single pressure measurements at any submerged position.

  18. Apparatus for in-situ calibration of instruments that measure fluid depth

    DOEpatents

    Campbell, M.D.

    1994-01-11

    The present invention provides a method and apparatus for in-situ calibration of distance measuring equipment. The method comprises obtaining a first distance measurement in a first location, then obtaining at least one other distance measurement in at least one other location of a precisely known distance from the first location, and calculating a calibration constant. The method is applied specifically to calculating a calibration constant for obtaining fluid level and embodied in an apparatus using a pressure transducer and a spacer of precisely known length. The calibration constant is used to calculate the depth of a fluid from subsequent single pressure measurements at any submerged position. 8 figures.

  19. Mathematical calibration of Ge detectors, and the instruments that use them

    SciTech Connect

    Bronson, F.L.; Young, B.

    1997-11-01

    Efficiency calibrations for Ge detectors are typically done with the use of multiple energy calibrations sources which are added to a bulk matrix intended to simulate the measurement sample, and then deposited in the sample container. This is rather easy for common laboratory samples. Bu, even there, for many environmental samples, waste assay samples, and operational health physics samples, accurate calibrations are difficult. For these situations, various mathematical corrections or direct calibration techniques are used at Canberra. EML has pioneered the use of mathematical calibrations following source-based detector characterization measurements for in situ measurements of environmental fallout. Canberra has expanded this by the use of MCNP for the source measurements required in EML. For other calibration situations, MCNP was used directly, as the primary calibration method. This is demonstrated to be at least as accurate as source based measurements, and probably better. Recently, a new method [ISOCS] has been developed and is nearing completion. This promises to be an easy to use calibration software that can be used by the customer for in situ gamma spectroscopy to accurately measure many large sized samples, such as boxes, drums, pipes, or to calibrate small laboratory-type samples. 8 refs., 8 figs., 5 tabs.

  20. Test Plan for a Calibration Demonstration System for the Reflected Solar Instrument for the Climate Absolute Radiance and Refractivity Observatory

    NASA Technical Reports Server (NTRS)

    Thome, Kurtis; McCorkel, Joel; Hair, Jason; McAndrew, Brendan; Daw, Adrian; Jennings, Donald; Rabin, Douglas

    2012-01-01

    The Climate Absolute Radiance and Refractivity Observatory (CLARREO) mission addresses the need to observe high-accuracy, long-term climate change trends and to use decadal change observations as the most critical method to determine the accuracy of climate change. One of the major objectives of CLARREO is to advance the accuracy of SI traceable absolute calibration at infrared and reflected solar wavelengths. This advance is required to reach the on-orbit absolute accuracy required to allow climate change observations to survive data gaps while remaining sufficiently accurate to observe climate change to within the uncertainty of the limit of natural variability. While these capabilities exist at NIST in the laboratory, there is a need to demonstrate that it can move successfully from NIST to NASA and/or instrument vendor capabilities for future spaceborne instruments. The current work describes the test plan for the Solar, Lunar for Absolute Reflectance Imaging Spectroradiometer (SOLARIS) which is the calibration demonstration system (CDS) for the reflected solar portion of CLARREO. The goal of the CDS is to allow the testing and evaluation of calibration approaches , alternate design and/or implementation approaches and components for the CLARREO mission. SOLARIS also provides a test-bed for detector technologies, non-linearity determination and uncertainties, and application of future technology developments and suggested spacecraft instrument design modifications. The end result of efforts with the SOLARIS CDS will be an SI-traceable error budget for reflectance retrieval using solar irradiance as a reference and methods for laboratory-based, absolute calibration suitable for climate-quality data collections. The CLARREO mission addresses the need to observe high-accuracy, long-term climate change trends and advance the accuracy of SI traceable absolute calibration. The current work describes the test plan for the SOLARIS which is the calibration demonstration

  1. Micro-Arcsec mission: implications of the monitoring, diagnostic and calibration of the instrument response in the data reduction chain. .

    NASA Astrophysics Data System (ADS)

    Busonero, D.; Gai, M.

    The goals of 21st century high angular precision experiments rely on the limiting performance associated to the selected instrumental configuration and observational strategy. Both global and narrow angle micro-arcsec space astrometry require that the instrument contributions to the overall error budget has to be less than the desired micro-arcsec level precision. Appropriate modelling of the astrometric response is required for optimal definition of the data reduction and calibration algorithms, in order to ensure high sensitivity to the astrophysical source parameters and in general high accuracy. We will refer to the framework of the SIM-Lite and the Gaia mission, the most challenging space missions of the next decade in the narrow angle and global astrometry field, respectively. We will focus our dissertation on the Gaia data reduction issues and instrument calibration implications. We describe selected topics in the framework of the Astrometric Instrument Modelling for the Gaia mission, evidencing their role in the data reduction chain and we give a brief overview of the Astrometric Instrument Model Data Analysis Software System, a Java-based pipeline under development by our team.

  2. SOLAR/SOLSPEC: Scientific Objectives, Instrument Performance and Its Absolute Calibration Using a Blackbody as Primary Standard Source

    NASA Astrophysics Data System (ADS)

    Thuillier, G.; Foujols, T.; Bolsée, D.; Gillotay, D.; Hersé, M.; Peetermans, W.; Decuyper, W.; Mandel, H.; Sperfeld, P.; Pape, S.; Taubert, D. R.; Hartmann, J.

    2009-06-01

    SOLAR is a set of three solar instruments measuring the total and spectral absolute irradiance from 16 nm to 3080 nm for solar, atmospheric and climatology physics. It is an external payload for the COLUMBUS laboratory launched on 7 February 2008. The mission’s primary objective is the measurement of the solar irradiance with the highest possible accuracy, and its variability using the following instruments: SOL-ACES (SOLar Auto-Calibrating EUV/UV Spectrophotometers) consists of four grazing incidence planar gratings measuring from 16 nm to 220 nm; SOLSPEC (SOLar SPECtrum) consists of three double gratings spectrometers, covering the range 165 nm to 3080 nm; and SOVIM (SOlar Variability Irradiance Monitor) is combining two types of absolute radiometers and three-channel filter - radiometers. SOLSPEC and SOL-ACES have been calibrated by primary standard radiation sources of the Physikalisch-Technische Bundesanstalt (PTB). Below we describe SOLSPEC, and its performance.

  3. Post calibration of the two-dimensional electron cyclotron emission imaging instrument with electron temperature characteristics of the magnetohydrodynamic instabilities

    SciTech Connect

    Choi, M. J.; Park, H. K.; Yun, G. S.; Nam, Y. B.; Choe, G. H.; Lee, W.; Jardin, S.

    2016-01-15

    The electron cyclotron emission imaging (ECEI) instrument is widely used to study the local electron temperature (T{sub e}) fluctuations by measuring the ECE intensity I{sub ECE} ∝ T{sub e} in tokamak plasmas. The ECEI measurement is often processed in a normalized fluctuation quantity against the time averaged value due to complication in absolute calibration. In this paper, the ECEI channels are relatively calibrated using the flat T{sub e} assumption of the sawtooth crash or the tearing mode island and a proper extrapolation. The 2-D relatively calibrated electron temperature (T{sub e,rel}) images are reconstructed and the displacement amplitude of the magnetohydrodynamic modes can be measured for the accurate quantitative growth analysis.

  4. Error Budget for a Calibration Demonstration System for the Reflected Solar Instrument for the Climate Absolute Radiance and Refractivity Observatory

    NASA Technical Reports Server (NTRS)

    Thome, Kurtis; McCorkel, Joel; McAndrew, Brendan

    2013-01-01

    A goal of the Climate Absolute Radiance and Refractivity Observatory (CLARREO) mission is to observe highaccuracy, long-term climate change trends over decadal time scales. The key to such a goal is to improving the accuracy of SI traceable absolute calibration across infrared and reflected solar wavelengths allowing climate change to be separated from the limit of natural variability. The advances required to reach on-orbit absolute accuracy to allow climate change observations to survive data gaps exist at NIST in the laboratory, but still need demonstration that the advances can move successfully from to NASA and/or instrument vendor capabilities for spaceborne instruments. The current work describes the radiometric calibration error budget for the Solar, Lunar for Absolute Reflectance Imaging Spectroradiometer (SOLARIS) which is the calibration demonstration system (CDS) for the reflected solar portion of CLARREO. The goal of the CDS is to allow the testing and evaluation of calibration approaches, alternate design and/or implementation approaches and components for the CLARREO mission. SOLARIS also provides a test-bed for detector technologies, non-linearity determination and uncertainties, and application of future technology developments and suggested spacecraft instrument design modifications. The resulting SI-traceable error budget for reflectance retrieval using solar irradiance as a reference and methods for laboratory-based, absolute calibration suitable for climatequality data collections is given. Key components in the error budget are geometry differences between the solar and earth views, knowledge of attenuator behavior when viewing the sun, and sensor behavior such as detector linearity and noise behavior. Methods for demonstrating this error budget are also presented.

  5. Prime candidate earth targets for the post-launch radiometric calibration of space-based optical imaging instruments

    USGS Publications Warehouse

    Teillet, P.M.; Barsi, J.A.; Chander, G.; Thome, K.J.

    2007-01-01

    This paper provides a comprehensive list of prime candidate terrestrial targets for consideration as benchmark sites for the post-launch radiometric calibration of space-based instruments. The key characteristics of suitable sites are outlined primarily with respect to selection criteria, spatial uniformity, and temporal stability. The establishment and utilization of such benchmark sites is considered an important element of the radiometric traceability of satellite image data products for use in the accurate monitoring of environmental change.

  6. The extended wedge method: Atomic force microscope friction calibration for improved tolerance to instrument misalignments, tip offset, and blunt probes

    SciTech Connect

    Khare, H. S.; Burris, D. L.

    2013-05-15

    One of the major challenges in understanding and controlling friction is the difficulty in bridging the length and time scales of macroscale contacts and those of the single asperity interactions they comprise. While the atomic force microscope (AFM) offers a unique ability to probe tribological surfaces in a wear-free single-asperity contact, instrument calibration challenges have limited the usefulness of this technique for quantitative nanotribological studies. A number of lateral force calibration techniques have been proposed and used, but none has gained universal acceptance due to practical considerations, configuration limitations, or sensitivities to unknowable error sources. This paper describes a simple extension of the classic wedge method of AFM lateral force calibration which: (1) allows simultaneous calibration and measurement on any substrate, thus eliminating prior tip damage and confounding effects of instrument setup adjustments; (2) is insensitive to adhesion, PSD cross-talk, transducer/piezo-tube axis misalignment, and shear-center offset; (3) is applicable to integrated tips and colloidal probes; and (4) is generally applicable to any reciprocating friction coefficient measurement. The method was applied to AFM measurements of polished carbon (99.999% graphite) and single crystal MoS{sub 2} to demonstrate the technique. Carbon and single crystal MoS{sub 2} had friction coefficients of {mu}= 0.20 {+-} 0.04 and {mu}= 0.006 {+-} 0.001, respectively, against an integrated Si probe. Against a glass colloidal sphere, MoS{sub 2} had a friction coefficient of {mu}= 0.005 {+-} 0.001. Generally, the measurement uncertainties ranged from 10%-20% and were driven by the effect of actual frictional variation on the calibration rather than calibration error itself (i.e., due to misalignment, tip-offset, or probe radius).

  7. Evaluation of Instrument Landing System DDM (Difference in Depth of Modulation) Calibration Accuracies.

    DTIC Science & Technology

    1983-12-01

    provided invaluable help in the development and completion of this thesis project. Sincere appreciation is expressed to Mr. William E. Herod , Chief of...0.01728 :I ; Fig. IV-13. Calibration Hierarchy & Accuracies. IV-18 L Ley ’ ! It is clear that if the calibration accuracies of figure IV-13 can be

  8. Impact of MODIS SWIR band calibration improvements on Level-3 atmospheric products

    NASA Astrophysics Data System (ADS)

    Wald, Andrew; Levy, Robert C.; Angal, Amit; Geng, Xu; Xiong, Jack; Hoffman, Kurt

    2016-05-01

    The spectral reflectance measured by the MODIS reflective solar bands (RSB) is used for retrieving many atmospheric science products. The accuracy of these products depends on the accuracy of the calibration of the RSB. To this end, the RSB of the MODIS instruments are primarily calibrated on-orbit using regular solar diffuser (SD) observations. For λ <0.94 μm the SD's on-orbit bi-directional reflectance factor (BRF) change is tracked using solar diffuser stability monitor (SDSM) observations. For λ <0.94 μm, the MODIS Characterization Support Team (MCST) developed, in MODIS Collection 6 (C6), a time-dependent correction using observations from pseudo-invariant earth-scene targets. This correction has been implemented in C6 for the Terra MODIS 1.24 μm band over the entire mission, and for the 1.38 μm band in the forward processing. As the instruments continue to operate beyond their design lifetime of six years, a similar correction is planned for other short-wave infrared (SWIR) bands as well. MODIS SWIR bands are used in deriving atmosphere products, including aerosol optical thickness, atmospheric total column water vapor, cloud fraction and cloud optical depth. The SD degradation correction in Terra bands 5 and 26 impact the spectral radiance and therefore the retrieval of these atmosphere products. Here, we describe the corrections to Bands 5 (1.24 μm) and 26 (1.38 μm), and produce three sets (B5, B26 correction = on/on, on/off, and off/off) of Terra-MODIS Level 1B (calibrated radiance product) data. By comparing products derived from these corrected and uncorrected Terra MODIS Level 1B (L1B) calibrations, dozens of L3 atmosphere products are surveyed for changes caused by the corrections, and representative results are presented. Aerosol and water vapor products show only small local changes, while some cloud products can change locally by >10%, which is a large change.

  9. XMM-Newton and Chandra cross-calibration using HIFLUGCS galaxy clusters . Systematic temperature differences and cosmological impact

    NASA Astrophysics Data System (ADS)

    Schellenberger, G.; Reiprich, T. H.; Lovisari, L.; Nevalainen, J.; David, L.

    2015-03-01

    Context. Robust X-ray temperature measurements of the intracluster medium (ICM) of galaxy clusters require an accurate energy-dependent effective area calibration. Since the hot gas X-ray emission of galaxy clusters does not vary on relevant timescales, they are excellent cross-calibration targets. Moreover, cosmological constraints from clusters rely on accurate gravitational mass estimates, which in X-rays strongly depend on cluster gas temperature measurements. Therefore, systematic calibration differences may result in biased, instrument-dependent cosmological constraints. This is of special interest in light of the tension between the Planck results of the primary temperature anisotropies of the cosmic microwave background (CMB) and Sunyaev-Zel'dovich-plus-X-ray cluster-count analyses. Aims: We quantify in detail the systematics and uncertainties of the cross-calibration of the effective area between five X-ray instruments, EPIC-MOS1/MOS2/PN onboard XMM-Newton and ACIS-I/S onboard Chandra, and the influence on temperature measurements. Furthermore, we assess the impact of the cross-calibration uncertainties on cosmology. Methods: Using the HIFLUGCS sample, consisting of the 64 X-ray brightest galaxy clusters, we constrain the ICM temperatures through spectral fitting in the same, mostly isothermal regions and compare the different instruments. We use the stacked residual ratio method to evaluate the cross-calibration uncertainties between the instruments as a function of energy. Our work is an extension to a previous one using X-ray clusters by the International Astronomical Consortium for High Energy Calibration (IACHEC) and is carried out in the context of IACHEC. Results: Performing spectral fitting in the full energy band, (0.7-7) keV, as is typical of the analysis of cluster spectra, we find that best-fit temperatures determined with XMM-Newton/EPIC are significantly lower than Chandra/ACIS temperatures. This confirms the previous IACHEC results obtained

  10. Calibration of speleothem δ18O records against hydroclimate instrumental records in Central Brazil

    NASA Astrophysics Data System (ADS)

    Moquet, J. S.; Cruz, F. W.; Novello, V. F.; Stríkis, N. M.; Deininger, M.; Karmann, I.; Santos, R. Ventura; Millo, C.; Apaestegui, J.; Guyot, J.-L.; Siffedine, A.; Vuille, M.; Cheng, H.; Edwards, R. L.; Santini, W.

    2016-04-01

    δ18O in speleothems is a powerful proxy for reconstruction of precipitation patterns in tropical and sub-tropical regions. The aim of this study is to calibrate the δ18O record of speleothems against historical precipitation and river discharge data in central Brazil, a region directly influenced by the Southern Atlantic Convergence Zone (SACZ), a major feature of the South American Monsoon System (SAMS). The present work is based on a sub-annual resolution speleothem record covering the last 141 years (the period between the years 1870 and 2011) from a cave in central Brazil. The comparison of this record with instrumental hydroclimate records since 1921 allows defining a strong relationship between precipitation variability and stable oxygen isotope ratios from speleothems. The results from a monitoring program of climatic parameters and isotopic composition of rainfall and cave seepage waters performed in the same cave, show that the rain δ18O variability is dominated by the amount effect in this region, while δ18O drip water remains almost constant over the monitored period (1.5 years). The δ18O of modern calcite, on the other hand, shows clear seasonal variations, with more negative values observed during the rainy season, which implies that other factors also influence the isotopic composition of carbonate. However, the relationship between δ18O of carbonate deposits and rainwater is supported by the results from the comparison between speleothem δ18O records and historical hydroclimate records. A significant correlation between speleothem δ18O and monsoon rainfall variability is observed on sub-decadal time scales, especially for the monsoon period (DJFM and NDJFM), once the rainfall record have been smoothed with a 7-9 years running mean. This study confirms that speleothem δ18O is directly associated with monsoon rainfall variability in central Brazil. The relationship between speleothem δ18O records and hydroclimatic historical records allows

  11. A new calibration system for lightweight, compact and mobile Cavity-Enhanced Differential Optical Absorption Spectroscopy instruments

    NASA Astrophysics Data System (ADS)

    Zielcke, Johannes; Horbanski, Martin; Pöhler, Denis; Frieß, Udo; Platt, Ulrich

    2013-04-01

    Absorption Spectroscopy has been employed for several decades now to study the earth's atmosphere. While the focus has been on remote sensing for a long time, lately there has been a renewed interest in in-situ methods, as point measurements allow an easier interpretation for highly inhomogeneous distributions of gases of interest compared to the integration approach of most remote sensing methods. One comparatively new method offering both advantages of in-situ measurements as well as being contactless is open-path Cavity-Enhanced Differential Optical Absorption Spectroscopy (CE-DOAS). Broadband open-path CE-DOAS instruments have been used for ten years now, and in the meantime allow the measurement of numerous atmospheric trace gases (e.g. NO2, NO3, IO, CHOCHO, HCHO). While those instruments were bulky and not very mobile at first, recent developments resulted in relatively lightweight (< 30 kg) instruments with a relatively low power consumption allowing mobile open-path measurements at remote field locations. An important operational issue has been the path length calibration in the field, necessary for the determination of the concentration of measured gases. Until now, often calibration gases were used with different scattering properties than air or known concentrations. However this methods has several major shortcomings, being rather inconvenient and cumbersome in the field with the need for compressed gas cylinders, as well as time consuming, preventing a quick check of the state of the instrument in the field after changing measurement locations. Here we present a new wavelength-resolved method for broadband CE-DOAS path length calibration. A small, custom made ring-down system is employed with a pulsed LED as light source. The wavelength is then resolved by tilting a narrow band interference filter. The system not only allows quick, automated path length calibrations without physical interaction on the instrument, but also saves weight, space and the

  12. Design and Ground Calibration of the Helioseismic and Magnetic Imager (HMI) Instrument on the Solar Dynamics Observatory (SDO)

    NASA Technical Reports Server (NTRS)

    Schou, J.; Scherrer, P. H.; Bush, R. I.; Wachter, R.; Couvidat, S.; Rabello-Soares, M. C.; Bogart, R. S.; Hoeksema, J. T.; Liu, Y.; Duvall, T. L., Jr.; Akin, D. J.; Allard, B. A.; Miles, J. W.; Rairden, R.; Shine, R. A.; Tarbell, T. D.; Title, A. M.; Wolfson, C. J.; Elmore, D. F.; Norton, A. A..; Tomczyk, S.

    2012-01-01

    The Helioseismic and Magnetic Imager (HMI) investigation will study the solar interior using helioseismic techniques as well as the magnetic field near the solar surface. The HMI instrument is part of the Solar Dynamics Observatory (SDO) that was launched on 11 February 2010. The instrument is designed to measure the Doppler shift, intensity, and vector magnetic field at the solar photosphere using the 6173 Fe I absorption line. The instrument consists of a front-window filter, a telescope, a set of wave plates for polarimetry, an image-stabilization system, a blocking filter, a five-stage Lyot filter with one tunable element, two wide-field tunable Michelson interferometers, a pair of 4096(exo 2) pixel cameras with independent shutters, and associated electronics. Each camera takes a full-disk image roughly every 3.75 seconds giving an overall cadence of 45 seconds for the Doppler, intensity, and line-of-sight magnetic-field measurements and a slower cadence for the full vector magnetic field. This article describes the design of the HMI instrument and provides an overview of the pre-launch calibration efforts. Overviews of the investigation, details of the calibrations, data handling, and the science analysis are provided in accompanying articles.

  13. Design and Ground Calibration of the Helioseismic and Magnetic Imager (HMI) Instrument on the Solar Dynamics Observatory (SDO)

    NASA Astrophysics Data System (ADS)

    Schou, J.; Scherrer, P. H.; Bush, R. I.; Wachter, R.; Couvidat, S.; Rabello-Soares, M. C.; Bogart, R. S.; Hoeksema, J. T.; Liu, Y.; Duvall, T. L.; Akin, D. J.; Allard, B. A.; Miles, J. W.; Rairden, R.; Shine, R. A.; Tarbell, T. D.; Title, A. M.; Wolfson, C. J.; Elmore, D. F.; Norton, A. A.; Tomczyk, S.

    2012-01-01

    The Helioseismic and Magnetic Imager (HMI) investigation ( Solar Phys. doi:10.1007/s11207-011-9834-2, 2011) will study the solar interior using helioseismic techniques as well as the magnetic field near the solar surface. The HMI instrument is part of the Solar Dynamics Observatory (SDO) that was launched on 11 February 2010. The instrument is designed to measure the Doppler shift, intensity, and vector magnetic field at the solar photosphere using the 6173 Å Fe i absorption line. The instrument consists of a front-window filter, a telescope, a set of waveplates for polarimetry, an image-stabilization system, a blocking filter, a five-stage Lyot filter with one tunable element, two wide-field tunable Michelson interferometers, a pair of 40962 pixel cameras with independent shutters, and associated electronics. Each camera takes a full-disk image roughly every 3.75 seconds giving an overall cadence of 45 seconds for the Doppler, intensity, and line-of-sight magnetic-field measurements and a slower cadence for the full vector magnetic field. This article describes the design of the HMI instrument and provides an overview of the pre-launch calibration efforts. Overviews of the investigation, details of the calibrations, data handling, and the science analysis are provided in accompanying articles.

  14. An Instrument for In Situ Measuring the Volume Scattering Function of Water: Design, Calibration and Primary Experiments

    PubMed Central

    Li, Cai; Cao, Wenxi; Yu, Jing; Ke, Tiancun; Lu, Guixin; Yang, Yuezhong; Guo, Chaoying

    2012-01-01

    The optical volume scattering function (VSF) of seawater is a fundamental property used in the calculation of radiative transfer for applications in the study of the upper-ocean heat balance, the photosynthetic productivity of the ocean, and the chemical transformation of photoreactive compounds. A new instrument to simultaneously measure the VSF in seven directions between 20° to 160°, the attenuation coefficient, and the depth of water is presented. The instrument is self-contained and can be automatically controlled by the depth under water. The self-contained data can be easily downloaded by an ultra-short-wave communication system. A calibration test was performed in the laboratory based on precise estimation of the scattering volume and optical radiometric calibration of the detectors. The measurement error of the VSF measurement instrument has been estimated in the laboratory based on the Mie theory, and the average error is less than 12%. The instrument was used to measure and analyze the variation characteristics of the VSF with angle, depth and water quality in Daya Bay for the first time. From these in situ data, we have found that the phase functions proposed by Fournier-Forand, measured by Petzold in San Diego Harbor and Sokolov in Black Sea do not fit with our measurements in Daya. These discrepancies could manly due to high proportion of suspended calcium carbonate mineral-like particles with high refractive index in Daya Bay. PMID:22666043

  15. The Calibration Data Archive and Analysis system for PDS, the high energy instrument on board the SAX satellite.

    NASA Astrophysics Data System (ADS)

    dal Fiume, Daniele; Frontera, Filippo; Orlandini, Mauro; Trifoglio, Massimo

    The PDS (Phoswich Detection System) is an array of four phoswich scintillation detectors (800 cm geometric area) to be flown on board the Italian astronomical satellite SAX (Frontera et al., Advances in Space Research , 11 , 281 ). On ground tests and calibrations on the assembled instrument are scheduled to start by the end of this year and to continue, with various steps, up to the pre--launch phase. Tests on electronics were already performed (Frontera et al., IEEE Trans. Nucl. Sci. , in press). During the operational phase the PDS group at TeSRE will continue to monitor the in flight performance of the instrument, and will mantain an archive containing in flight data and calibrations to be used for this monitoring. In this paper we report the architectural design of the data analysis and archival system for PDS calibration data. The data will be obtained both from ground calibrations, and during the operative phase of SAX. The system is based on a network of workstations, with one of them (a HP9000/735 workstation) acting as a database server, and the others as clients. The system includes ~ 3 GB of magnetic disc space (current figure; to be upgraded in the next phases), magnetooptical rewritable disks, CD-ROMs. The data archival is based on a commercial relational database. Data hierarchy will be described and data retrieval will be outlined. Data analysis will be based on both home--made tools and on IDL. Even if PDS is a non--imaging instrument, moderate capability to manipulate pseudo--images (matrices of counts versus Pulse Height Amplitude versus Pulse Shape) is required. Some of the required functionalities are non--standard image manipulations. A scheme of data reduction and of data manipulation will be presented. Current status of the realization will be discussed.

  16. Calibration of erythemally weighted broadband instruments: A comparison between PMOD/WRC and MSL

    SciTech Connect

    Swift, Neil; Nield, Kathryn; Hamlin, John; Huelsen, Gregor; Groebner, Julian

    2013-05-10

    A Yankee Environmental Systems (YES) UVB-1 ultraviolet pyranometer, designed to measure erythemally weighted total solar irradiance, was calibrated by the Measurement Standards Laboratory (MSL) in Lower Hutt, New Zealand during August 2010. The calibration was then repeated during July and August 2011 by the Physikalisch-Meteorologisches Obervatorium Davos, World Radiation Center (PMOD/WRC) located in Davos, Switzerland. Calibration results show that measurements of the relative spectral and angular response functions at the two institutes are in excellent agreement, thus providing a good degree of confidence in these measurement facilities. However, measurements to convert the relative spectral response into an absolute calibration disagree significantly depending on whether an FEL lamp or solar spectra are used to perform this scaling. This is the first serious comparison of these scaling methods to formally explore the potential systematic errors which could explain the discrepancy.

  17. Impact of length of calibration period on the APEX model water quantity and quality simulation performance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Availability of continuous long-term measured data for model calibration and validation is limited due to time and resources constraints. As a result, hydrologic and water quality models are calibrated and, if possible, validated when measured data is available. Past work reported on the impact of t...

  18. Calibration of Nu-Instruments Noblesse multicollector mass spectrometers for argon isotopic measurements using a newly developed reference gas

    USGS Publications Warehouse

    Coble, M.A.; Grove, M.; Calvert, A.T.

    2011-01-01

    The greatest challenge limiting 40Ar/39Ar multicollection measurements is the availability of appropriate standard gasses to intercalibrate detectors. In particular, use of zoom lens ion-optics to steer and focus ion beams into a fixed detector array (i.e., Nu Instruments Noblesse) makes intercalibration of multiple detectors challenging because different ion-optic tuning conditions are required for optimal peak shape and sensitivity at different mass stations. We have found that detector efficiency and mass discrimination are affected by changes in ion-optic tuning parameters. Reliance upon an atmospheric Ar standard to calibrate the Noblesse is problematic because there is no straightforward way to relate atmospheric 40Ar and 36Ar to measurements of 40Ar and 39Ar if they are measured on separate detectors. After exploring alternative calibration approaches, we have concluded that calibration of the Noblesse is best performed using exactly the same source, detector, and ion-optic tuning settings as those used in routine 40Ar/39Ar analysis. To accomplish this, we have developed synthetic reference gasses containing 40Ar, 39Ar and 38Ar produced by mixing gasses derived from neutron-irradiated sanidine with an enriched 38Ar spike. We present a new method for calibrating the Noblesse based on use of both atmospheric Ar and the synthetic reference gasses. By combining atmospheric Ar and synthetic reference gas in different ways, we can directly measure 40Ar/39Ar, 38Ar/39Ar, and 36Ar/39Ar correction factors over ratios that vary from 0.5 to 460. These correction factors are reproducible to better than ??0.5??? (2?? standard error) over intervals spanning ~24h but can vary systematically by ~4% over 2weeks of continuous use when electron multiplier settings are held constant. Monitoring this variation requires daily calibration of the instrument. Application of the calibration method to 40Ar/39Ar multicollection measurements of widely used sanidine reference materials

  19. Calibration between Color Camera and 3D LIDAR Instruments with a Polygonal Planar Board

    PubMed Central

    Park, Yoonsu; Yun, Seokmin; Won, Chee Sun; Cho, Kyungeun; Um, Kyhyun; Sim, Sungdae

    2014-01-01

    Calibration between color camera and 3D Light Detection And Ranging (LIDAR) equipment is an essential process for data fusion. The goal of this paper is to improve the calibration accuracy between a camera and a 3D LIDAR. In particular, we are interested in calibrating a low resolution 3D LIDAR with a relatively small number of vertical sensors. Our goal is achieved by employing a new methodology for the calibration board, which exploits 2D-3D correspondences. The 3D corresponding points are estimated from the scanned laser points on the polygonal planar board with adjacent sides. Since the lengths of adjacent sides are known, we can estimate the vertices of the board as a meeting point of two projected sides of the polygonal board. The estimated vertices from the range data and those detected from the color image serve as the corresponding points for the calibration. Experiments using a low-resolution LIDAR with 32 sensors show robust results. PMID:24643005

  20. Impact of model development, calibration and validation decisions on hydrological simulations in West Lake Erie Basin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Watershed simulation models are used extensively to investigate hydrologic processes, landuse and climate change impacts, pollutant load assessments and best management practices (BMPs). Developing, calibrating and validating these models require a number of critical decisions that will influence t...

  1. Theoretical model atmosphere spectra used for the calibration of infrared instruments

    NASA Astrophysics Data System (ADS)

    Decin, L.; Eriksson, K.

    2007-09-01

    Context: One of the key ingredients in establishing the relation between input signal and output flux from a spectrometer is accurate determination of the spectrophotometric calibration. In the case of spectrometers onboard satellites, the accuracy of this part of the calibration pedigree is ultimately linked to the accuracy of the set of reference spectral energy distributions (SEDs) that the spectrophotometric calibration is built on. Aims: In this paper, we deal with the spectrophotometric calibration of infrared (IR) spectrometers onboard satellites in the 2 to 200 μm wavelength range. We aim at comparing the different reference SEDs used for the IR spectrophotometric calibration. The emphasis is on the reference SEDs of stellar standards with spectral type later than A0, with special focus on the theoretical model atmosphere spectra. Methods: Using the MARCS model atmosphere code, spectral reference SEDs were constructed for a set of IR stellar standards (A dwarfs, solar analogs, G9-M0 giants). A detailed error analysis was performed to estimate proper uncertainties on the predicted flux values. Results: It is shown that the uncertainty on the predicted fluxes can be as high as 10%, but in case high-resolution observational optical or near-IR data are available, and IR excess can be excluded, the uncertainty on medium-resolution SEDs can be reduced to 1-2% in the near-IR, to ~3% in the mid-IR, and to ~5% in the far-IR. Moreover, it is argued that theoretical stellar atmosphere spectra are at the moment the best representations for the IR fluxes of cool stellar standards. Conclusions: When aiming at a determination of the spectrophotometric calibration of IR spectrometers better than 3%, effort should be put into constructing an appropriate set of stellar reference SEDs based on theoretical atmosphere spectra for some 15 standard stars with spectral types between A0 V and M0 III.

  2. Borehole strainmeter measurements spanning the 2014, Mw6.0 South Napa Earthquake, California: The effect from instrument calibration

    USGS Publications Warehouse

    Langbein, John O.

    2015-01-01

    The 24 August 2014 Mw6.0 South Napa, California earthquake produced significant offsets on 12 borehole strainmeters in the San Francisco Bay area. These strainmeters are located between 24 and 80 km from the source and the observed offsets ranged up to 400 parts-per-billion (ppb), which exceeds their nominal precision by a factor of 100. However, the observed offsets of tidally calibrated strains differ by up to 130 ppb from predictions based on a moment tensor derived from seismic data. The large misfit can be attributed to a combination of poor instrument calibration and better modeling of the strain fit from the earthquake. Borehole strainmeters require in-situ calibration, which historically has been accomplished by comparing their measurements of Earth tides with the strain-tides predicted by a model. Although the borehole strainmeter accurately measure the deformation within the borehole, the long-wavelength strain signals from tides or other tectonic processes recorded in the borehole are modified by the presence of the borehole and the elastic properties of the grout and the instrument. Previous analyses of surface-mounted, strainmeter data and their relationship with the predicted tides suggest that tidal models could be in error by 30%. The poor fit of the borehole strainmeter data from this earthquake can be improved by simultaneously varying the components of the model tides up to 30% and making small adjustments to the point-source model of the earthquake, which reduces the RMS misfit from 130 ppb to 18 ppb. This suggests that relying on tidal models to calibrate borehole strainmeters significantly reduces their accuracy.

  3. The Impact of Indoor and Outdoor Radiometer Calibration on Solar Measurements

    SciTech Connect

    Habte, Aron; Sengupta, Manajit; Andreas, Afshin; Reda, Ibrahim; Robinson, Justin

    2016-06-02

    This study addresses the effect of calibration methodologies on calibration responsivities and the resulting impact on radiometric measurements. The calibration responsivities used in this study are provided by NREL's broadband outdoor radiometer calibration (BORCAL) and a few prominent manufacturers. The BORCAL method provides outdoor calibration responsivity of pyranometers and pyrheliometers at a 45 degree solar zenith angle and responsivity as a function of solar zenith angle determined by clear-sky comparisons to reference irradiance. The BORCAL method also employs a thermal offset correction to the calibration responsivity of single-black thermopile detectors used in pyranometers. Indoor calibrations of radiometers by their manufacturers are performed using a stable artificial light source in a side-by-side comparison of the test radiometer under calibration to a reference radiometer of the same type. These different methods of calibration demonstrated 1percent to 2 percent differences in solar irradiance measurement. Analyzing these values will ultimately enable a reduction in radiometric measurement uncertainties and assist in developing consensus on a standard for calibration.

  4. Precision DSN Radiometer Systems: Impact on Microwave Calibrations

    NASA Technical Reports Server (NTRS)

    Stelzried, C. T.; Klein, M. J.

    1994-01-01

    The NASA Deep Space Network (DSN) has a long history of providing large parabolic dish antennas with precision surfaces, low-loss feeds and ultra-low noise amplifiers for deep space telecommunications. To realize the benefits of high sensitivity, it is important that receiving systems are accurately calibrated and monitored to maintain peak performance.

  5. Absolute calibration and beam reconstruction of MITO(a ground-based instrument in the millimetric region)

    NASA Astrophysics Data System (ADS)

    Savini, G.; Orlando, A.; Battistelli, E. S.; De Petris, M.; Lamagna, L.; Luzzi, G.; Palladino, E.

    2003-09-01

    An efficient sky data reconstruction derives from a precise characterization of the observing instrument. Here we describe the reconstruction of performances of a single-pixel 4-band photometer installed at MITO (Millimeter and Infrared Testagrigia Observatory) focal plane. The strategy of differential sky observations at millimeter wavelengths, by scanning the field of view at constant elevation wobbling the subreflector, induces a good knowledge of beam profile and beam-throw amplitude, allowing efficient data recovery. The problems that arise estimating the detectors throughput by drift scanning on planets are shown. Atmospheric transmission, monitored by skydip technique, is considered for deriving final responsivities for the 4 channels using planets as primary calibrators.

  6. The slant path atmospheric refraction calibrator - An instrument to measure the microwave propagation delays induced by atmospheric water vapor

    NASA Technical Reports Server (NTRS)

    Walter, Steven J.; Bender, Peter L.

    1992-01-01

    The water vapor-induced propagation delay experienced by a radio signal traversing the atmosphere is characterized by the Slant Path Atmospheric Refraction Calibrator (SPARC), which measures the difference in the travel times between an optical and a microwave signal propagating along the same atmospheric path with an accuracy of 15 picosec or better. Attention is given to the theoretical and experimental issues involved in measuring the delay induced by water vapor; SPARC measurements conducted along a 13.35-km ground-based path are presented, illustrating the instrument's stability, precision, and accuracy.

  7. Instrument development and field application of the in situ pH Calibrator at the Ocean Observatory

    NASA Astrophysics Data System (ADS)

    Tan, C.; Ding, K.; Seyfried, W. E.

    2012-12-01

    A novel, self-calibrating instrument for in-situ measurement of pH in deep sea environments up to 4000 m has recently been developed. The device utilizes a compact fluid delivery system to perform measurement and two-point calibration of the solid state pH sensor array (Ir|IrOx| Ag|AgCl), which is sealed in a flow cell to enhance response time. The fluid delivery system is composed of a metering pump and valves, which periodically deliver seawater samples into the flow cell to perform measurements. Similarly, pH buffer solutions can be delivered into the flow cell to calibrate the electrodes under operational conditions. Sensor signals are acquired and processed by a high resolution (0.25 mV) datalogger circuit with a size of 114 mm×31 mm×25 mm. Eight input channels are available: two high impedance sensor input channels, two low impedance sensor input channel, two thermocouple input channels and two thermistor input channels. These eight channels provide adequate measurement flexibility to enhance applications in deep sea environments. The two high impedance channels of the datalogger are especially designed with the input impedance of 1016 Ω for YSZ (yittria-stabilized zirconia) ceramic electrodes characterized by the extremely low input bias current and high resistance. Field tests have been performed in 2008 by ROV at the depth up to 3200 m. Using the continuous power supply and TCP/IP network capability of the Monterey Accelerated Research System (MARS) ocean observatory, the so-called "pH Calibrator" has the capability of long term operation up to six months. In the observatory mode, the electronics are configured with DC-DC power converter modules and Ethernet to serial module to gain access to the science port of seafloor junction box. The pH Calibrator will be deployed at the ocean observatory in October and the in situ data will be on line on the internet. The pH Calibrator presents real time pH data at high pressures and variable temperatures, while

  8. Detecting trends in regional ecosystem functioning: the importance of field data for calibrating and validating NEON airborne remote sensing instruments and science data products

    NASA Astrophysics Data System (ADS)

    McCorkel, J.; Kuester, M. A.; Johnson, B. R.; Krause, K.; Kampe, T. U.; Moore, D. J.

    2011-12-01

    The National Ecological Observatory Network (NEON) is a research facility under development by the National Science Foundation to improve our understanding of and ability to forecast the impacts of climate change, land-use change, and invasive species on ecology. The infrastructure, designed to operate over 30 years or more, includes site-based flux tower and field measurements, coordinated with airborne remote sensing observations to observe key ecological processes over a broad range of temporal and spatial scales. NEON airborne data on vegetation biochemical, biophysical, and structural properties and on land use and land cover will be captured at 1 to 2 meter resolution by an imaging spectrometer, a small-footprint waveform-LiDAR and a high-resolution digital camera. Annual coverage of the 60 NEON sites and capacity to support directed research flights or respond to unexpected events will require three airborne observation platforms (AOP). The integration of field and airborne data with satellite observations and other national geospatial data for analysis, monitoring and input to ecosystem models will extend NEON observations to regions across the United States not directly sampled by the observatory. The different spatial scales and measurement methods make quantitative comparisons between remote sensing and field data, typically collected over small sample plots (e.g. < 0.2 ha), difficult. New approaches to developing temporal and spatial scaling relationships between these data are necessary to enable validation of airborne and satellite remote sensing data and for incorporation of these data into continental or global scale ecological models. In addition to consideration of the methods used to collect ground-based measurements, careful calibration of the remote sensing instrumentation and an assessment of the accuracy of algorithms used to derive higher-level science data products are needed. Furthermore, long-term consistency of the data collected by all

  9. Guide for establishing and maintaining a calibration-constancy intercomparison system for microwave-oven-compliance survey instruments (revised)

    SciTech Connect

    Not Available

    1988-03-01

    Public Law 90-602, the Radiation Control for Health and Safety Act of 1968 (the Act), directs the Department of Health and Human Services to evaluate production-testing and quality-control programs carried out by the industry to assure adequacy of safeguards against hazardous electronic-product radiation and to assure that the products comply with performance standards. Under the Act, manufacturers of microwave ovens, a product listed under 21 CFR 1002.61, are required to certify that their microwave ovens are in compliance with all of the applicable provisions of the Federal Performance Standard for Microwave Ovens, 21 CFR 1030.10. In order to comply with microwave-emission-level provisions of the performance standard, manufacturers must use properly calibrated microwave-leakage measurement instruments in their production and quality control testing programs. This document was prepared in order to assist the microwave oven manufacturers in establishing and maintaining a calibration-constancy intercomparison system for compliance survey instruments and replaces guidance previously issued by the Center for Devices and Radiological Health (the Center).

  10. Calibrating the ChemCam laser-induced breakdown spectroscopy instrument for carbonate minerals on Mars

    SciTech Connect

    Lanza, Nina L.; Wiens, Roger C.; Clegg, Samuel M.; Ollila, Ann M.; Humphries, Seth D.; Newsom, Horton E.; Barefield, James E.

    2010-05-01

    The ChemCam instrument suite onboard the NASA Mars Science Laboratory rover includes the first laser-induced breakdown spectroscopy (LIBS) instrument for extraterrestrial applications. Here we examine carbonate minerals in a simulated martian environment to better understand the LIBS signature of these materials on Mars. Both chemical composition and rock type are determined using multivariate analysis techniques. Composition is confirmed using scanning electron microscopy. Our results show that ChemCam can recognize and differentiate between different types of carbonate materials on Mars.

  11. The Fermi Large Area Telescope on Orbit: Event Classification, Instrument Response Functions, and Calibration

    NASA Technical Reports Server (NTRS)

    Ackermann, M.; Ajello, M.; Albert, A.; Allafort, A.; Atwood, W. B.; Axelsson, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Bissaldi, E.; Blandford, R. D.; Celik, Q.; Cobet, R.; Davis, D. S.; Ferrara, E. C.; Gehrels, N.; Guiriec, S.; McConville, W.; McEnery, J. E.; Nemmen, R.; Perkins, J. S.; Thompson, D. J.

    2012-01-01

    The Fermi Large Area Telescope (Fermi-LAT, hereafter LAT), the primary instrument on the Fermi Gamma-ray Space Telescope (Fermi) mission, is an imaging, wide field-of-view, high-energy -ray telescope, covering the energy range from 20 MeV to more than 300 GeV. During the first years of the mission the LAT team has gained considerable insight into the in-flight performance of the instrument. Accordingly, we have updated the analysis used to reduce LAT data for public release as well as the Instrument Response Functions (IRFs), the description of the instrument performance provided for data analysis. In this paper we describe the effects that motivated these updates. Furthermore, we discuss how we originally derived IRFs from Monte Carlo simulations and later corrected those IRFs for discrepancies observed between flight and simulated data. We also give details of the validations performed using flight data and quantify the residual uncertainties in the IRFs. Finally, we describe techniques the LAT team has developed to propagate those uncertainties into estimates of the systematic errors on common measurements such as fluxes and spectra of astrophysical sources.

  12. THE FERMI LARGE AREA TELESCOPE ON ORBIT: EVENT CLASSIFICATION, INSTRUMENT RESPONSE FUNCTIONS, AND CALIBRATION

    SciTech Connect

    Ackermann, M.; Ajello, M.; Allafort, A.; Bechtol, K.; Blandford, R. D.; Bloom, E. D.; Bogart, J. R.; Borgland, A. W.; Bottacini, E.; Albert, A.; Atwood, W. B.; Bouvier, A.; Axelsson, M.; Baldini, L.; Ballet, J.; Bastieri, D.; Bellazzini, R.; Bissaldi, E.; Bonamente, E. E-mail: luca.baldini@pi.infn.it; and others

    2012-11-15

    The Fermi Large Area Telescope (Fermi-LAT, hereafter LAT), the primary instrument on the Fermi Gamma-ray Space Telescope (Fermi) mission, is an imaging, wide field-of-view, high-energy {gamma}-ray telescope, covering the energy range from 20 MeV to more than 300 GeV. During the first years of the mission, the LAT team has gained considerable insight into the in-flight performance of the instrument. Accordingly, we have updated the analysis used to reduce LAT data for public release as well as the instrument response functions (IRFs), the description of the instrument performance provided for data analysis. In this paper, we describe the effects that motivated these updates. Furthermore, we discuss how we originally derived IRFs from Monte Carlo simulations and later corrected those IRFs for discrepancies observed between flight and simulated data. We also give details of the validations performed using flight data and quantify the residual uncertainties in the IRFs. Finally, we describe techniques the LAT team has developed to propagate those uncertainties into estimates of the systematic errors on common measurements such as fluxes and spectra of astrophysical sources.

  13. Nanobeacon: A low cost time calibration instrument for the KM3NeT neutrino telescope

    SciTech Connect

    Calvo, David [IFIC. Instituto de Física Corpuscular, CSIC-Universidad de Valencia, C Collaboration: KM3NeT Collaboration

    2014-11-18

    The KM3NeT collaboration aims at the construction of a multi-km3 high-energy neutrino telescope in the Mediterranean Sea consisting of a matrix of pressure resistant glass spheres holding each one a set (31) of small area photomultipliers. The main goal of the telescope is to observe cosmic neutrinos through the Cherenkov light induced in sea water by charged particles produced in neutrino interactions with the surrounding medium. A relative time calibration between photomultipliers of the order of 1 ns is required to achieve an optimal performance. Due to the high volume to be covered by KM3NeT, a cost reduction of the different systems is a priority. To this end a very low price calibration device, the so called Nanobeacon, has been designed and developed. At present one of such devices has already been integrated successfully at the KM3NeT telescope and eight of them in the Nemo Tower Phase II. In this article the main properties and operation of this device are described.

  14. Design and Instrumentation of a Measurement and Calibration System for an Acoustic Telemetry System

    SciTech Connect

    Deng, Zhiqun; Weiland, Mark A.; Carlson, Thomas J.; Eppard, M. B.

    2010-03-31

    The Juvenile Salmon Acoustic Telemetry System (JSATS) is an active sensing technology developed by Portland District, the U.S. Army Corps of Engineers for detecting and tracking small fish. It is used at hydroelectric projects and in the laboratory for evaluating behavior and survival of juvenile salmonids migrating through the Federal Columbia River Power System to the Pacific Ocean. It provides critical data for salmon protection and development of more “fish-friendly” hydroelectric facilities. The objective of this study was to design and build a measurement and calibration system for evaluating the JSATS component, because the JSATS requires comprehensive acceptance and performance testing in a controlled environment before it is deployed in the field. The system consists of a reference transducer, a water test tank lined with anechoic material, a motion control unit, a reference receiver, a signal conditioner and amplifier unit, a data acquisition board, MATLAB control and analysis interface, and a computer. The fully integrated system has been evaluated successfully at various simulated distances and using different encoded signals at frequencies within the bandwidth of the JSATS transmitter. It provides accurate acoustic mapping capability in a controlled environment and automates the process that allows real-time measurements and evaluation of the piezoelectric transducers, sensors, or the acoustic fields. The measurement and calibration system has been in use since 2009 for acceptance and performance testing of, and further improvements to, the JSATS.

  15. Development of a Pattern Recognition Methodology for Determining Operationally Optimal Heat Balance Instrumentation Calibration Schedules

    SciTech Connect

    Kurt Beran; John Christenson; Dragos Nica; Kenny Gross

    2002-12-15

    The goal of the project is to enable plant operators to detect with high sensitivity and reliability the onset of decalibration drifts in all of the instrumentation used as input to the reactor heat balance calculations. To achieve this objective, the collaborators developed and implemented at DBNPS an extension of the Multivariate State Estimation Technique (MSET) pattern recognition methodology pioneered by ANAL. The extension was implemented during the second phase of the project and fully achieved the project goal.

  16. Overview of NASA Earth Observing Systems Terra and Aqua Moderate Resolution Imaging Spectroradiometer Instrument Calibration Algorithms and On-Orbit Performance

    NASA Technical Reports Server (NTRS)

    Xiong, Xiaoxiong; Wenny, Brian N.; Barnes, William L.

    2009-01-01

    Since launch, the Terra and Aqua moderate resolution imaging spectroradiometer (MODIS) instruments have successfully operated on-orbit for more than 9 and 6.5 years, respectively. Iv1ODIS, a key instrument for the NASA's Earth Observing System (EOS) missions, was designed to make continuous observations for studies of Earth's land, ocean, and atmospheric properties and to extend existing data records from heritage earth-observing sensors. In addition to frequent global coverage, MODIS observations are made in 36 spectral bands, covering both solar reflective and thermal emissive spectral regions. Nearly 40 data products are routinely generated from MODIS' observations and publicly distributed for a broad range of applications. Both instruments have produced an unprecedented amount of data in support of the science community. As a general reference for understanding sensor operation and calibration, and thus science data quality, we ;provide an overview of the MODIS instruments and their pre-launch calibration and characterization, and describe their on-orbit calibration algorithms and performance. On-orbit results from both Terra and Aqua MODIS radiometric, spectral, and "spatial calibration are discussed. Currently, both instruments, including their on-board calibration devices, are healthy and are expected to continue operation for several }rears to come.

  17. Calibration and assessment of full-field optical strain measurement procedures and instrumentation

    NASA Astrophysics Data System (ADS)

    Kujawinska, Malgorzata; Patterson, E. A.; Burguete, R.; Hack, E.; Mendels, D.; Siebert, T.; Whelan, Maurice

    2006-09-01

    There are no international standards or norms for the use of optical techniques for full-field strain measurement. In the paper the rationale and design of a reference material and a set of standarized materials for the calibration and evaluation of optical systems for full-field measurements of strain are outlined. A classification system for the steps in the measurement process is also proposed and allows the development of a unified approach to diagnostic testing of components in an optical system for strain measurement based on any optical technique. The results described arise from a European study known as SPOTS whose objectives were to begin to fill the gap caused by a lack of standards.

  18. Instrumentation and calibration methods for the multichannel measurement of phase and amplitude in optical tomography

    SciTech Connect

    Nissilae, Ilkka; Noponen, Tommi; Kotilahti, Kalle; Katila, Toivo; Lipiaeinen, Lauri; Tarvainen, Tanja; Schweiger, Martin; Arridge, Simon

    2005-04-01

    In this article, we describe the multichannel implementation of an intensity modulated optical tomography system developed at Helsinki University of Technology. The system has two time-multiplexed wavelengths, 16 time-multiplexed source fibers and 16 parallel detection channels. The gain of the photomultiplier tubes (PMTs) is individually adjusted during the measurement sequence to increase the dynamic range of the system by 10{sup 4}. The PMT used has a high quantum efficiency in the near infrared (8% at 800 nm), a fast settling time, and low hysteresis. The gain of the PMT is set so that the dc anode current is below 80 nA, which allows the measurement of phase independently of the intensity. The system allows measurements of amplitude at detected intensities down to 1 fW, which is sufficient for transmittance measurements of the female breast, the forearm, and the brain of early pre-term infants. The mean repeatability of phase and the logarithm of amplitude (ln A) at 100 MHz were found to be 0.08 deg. and 0.004, respectively, in a measurement of a 7 cm phantom with an imaging time of 5 s per source and source optical power of 8 mW. We describe a three-step method of calibrating the phase and amplitude measurements so that the absolute absorption and scatter in tissue may be measured. A phantom with two small cylindrical targets and a second phantom with three rods are measured and reconstructions made from the calibrated data are shown and compared with reconstructions from simulated data.

  19. Readily synthesized calibration compounds for quadrupole and magnetic instruments for use over the mass range to 2000 daltons.

    PubMed

    Hsu, F F; Tyler, A N; Sherman, W R

    1991-06-01

    Volatile mass calibration standards have been prepared by esterifying beta-cellobiose (4-beta-D-glucopyranosyl-D-glucose) with a mixture of heptafluorobutyric (HFB) anhydride and pentafluoropropionic (PFP) anhydride. The mixed esters produce spectra that are useful for mass spectrometer calibration with positive or negative ion methane chemical ionization and electron impact over the mass range 300-2000. The spectra contain prominent ions spaced at m/z 20 and m/z 50 intervals. Using the mixed ester with direct insertion probe introduction gives intense spectra that persist for tens of minutes. All signals above m/z 194 derived from these substances disappear rapidly upon withdrawal of the probe. The composition and exact masses are given for the positive and negative ion spectra of a mixed HFB/PFP ester of beta-cellobiose. Two other calibrants are described: one made from beta-cellobiose using a mixture of HFB, PFP and trifluoroacetic anhydrides, and another the HFB/PFP mixed ester of perseitol. These are examples of the flexibility of this approach with respect to mass range and ion composition.

  20. Regression calibration with instrumental variables for longitudinal models with interaction terms, and application to air pollution studies

    PubMed Central

    Strand, M; Sillau, S; Grunwald, G K; Rabinovitch, N

    2015-01-01

    In this paper, we derive forms of estimators and associated variances for regression calibration with instrumental variables in longitudinal models that include interaction terms between two unobservable predictors and interactions between these predictors and covariates not measured with error; the inclusion of the latter interactions generalize results we previously reported. The methods are applied to air pollution and health data collected on children with asthma. The new methods allow for the examination of how the relationship between health outcome leukotriene E4 (LTE4, a biomarker of inflammation) and two unobservable pollutant exposures and their interaction are modified by the presence or absence of upper respiratory infections. The pollutant variables include secondhand smoke and ambient (outdoor) fine particulate matter. Simulations verify the accuracy of the proposed methods under various conditions. PMID:26640396

  1. Lifetime and Failure Characteristics of Pt/Ne Hollow Cathode Lamps Used as Calibration Sources for UV Space Instruments

    NASA Astrophysics Data System (ADS)

    Nave, Gillian; Sansonetti, Craig J.; Penton, Steven V.; Cunningham, Nathaniel; Beasley, Matthew; Osterman, Steven; Kerber, Florian; (Tony Keyes, Charles D.; Rosa, Michael R.

    2012-12-01

    We report accelerated aging tests on three Pt/Ne lamps from the same manufacturing run as lamps installed on the Cosmic Origins Spectrograph (COS). One lamp was aged in air at the National Institute of Standards and Technology (NIST) at a current of 10 mA and 50% duty cycle (30 s on, 30 s off) until failure. Two other lamps were aged by the COS instrument development team in a vacuum chamber. Initial radiometrically calibrated spectra were taken of all three lamps at NIST. Calibrated spectra of the air-aged lamp were taken after 206, 500, 778, 783 and 897 hr of operation. Spectra of the vacuum-aged lamps were taken after 500 hr for both lamps, and after 1000 hr for one of the lamps. During vacuum aging, the lamp voltage, photometric stability and temperature were monitored. All three lamps lasted for over 900 hr (100,000 cycles) when run at 10 mA, sufficient for 10–12 years of operation on COS. The total output dropped by less than 15% over 500 hr, with short-term repeatability within a few percent. We recommend that future space operation of these lamps include the lamp voltage in the telemetry as a diagnostic for the lamp aging.

  2. The System of the Calibration for Visibility Measurement Instrument Under the Atmospheric Aerosol Simulation Environment

    NASA Astrophysics Data System (ADS)

    Shu, Zhifeng; Yang, ShaoChen; Xu, Wenjing

    2016-06-01

    Visibility is one of the most important parameters for meteorological observation and numerical weather prediction (NWP).It is also an important factor in everyday life, mainly for surface and air traffic especially in the Aeronautical Meteorology. The visibility decides the taking off and landing of aircraft. If the airport visibility is lower than requirement for aircraft taking off stipulated by International Civil Aviation Administration, then the aircraft must be parked at the airport. So the accurate measurement of visibility is very important. Nowadays, many devices can be measured the visibility or meteorological optical range (MOR) such as Scatterometers, Transmissometers and visibility lidar. But there is not effective way to verify the accuracy of these devices expect the artificial visual method. We have developed a visibility testing system that can be calibration and verification these devices. The system consists of laser transmitter, optical chopper, phase-locking amplifier, the moving optic receiving system, signal detection and data acquisition system, atmospheric aerosol simulation chamber. All of them were placed in the atmosphere aerosol simulation chamber with uniform aerosol concentration. The Continuous wave laser, wavelength 550nm, has been transmitted into the collimation system then the laser beam expanded into 40mm diameter for compressing the laser divergence angle before modulated by optical chopper. The expanding beam transmitting in the atmosphere aerosol cabin received by the optic receiving system moving in the 50m length precision guide with 100mm optical aperture. The data of laser signal has been acquired by phase-locking amplifier every 5 meter range. So the 10 data points can be detected in the 50 meters guide once. The slope of the fitting curve can be obtained by linear fitting these data using the least square method. The laser extinction coefficient was calculated from the slope using the Koschmieder formula, then it been

  3. The Moon Mineralogy Mapper (M3) imaging spectrometer for lunar science: Instrument description, calibration, on-orbit measurements, science data calibration and on-orbit validation

    USGS Publications Warehouse

    Green, R.O.; Pieters, C.; Mouroulis, P.; Eastwood, M.; Boardman, J.; Glavich, T.; Isaacson, P.; Annadurai, M.; Besse, S.; Barr, D.; Buratti, B.; Cate, D.; Chatterjee, A.; Clark, R.; Cheek, L.; Combe, J.; Dhingra, D.; Essandoh, V.; Geier, S.; Goswami, J.N.; Green, R.; Haemmerle, V.; Head, J.; Hovland, L.; Hyman, S.; Klima, R.; Koch, T.; Kramer, G.; Kumar, A.S.K.; Lee, Kenneth; Lundeen, S.; Malaret, E.; McCord, T.; McLaughlin, S.; Mustard, J.; Nettles, J.; Petro, N.; Plourde, K.; Racho, C.; Rodriquez, J.; Runyon, C.; Sellar, G.; Smith, C.; Sobel, H.; Staid, M.; Sunshine, J.; Taylor, L.; Thaisen, K.; Tompkins, S.; Tseng, H.; Vane, G.; Varanasi, P.; White, M.; Wilson, D.

    2011-01-01

    The NASA Discovery Moon Mineralogy Mapper imaging spectrometer was selected to pursue a wide range of science objectives requiring measurement of composition at fine spatial scales over the full lunar surface. To pursue these objectives, a broad spectral range imaging spectrometer with high uniformity and high signal-to-noise ratio capable of measuring compositionally diagnostic spectral absorption features from a wide variety of known and possible lunar materials was required. For this purpose the Moon Mineralogy Mapper imaging spectrometer was designed and developed that measures the spectral range from 430 to 3000 nm with 10 nm spectral sampling through a 24 degree field of view with 0.7 milliradian spatial sampling. The instrument has a signal-to-noise ratio of greater than 400 for the specified equatorial reference radiance and greater than 100 for the polar reference radiance. The spectral cross-track uniformity is >90% and spectral instantaneous field-of-view uniformity is >90%. The Moon Mineralogy Mapper was launched on Chandrayaan-1 on the 22nd of October. On the 18th of November 2008 the Moon Mineralogy Mapper was turned on and collected a first light data set within 24 h. During this early checkout period and throughout the mission the spacecraft thermal environment and orbital parameters varied more than expected and placed operational and data quality constraints on the measurements. On the 29th of August 2009, spacecraft communication was lost. Over the course of the flight mission 1542 downlinked data sets were acquired that provide coverage of more than 95% of the lunar surface. An end-to-end science data calibration system was developed and all measurements have been passed through this system and delivered to the Planetary Data System (PDS.NASA.GOV). An extensive effort has been undertaken by the science team to validate the Moon Mineralogy Mapper science measurements in the context of the mission objectives. A focused spectral, radiometric

  4. Design and instrumentation of a measurement and calibration system for an acoustic telemetry system.

    PubMed

    Deng, Zhiqun; Weiland, Mark; Carlson, Thomas; Eppard, M Brad

    2010-01-01

    The Juvenile Salmon Acoustic Telemetry System (JSATS) is an active sensing technology developed by the U.S. Army Corps of Engineers, Portland District, for detecting and tracking small fish. It is used primarily for evaluating behavior and survival of juvenile salmonids migrating through the Federal Columbia River Power System to the Pacific Ocean. It provides critical data for salmon protection and development of more "fish-friendly" hydroelectric facilities. The objective of this study was to design and build a Measurement and Calibration System (MCS) for evaluating the JSATS components, because the JSATS requires comprehensive acceptance and performance testing in a controlled environment before it is deployed in the field. The MCS consists of a reference transducer, a water test tank lined with anechoic material, a motion control unit, a reference receiver, a signal conditioner and amplifier unit, a data acquisition board, MATLAB control and analysis interface, and a computer. The fully integrated MCS has been evaluated successfully at various simulated distances and using different encoded signals at frequencies within the bandwidth of the JSATS transmitter. The MCS provides accurate acoustic mapping capability in a controlled environment and automates the process that allows real-time measurements and evaluation of the piezoelectric transducers, sensors, or the acoustic fields. The MCS has been in use since 2009 for acceptance and performance testing of, and further improvements to, the JSATS.

  5. Construction and calibration of an instrument for three-dimensional ion imaging

    SciTech Connect

    Koszinowski, Konrad; Goldberg, Noah T.; Pomerantz, Andrew E.; Zare, Richard N.

    2006-10-07

    We describe a new instrument based on a delay-line detector for imaging the complete three-dimensional velocity distribution of photoionized products from photoinitiated reactions. Doppler-free [2+1] resonantly enhanced multiphoton ionization (REMPI) of H and D atoms formed upon photolysis of HBr and DBr in the range 203 nm{<=}{lambda}{sub photolysis}{<=}243 nm yields radial speeds measured to be accurate within 1% of those calculated. The relative speed resolution is about 5% and limited by photoionization recoil broadening. A relative speed resolution of 3.4% is obtained for [3+1] REMPI, which minimizes the ionization recoil. We also determine the branching ratio between ground-state and spin-orbit-excited product channels and their associated anisotropies. We find that DBr photolysis dynamics differs slightly from its HBr counterpart.

  6. ON-LINE SELF-CALIBRATING SINGLE CRYSTAL SAPPHIRE OPTICAL SENSOR INSTRUMENTATION FOR ACCURATE AND RELIABLE COAL GASIFIER TEMPERATURE MEASUREMENT

    SciTech Connect

    Kristie Cooper; Gary Pickrell; Anbo Wang; Zhengyu Huang

    2004-04-01

    This report summarizes technical progress over the third six month period of the Phase II program ''On-Line Self-Calibrating Single Crystal Sapphire Optical Sensor Instrumentation for Accurate and Reliable Coal Gasifier Temperature Measurement'', funded by the Federal Energy Technology Center of the U.S. Department of Energy, and performed by the Center for Photonics Technology of the Bradley Department of Electrical and Computer Engineering at Virginia Tech. The outcome of the first phase of this program was the selection of broadband polarimetric differential interferometry (BPDI) for further prototype instrumentation development. This approach is based on the measurement of the optical path difference (OPD) between two orthogonally polarized light beams in a single-crystal sapphire disk. The objective of this program is to bring the BPDI sensor technology, which has already been demonstrated in the laboratory, to a level where the sensor can be deployed in the harsh industrial environments and will become commercially viable. Research efforts were focused on sensor probe design and machining, sensor electronics design, software algorithm design, sensor field installation procedures, and sensor remote data access and control. Field testing will begin in the next several weeks.

  7. On-Line Self-Calibrating Single Crystal Sapphire Optical Sensor Instrumentation for Accurate and Reliable Coal Gasifier Temperature Measurement

    SciTech Connect

    Kristie Cooper; Gary Pickrell; Anbo Wang

    2005-11-01

    This report summarizes technical progress April-September 2005 on the Phase II program ''On-Line Self-Calibrating Single Crystal Sapphire Optical Sensor Instrumentation for Accurate and Reliable Coal Gasifier Temperature Measurement'', funded by the Federal Energy Technology Center of the U.S. Department of Energy, and performed by the Center for Photonics Technology of the Bradley Department of Electrical and Computer Engineering at Virginia Tech. The outcome of the first phase of this program was the selection of broadband polarimetric differential interferometry (BPDI) for further prototype instrumentation development. This approach is based on the measurement of the optical path difference (OPD) between two orthogonally polarized light beams in a single-crystal sapphire disk. The objective of this program is to bring the sensor technology, which has already been demonstrated in the laboratory, to a level where the sensor can be deployed in the harsh industrial environments and will become commercially viable. Due to the difficulties described on the last report, field testing of the BPDI system has not continued to date. However, we have developed an alternative high temperature sensing solution, which is described in this report. The sensing system will be installed and tested at TECO's Polk Power Station. Following a site visit in June 2005, our efforts have been focused on preparing for that field test, including he design of the sensor mechanical packaging, sensor electronics, the data transfer module, and the necessary software codes to accommodate this application.. We are currently ready to start sensor fabrication.

  8. On-Line Self-Calibrating Single Crystal Sapphire Optical Sensor Instrumentation for Accurate and Reliable Coal Gasifier Temperature Measurement

    SciTech Connect

    Kristie Cooper; Anbo Wang

    2007-03-31

    This report summarizes technical progress October 2006 - March 2007 on the Phase II program ''On-Line Self-Calibrating Single Crystal Sapphire Optical Sensor Instrumentation for Accurate and Reliable Coal Gasifier Temperature Measurement'', funded by the Federal Energy Technology Center of the U.S. Department of Energy, and performed by the Center for Photonics Technology of the Bradley Department of Electrical and Computer Engineering at Virginia Tech. The outcome of the first phase of this program was the selection of broadband polarimetric differential interferometry (BPDI) for further prototype instrumentation development. This approach is based on the measurement of the optical path difference (OPD) between two orthogonally polarized light beams in a single-crystal sapphire disk. During the second phase, an alternative high temperature sensing system based on Fabry-Perot interferometry was developed that offers a number of advantages over the BPDI solution. The objective of this program is to bring the sensor technology, which has already been demonstrated in the laboratory, to a level where the sensor can be deployed in the harsh industrial environments and will become commercially viable. The sapphire wafer-based interferometric sensing system that was installed at TECO's Polk Power Station remained in operation for seven months. Our efforts have been focused on monitoring and analyzing the real-time data collected, and preparing for a second field test.

  9. ON-LINE SELF-CALIBRATING SINGLE CRYSTAL SAPPHIRE OPTICAL SENSOR INSTRUMENTATION FOR ACCURATE AND RELIABLE COAL GASIFIER TEMPERATURE MEASUREMENT

    SciTech Connect

    Kristie Cooper; Gary Pickrell; Anbo Wang

    2003-11-01

    This report summarizes technical progress over the second six month period of the Phase II program ''On-Line Self-Calibrating Single Crystal Sapphire Optical Sensor Instrumentation for Accurate and Reliable Coal Gasifier Temperature Measurement'', funded by the Federal Energy Technology Center of the U.S. Department of Energy, and performed by the Center for Photonics Technology of the Bradley Department of Electrical and Computer Engineering at Virginia Tech. The outcome of the first phase of this program was the selection of broadband polarimetric differential interferometry (BPDI) for further prototype instrumentation development. This approach is based on the measurement of the optical path difference (OPD) between two orthogonally polarized light beams in a single-crystal sapphire disk. The objective of this program is to bring the BPDI sensor technology, which has already been demonstrated in the laboratory, to a level where the sensor can be deployed in the harsh industrial environments and will become commercially viable. Research efforts were focused on evaluating corrosion effects in single crystal sapphire at temperatures up to 1400 C, and designing the sensor mechanical packaging with input from Wabash River Power Plant. Upcoming meetings will establish details for the gasifier field test.

  10. ON-LINE SELF-CALIBRATING SINGLE CRYSTAL SAPPHIRE OPTICAL SENSOR INSTRUMENTATION FOR ACCURATE AND RELIABLE COAL GASIFIER TEMPERATURE MEASUREMENT

    SciTech Connect

    Kristie Cooper; Gary Pickrell; Anbo Wang; Zhengyu Huang; Yizheng Zhu

    2005-04-01

    This report summarizes technical progress October 2004-March 2005 on the Phase II program ''On-Line Self-Calibrating Single Crystal Sapphire Optical Sensor Instrumentation for Accurate and Reliable Coal Gasifier Temperature Measurement'', funded by the Federal Energy Technology Center of the U.S. Department of Energy, and performed by the Center for Photonics Technology of the Bradley Department of Electrical and Computer Engineering at Virginia Tech. The outcome of the first phase of this program was the selection of broadband polarimetric differential interferometry (BPDI) for further prototype instrumentation development. This approach is based on the measurement of the optical path difference (OPD) between two orthogonally polarized light beams in a single-crystal sapphire disk. The objective of this program is to bring the BPDI sensor technology, which has already been demonstrated in the laboratory, to a level where the sensor can be deployed in the harsh industrial environments and will become commercially viable. Due to the difficulties described on the last report, field testing of the BPDI system has not continued to date. However, we have developed an alternative high temperature sensing solution, which is described in this report.

  11. JPSS-1 VIIRS DNB nonlinearity and its impact on SDR calibration

    NASA Astrophysics Data System (ADS)

    Lee, Shihyan; Wang, Wenhui; Cao, Changyong

    2015-09-01

    During JPSS-1 VIIRS testing at Raytheon El Segundo, a larger than expected radiometric response nonlinearity was discovered in Day-Nigh Band (DNB). In addition, the DNB nonlinearity is aggregation mode dependent, where the most severe non-linear behavior are the aggregation modes used at high scan angles (<~50 degree). The DNB aggregation strategy was subsequently modified to remove modes with the most significant non-linearity. We characterized the DNB radiometric response using pre-launch tests with the modified aggregation strategy. The test data show the DNB non-linearity varies at each gain stages, detectors and aggregation modes. The non-linearity is most significant in the Low Gain Stage (LGS) and could vary from sample-to-sample. The non-linearity is also more significant in EV than in calibration view samples. The HGS nonlinearity is difficult to quantify due to the higher uncertainty in determining source radiance. Since the radiometric response non-linearity is most significant at low dn ranges, it presents challenge in DNB cross-stage calibration, an critical path to calibration DNB's High Gain Stage (HGS) for nighttime imagery. Based on the radiometric characterization, we estimated the DNB on-orbit calibration accuracy and compared the expected DNB calibration accuracy using operational calibration approaches. The analysis showed the non-linearity will result in cross-stage gain ratio bias, and have the most significant impact on HGS. The HGS calibration accuracy can be improved when either SD data or only the more linearly behaved EV pixels are used in cross-stage calibration. Due to constrain in test data, we were not able to achieve a satisfactory accuracy and uniformity for the JPSS-1 DNB nighttime imagery quality. The JPSS-1 DNB nonlinearity is a challenging calibration issue which will likely require special attention after JPSS-1 launch.

  12. The Calibration and Characterization of Earth Remote Sensing and Environmental Monitoring Instruments. Chapter 10

    NASA Technical Reports Server (NTRS)

    Butler, James J.; Johnson, B. Carol; Barnes, Robert A.

    2005-01-01

    The use of remote sensing instruments on orbiting satellite platforms in the study of Earth Science and environmental monitoring was officially inaugurated with the April 1, 1960 launch of the Television Infrared Observation Satellite (TIROS) [1]. The first TIROS accommodated two television cameras and operated for only 78 days. However, the TIROS program, in providing in excess of 22,000 pictures of the Earth, achieved its primary goal of providing Earth images from a satellite platform to aid in identifying and monitoring meteorological processes. This marked the beginning of what is now over four decades of Earth observations from satellite platforms. reflected and emitted radiation from the Earth using instruments on satellite platforms. These measurements are input to climate models, and the model results are analyzed in an effort to detect short and long-term changes and trends in the Earth's climate and environment, to identify the cause of those changes, and to predict or influence future changes. Examples of short-term climate change events include the periodic appearance of the El Nino-Southern Oscillation (ENSO) in the tropical Pacific Ocean [2] and the spectacular eruption of Mount Pinatubo on the Philippine island of Luzon in 1991. Examples of long term climate change events, which are more subtle to detect, include the destruction of coral reefs, the disappearance of glaciers, and global warming. Climatic variability can be both large and small scale and can be caused by natural or anthropogenic processes. The periodic El Nino event is an example of a natural process which induces significant climatic variability over a wide range of the Earth. A classic example of a large scale anthropogenic influence on climate is the well-documented rapid increase of atmospheric carbon dioxide occurring since the beginning of the Industrial Revolution [3]. An example of the study of a small-scale anthropogenic influence in climate variability is the Atlanta Land

  13. Explosive reaction of cased charges generated by impacts of. 30 calibre bullets

    SciTech Connect

    Honodel, C A

    1981-07-22

    Several high explosive formulations have recently been compared in a series of impact tests where samples of each composition were encased in a test fixture designed in flat geometry mocking an HE loaded artillery projectile. The purpose of the ongoing test series is to determine the relative rate of chemical energy release or explosiveness of several standard and research insensitive high explosive (IHE) main charge compositions. The triggering stimulus is the impact of .30 calibre ball bullets fired at normal muzzle velocity.

  14. Controlled Impact Demonstration instrumented test dummies installed in plane

    NASA Technical Reports Server (NTRS)

    1984-01-01

    In this photograph are seen some of dummies in the passenger cabin of the B-720 aircraft. NASA Langley Research Center instrumented a large portion of the aircraft and the dummies for loads in a crashworthiness research program. In 1984 NASA Dryden Flight Research Facility and the Federal Aviation Adimistration (FAA) teamed-up in a unique flight experiment called the Controlled Impact Demonstration (CID). The test involved crashing a Boeing 720 aircraft with four JT3C-7 engines burning a mixture of standard fuel with an additive called Anti-misting Kerosene (AMK) designed to supress fire. In a typical aircraft crash, fuel spilled from ruptured fuel tanks forms a fine mist that can be ignited by a number of sources at the crash site. In 1984 the NASA Dryden Flight Research Facility (after 1994 a full-fledged Center again) and the Federal Aviation Administration (FAA) teamed-up in a unique flight experiment called the Controlled Impact Demonstration (CID), to test crash a Boeing 720 aircraft using standard fuel with an additive designed to supress fire. The additive, FM-9, a high-molecular-weight long-chain polymer, when blended with Jet-A fuel had demonstrated the capability to inhibit ignition and flame propagation of the released fuel in simulated crash tests. This anti-misting kerosene (AMK) cannot be introduced directly into a gas turbine engine due to several possible problems such as clogging of filters. The AMK must be restored to almost Jet-A before being introduced into the engine for burning. This restoration is called 'degradation' and was accomplished on the B-720 using a device called a 'degrader.' Each of the four Pratt & Whitney JT3C-7 engines had a 'degrader' built and installed by General Electric (GE) to break down and return the AMK to near Jet-A quality. In addition to the AMK research the NASA Langley Research Center was involved in a structural loads measurement experiment, which included having instrumented dummies filling the seats in the

  15. Evaluating the Impacts of Unexpected Forest Disturbances on Paired Catchment Calibrations of Sediment Yield and Turbidity

    NASA Astrophysics Data System (ADS)

    Herlein, K.; Silins, U.; Williams, C.; Wagner, M. J.; Martens, A. M.

    2015-12-01

    The paired catchment approach of studying the impacts of disturbance on catchment hydrology remains as perhaps the most powerful approach for direct verification of catchment scale impacts from disturbance. However, paired catchment studies are also dependent on the stability of the relationships between treated and reference catchments during calibration and evaluation periods. A long-term paired catchment study of forest harvest impacts on sediment yield and turbidity in the Rocky Mountains of southwestern Alberta, Canada has a robust 11-year pre-treatment data record. The study intends to evaluate three alternative logging practices: clear-cutting, strip-shelterwood, and partial cutting. 3 sub-catchments in Star Creek (1035 ha) underwent harvest treatments while North York Creek (865 Ha) serves as the reference. The objective of this particular study was to explore the potential effects of unplanned and unanticipated watershed changes in two watersheds during an 11-year calibration. Sediment yield (kg ha-1 d-1) and turbidity (NTU) were monitored throughout the calibration period (2004-2014) prior to the 2015 harvest in Star Creek. Two unanticipated disturbances including backcountry trail rehabilitation in North York (2010) followed by a >100 year storm event in both watersheds in June 2013 may have affected the sediment yield and turbidity calibration relationships. Analysis of covariance (ANCOVA) was used to evaluate the effects of this trail rehabilitation and flooding by comparing the calibration relationships before and after these disturbances. Despite qualitative field observations of periodically affected sediment regimes, no impact on pre- or post- calibration relationships was observed. Backcountry trail rehabilitation in North York (p=0.904 and 0.416 for sediment yield and turbidity, respectively) or flooding in both watersheds (p=0.364 and 0.204 for sediment yield and turbidity, respectively) did not produce significant changes to the calibrations

  16. Field and laboratory calibration of impact plates for measuring coarse bed load transport

    Technology Transfer Automated Retrieval System (TEKTRAN)

    During 2008-2009, an array of impact plates instrumented with either accelerometers or geophones was installed over a channel spanning weir in the Elwha River in Washington, USA. The impact system is the first permanent installation of its kind in North America. The system was deployed to measure th...

  17. The Use of Transfer Radiometers in Validating the Visible through Shortwave Infrared Calibrations of Radiance Sources Used by Instruments in NASA's Earth Observing System

    NASA Technical Reports Server (NTRS)

    Butler, James J.; Barnes, Robert A.

    2002-01-01

    The detection and study of climate change over a time frame of decades requires successive generations of satellite, airborne, and ground-based instrumentation carefully calibrated against a common radiance scale. In NASA s Earth Observing System (EOS) program, the pre-launch radiometric calibration of these instruments in the wavelength region from 400 nm to 2500 nm is accomplished using internally illuminated integrating spheres and diffuse reflectance panels illuminated by irradiance standard lamps. Since 1995, the EOS Calibration Program operating within the EOS Project Science Office (PSO) has enlisted the expertise of national standards laboratories and government and university metrology laboratories in an effort to validate the radiance scales assigned to sphere and panel radiance sources by EOS instrument calibration facilities. This state-of-the-art program has been accomplished using ultra-stable transfer radiometers independently calibrated by the above participating institutions. In ten comparisons since February 1995, the agreement between the radiance measurements of the transfer radiometers is plus or minus 1.80% at 411 nm, plus or minus 1.31% at 552.5 nm, plus or minus 1.32% at 868.0 nm, plus or minus 2.54% at 1622nm, and plus or minus 2.81% at 2200nm (sigma =1).

  18. Laboratory Instrumentation: An Exploration of the Impact of Instrumentation on Student Learning

    ERIC Educational Resources Information Center

    Warner, Don L.; Brown, Eric C.; Shadle, Susan E.

    2016-01-01

    Academic programs generally work to make their laboratory curriculum both as instrumentation rich and up to date as possible. However, little is known about the relationship between the use of instrumentation in the curriculum and student learning. As part of our department's ongoing assessment efforts, a project was designed to probe this…

  19. Mars Albedo Measurement in the Near IR Range for Additional Calibration of the TIRVIM Instrument of the ExoMars-2016 Mission

    NASA Astrophysics Data System (ADS)

    Maslov, I. A.; Shenavrin, V. I.; Grigoriev, A. V.; Moshkin, B. E.; Shakun, A. V.

    2017-01-01

    Results of ground-based measurements of the Mars albedo in the spectral range 1-5 μm, which were held in the days close to the session of measurements from the Mars orbit by the Russian device TIRVIM, are presented. The obtained data can be used to refine the calibration of the instrument.

  20. Design, Calibration, and Expected On-Orbit Performance of the GOES-R MPS-LO Suprathermal Plasma Analyzer Instrument

    NASA Astrophysics Data System (ADS)

    Golightly, M. J.; McGarity, J. O.; Dichter, B. K.; Galica, G. E.

    2015-12-01

    The next generation U.S. geosynchronous weather satellite—GOES series R-U—will include for the first time a suprathermal plasma analyzer. The Magnetospheric Particle Sensor-Low (MPS-LO), an electrostatic analyzer utilizing triquadrispheric geometry (270° turn)deflection electrodes, will measure the flux of electrons and ions with energies between 30 eV - 30 keV in fifteen logarithmically-spaced differential energy channels and arrival direction in twelve angular bins. MPS-LO consists of two sensor heads mounted in a common electronics box. Each sensor head contains a set of deflection electrodes, microchannel plates, and segmented detector anodes. The common electronics box provides the power and I/O interface with a data processing unit, voltage supplies for all of the instrument's electronics, high voltage for the deflection electrodes, in-flight calibration pulsers, and the digital electronics to process signals from sensor heads' detector anodes. Great care was taken in the manufacture and mounting of the triquadrisphere deflection electrodes; each electrode was machined from a single piece of aluminum and specific electrode combinations were mounted with precision machined spacers and matched drilling. The precise fabrication and assembly resulted in near perfect spherical electric fields between the electrodes. The triquadrispheric electrode shape also prevents photons from reaching the detection elements-as a result, MPS-LO is solar blind. The combined field-of-view for the two sensor heads is 180° x 5°, with the larger angle in a plane perpendicular to the spacecraft's orbit and its central axis oriented anti-Earthward. An incident particle's arrival direction is determined in one of twelve 15° x 5° angular zones. A set of shielded anodes is used to measure the background caused by penetrating charged particles that reach the MCPs; this background data is used to correct the MPS-LO data. The instrument's energy resolution ΔE/E is 5.8%.

  1. Cross-calibration Of The X-ray Instruments Onboard The Chandra, Suzaku, Swift, And XMM-Newton Observatories Using 1E 0102.2-7219

    NASA Astrophysics Data System (ADS)

    Plucinsky, Paul P.; Beardmore, A. P.; DePasquale, J. M.; Dewey, D.; Foster, A. R.; Haberl, F.; Miller, E.; Pollock, A. M. T.; Sembay, S.; Smith, R. K.

    2011-09-01

    The flight calibration of the spectral response of CCD instruments below 1.5 keV is difficult in general because of the lack of strong lines in the on-board calibration sources. This calibration is also a function of time due to the effects of radiation damage on the CCDs and/or the accumulation of a contamination layer on the filters or CCDs. We desire a simple comparison of the absolute effective areas of the current generation of CCD instruments in the 0.5-1.0 keV range, specifically: Chandra ACIS, XMM-Newton EPIC (MOS and pn), Suzaku XIS, and Swift XRT. We have been using 1E 0102.2-7219 (hereafter E0102) since it has strong lines of O, Ne, and Mg below 1.5 keV and little or no Fe emission. The spectrum of E0102 has been well-characterized using the RGS grating instrument on XMM-Newton and the HETG grating instrument on Chandra. We have developed an empirical model for E0102 that includes Gaussians for the identified lines, two absorption components (one for the Galaxy and one for the SMC), and two continuum components with different temperatures. In our fits, the model is highly constrained in that only the normalizations of the four brightest line complexes (the O VII triplet, the O VIII Ly-α line, the Ne IX triplet, and the Ne X Ly-α line) and an overall normalization are allowed to vary. In our previous study in 2008, we found that most of the fitted line normalizations agreed to within +/- 10% (28 of 32 line normalizations). We have now expanded this study to include more recent data from these missions using the latest calibration updates and we will report on the current level of agreement amongst these instruments. This work is based on the activities of the International Astronomical Consortium for High Energy Calibration (IACHEC).

  2. Field observations of particle impacts by debris flows and debris floods on instrumented rock samples

    NASA Astrophysics Data System (ADS)

    McArdell, B. W.; Hsu, L.; Fritschi, B.; Dietrich, W. E.

    2011-12-01

    Bedrock incision and sediment entrainment by debris flows are important processes in torrent channels. As part of our effort to gain a better understanding of these processes, we installed instrumented rock samples in the bed of the Illgraben channel. Three rock samples, 0.4 m long (in the flow direction), 0.3 m wide, and 0.2 m thick, were installed in steel frames which were mounted on the upslope side of a concrete check dam, with the surface of the stones flush with the channel bed. Accelerometer sensors were installed on the bottom of one rock sample, with a range of up to 500 g (vertical) and 200 g (horizontal, parallel to the channel axis), where g is the acceleration due to gravity. Elastomer elements, typically used in the field as overload protection for load sensors, were placed between the rock samples and the steel frames. Data were sampled at 2 kHz and stored on a computer outside of the channel. The sensors provided data for 4 debris floods and part of one debris flow. For all of the events, the vertical acceleration data indicate a large background noise in the range of ±10 g, punctuated by very short duration impulses of up to several hundred g. The large accelerations are interpreted to represent hard impacts of cobbles or boulders in the flow with the rock tablet. Using a value of >20 g to define the occurrence of a large particle impact, it is possible to differentiate between debris floods (which have on the order of 0.1 impact per second) and the debris flow (on the order of 1 impact per second). The frequency of the sampling is too small to resolve details about the impacts, so it is not possible to precisely determine the maximum accelerations. However the peak recorded values are larger for debris flows, with values up to the measurement limit of the sensors, whereas for floods the maximum accelerations are typically less than 100 g. The results for the accelerometer which measures accelerations in the downstream direction generally mirror

  3. Calibration of impact ionization cosmic dust detectors: first tests to investigate how the dust density influences the signal

    NASA Astrophysics Data System (ADS)

    Jasmin Sterken, Veerle; Moragas-Klostermeyer, Georg; Hillier, Jon; Fielding, Lee; Lovett, Joseph; Armes, Steven; Fechler, Nina; Srama, Ralf; Bugiel, Sebastian; Hornung, Klaus

    2016-10-01

    Impact ionization experiments have been performed since more than 40 years for calibrating cosmic dust detectors. A linear Van de Graaff dust accelerator was used to accelerate the cosmic dust analogues of submicron to micron-size to speeds up to 80 km s^-1. Different materials have been used for calibration: iron, carbon, metal-coated minerals and most recently, minerals coated with conductive polymers. While different materials with different densities have been used for instrument calibration, a comparative analysis of dust impacts of equal material but different density is necessary: porous or aggregate-like particles are increasingly found to be present in the solar system: e.g. dust from comet 67P Churyumov-Gerasimenko [Fulle et al 2015], aggregate particles from the plumes of Enceladus [Gao et al 2016], and low-density interstellar dust [Westphal 2014 et al, Sterken et al 2015]. These recalibrations are relevant for measuring the size distributions of interplanetary and interstellar dust and thus mass budgets like the gas-to-dust mass ratio in the local interstellar cloud.We report about the calibrations that have been performed at the Heidelberg dust accelerator facility for investigating the influence of particle density on the impact ionization charge. We used the Cassini Cosmic Dust Analyzer for the target, and compared hollow versus compact silica particles in our study as a first attempt to investigate experimentally the influence of dust density on the signals obtained. Also, preliminary tests with carbon aerogel were performed, and (unsuccessful) attempts to accelerate silica aerogel. In this talk we explain the motivation of the study, the experiment set-up, the preparation of — and the materials used, the results and plans and recommendations for future tests.Fulle, M. et al 2015, The Astrophysical Journal Letters, Volume 802, Issue 1, article id. L12, 5 pp. (2015)Gao, P. et al 2016, Icarus, Volume 264, p. 227-238Westphal, A. et al 2014, Science

  4. Impact of Smoke Exposure on Digital Instrumentation and Control

    SciTech Connect

    Tanaka, Tina J.; Nowlen, Steven P.; Korsah, Kofi; Wood, Richard T.; Antonescu, Christina E.

    2003-08-15

    Smoke can cause interruptions and upsets in active electronics. Because nuclear power plants are replacing analog with digital instrumentation and control systems, qualification guidelines for new systems are being reviewed for severe environments such as smoke and electromagnetic interference. Active digital systems, individual components, and active circuits have been exposed to smoke in a program sponsored by the U.S. Nuclear Regulatory Commission. The circuits and systems were all monitored during the smoke exposure, indicating any immediate effects of the smoke. The results of previous smoke exposure studies have been reported in various publications. The major immediate effect of smoke has been to increase leakage currents and to cause momentary upsets and failures in digital systems. This paper presents new results from conformal coatings, memory chips, and hard drive tests.The best conformal coatings were found to be polyurethane, parylene, and acrylic (when applied by dipping). Conformal coatings can reduce smoke-induced leakage currents and protect against metal loss through corrosion. However conformal coatings are typically flammable, so they do increase material flammability. Some of the low-voltage biased memory chips failed during a combination of high smoke and high humidity. Typically, smoke along with heat and humidity is expected during fire, rather than smoke alone. Thus, due to high sensitivity of digital circuits to heat and humidity, it is hypothesized that the impact of smoke may be secondary.Low-voltage (3.3-V) static random-access memory (SRAMs) were found to be the most vulnerable to smoke. Higher bias voltages decrease the likelihood of failure. Erasable programmable read-only memory (EPROMs) and nonvolatile SRAMs were very smoke tolerant. Failures of the SRAMs occurred when two conditions were present: high density of smoke and high humidity. As the high humidity was present for only part of the test, the failures were intermittent. All

  5. High precision tilt stage as a key element to a universal test mirror for characterization and calibration of slope measuring instruments.

    PubMed

    Yashchuk, Valeriy V; Artemiev, Nikolay A; Centers, Gary; Chaubard, Arthur; Geckeler, Ralf D; Lacey, Ian; Marth, Harry; McKinney, Wayne R; Noll, Tino; Siewert, Frank; Winter, Mathias; Zeschke, Thomas

    2016-05-01

    The ultimate performance of surface slope metrology instrumentation, such as long trace profilers and auto-collimator based deflectometers, is limited by systematic errors that are increased when the entire angular range is used for metrology of significantly curved optics. At the ALS X-Ray Optics Laboratory, in collaboration with the HZB/BESSY-II and PTB (Germany) metrology teams, we are working on a calibration method for deflectometers, based on a concept of a universal test mirror (UTM) [V. V. Yashchuk et al., Proc. SPIE 6704, 67040A (2007)]. Potentially, the UTM method provides high performance calibration and accounts for peculiarities of the optics under test (e.g., slope distribution) and the experimental arrangement (e.g., the distance between the sensor and the optic under test). At the same time, the UTM calibration method is inherently universal, applicable to a variety of optics and experimental arrangements. In this work, we present the results of tests with a key component of the UTM system, a custom high precision tilt stage, which has been recently developed in collaboration with Physik Instrumente, GmbH. The tests have demonstrated high performance of the stage and its capability (after additional calibration) to provide angular calibration of surface slope measuring profilers over the entire instrumental dynamic range with absolute accuracy better than 30 nrad. The details of the stage design and tests are presented. We also discuss the foundation of the UTM method and calibration algorithm, as well as the possible design of a full scale UTM system.

  6. Calibration Systems Final Report

    SciTech Connect

    Myers, Tanya L.; Broocks, Bryan T.; Phillips, Mark C.

    2006-02-01

    The Calibration Systems project at Pacific Northwest National Laboratory (PNNL) is aimed towards developing and demonstrating compact Quantum Cascade (QC) laser-based calibration systems for infrared imaging systems. These on-board systems will improve the calibration technology for passive sensors, which enable stand-off detection for the proliferation or use of weapons of mass destruction, by replacing on-board blackbodies with QC laser-based systems. This alternative technology can minimize the impact on instrument size and weight while improving the quality of instruments for a variety of missions. The potential of replacing flight blackbodies is made feasible by the high output, stability, and repeatability of the QC laser spectral radiance.

  7. Anemometer calibrator

    NASA Technical Reports Server (NTRS)

    Bate, T.; Calkins, D. E.; Price, P.; Veikins, O.

    1971-01-01

    Calibrator generates accurate flow velocities over wide range of gas pressure, temperature, and composition. Both pressure and flow velocity can be maintained within 0.25 percent. Instrument is essentially closed loop hydraulic system containing positive displacement drive.

  8. Impact of Land Model Calibration on Coupled Land-Atmosphere Prediction

    NASA Technical Reports Server (NTRS)

    Santanello, Joseph A., Jr.; Kumar, Sujay V.; Peters-Lidard, Christa D.; Harrison, Ken; Zhou, Shujia

    2012-01-01

    Land-atmosphere (L-A) interactions play a critical role in determining the diurnal evolution of both planetary boundary layer (PBL) and land surface heat and moisture budgets, as well as controlling feedbacks with clouds and precipitation that lead to the persistence of dry and wet regimes. Recent efforts to quantify the strength of L-A coupling in prediction models have produced diagnostics that integrate across both the land and PBL components of the system. In this study, we examine the impact of improved specification of land surface states, anomalies, and fluxes on coupled WRF forecasts during the summers of extreme dry and wet land surface conditions in the U.S. Southern Great Plains. The improved land initialization and surface flux parameterizations are obtained through calibration of the Noah land surface model using the new optimization and uncertainty estimation subsystem in NASA's Land Information System (LIS-OPT/UE). The impact of the calibration on the a) spinup of the land surface used as initial conditions, and b) the simulated heat and moisture states and fluxes of the coupled WRF simulations is then assessed. Changes in ambient weather and land-atmosphere coupling are evaluated along with measures of uncertainty propagation into the forecasts. In addition, the sensitivity of this approach to the period of calibration (dry, wet, average) is investigated. Results indicate that the offline calibration leads to systematic improvements in land-PBL fluxes and near-surface temperature and humidity, and in the process provide guidance on the questions of what, how, and when to calibrate land surface models for coupled model prediction.

  9. Impact of the calibration period on the conceptual rainfall-runoff model parameter estimates

    NASA Astrophysics Data System (ADS)

    Todorovic, Andrijana; Plavsic, Jasna

    2015-04-01

    . Correlation coefficients among optimised model parameters and total precipitation P, mean temperature T and mean flow Q are calculated to give an insight into parameter dependence on the hydrometeorological drivers. The results reveal high sensitivity of almost all model parameters towards calibration period. The highest variability is displayed by the refreezing coefficient, water holding capacity, and temperature gradient. The only statistically significant (decreasing) trend is detected in the evapotranspiration reduction threshold. Statistically significant correlation is detected between the precipitation gradient and precipitation depth, and between the time-area histogram base and flows. All other correlations are not statistically significant, implying that changes in optimised parameters cannot generally be linked to the changes in P, T or Q. As for the model performance, the model reproduces the observed runoff satisfactorily, though the runoff is slightly overestimated in wet periods. The Nash-Sutcliffe efficiency coefficient (NSE) ranges from 0.44 to 0.79. Higher NSE values are obtained over wetter periods, what is supported by statistically significant correlation between NSE and flows. Overall, no systematic variations in parameters or in model performance are detected. Parameter variability may therefore rather be attributed to errors in data or inadequacies in the model structure. Further research is required to examine the impact of the calibration strategy or model structure on the variability in optimised parameters in time.

  10. Calibration of the Fluorine, Chlorine and Hydrogen Content of Apatites With the ChemCam LIBS Instrument

    NASA Technical Reports Server (NTRS)

    Meslin, P.-Y.; Cicutto, L.; Forni, O.; Drouet, C.; Rapin, W.; Nachon, M.; Cousin, A.; Blank, J. G.; McCubbin, F. M.; Gasnault, O.; Newsom, H.; Mangold, N.; Schroeder, S.; Sautter, V.; Maurice, S.; Wiens, R. C.

    2016-01-01

    Determining the composition of apatites is important to understand the behavior of volatiles during planetary differentiation. Apatite is an ubiquitous magmatic mineral in the SNC meteorites. It is a significant reservoir of halogens in these meteorites and has been used to estimate the halogen budget of Mars. Apatites have been identified in sandstones and pebbles at Gale crater by ChemCam, a Laser-Induced Breakdown Spectroscometer (LIBS) instrument onboard the Curiosity rover. Their presence was inferred from correlations between calcium, fluorine (using the CaF molecular band centered near 603 nm, whose detection limit is much lower that atomic or ionic lines and, in some cases, phosphorus (whose detection limit is much larger). An initial quantification of fluorine, based on fluorite (CaF2)/basalt mixtures and obtained at the LANL laboratory, indicated that the excess of F/Ca (compared to the stoichiometry of pure fluorapatites) found on Mars in some cases could be explained by the presence of fluorite. Chlorine was not detected in these targets, at least above a detection limit of 0.6 wt% estimated from. Fluorapatite was later also detected by X-ray diffraction (with CheMin) at a level of approx.1wt% in the Windjana drill sample (Kimberley area), and several points analyzed by ChemCam in this area also revealed a correlation between Ca and F. The in situ detection of F-rich, Cl-poor apatites contrasts with the Cl-rich, F-poor compositions of apatites found in basaltic shergottites and in gabbroic clasts from the martian meteorite NWA 7034, which were also found to be more Cl-rich than apatites from basalts on Earth, the Moon, or Vesta. The in situ observations could call into question one of the few possible explanations brought forward to explain the SNC results, namely that Mars may be highly depleted in fluorine. The purpose of the present study is to refine the calibration of the F, Cl, OH and P signals measured by the ChemCam LIBS instrument, initiated

  11. Impact of new instrumentation on advanced turbine research

    NASA Technical Reports Server (NTRS)

    Graham, R. W.

    1980-01-01

    A description is presented of an orderly test program that progresses from the simplest stationary geometry to the more complex, three dimensional, rotating turbine stage. The instrumentation requirements for this evolution of testing are described. The heat transfer instrumentation is emphasized. Recent progress made in devising new measurement techniques has greatly improved the development and confirmation of more accurate analytical methods for the prediction of turbine performance and heat transfer. However, there remain challenging requirements for novel measurement techniques that could advance the future research to be done in rotating blade rows of turbomachines.

  12. Calibration Techniques

    NASA Astrophysics Data System (ADS)

    Wurz, Peter; Balogh, Andre; Coffey, Victoria; Dichter, Bronislaw K.; Kasprzak, Wayne T.; Lazarus, Alan J.; Lennartsson, Walter; McFadden, James P.

    Calibration and characterization of particle instruments with supporting flight electronics is necessary for the correct interpretation of the returned data. Generally speaking, the instrument will always return a measurement value (typically in form of a digital number), for example a count rate, for the measurement of an external quantity, which could be an ambient neutral gas density, an ion composition (species measured and amount), or electron density. The returned values are used then to derive parameters associated with the distribution such as temperature, bulk flow speed, differential energy flux and others. With the calibration of the instrument the direct relationship between the external quantity and the returned measurement value has to be established so that the data recorded during flight can be correctly interpreted. While calibration and characterization of an instrument are usually done in ground-based laboratories prior to integration of the instrument in the spacecraft, it can also be done in space.

  13. Cross-calibration of the Instruments Onboard the Chandra, Suzaku, Swift, and XMM-Newton Observatories Using 1E 0102.2-7219: An IACHEC Study

    NASA Astrophysics Data System (ADS)

    Plucinsky, Paul P.; Beardmore, A. P.; DePasquale, J. M.; Dewey, D.; Foster, A.; Haberl, F.; Miller, E. D.; Pollock, A.; Posson-Brown, J.; Sembay, S.; Smith, R. K.

    2013-04-01

    We report on our continuing efforts to compare the time-dependent calibrations of the current generation of CCD instruments onboard the Chandra, Suzaku, Swift, and XMM-Newton observatories using the brightest supernova remnant in the Small Magellanic Cloud, 1E0102.2-7219 (hereafter E0102). This calibration is a function of time due to the effects of radiation damage on the CCDs and the accumulation of a contamination layer on the filters or CCDs. We desire a simple comparison of the absolute effective areas in the 0.5-1.0 keV bandpass. The spectrum of E0102 has been well-characterized using the RGS grating instrument on XMM-Newton and the HETG grating instrument on Chandra. We have developed an empirical model for E0102 that includes Gaussians for the identified lines, two absorption components, and two continuum components with different temperatures. In our fits, the model is highly constrained in that only the normalizations of the four brightest line complexes (the O VII triplet, the O VIII Ly-alpha line, the Ne IX triplet, and the Ne X Ly-alpha line) and an overall normalization are allowed to vary. In our previous study, we found that based on observations early in the missions, most of the fitted line normalizations agreed to within +/- 10%. We have now expanded this study to include more recent data from these missions using the latest calibration updates and we will report on the current level of agreement amongst these instruments. This work is based on the activities of the International Astronomical Consortium for High Energy Calibration (IACHEC).

  14. Cross-calibration of the CCD Instruments onboard the Chandra, Suzaku, Swift, and XMM-Newton Observatories using 1E 0102.2-7219

    NASA Astrophysics Data System (ADS)

    Plucinsky, Paul P.; Beardmore, Andrew P.; Foster, Adam; Guainazzi, Matteo; Haberl, Frank; Miller, Eric; Pollock, Andrew; Sembay, Steve; Stuhlinger, Martin

    2016-04-01

    We report on our continuing efforts to compare the time-dependent calibrations of the current generation of CCD instruments onboard the Chandra, Suzaku, Swift, and XMM-Newton observatories using the brightest supernova remnant in the Small Magellanic Cloud, 1E 0102.2-7219 (hereafter E0102). This calibration is a function of time due to the effects of radiation damage on the CCDs and the accumulation of a contamination layer on the filters or CCDs. We desire a simple comparison of the absolute effective areas in the 0.5-1.0 keV bandpass. The spectrum of E0102 has been well-characterized using the RGS grating instrument on XMM-Newton and the HETG grating instrument on Chandra. We have developed an empirical model for E0102 that includes Gaussians for the identified lines, two absorption components, and two continuum components with different temperatures. In our fits, the model is highly constrained in that only the normalizations of the four brightest line complexes (the O VII triplet, the O VIII Ly-alpha line, the Ne IX triplet, and the Ne X Ly-alpha line) and an overall normalization are allowed to vary. In our previous study, we found that based on observations early in the missions, most of the fitted line normalizations agreed to within +/- 10%. We have now expanded this study to include more recent data from these missions using the latest calibration updates and we will report on the current level of agreement amongst these instruments. This work is based on the activities of the International Astronomical Consortium for High Energy Calibration (IACHEC).

  15. Cross-calibration of the X-ray Instruments onboard the Chandra, Suzaku, Swift, & XMM-Newton Observatories using 1E 0102.2-7219

    NASA Astrophysics Data System (ADS)

    Plucinsky, Paul P.; Beardmore, Andrew P; Dewey, Daniel; Foster, Adam; Haberl, Frank; Miller, Eric D.; Pollock, Andrew; Sembay, Steve; Smith, Randall K.

    2014-08-01

    We report on our continuing efforts to compare the time-dependent calibrations of the current generation of CCD instruments onboard the Chandra, Suzaku, Swift, and XMM-Newton observatories using the brightest supernova remnant in the Small Magellanic Cloud, 1E 0102.2-7219 (hereafter E0102). This calibration is a function of time due to the effects of radiation damage on the CCDs and the accumulation of a contamination layer on the filters or CCDs. We desire a simple comparison of the absolute effective areas in the 0.5-1.0 keV bandpass. The spectrum of E0102 has been well-characterized using the RGS grating instrument on XMM-Newton and the HETG grating instrument on Chandra. We have developed an empirical model for E0102 that includes Gaussians for the identified lines, two absorption components, and two continuum components with different temperatures. In our fits, the model is highly constrained in that only the normalizations of the four brightest line complexes (the O VII triplet, the O VIII Ly-alpha line, the Ne IX triplet, and the Ne X Ly-alpha line) and an overall normalization are allowed to vary. In our previous study, we found that based on observations early in the missions, most of the fitted line normalizations agreed to within +/- 10%. We have now expanded this study to include more recent data from these missions using the latest calibration updates and we will report on the current level of agreement amongst these instruments. This work is based on the activities of the International Astronomical Consortium for High Energy Calibration (IACHEC).

  16. Use of Transportable Radiation Detection Instruments to Assess Internal Contamination from Intakes of Radionuclides Part II: Calibration Factors and ICAT Computer Program.

    PubMed

    Anigstein, Robert; Olsher, Richard H; Loomis, Donald A; Ansari, Armin

    2016-12-01

    The detonation of a radiological dispersion device or other radiological incidents could result in widespread releases of radioactive materials and intakes of radionuclides by affected individuals. Transportable radiation monitoring instruments could be used to measure radiation from gamma-emitting radionuclides in the body for triaging individuals and assigning priorities to their bioassay samples for in vitro assessments. The present study derived sets of calibration factors for four instruments: the Ludlum Model 44-2 gamma scintillator, a survey meter containing a 2.54 × 2.54-cm NaI(Tl) crystal; the Captus 3000 thyroid uptake probe, which contains a 5.08 × 5.08-cm NaI(Tl) crystal; the Transportable Portal Monitor Model TPM-903B, which contains two 3.81 × 7.62 × 182.9-cm polyvinyltoluene plastic scintillators; and a generic instrument, such as an ionization chamber, that measures exposure rates. The calibration factors enable these instruments to be used for assessing inhaled or ingested intakes of any of four radionuclides: Co, I, Cs, and Ir. The derivations used biokinetic models embodied in the DCAL computer software system developed by the Oak Ridge National Laboratory and Monte Carlo simulations using the MCNPX radiation transport code. The three physical instruments were represented by MCNP models that were developed previously. The affected individuals comprised children of five ages who were represented by the revised Oak Ridge National Laboratory pediatric phantoms, and adult men and adult women represented by the Adult Reference Computational Phantoms described in Publication 110 of the International Commission on Radiological Protection. These calibration factors can be used to calculate intakes; the intakes can be converted to committed doses by the use of tabulated dose coefficients. These calibration factors also constitute input data to the ICAT computer program, an interactive Microsoft Windows-based software package that estimates intakes of

  17. Instrumentation for Spectroscopy of Impact Initiation of Reactive Materials

    DTIC Science & Technology

    2015-04-14

    will be used to study the emission from small particles of reactive nanomaterials that are initiated by impact with a flyer plate . The emission...study the emission from small particles of reactive nanomaterials that are initiated by impact with a flyer plate . The emission spectra so obtained...this scenario. Our approach to understanding these shock mechanisms is to perform experiments where laser-launched flyer plates impact reactive

  18. Impact of Spatial Scale on Calibration and Model Output for a Grid-based SWAT Model

    NASA Astrophysics Data System (ADS)

    Pignotti, G.; Vema, V. K.; Rathjens, H.; Raj, C.; Her, Y.; Chaubey, I.; Crawford, M. M.

    2014-12-01

    The traditional implementation of the Soil and Water Assessment Tool (SWAT) model utilizes common landscape characteristics known as hydrologic response units (HRUs). Discretization into HRUs provides a simple, computationally efficient framework for simulation, but also represents a significant limitation of the model as spatial connectivity between HRUs is ignored. SWATgrid, a newly developed, distributed version of SWAT, provides modified landscape routing via a grid, overcoming these limitations. However, the current implementation of SWATgrid has significant computational overhead, which effectively precludes traditional calibration and limits the total number of grid cells in a given modeling scenario. Moreover, as SWATgrid is a relatively new modeling approach, it remains largely untested with little understanding of the impact of spatial resolution on model output. The objective of this study was to determine the effects of user-defined input resolution on SWATgrid predictions in the Upper Cedar Creek Watershed (near Auburn, IN, USA). Original input data, nominally at 30 m resolution, was rescaled for a range of resolutions between 30 and 4,000 m. A 30 m traditional SWAT model was developed as the baseline for model comparison. Monthly calibration was performed, and the calibrated parameter set was then transferred to all other SWAT and SWATgrid models to focus the effects of resolution on prediction uncertainty relative to the baseline. Model output was evaluated with respect to stream flow at the outlet and water quality parameters. Additionally, output of SWATgrid models were compared to output of traditional SWAT models at each resolution, utilizing the same scaled input data. A secondary objective considered the effect of scale on calibrated parameter values, where each standard SWAT model was calibrated independently, and parameters were transferred to SWATgrid models at equivalent scales. For each model, computational requirements were evaluated

  19. A Review of Instrumented Equipment to Investigate Head Impacts in Sport

    PubMed Central

    2016-01-01

    Contact, collision, and combat sports have more head impacts as compared to noncontact sports; therefore, such sports are uniquely suited to the investigation of head impact biomechanics. Recent advances in technology have enabled the development of instrumented equipment, which can estimate the head impact kinematics of human subjects in vivo. Literature pertaining to head impact measurement devices was reviewed and usage, in terms of validation and field studies, of such devices was discussed. Over the past decade, instrumented equipment has recorded millions of impacts in the laboratory, on the field, in the ring, and on the ice. Instrumented equipment is not without limitations; however, in vivo head impact data is crucial to investigate head injury mechanisms and further the understanding of concussion. PMID:27594780

  20. Influence of three common calibration metrics on the diagnosis of climate change impacts on water resources

    NASA Astrophysics Data System (ADS)

    Seiller, G.; Roy, R.; Anctil, F.

    2017-04-01

    Uncertainties associated to the evaluation of the impacts of climate change on water resources are broad, from multiple sources, and lead to diagnoses sometimes difficult to interpret. Quantification of these uncertainties is a key element to yield confidence in the analyses and to provide water managers with valuable information. This work specifically evaluates the influence of hydrological modeling calibration metrics on future water resources projections, on thirty-seven watersheds in the Province of Québec, Canada. Twelve lumped hydrologic models, representing a wide range of operational options, are calibrated with three common objective functions derived from the Nash-Sutcliffe efficiency. The hydrologic models are forced with climate simulations corresponding to two RCP, twenty-nine GCM from CMIP5 (Coupled Model Intercomparison Project phase 5) and two post-treatment techniques, leading to future projections in the 2041-2070 period. Results show that the diagnosis of the impacts of climate change on water resources are quite affected by the hydrologic models selection and calibration metrics. Indeed, for the four selected hydrological indicators, dedicated to water management, parameters from the three objective functions can provide different interpretations in terms of absolute and relative changes, as well as projected changes direction and climatic ensemble consensus. The GR4J model and a multimodel approach offer the best modeling options, based on calibration performance and robustness. Overall, these results illustrate the need to provide water managers with detailed information on relative changes analysis, but also absolute change values, especially for hydrological indicators acting as security policy thresholds.

  1. Development and Calibration of a System-Integrated Rotorcraft Finite Element Model for Impact Scenarios

    NASA Technical Reports Server (NTRS)

    Annett, Martin S.; Horta, Lucas G.; Jackson, Karen E.; Polanco, Michael A.; Littell, Justin D.

    2012-01-01

    Two full-scale crash tests of an MD-500 helicopter were conducted in 2009 and 2010 at NASA Langley's Landing and Impact Research Facility in support of NASA s Subsonic Rotary Wing Crashworthiness Project. The first crash test was conducted to evaluate the performance of an externally mounted composite deployable energy absorber (DEA) under combined impact conditions. In the second crash test, the energy absorber was removed to establish baseline loads that are regarded as severe but survivable. The presence of this energy absorbing device reduced the peak impact acceleration levels by a factor of three. Accelerations and kinematic data collected from the crash tests were compared to a system-integrated finite element model of the test article developed in parallel with the test program. In preparation for the full-scale crash test, a series of sub-scale and MD-500 mass simulator tests were conducted to evaluate the impact performances of various components and subsystems, including new crush tubes and the DEA blocks. Parameters defined for the system-integrated finite element model were determined from these tests. Results from 19 accelerometers placed throughout the airframe were compared to finite element model responses. The model developed for the purposes of predicting acceleration responses from the first crash test was inadequate when evaluating more severe conditions seen in the second crash test. A newly developed model calibration approach that includes uncertainty estimation, parameter sensitivity, impact shape orthogonality, and numerical optimization was used to calibrate model results for the full-scale crash test without the DEA. This combination of heuristic and quantitative methods identified modeling deficiencies, evaluated parameter importance, and proposed required model changes. The multidimensional calibration techniques presented here are particularly effective in identifying model adequacy. Acceleration results for the calibrated model were

  2. Radio metric errors due to mismatch and offset between a DSN antenna beam and the beam of a troposphere calibration instrument

    NASA Technical Reports Server (NTRS)

    Linfield, R. P.; Wilcox, J. Z.

    1993-01-01

    Two components of the error of a troposphere calibration measurement were quantified by theoretical calculations. The first component is a beam mismatch error, which occurs when the calibration instrument senses a conical volume different from the cylindrical volume sampled by a Deep Space Network (DSN) antenna. The second component is a beam offset error, which occurs if the calibration instrument is not mounted on the axis of the DSN antenna. These two error sources were calculated for both delay (e.g., VLBI) and delay rate (e.g., Doppler) measurements. The beam mismatch error for both delay and delay rate drops rapidly as the beamwidth of the troposphere calibration instrument (e.g., a water vapor radiometer or an infrared Fourier transform spectrometer) is reduced. At a 10-deg elevation angle, the instantaneous beam mismatch error is 1.0 mm for a 6-deg beamwidth and 0.09 mm for a 0.5-deg beam (these are the full angular widths of a circular beam with uniform gain out to a sharp cutoff). Time averaging for 60-100 sec will reduce these errors by factors of 1.2-2.2. At a 20-deg elevation angle, the lower limit for current Doppler observations, the beam-mismatch delay rate error is an Allan standard deviation over 100 sec of 1.1 x 10(exp -14) with a 4-deg beam and 1.3 x 10(exp -l5) for a 0.5-deg beam. A 50-m beam offset would result in a fairly modest (compared to other expected error sources) delay error (less than or equal to 0.3 mm for 60-sec integrations at any elevation angle is greater than or equal to 6 deg). However, the same offset would cause a large error in delay rate measurements (e.g., an Allan standard deviation of 1.2 x 10(exp -14) over 100 sec at a 20-deg elevation angle), which would dominate over other known error sources if the beamwidth is 2 deg or smaller. An on-axis location is essential for accurate troposphere calibration of delay rate measurements. A half-power beamwidth (for a beam with a tapered gain profile) of 1.2 deg or smaller is

  3. New instrument for tribocharge measurement due to single particle impacts

    NASA Astrophysics Data System (ADS)

    Watanabe, Hideo; Ghadiri, Mojtaba; Matsuyama, Tatsushi; Long Ding, Yu; Pitt, Kendal G.

    2007-02-01

    During particulate solid processing, particle-particle and particle-wall collisions can generate electrostatic charges. This may lead to a variety of problems ranging from fire and explosion hazards to segregation, caking, and blocking. A fundamental understanding of the particle charging in such situations is therefore essential. For this purpose we have developed a new device that can measure charge transfer due to impact between a single particle and a metal plate. The device consists of an impact test system and two sets of Faraday cage and preamplifier for charge measurement. With current amplifiers, high-resolution measurements of particle charges of approximately 1 and 10fC have been achieved before and after the impact, respectively. The device allows charge measurements of single particles with a size as small as ˜100μm impacting on the target at different incident angles with a velocity up to about 80m/s. Further analyses of the charge transfer as a function of particle initial charge define an equilibrium charge, i.e., an initial charge level prior to impact for which no net charge transfer would occur as a result of impact.

  4. New instrument for tribocharge measurement due to single particle impacts

    SciTech Connect

    Watanabe, Hideo; Ghadiri, Mojtaba; Matsuyama, Tatsushi; Ding Yulong; Pitt, Kendal G.

    2007-02-15

    During particulate solid processing, particle-particle and particle-wall collisions can generate electrostatic charges. This may lead to a variety of problems ranging from fire and explosion hazards to segregation, caking, and blocking. A fundamental understanding of the particle charging in such situations is therefore essential. For this purpose we have developed a new device that can measure charge transfer due to impact between a single particle and a metal plate. The device consists of an impact test system and two sets of Faraday cage and preamplifier for charge measurement. With current amplifiers, high-resolution measurements of particle charges of approximately 1 and 10 fC have been achieved before and after the impact, respectively. The device allows charge measurements of single particles with a size as small as {approx}100 {mu}m impacting on the target at different incident angles with a velocity up to about 80 m/s. Further analyses of the charge transfer as a function of particle initial charge define an equilibrium charge, i.e., an initial charge level prior to impact for which no net charge transfer would occur as a result of impact.

  5. New instrument for tribocharge measurement due to single particle impacts.

    PubMed

    Watanabe, Hideo; Ghadiri, Mojtaba; Matsuyama, Tatsushi; Ding, Yu Long; Pitt, Kendal G

    2007-02-01

    During particulate solid processing, particle-particle and particle-wall collisions can generate electrostatic charges. This may lead to a variety of problems ranging from fire and explosion hazards to segregation, caking, and blocking. A fundamental understanding of the particle charging in such situations is therefore essential. For this purpose we have developed a new device that can measure charge transfer due to impact between a single particle and a metal plate. The device consists of an impact test system and two sets of Faraday cage and preamplifier for charge measurement. With current amplifiers, high-resolution measurements of particle charges of approximately 1 and 10 fC have been achieved before and after the impact, respectively. The device allows charge measurements of single particles with a size as small as approximately 100 microm impacting on the target at different incident angles with a velocity up to about 80 m/s. Further analyses of the charge transfer as a function of particle initial charge define an equilibrium charge, i.e., an initial charge level prior to impact for which no net charge transfer would occur as a result of impact.

  6. ORNL calibrations facility

    SciTech Connect

    Berger, C.D.; Gupton, E.D.; Lane, B.H.; Miller, J.H.; Nichols, S.W.

    1982-08-01

    The ORNL Calibrations Facility is operated by the Instrumentation Group of the Industrial Safety and Applied Health Physics Division. Its primary purpose is to maintain radiation calibration standards for calibration of ORNL health physics instruments and personnel dosimeters. This report includes a discussion of the radioactive sources and ancillary equipment in use and a step-by-step procedure for calibration of those survey instruments and personnel dosimeters in routine use at ORNL.

  7. Calibration of the Dust Impact Monitor DIM onboard Rosetta/Philae

    NASA Astrophysics Data System (ADS)

    Krueger, Harald; Seidensticker, Klaus; Fischer, Hans-Herbert; Hirn, Attila; Loose, Alexander; Peter, Attila; Ossowski, Thomas; Flandes, Alberto; Herwig, Alexander; Apathy, Istvan; Arnold, Walter; Sperl, Mathias

    2012-07-01

    The Rosetta lander spacecraft Philae will land on the nucleus surface of comet 67P/Churyumov-Gerasimenko in late 2014. It is equipped with the Dust Impact Monitor instrument (DIM). DIM is part of the SESAME instrument package onboard Philae [Seidensticker et al., 2007] and consists of three piezoelectric PZT sensors. Each sensor is mounted on the outer side of a cube, facing in orthogonal directions, this way allowing for the detection of grains approaching normal to the nucleus surface and from two horizontal directions. DIM's total sensitive area is approximately 70 cm^2. It will measure impacts of sub-millimeter and millimeter sized ice and dust particles that are emitted from the nucleus and transported into the cometary coma by the escaping gas flow. A grain-size dependent fraction of the emitted grains is expected to fall back to the nucleus surface due to gravity.

  8. Design, calibration and validation of a novel 3D printed instrumented spatial linkage that measures changes in the rotational axes of the tibiofemoral joint.

    PubMed

    Bonny, Daniel P; Hull, M L; Howell, S M

    2014-01-01

    An accurate axis-finding technique is required to measure any changes from normal caused by total knee arthroplasty in the flexion-extension (F-E) and longitudinal rotation (LR) axes of the tibiofemoral joint. In a previous paper, we computationally determined how best to design and use an instrumented spatial linkage (ISL) to locate the F-E and LR axes such that rotational and translational errors were minimized. However, the ISL was not built and consequently was not calibrated; thus the errors in locating these axes were not quantified on an actual ISL. Moreover, previous methods to calibrate an ISL used calibration devices with accuracies that were either undocumented or insufficient for the device to serve as a gold-standard. Accordingly, the objectives were to (1) construct an ISL using the previously established guidelines,(2) calibrate the ISL using an improved method, and (3) quantify the error in measuring changes in the F-E and LR axes. A 3D printed ISL was constructed and calibrated using a coordinate measuring machine, which served as a gold standard. Validation was performed using a fixture that represented the tibiofemoral joint with an adjustable F-E axis and the errors in measuring changes to the positions and orientations of the F-E and LR axes were quantified. The resulting root mean squared errors (RMSEs) of the calibration residuals using the new calibration method were 0.24, 0.33, and 0.15 mm for the anterior-posterior, medial-lateral, and proximal-distal positions, respectively, and 0.11, 0.10, and 0.09 deg for varus-valgus, flexion-extension, and internal-external orientations, respectively. All RMSEs were below 0.29% of the respective full-scale range. When measuring changes to the F-E or LR axes, each orientation error was below 0.5 deg; when measuring changes in the F-E axis, each position error was below 1.0 mm. The largest position RMSE was when measuring a medial-lateral change in the LR axis (1.2 mm). Despite the large size

  9. The tabletting machine as an analytical instrument: qualification of the measurement devices for punch forces and validation of the calibration procedures.

    PubMed

    Belda, P M; Mielck, J B

    1998-11-01

    The quality of force measurement in an eccentric tabletting machine equipped with piezo-electric load washers mounted under pre-stress at the upper and lower punches, and the reliability of their calibration in situ and under working conditions were carefully investigated, since this tabletting machine is used as an 'analytical instrument' for the evaluation of the compression behaviour of pharmaceutical materials. For a quasistatic calibration procedure the repeatability under standard conditions and the robustness against variations in machine settings, installation conditions, equipment and handling were evaluated. Two differently constructed reference load cells equipped with strain gauges were used for the calibration of the upper punch sensor. The lower punch sensor was calibrated against the upper one. Except for a mechanical hysteresis, owing to uneven stress distribution over the piezo-electric sensors, the results of the quasistatic measurements are assessed to be satisfactory. In addition, dynamic calibrations were performed. One of the strain-gauged load cells was used in addition to two piezo-electric load washers installed without pre-stress. The dynamic behaviour of all the transducers used is deficient. While for the piezo-electric sensors a significant change in the slope of the calibration function with respect to the quasistatic behaviour was observed, for the strain-gauged load cell a pronounced hysteresis must be noted. Comparing the dynamic behaviour at different profiles of rates of force development generated by variations in machine speed and by maximum force setting, the variability in the sensitivity of the upper and lower punch piezo-electric load washers is comparatively small.

  10. Ice Particle Impact on Cloud Water Content Instrumentation

    NASA Technical Reports Server (NTRS)

    Emery, Edward F.; Miller, Dean R.; Plaskon, Stephen R.; Strapp, Walter; Lillie, Lyle

    2004-01-01

    Determining the total amount of water contained in an icing cloud necessitates the measurement of both the liquid droplets and ice particles. One commonly accepted method for measuring cloud water content utilizes a hot wire sensing element, which is maintained at a constant temperature. In this approach, the cloud water content is equated with the power required to keep the sense element at a constant temperature. This method inherently assumes that impinging cloud particles remain on the sensing element surface long enough to be evaporated. In the case of ice particles, this assumption requires that the particles do not bounce off the surface after impact. Recent tests aimed at characterizing ice particle impact on a thermally heated wing section, have raised questions about the validity of this assumption. Ice particles were observed to bounce off the heated wing section a very high percentage of the time. This result could have implications for Total Water Content sensors which are designed to capture ice particles, and thus do not account for bouncing or breakup of ice particles. Based on these results, a test was conducted to investigate ice particle impact on the sensing elements of the following hot-wire cloud water content probes: (1) Nevzorov Total Water Content (TWC)/Liquid Water Content (LWC) probe, (2) Science Engineering Associates TWC probe, and (3) Particle Measuring Systems King probe. Close-up video imaging was used to study ice particle impact on the sensing element of each probe. The measured water content from each probe was also determined for each cloud condition. This paper will present results from this investigation and attempt to evaluate the significance of ice particle impact on hot-wire cloud water content measurements.

  11. ABSOLUTE FLUX CALIBRATION OF THE IRAC INSTRUMENT ON THE SPITZER SPACE TELESCOPE USING HUBBLE SPACE TELESCOPE FLUX STANDARDS

    SciTech Connect

    Bohlin, R. C.; Gordon, K. D.; Deustua, S.; Ferguson, H. C.; Flanagan, K.; Kalirai, J.; Meixner, M.; Rieke, G. H.; Engelbracht, C.; Su, K. Y. L.; Ardila, D.; Tremblay, P.-E.

    2011-05-15

    The absolute flux calibration of the James Webb Space Telescope (JWST) will be based on a set of stars observed by the Hubble and Spitzer Space Telescopes. In order to cross-calibrate the two facilities, several A, G, and white dwarf stars are observed with both Spitzer and Hubble and are the prototypes for a set of JWST calibration standards. The flux calibration constants for the four Spitzer IRAC bands 1-4 are derived from these stars and are 2.3%, 1.9%, 2.0%, and 0.5% lower than the official cold-mission IRAC calibration of Reach et al., i.e., in agreement within their estimated errors of {approx}2%. The causes of these differences lie primarily in the IRAC data reduction and secondarily in the spectral energy distributions of our standard stars. The independent IRAC 8 {mu}m band-4 fluxes of Rieke et al. are about 1.5% {+-} 2% higher than those of Reach et al. and are also in agreement with our 8 {mu}m result.

  12. Design, Calibration and Specifications of the Space Environment in-Situ Suite (SEISSS) Space Weather Instruments for the GOES-R Program

    NASA Astrophysics Data System (ADS)

    Dichter, B.; Galica, G. E.; McGarity, J. O.; Mullen, E. G.; Hanser, F. A.; Tsui, S.; Lopate, C.; Connell, J. J.

    2014-12-01

    The next generation GOES spacecraft will continue the long-term operational measurement of the charged particle environment in geosynchronous orbit with the SEISS space environment monitors. The suite comprises five instruments that measure electrons and ions in multiple energy ranges and a data processing unit. Two of the instruments, MPS-LO and EHIS provide new measurement capabilities compared with previous GOES environmental monitors. The MPS-LO (new to GOES) is an electrostatic instrument that measures electrons and ions from 30 eV to 30 keV in 15 logarithmically spaced energy bins. Its twelve 15ox5o angular channels provide a 180o FOV oriented north to south. The MPS-HI instrument, using solid state Si detector telescopes, covers the energy range of 50 keV to 4 MeV for electrons and 80 keV to 10 MeV for protons each along five 15o half angle look angles spaced 35o apart. High energy solar and galactic protons in the range of 1 to 500 MeV are measured by the SGPS, which also has an integral channel above 500 MeV. This broad energy range is divided into three sub-ranges, 1-25, 25-80 and 80-500 MeV, each measured by a separate Si detector telescope. The opening half-angles of the telescopes are 30o, 30o and 45o respectively. There are east and west oriented SGPS instruments. Energetic heavy ions are detected by EHIS, also consisting of solid state detectors, in thirty individual species from H to Ni and in five logarithmically spaced energy bands from 10 MeV/n to 200 MeV/n. The FOV is a 30oopening half-angle cone. Extensive calibrations at accelerator facilities have been performed to verify the 25% accuracy of each instrument's geometric factor. In addition, performances of the solid state detector instruments have been modeled using the GEANT and FLUKA Monte Carlo codes and the results compared to calibration measurements. Energy overlap regions of the instruments will be used to improve the quality and self-consistency of the data sets.

  13. Instrumented impact and residual tensile strength testing of eight-ply carbon eopoxy specimens

    NASA Technical Reports Server (NTRS)

    Nettles, A. T.

    1990-01-01

    Instrumented drop weight impact testing was utilized to examine a puncture-type impact on thin carbon-epoxy coupons. Four different material systems with various eight-ply lay-up configurations were tested. Specimens were placed over a 10.3-mm diameter hole and impacted with a smaller tup (4.2-mm diameter) than those used in previous studies. Force-time plots as well as data on absorbed energy and residual tensile strength were gathered and examined. It was found that a critical impact energy level existed for each material tested, at which point tensile strength began to rapidly decrease with increasing impact energy.

  14. Transient Inverse Calibration of Hanford Site-Wide Groundwater Model to Hanford Operational Impacts - 1943 to 1996

    SciTech Connect

    Cole, Charles R; Bergeron, Marcel P; Wurstner, Signe K; Thorne, Paul D; Orr, Samuel; Mckinley, Mathew I

    2001-05-31

    This report describes a new initiative to strengthen the technical defensibility of predictions made with the Hanford site-wide groundwater flow and transport model. The focus is on characterizing major uncertainties in the current model. PNNL will develop and implement a calibration approach and methodology that can be used to evaluate alternative conceptual models of the Hanford aquifer system. The calibration process will involve a three-dimensional transient inverse calibration of each numerical model to historical observations of hydraulic and water quality impacts to the unconfined aquifer system from Hanford operations since the mid-1940s.

  15. The SNOOPY Angle of Repose Experiment: Calibration of an Instrument to Determine the Angle of Repose of Martian Dust

    NASA Technical Reports Server (NTRS)

    Moeller, L. E.; Kuhlman, K. R.; Marshall, J. R.; Towner, M. C.

    2002-01-01

    The present work calibrates the Student Nanoexperiments for Outreach and Observational Planetary Inquiry (SNOOPY) Angle of Repose experiment. Using particulate collection on small marbles, the measured angles of repose compare well to experimental data and theoretical predictions. Additional information is contained in the original extended abstract.

  16. Fabrication of Sulfate-bearing Ceramic Calibration Targets for the ChemCam Laser Spectroscopy Instrument, Mars Science Lander

    NASA Astrophysics Data System (ADS)

    Vaniman, D. T.; Clegg, S.; Lanza, N.; Newsom, H.; Wiens, R. C.; Chemcam Team

    2009-03-01

    A need for sulfur-bearing calibration targets for LIBS analysis by ChemCam on the Mars Science Lander required development of low-fire ceramics. A range of sulfur contents can be obtained that mimic soil or rock at the potential landing sites.

  17. A new self-calibrated procedure for impact detection and location on flat surfaces.

    PubMed

    Somolinos, José A; López, Amable; Morales, Rafael; Morón, Carlos

    2013-05-30

    Many analyses of acoustic signals processing have been proposed for different applications over the last few years. When considering a bar-based structure, if the material through which the sound waves propagate is considered to be acoustically homogeneous and the sound speed is well known, then it is possible to determine the position and time of impact by a simple observation of the arrival times of the signals of all the transducers that are strategically disposed on the structure. This paper presents a generalized method for impact detection and location on a flat plate, together with a calibration procedure with which to obtain the sound speed from only one set of measurements. This propagation speed is not well known as a result of either imprecise material properties or the overlapping of longitudinal and transversal waves with different propagation velocities. The use of only three piezoelectric sensors allows the position and time of impact on the flat plate to be obtained when the sound speed is well known, while the use of additional sensors permits a larger detection area to be covered, helps to estimate the sound speed and/or avoids the wrong timing of difference measurements. Experimental results are presented using a robot with a specially designed knocking tool that produces impacts on a metallic flat plate.

  18. A New Self-Calibrated Procedure for Impact Detection and Location on Flat Surfaces

    PubMed Central

    Somolinos, José A.; López, Amable; Morales, Rafael; Morón, Carlos

    2013-01-01

    Many analyses of acoustic signals processing have been proposed for different applications over the last few years. When considering a bar-based structure, if the material through which the sound waves propagate is considered to be acoustically homogeneous and the sound speed is well known, then it is possible to determine the position and time of impact by a simple observation of the arrival times of the signals of all the transducers that are strategically disposed on the structure. This paper presents a generalized method for impact detection and location on a flat plate, together with a calibration procedure with which to obtain the sound speed from only one set of measurements. This propagation speed is not well known as a result of either imprecise material properties or the overlapping of longitudinal and transversal waves with different propagation velocities. The use of only three piezoelectric sensors allows the position and time of impact on the flat plate to be obtained when the sound speed is well known, while the use of additional sensors permits a larger detection area to be covered, helps to estimate the sound speed and/or avoids the wrong timing of difference measurements. Experimental results are presented using a robot with a specially designed knocking tool that produces impacts on a metallic flat plate. PMID:23722825

  19. Stacked Weak Lensing Mass Calibration: Estimators, Systematics, and Impact on Cosmological Parameter Constraints

    NASA Astrophysics Data System (ADS)

    Rozo, Eduardo; Wu, Hao-Yi; Schmidt, Fabian

    2011-07-01

    When extracting the weak lensing shear signal, one may employ either locally normalized or globally normalized shear estimators. The former is the standard approach when estimating cluster masses, while the latter is the more common method among peak finding efforts. While both approaches have identical signal-to-noise in the weak lensing limit, it is possible that higher order corrections or systematic considerations make one estimator preferable over the other. In this paper, we consider the efficacy of both estimators within the context of stacked weak lensing mass estimation in the Dark Energy Survey (DES). We find that the two estimators have nearly identical statistical precision, even after including higher order corrections, but that these corrections must be incorporated into the analysis to avoid observationally relevant biases in the recovered masses. We also demonstrate that finite bin-width effects may be significant if not properly accounted for, and that the two estimators exhibit different systematics, particularly with respect to contamination of the source catalog by foreground galaxies. Thus, the two estimators may be employed as a systematic cross-check of each other. Stacked weak lensing in the DES should allow for the mean mass of galaxy clusters to be calibrated to ≈2% precision (statistical only), which can improve the figure of merit of the DES cluster abundance experiment by a factor of ~3 relative to the self-calibration expectation. A companion paper investigates how the two types of estimators considered here impact weak lensing peak finding efforts.

  20. Stacked Weak Lensing Mass Calibration: Estimators, Systematics, and Impact on Cosmological Parameter Constraints

    SciTech Connect

    Rozo, Eduardo; Wu, Hao-Yi; Schmidt, Fabian; /Caltech

    2011-11-04

    When extracting the weak lensing shear signal, one may employ either locally normalized or globally normalized shear estimators. The former is the standard approach when estimating cluster masses, while the latter is the more common method among peak finding efforts. While both approaches have identical signal-to-noise in the weak lensing limit, it is possible that higher order corrections or systematic considerations make one estimator preferable over the other. In this paper, we consider the efficacy of both estimators within the context of stacked weak lensing mass estimation in the Dark Energy Survey (DES). We find that the two estimators have nearly identical statistical precision, even after including higher order corrections, but that these corrections must be incorporated into the analysis to avoid observationally relevant biases in the recovered masses. We also demonstrate that finite bin-width effects may be significant if not properly accounted for, and that the two estimators exhibit different systematics, particularly with respect to contamination of the source catalog by foreground galaxies. Thus, the two estimators may be employed as a systematic cross-check of each other. Stacked weak lensing in the DES should allow for the mean mass of galaxy clusters to be calibrated to {approx}2% precision (statistical only), which can improve the figure of merit of the DES cluster abundance experiment by a factor of {approx}3 relative to the self-calibration expectation. A companion paper investigates how the two types of estimators considered here impact weak lensing peak finding efforts.

  1. In situ calibration of the Gamma Reaction History instrument using reference samples ("pucks") for areal density measurements

    NASA Astrophysics Data System (ADS)

    Hoffman, N. M.; Herrmann, H. W.; Kim, Y. H.; Hsu, H. H.; Horsfield, C. J.; Rubery, M. S.; Wilson, D. C.; Stoeffl, W. W.; Young, C. S.; Mack, J. M.; Miller, E. K.; Grafil, E.; Evans, S. C.; Sedillo, T. J.; Glebov, V. Yu.; Duffy, T.

    2013-11-01

    The introduction of a sample of carbon, for example a disk or "puck", near an imploding DT-filled capsule creates a source of 12C gamma rays that can serve as a reference for calibrating the response of the Gamma Reaction History (GRH) detector [1]. Such calibration is important in the measurement of ablator areal density ⟨ρR⟩abl in plastic-ablator DT-filled capsules at OMEGA [2], by allowing ⟨ρR⟩abl to be inferred as a function of ratios of signals rather than from absolute measurements of signal magnitudes. Systematic uncertainties in signal measurements and detector responses therefore cancel, permitting more accurate measurements of ⟨ρR⟩abl.

  2. Evaluating the effectiveness of impact assessment instruments: Theorising the nature and implications of their political constitution

    SciTech Connect

    Cashmore, Matthew; Richardson, Tim; Hilding-Ryedvik, Tuija; Emmelin, Lars

    2010-11-15

    The central role of impact assessment instruments globally in policy integration initiatives has been cemented in recent years. Associated with this trend, but also reflecting political emphasis on greater accountability in certain policy sectors and a renewed focus on economic competitiveness in Western countries, demand has increased for evidence that these instruments are effective (however defined). Resurgent interest in evaluation has not, however, been accompanied by the conceptual developments required to redress longstanding theoretical problems associated with such activities. In order to sharpen effectiveness evaluation theory for impact assessment instruments this article critically examines the neglected issue of their political constitution. Analytical examples are used to concretely explore the nature and significance of the politicisation of impact assessment. It is argued that raising awareness about the political character of impact assessment instruments, in itself, is a vital step in advancing effectiveness evaluation theory. Broader theoretical lessons on the framing of evaluation research are also drawn from the political analysis. We conclude that, at least within the contemporary research context, learning derived from analysing the meaning and implications of plural interpretations of effectiveness represents the most constructive strategy for advancing impact assessment and policy integration theory.

  3. Spectal Responsivity Calibration of the Large Format Si:As FPAs in the Wide-Field Infrared Explorer (WIRE) Instrument

    NASA Astrophysics Data System (ADS)

    Peterson, J.; Sevilla, P.; Gibbons, W.; Herter, T.

    1998-09-01

    The Wide-Field Infrared Explorer (WIRE) is a small cryogenic spaceborne infrared telescope being readied for launch in September 1998 as the fifth of NASA's Small Explorers. WIRE illuminates two 128 x 128 Si:As Focal Plane Arrays (FPAs) produced by Boeing North American with a 30 cm diameter Ritchey Cretien diamond turned mirror system. A dichroic beam splitter and band-pass filter define two broad pass bands for a deep pointed survey to search for protogalaxies and to study the evolution of starburst galaxies. The Space Dynamics Laboratory at Utah State University (SDL/USU) measured the spectral responsivity of the WIRE sensor using the SDL multifunction infrared calibrator (MIC2) and a step- scan interferometer. The primary objective of the spectral responsivity calibration was the array-average relative spectral responsivity (RSR) measurement of each WIRE FPA under nominal operating conditions. The array-average RSR measurement is composed of two parts, a high spectral resolution in-band measurement and an out-of-band measurement that extended the noise floor of the RSR measurement outside the WIRE spectral passbands to approximately 1E-5 of the in-band peak. In addition to the array average RSR at nominal operating conditions, SDL personnel also investigated the WIRE RSR sensitivity to FPA position, temperature and bias voltage. The WIRE spectral calibration method is described, and the results are presented.

  4. Using NEXRAD Radar Rainfall to Calibrate a Development Impact Model in a Coastal Watershed

    NASA Astrophysics Data System (ADS)

    Sebastian, A.; Bedient, P.

    2012-12-01

    Low slopes and shallow, impermeable soils are characteristic of the Upper Texas Gulf Coast. These, coupled with large rainfall events, contribute to wide floodplains and ponding. Rapid, high intensity development has further exacerbated flooding in this coastal region. The Clear Creek Watershed is located in southeast Houston and empties into Galveston Bay. During the past decade, the watershed has been impacted by significant historical coastal storms and rainfall events such as Tropical Storm Allison (2001), Hurricane Ike (2008), and the April 2009 Event. In this study, we employ a calibrated, distributed hydrologic model and pre- and LID-development models to analyze how development characteristics have contributed to costly flooding in coastal watersheds. In 2012, Brody et al. used FEMA floodclaims collected over the 11-year period between 1999 and 2009 to examine the pattern of flood loss across the Clear Creek watershed. The results showed that the 100-year floodplain did not adequately represent overall or event-specific loss. Using a spatial cluster analysis, the Turkey Creek sub-area of the Clear Creek watershed was pin-pointed as an area of statistically significant flood loss, an area where there were a considerable number of high-value flood claims. This area is characterized by high-density, poorly constructed development and frequent flooding. In parallel with Brody's study of flood-risk indicators, our study aims to examine the behavior of the flood-wave in the coastal watershed and how it is affected by different development patterns. A distributed hydrologic VfloTM model was built for Turkey Creek using 2008 CCAP land cover data and calibrated using NEXRAD radar rainfall for the Hurricane Ike (2008) and April 2009 events. Once the model was calibrated, both pre- and LID-development models were built using historical land cover data. These models were used to identify how development patterns have influence the flood hydrograph. Early results

  5. Assessing the Impact of Cancer: Development of a new instrument for long-term survivors

    PubMed Central

    Zebrack, Brad J.; Ganz, Patricia A.; Bernaards, Coen A.; Petersen, Laura; Abraham, Laura

    2013-01-01

    Objective To develop and evaluate a new instrument that measures aspects of long-term survivorship not measured by existing tools. Methods In qualitative interviews, 47 long-term cancer survivors (LTS) detailed ways that cancer has impacted their lives. Content analysis resulted in the creation of 325 candidate items for inclusion in a new Impact of Cancer (IOC) instrument. Following expert review, item reduction and pilot testing, 81 items were administered with other established health status and quality of life (QOL) instruments to 193 LTS of breast, prostate, colorectal cancers and lymphoma. Internal consistency reliability and validity of newly-derived scales was assessed. Results Factor analysis of items using a priori QOL domains resulted in the derivation of ten new and specific subscales: health awareness, body changes, health worries, positive and negative self-evaluation, positive and negative life outlook, social life interferences, relationships, and meaning of cancer. Internal consistency measurements for these subscales ranged from 0.67 to 0.89. Expected associations within and among the IOC subscales and standardized measures of health status and QOL were observed, as were some unexpected findings. Conclusions Psychometric analysis indicated that this initial version of the Impact of Cancer instrument measures distinct and relevant constructs for LTS. Future work is necessary to confirm the factor structure, responsiveness and further validation of the instrument. PMID:16097041

  6. Radio source calibration for the Very Small Array and other cosmic microwave background instruments at around 30 GHz

    NASA Astrophysics Data System (ADS)

    Hafez, Yaser A.; Davies, Rod D.; Davis, Richard J.; Dickinson, Clive; Battistelli, Elia S.; Blanco, Francisco; Cleary, Kieran; Franzen, Thomas; Genova-Santos, Ricardo; Grainge, Keith; Hobson, Michael P.; Jones, Michael E.; Lancaster, Katy; Lasenby, Anthony N.; Padilla-Torres, Carmen P.; Rubiño-Martin, José Alberto; Rebolo, Rafael; Saunders, Richard D. E.; Scott, Paul F.; Taylor, Angela C.; Titterington, David; Tucci, Marco; Watson, Robert A.

    2008-08-01

    Accurate calibration of data is essential for the current generation of cosmic microwave background (CMB) experiments. Using data from the Very Small Array (VSA), we describe procedures which will lead to an accuracy of 1 per cent or better for experiments such as the VSA and CBI. Particular attention is paid to the stability of the receiver systems, the quality of the site and frequent observations of reference sources. At 30 GHz the careful correction for atmospheric emission and absorption is shown to be essential for achieving 1 per cent precision. The sources for which a 1 per cent relative flux density calibration was achieved included Cas A, Cyg A, Tau A and NGC 7027 and the planets Venus, Jupiter and Saturn. A flux density, or brightness temperature in the case of the planets, was derived at 33 GHz relative to Jupiter which was adopted as the fundamental calibrator. A spectral index at ~30 GHz is given for each. Cas A, Tau A, NGC 7027 and Venus were examined for variability. Cas A was found to be decreasing at 0.394 +/- 0.019 per cent yr-1 over the period 2001 March to 2004 August. In the same period Tau A was decreasing at 0.22 +/- 0.07 per cent yr-1. A survey of the published data showed that the planetary nebula NGC 7027 decreased at 0.16 +/- 0.04 per cent yr-1 over the period 1967-2003. Venus showed an insignificant (1.5 +/- 1.3 per cent) variation with Venusian illumination. The integrated polarization of Tau A at 33 GHz was found to be 7.8 +/- 0.6 per cent at position angle =148° +/- 3°.

  7. Station to instrumented aircraft L-band telemetry system and RF signal controller for spacecraft simulations and station calibration

    NASA Technical Reports Server (NTRS)

    Scaffidi, C. A.; Stocklin, F. J.; Feldman, M. B.

    1971-01-01

    An L-band telemetry system designed to provide the capability of near-real-time processing of calibration data is described. The system also provides the capability of performing computerized spacecraft simulations, with the aircraft as a data source, and evaluating the network response. The salient characteristics of a telemetry analysis and simulation program (TASP) are discussed, together with the results of TASP testing. The results of the L-band system testing have successfully demonstrated the capability of near-real-time processing of telemetry test data, the control of the ground-received signal to within + or - 0.5 db, and the computer generation of test signals.

  8. Complete elliptical ring geometry provides energy and instrument calibration for synchrotron-based two-dimensional X-ray diffraction.

    PubMed

    Hart, Michael L; Drakopoulos, Michael; Reinhard, Christina; Connolley, Thomas

    2013-10-01

    A complete calibration method to characterize a static planar two-dimensional detector for use in X-ray diffraction at an arbitrary wavelength is described. This method is based upon geometry describing the point of intersection between a cone's axis and its elliptical conic section. This point of intersection is neither the ellipse centre nor one of the ellipse focal points, but some other point which lies in between. The presented solution is closed form, algebraic and non-iterative in its application, and gives values for the X-ray beam energy, the sample-to-detector distance, the location of the beam centre on the detector surface and the detector tilt relative to the incident beam. Previous techniques have tended to require prior knowledge of either the X-ray beam energy or the sample-to-detector distance, whilst other techniques have been iterative. The new calibration procedure is performed by collecting diffraction data, in the form of diffraction rings from a powder standard, at known displacements of the detector along the beam path.

  9. Rigorous noise test and calibration check of strong-motion instrumentation at the Conrad Observatory in Austria.

    NASA Astrophysics Data System (ADS)

    Steiner, R.; Costa, G.; Lenhardt, W.; Horn, N.; Suhadolc, P.

    2012-04-01

    In the framework of the European InterregIV Italy/Austria project: "HAREIA - Historical and Recent Earthquakes in Italy and Austria" the Central Institute for Meteorology and Geodynamics (ZAMG) and Mathematic and Geosciences Department of University of Trieste (DMG) are upgrading the transfrontier seismic network of South-Eastern Alps with new 12 accelerometric stations to enhance the strong motion instrument density near the Austria/Italy border. Various public institutions of the provinces Alto Adige (Bolzano Province), Veneto (ARPAV) and Friuli Venezia Giulia (Regional Civil Defense) in Italy and in the Austrian province of Tyrol are involved in the project. The site selection was carried out to improve the present local network geometry thus meeting the needs of public Institutions in the involved regions. In Tyrol and Alto Adige some strategic buildings (hospitals and public buildings) have been selected, whereas in Veneto and Friuli Venezia Giulia the sites are in the free field, mainly located near villages. The instruments will be installed in an innovative box, designed by ZAMG, that provides electric and water isolation. The common choice regarding the instrument selection has been the new Kinemetrics Basalt ® accelerograph to guarantee homogeneity with the already installed instrumentation and compatibility with the software already in use at the different seismic institutions in the area. Prior to deployment the equipment was tested at the Conrad Observatory and a common set-up has been devised. The Conrad Observatory, seismically particularly quiet, permits to analyze both the sensor and the acquisition system noise. The instruments were connected to the network and the data sent in real-time to the ZAMG data center in Vienna and the DMG data center in Trieste. The data have been collected in the database and analyzed using signal processing modules PQLX and Matlab. The data analysis of the recordings at the ultra-quiet Conrad Observatory pointed out

  10. Low velocity instrumented impact testing of four new damage tolerant carbon/epoxy composite systems

    NASA Technical Reports Server (NTRS)

    Lance, D. G.; Nettles, A. T.

    1990-01-01

    Low velocity drop weight instrumented impact testing was utilized to examine the damage resistance of four recently developed carbon fiber/epoxy resin systems. A fifth material, T300/934, for which a large data base exists, was also tested for comparison purposes. A 16-ply quasi-isotropic lay-up configuration was used for all the specimens. Force/absorbed energy-time plots were generated for each impact test. The specimens were cross-sectionally analyzed to record the damage corresponding to each impact energy level. Maximum force of impact versus impact energy plots were constructed to compare the various systems for impact damage resistance. Results show that the four new damage tolerant fiber/resin systems far outclassed the T300/934 material. The most damage tolerant material tested was the IM7/1962 fiber/resin system.

  11. Calibration and validation of earthquake catastrophe models. Case study: Impact Forecasting Earthquake Model for Algeria

    NASA Astrophysics Data System (ADS)

    Trendafiloski, G.; Gaspa Rebull, O.; Ewing, C.; Podlaha, A.; Magee, B.

    2012-04-01

    Calibration and validation are crucial steps in the production of the catastrophe models for the insurance industry in order to assure the model's reliability and to quantify its uncertainty. Calibration is needed in all components of model development including hazard and vulnerability. Validation is required to ensure that the losses calculated by the model match those observed in past events and which could happen in future. Impact Forecasting, the catastrophe modelling development centre of excellence within Aon Benfield, has recently launched its earthquake model for Algeria as a part of the earthquake model for the Maghreb region. The earthquake model went through a detailed calibration process including: (1) the seismic intensity attenuation model by use of macroseismic observations and maps from past earthquakes in Algeria; (2) calculation of the country-specific vulnerability modifiers by use of past damage observations in the country. The use of Benouar, 1994 ground motion prediction relationship was proven as the most appropriate for our model. Calculation of the regional vulnerability modifiers for the country led to 10% to 40% larger vulnerability indexes for different building types compared to average European indexes. The country specific damage models also included aggregate damage models for residential, commercial and industrial properties considering the description of the buildings stock given by World Housing Encyclopaedia and the local rebuilding cost factors equal to 10% for damage grade 1, 20% for damage grade 2, 35% for damage grade 3, 75% for damage grade 4 and 100% for damage grade 5. The damage grades comply with the European Macroseismic Scale (EMS-1998). The model was validated by use of "as-if" historical scenario simulations of three past earthquake events in Algeria M6.8 2003 Boumerdes, M7.3 1980 El-Asnam and M7.3 1856 Djidjelli earthquake. The calculated return periods of the losses for client market portfolio align with the

  12. Calibration Model for Apnea-Hypopnea Indices: Impact of Alternative Criteria for Hypopneas

    PubMed Central

    Ho, Vu; Crainiceanu, Ciprian M.; Punjabi, Naresh M.; Redline, Susan; Gottlieb, Daniel J.

    2015-01-01

    Study Objective: To characterize the association among apnea-hypopnea indices (AHIs) determined using three common metrics for defining hypopnea, and to develop a model to calibrate between these AHIs. Design: Cross-sectional analysis of Sleep Heart Health Study Data. Setting: Community-based. Participants: There were 6,441 men and women age 40 y or older. Measurement and Results: Three separate AHIs have been calculated, using all apneas (defined as a decrease in airflow greater than 90% from baseline for ≥ 10 sec) plus hypopneas (defined as a decrease in airflow or chest wall or abdominal excursion greater than 30% from baseline, but not meeting apnea definitions) associated with either: (1) a 4% or greater fall in oxyhemoglobin saturation—AHI4; (2) a 3% or greater fall in oxyhemoglobin saturation—AHI3; or (3) a 3% or greater fall in oxyhemoglobin saturation or an event-related arousal—AHI3a. Median values were 5.4, 9.7, and 13.4 for AHI4, AHI3, and AHI3a, respectively (P < 0.0001). Penalized spline regression models were used to compare AHI values across the three metrics and to calculate prediction intervals. Comparison of regression models demonstrates divergence in AHI scores among the three methods at low AHI values and gradual convergence at higher levels of AHI. Conclusions: The three methods of scoring hypopneas yielded significantly different estimates of the apnea-hypopnea index (AHI), although the relative difference is reduced in severe disease. The regression models presented will enable clinicians and researchers to more appropriately compare AHI values obtained using differing metrics for hypopnea. Citation: Ho V, Crainiceanu CM, Punjabi NM, Redline S, Gottlieb DJ. Calibration model for apnea-hypopnea indices: impact of alternative criteria for hypopneas. SLEEP 2015;38(12):1887–1892. PMID:26564122

  13. Testing the impact of calibration on molecular divergence times using a fossil-rich group: the case of Nothofagus (Fagales).

    PubMed

    Sauquet, Hervé; Ho, Simon Y W; Gandolfo, Maria A; Jordan, Gregory J; Wilf, Peter; Cantrill, David J; Bayly, Michael J; Bromham, Lindell; Brown, Gillian K; Carpenter, Raymond J; Lee, Daphne M; Murphy, Daniel J; Sniderman, J M Kale; Udovicic, Frank

    2012-03-01

    Although temporal calibration is widely recognized as critical for obtaining accurate divergence-time estimates using molecular dating methods, few studies have evaluated the variation resulting from different calibration strategies. Depending on the information available, researchers have often used primary calibrations from the fossil record or secondary calibrations from previous molecular dating studies. In analyses of flowering plants, primary calibration data can be obtained from macro- and mesofossils (e.g., leaves, flowers, and fruits) or microfossils (e.g., pollen). Fossil data can vary substantially in accuracy and precision, presenting a difficult choice when selecting appropriate calibrations. Here, we test the impact of eight plausible calibration scenarios for Nothofagus (Nothofagaceae, Fagales), a plant genus with a particularly rich and well-studied fossil record. To do so, we reviewed the phylogenetic placement and geochronology of 38 fossil taxa of Nothofagus and other Fagales, and we identified minimum age constraints for up to 18 nodes of the phylogeny of Fagales. Molecular dating analyses were conducted for each scenario using maximum likelihood (RAxML + r8s) and Bayesian (BEAST) approaches on sequence data from six regions of the chloroplast and nuclear genomes. Using either ingroup or outgroup constraints, or both, led to similar age estimates, except near strongly influential calibration nodes. Using "early but risky" fossil constraints in addition to "safe but late" constraints, or using assumptions of vicariance instead of fossil constraints, led to older age estimates. In contrast, using secondary calibration points yielded drastically younger age estimates. This empirical study highlights the critical influence of calibration on molecular dating analyses. Even in a best-case situation, with many thoroughly vetted fossils available, substantial uncertainties can remain in the estimates of divergence times. For example, our estimates for

  14. Impact of the Timing of a SAR Image Acquisition on the Calibration of a Flood Inundation Model

    NASA Technical Reports Server (NTRS)

    Gobeyn, Sacha; Van Wesemael, Alexandra; Neal, Jeffrey; Lievens, Hans; Van Eerdenbrugh, Katrien; De Vleeschouwer, Niels; Vernieuwe, Hilde; Schumann, Guy J.-P.; Di Baldassarre, Giuliano; De Baets, Bernard; Bates, Paul D.; Verhoest, Niko E. C.

    2016-01-01

    Synthetic Aperture Radar (SAR) data have proven to be a very useful source of information for the calibration of flood inundation models. Previous studies have focused on assigning uncertainties to SAR images in order to improve flood forecast systems (e.g. Giustarini et al. (2015) and Stephens et al. (2012)). This paper investigates whether the timing of a SAR acquisition of a flood has an important impact on the calibration of a flood inundation model. As no suitable time series of SAR data exists, we generate a sequence of consistent SAR images through the use of a synthetic framework. This framework uses two available ERS-2 SAR images of the study area, one taken during the flood event of interest, the second taken during a dry reference period. The obtained synthetic observations at different points in time during the flood event are used to calibrate the flood inundation model. The results of this study indicate that the uncertainty of the roughness parameters is lower when the model is calibrated with an image taken before rather than during or after the flood peak. The results also show that the error on the modeled extent is much lower when the model is calibrated with a pre-flood peak image than when calibrated with a near-flood peak or a post-flood peak image. It is concluded that the timing of the SAR image acquisition of the flood has a clear impact on the model calibration and consequently on the precision of the predicted flood extent.

  15. Impact of the timing of a SAR image acquisition on the calibration of a flood inundation model

    NASA Astrophysics Data System (ADS)

    Gobeyn, Sacha; Van Wesemael, Alexandra; Neal, Jeffrey; Lievens, Hans; Eerdenbrugh, Katrien Van; De Vleeschouwer, Niels; Vernieuwe, Hilde; Schumann, Guy J.-P.; Di Baldassarre, Giuliano; Baets, Bernard De; Bates, Paul D.; Verhoest, Niko E. C.

    2017-02-01

    Synthetic Aperture Radar (SAR) data have proven to be a very useful source of information for the calibration of flood inundation models. Previous studies have focused on assigning uncertainties to SAR images in order to improve flood forecast systems (e.g. Giustarini et al. (2015) and Stephens et al. (2012)). This paper investigates whether the timing of a SAR acquisition of a flood has an important impact on the calibration of a flood inundation model. As no suitable time series of SAR data exists, we generate a sequence of consistent SAR images through the use of a synthetic framework. This framework uses two available ERS-2 SAR images of the study area, one taken during the flood event of interest, the second taken during a dry reference period. The obtained synthetic observations at different points in time during the flood event are used to calibrate the flood inundation model. The results of this study indicate that the uncertainty of the roughness parameters is lower when the model is calibrated with an image taken before rather than during or after the flood peak. The results also show that the error on the modelled extent is much lower when the model is calibrated with a pre-flood peak image than when calibrated with a near-flood peak or a post-flood peak image. It is concluded that the timing of the SAR image acquisition of the flood has a clear impact on the model calibration and consequently on the precision of the predicted flood extent.

  16. The impact of the long-term playing of musical instruments on the stomatognathic system - review.

    PubMed

    Głowacka, Arleta; Matthews-Kozanecka, Maja; Kawala, Maciej; Kawala, Beata

    2014-01-01

    In this article, we have made a review of the influence of playing musical instruments on the formation of malocclusion and TMJ disorders in musicians. Primary attention was paid to the effects of wind and stringed instruments. The aim of the article was the presentation of research and opinions about this problem in the last 25 years. It is reported that long-term and repetitive playing of musical instruments, particularly stringed (violin and viola) and wind instruments can cause dysfunctions of the stomatognathic system. The impact of wind instruments was assessed in terms of the type of mouthpiece. We studied the possibility of repositioning the front teeth and reducing the width of the upper dental arch and overbite. There were also reports on the use of a specific instrument to improve the child's occlusion. Studies have also been performed on the usefulness of relaxation plates in order to improve, and even prevent, dysfunction caused by the constant stress on the same parts of the stomatognathic system. The experiments were mainly based on interviews, dental cast analyses and cephalometric analyses. Additional methods were dynamometer tests and muscle tension palpation.

  17. The impact of crosstalk in the X-IFU instrument on Athena science cases

    NASA Astrophysics Data System (ADS)

    den Hartog, R.; Peille, P.; Dauser, T.; Jackson, B.; Bandler, S.; Barret, D.; Brand, T.; den Herder, J.-W.; Kiviranta, M.; van der Kuur, J.; Smith, S.; Wilms, J.

    2016-07-01

    In this paper we present a first assessment of the impact of various forms of instrumental crosstalk on the science performance of the X-ray Integral Field Unit (X-IFU) on the Athena X-ray mission. This assessment is made using the SIXTE end-to-end simulator in the context of one of the more technically challenging science cases for the XIFU instrument. Crosstalk considerations may influence or drive various aspects of the design of the array of high-countrate Transition Edge Sensor (TES) detectors and its Frequency Domain Multiplexed (FDM) readout architecture.

  18. Calibrating MMS Electron Drift Instrument (EDI) Ambient Electron Flux Measurements and Characterizing 3D Electric Field Signatures of Magnetic Reconnection

    NASA Astrophysics Data System (ADS)

    Shuster, J. R.; Torbert, R. B.; Vaith, H.; Argall, M. R.; Li, G.; Chen, L. J.; Ergun, R. E.; Lindqvist, P. A.; Marklund, G. T.; Khotyaintsev, Y. V.; Russell, C. T.; Magnes, W.; Le Contel, O.; Pollock, C. J.; Giles, B. L.

    2015-12-01

    The electron drift instruments (EDIs) onboard each MMS spacecraft are designed with large geometric factors (~0.01cm2 str) to facilitate detection of weak (~100 nA) electron beams fired and received by the two gun-detector units (GDUs) when EDI is in its "electric field mode" to determine the local electric and magnetic fields. A consequence of the large geometric factor is that "ambient mode" electron flux measurements (500 eV electrons having 0°, 90°, or 180° pitch angle) can vary depending on the orientation of the EDI instrument with respect to the magnetic field, a nonphysical effect that requires a correction. Here, we present determinations of the θ- and ø-dependent correction factors for the eight EDI GDUs, where θ (ø) is the polar (azimuthal) angle between the GDU symmetry axis and the local magnetic field direction, and compare the corrected fluxes with those measured by the fast plasma instrument (FPI). Using these corrected, high time resolution (~1,000 samples per second) ambient electron fluxes, combined with the unprecedentedly high resolution 3D electric field measurements taken by the spin-plane and axial double probes (SDP and ADP), we are equipped to accurately detect electron-scale current layers and electric field waves associated with the non-Maxwellian (anisotropic and agyrotropic) particle distribution functions predicted to exist in the reconnection diffusion region. We compare initial observations of the diffusion region with distributions and wave analysis from PIC simulations of asymmetric reconnection applicable for modeling reconnection at the Earth's magnetopause, where MMS will begin Science Phase 1 as of September 1, 2015.

  19. Calibration-induced uncertainty of the EPIC model to estimate climate change impact on global maize yield

    NASA Astrophysics Data System (ADS)

    Xiong, Wei; Skalský, Rastislav; Porter, Cheryl H.; Balkovič, Juraj; Jones, James W.; Yang, Di

    2016-09-01

    Understanding the interactions between agricultural production and climate is necessary for sound decision-making in climate policy. Gridded and high-resolution crop simulation has emerged as a useful tool for building this understanding. Large uncertainty exists in this utilization, obstructing its capacity as a tool to devise adaptation strategies. Increasing focus has been given to sources of uncertainties for climate scenarios, input-data, and model, but uncertainties due to model parameter or calibration are still unknown. Here, we use publicly available geographical data sets as input to the Environmental Policy Integrated Climate model (EPIC) for simulating global-gridded maize yield. Impacts of climate change are assessed up to the year 2099 under a climate scenario generated by HadEM2-ES under RCP 8.5. We apply five strategies by shifting one specific parameter in each simulation to calibrate the model and understand the effects of calibration. Regionalizing crop phenology or harvest index appears effective to calibrate the model for the globe, but using various values of phenology generates pronounced difference in estimated climate impact. However, projected impacts of climate change on global maize production are consistently negative regardless of the parameter being adjusted. Different values of model parameter result in a modest uncertainty at global level, with difference of the global yield change less than 30% by the 2080s. The uncertainty subjects to decrease if applying model calibration or input data quality control. Calibration has a larger effect at local scales, implying the possible types and locations for adaptation.

  20. Pre-flight calibration and initial data processing for the ChemCam laser-induced breakdown spectroscopy instrument on the Mars Science Laboratory rover

    USGS Publications Warehouse

    Wiens, R.C.; Maurice, S.; Lasue, J.; Forni, O.; Anderson, R.B.; Clegg, S.; Bender, S.; Blaney, D.; Barraclough, B.L.; Cousin, A.; DeFlores, L.; Delapp, D.; Dyar, M.D.; Fabre, C.; Gasnault, O.; Lanza, N.; Mazoyer, J.; Melikechi, N.; Meslin, P.-Y.; Newsom, H.; Ollila, A.; Perez, R.; Tokar, R.; Vaniman, D.

    2013-01-01

    The ChemCam instrument package on the Mars Science Laboratory rover, Curiosity, is the first planetary science instrument to employ laser-induced breakdown spectroscopy (LIBS) to determine the compositions of geological samples on another planet. Pre-processing of the spectra involves subtracting the ambient light background, removing noise, removing the electron continuum, calibrating for the wavelength, correcting for the variable distance to the target, and applying a wavelength-dependent correction for the instrument response. Further processing of the data uses multivariate and univariate comparisons with a LIBS spectral library developed prior to launch as well as comparisons with several on-board standards post-landing. The level-2 data products include semi-quantitative abundances derived from partial least squares regression. A LIBS spectral library was developed using 69 rock standards in the form of pressed powder disks, glasses, and ceramics to minimize heterogeneity on the scale of the observation (350–550 μm dia.). The standards covered typical compositional ranges of igneous materials and also included sulfates, carbonates, and phyllosilicates. The provenance and elemental and mineralogical compositions of these standards are described. Spectral characteristics of this data set are presented, including the size distribution and integrated irradiances of the plasmas, and a proxy for plasma temperature as a function of distance from the instrument. Two laboratory-based clones of ChemCam reside in Los Alamos and Toulouse for the purpose of adding new spectra to the database as the need arises. Sensitivity to differences in wavelength correlation to spectral channels and spectral resolution has been investigated, indicating that spectral registration needs to be within half a pixel and resolution needs to match within 1.5 to 2.6 pixels. Absolute errors are tabulated for derived compositions of each major element in each standard using PLS regression

  1. Inherent calibration of a blue LED-CE-DOAS instrument to measure iodine oxide, glyoxal, methyl glyoxal, nitrogen dioxide, water vapour and aerosol extinction in open cavity mode

    NASA Astrophysics Data System (ADS)

    Thalman, R.; Volkamer, R.

    2010-12-01

    The combination of Cavity Enhanced Absorption Spectroscopy (CEAS) with broad-band light sources (e.g. Light-Emitting Diodes, LEDs) lends itself to the application of cavity enhanced Differential Optical Absorption Spectroscopy (CE-DOAS) to perform sensitive and selective point measurements of multiple trace gases and aerosol extinction with a single instrument. In contrast to other broad-band CEAS techniques, CE-DOAS relies only on the measurement of relative intensity changes, i.e. does not require knowledge of the light intensity in the absence of trace gases and aerosols (I0). We have built a prototype LED-CE-DOAS instrument in the blue spectral range (420-490 nm) to measure nitrogen dioxide (NO2), glyoxal (CHOCHO), methyl glyoxal (CH3COCHO), iodine oxide (IO), water vapour (H2O) and oxygen dimers (O4). We demonstrate the first direct detection of methyl glyoxal, and the first CE-DOAS detection of CHOCHO and IO. The instrument is further inherently calibrated for light extinction from the cavity by observing O4 or H2O (at 477 nm and 443 nm) and measuring the pressure, relative humidity and temperature independently. This approach is demonstrated by experiments where laboratory aerosols of known size and refractive index were generated and their extinction measured. The measured extinctions were then compared to the theoretical extinctions calculated using Mie theory (3-7 × 10-7cm-1). Excellent agreement is found from both the O4 and H2O retrievals. This enables the first inherently calibrated CEAS measurement at blue wavelengths in open cavity mode, and eliminates the need for sampling lines to supply air to the cavity, i.e., keep the cavity enclosed and/or aerosol free. Measurements in open cavity mode are demonstrated for CHOCHO, CH3COCHO, NO2, H2O and aerosol extinction. Our prototype LED-CE-DOAS provides a low cost, yet research grade innovative instrument for applications in simulation chambers and in the open atmosphere.

  2. Measurement of driver calibration and the impact of feedback on drivers' estimates of performance.

    PubMed

    Roberts, Shannon C; Horrey, William J; Liang, Yulan

    2016-03-01

    Recent studies focused on driver calibration show that drivers are often miscalibrated, either over confident or under confident, and the magnitude of this miscalibration changes under different conditions. Previous work has demonstrated behavioral and performance benefits of feedback, yet these studies have not explicitly examined the issue of calibration. The objective of this study was to examine driver calibration, i.e., the degree to which drivers are accurately aware of their performance, and determine whether feedback alters driver calibration. Twenty-four drivers completed a series of driving tasks (pace clocks, traffic light, speed maintenance, and traffic cones) on a test track. Drivers drove three different blocks around the test track: (1) baseline block, where no participants received feedback; (2) feedback block, where half of the participants received performance feedback while the other half received no feedback; (3) a no feedback block, where no participants received feedback. Results indicated that across two different calibration measures, drivers were sufficiently calibrated to the pace clocks, traffic light, and traffic cone tasks. Drivers were not accurately aware of their performance regarding speed maintenance, though receiving feedback on this task improved calibration. Proper and accurate measurements of driver calibration are needed before designing performance feedback to improve calibration as these feedback systems may not always yield the intended results.

  3. A new instrument for the delivery of the impacted dead fetus.

    PubMed

    Belfort, M A

    1988-10-01

    When a fetus dies during labor, it is best to deliver the dead fetus with a minimum of maternal trauma. Especially in underdeveloped countries, where obstetric facilities are limited, maternal mortality and morbidity rates associated with cesarean sections are high. The established methods of craniotomy and subsequent delivery often cause destruction of maternal tissue. Thus, a new destructive instrument for the delivery of the dead impacted fetus has been developed at the Groote Schuur Hospital in Capetown, South Africa. Made from stainless steel, it has been named the Groote Schuur Hospital Perforator and Bone Screw. The instrument has so far been used in 3 cases, in operations that caused minimal maternal discomfort and no maternal injury. The instrument is described and instructions are given for its use.

  4. Instrument study of the Lunar Dust eXplorer (LDX) for a lunar lander mission II: Laboratory model calibration

    NASA Astrophysics Data System (ADS)

    Li, Yanwei; Strack, Heiko; Bugiel, Sebastian; Wu, Yiyong; Srama, Ralf

    2015-10-01

    A dust trajectory detector placed on the lunar surface is exposed to extend people's knowledge on the dust environment above the lunar surface. The new design of Lunar Dust eXplorer (LDX) is well suited for lunar or asteroid landers with a broad range of particle charges (0.1-10 fC), speeds (few m s-1 to few km s-1) and sizes (0.1-10 μ m). The calibration of dust trajectory detector is important for the detector development. We do present experimental results to characterize the accuracy of the newly developed LDX laboratory model. Micron sized iron particles were accelerated to speed between 0.5 and 20 km s-1 with primary charges larger than 1 fC. The achieved accuracies of the detector are ± 5 % and ± 7 % for particle charge and speed, respectively. Dust trajectories can be determined with measurement accuracy better than ± 2°. A dust sensor of this type is suited for the exploration of the surface of small bodies without an atmosphere like the Earth's moon or asteroids in future, and the minisatellites are also suitable carriers for the study of interplanetary dust and manned debris on low Earth orbits.

  5. Investigation of the dynamic thermal infrared signatures of a calibration target instrumented with a network of 1-wire temperature sensors

    NASA Astrophysics Data System (ADS)

    Lewis, Gareth D.; Merken, Patrick

    2016-05-01

    In this paper, we describe the temperature and thermal variations from a painted geometrical target (CUBI) fitted with a network of internally mounted 1-wire temperature sensors. The sensors, which were calibrated in a temperature-controlled oven, were recorded every 20 seconds over a period from May to December 2015. This amounts to an archive of approximately 180 days of near uninterrupted data. Two meteorological stations collocated with the CUBI on a roof test site, record relevant environmental parameters every few minutes. In this paper, we analyze the data for only one day, 2 October 2015, for which a wavelet analysis highlights the contribution of different temporal fluctuations to total signature. We selected this specific day since it represented simple environmental conditions, and additionally images from a 3-5 microns (MWIR) thermal imager were recorded. Finally, we demonstrate that a wavelet decomposition of the temperature signature to be a useful method to characterize dynamic temperature changes, and perhaps a method to verify prediction models for varying fluctuation scales.

  6. Satellite Instrument Calibration for Measuring Global Climate Change. Report of a Workshop at the University of Maryland Inn and Conference Center, College Park, MD. , November 12-14, 2002

    NASA Technical Reports Server (NTRS)

    Ohring, G.; Wielicki, B.; Spencer, R.; Emery, B.; Datla, R.

    2004-01-01

    Measuring the small changes associated with long-term global climate change from space is a daunting task. To address these problems and recommend directions for improvements in satellite instrument calibration some 75 scientists, including researchers who develop and analyze long-term data sets from satellites, experts in the field of satellite instrument calibration, and physicists working on state of the art calibration sources and standards met November 12 - 14, 2002 and discussed the issues. The workshop defined the absolute accuracies and long-term stabilities of global climate data sets that are needed to detect expected trends, translated these data set accuracies and stabilities to required satellite instrument accuracies and stabilities, and evaluated the ability of current observing systems to meet these requirements. The workshop's recommendations include a set of basic axioms or overarching principles that must guide high quality climate observations in general, and a roadmap for improving satellite instrument characterization, calibration, inter-calibration, and associated activities to meet the challenge of measuring global climate change. It is also recommended that a follow-up workshop be conducted to discuss implementation of the roadmap developed at this workshop.

  7. SU-E-T-391: Evaluation of Image Parameters Impact On the CT Calibration Curve for Proton Therapy

    SciTech Connect

    Xiao, Z; Reyhan, M; Huang, Q; Zhang, M; Yue, N; Chen, T

    2015-06-15

    Purpose: The calibration of the Hounsfield units (HU) to relative proton stopping powers (RSP) is a crucial component in assuring the accurate delivery of proton therapy dose distributions to patients. The purpose of this work is to assess the uncertainty of CT calibration considering the impact of CT slice thickness, position of the plug within the phantom and phantom sizes. Methods: Stoichiometric calibration method was employed to develop the CT calibration curve. Gammex 467 tissue characterization phantom was scanned in Tomotherapy Cheese phantom and Gammex 451 phantom by using a GE CT scanner. Each plug was individually inserted into the same position of inner and outer ring of phantoms at each time, respectively. 1.25 mm and 2.5 mm slice thickness were used. Other parameters were same. Results: HU of selected human tissues were calculated based on fitted coefficient (Kph, Kcoh and KKN), and RSP were calculated according to the Bethe-Bloch equation. The calibration curve was obtained by fitting cheese phantom data with 1.25 mm thickness. There is no significant difference if the slice thickness, phantom size, position of plug changed in soft tissue. For boney structure, RSP increases up to 1% if the phantom size and the position of plug changed but keep the slice thickness the same. However, if the slice thickness varied from the one in the calibration curve, 0.5%–3% deviation would be expected depending on the plug position. The Inner position shows the obvious deviation (averagely about 2.5%). Conclusion: RSP shows a clinical insignificant deviation in soft tissue region. Special attention may be required when using a different slice thickness from the calibration curve for boney structure. It is clinically practical to address 3% deviation due to different thickness in the definition of clinical margins.

  8. Evaluation of impact of length of calibration time period on the APEX model streamflow simulation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Due to resource constraints, continuous long-term measured data for model calibration and validation (C/V) are rare. As a result, most hydrologic and water quality models are calibrated and, if possible, validated using limited available measured data. However, little research has been carried out t...

  9. SUMS calibration test report

    NASA Technical Reports Server (NTRS)

    Robertson, G.

    1982-01-01

    Calibration was performed on the shuttle upper atmosphere mass spectrometer (SUMS). The results of the calibration and the as run test procedures are presented. The output data is described, and engineering data conversion factors, tables and curves, and calibration on instrument gauges are included. Static calibration results which include: instrument sensitive versus external pressure for N2 and O2, data from each scan of calibration, data plots from N2 and O2, and sensitivity of SUMS at inlet for N2 and O2, and ratios of 14/28 for nitrogen and 16/32 for oxygen are given.

  10. Definition of the limit of quantification in the presence of instrumental and non-instrumental errors. Comparison among various definitions applied to the calibration of zinc by inductively coupled plasma-mass spectrometry

    NASA Astrophysics Data System (ADS)

    Badocco, Denis; Lavagnini, Irma; Mondin, Andrea; Favaro, Gabriella; Pastore, Paolo

    2015-12-01

    The limit of quantification (LOQ) in the presence of instrumental and non-instrumental errors was proposed. It was theoretically defined combining the two-component variance regression and LOQ schemas already present in the literature and applied to the calibration of zinc by the ICP-MS technique. At low concentration levels, the two-component variance LOQ definition should be always used above all when a clean room is not available. Three LOQ definitions were accounted for. One of them in the concentration and two in the signal domain. The LOQ computed in the concentration domain, proposed by Currie, was completed by adding the third order terms in the Taylor expansion because they are of the same order of magnitude of the second ones so that they cannot be neglected. In this context, the error propagation was simplified by eliminating the correlation contributions by using independent random variables. Among the signal domain definitions, a particular attention was devoted to the recently proposed approach based on at least one significant digit in the measurement. The relative LOQ values resulted very large in preventing the quantitative analysis. It was found that the Currie schemas in the signal and concentration domains gave similar LOQ values but the former formulation is to be preferred as more easily computable.

  11. Nimbus-7 TOMS Version 7 Calibration

    NASA Technical Reports Server (NTRS)

    Wellemeyer, C. G.; Taylor, S. L.; Jaross, G.; DeLand, M. T.; Seftor, C. J.; Labow, G.; Swissler, T. J.; Cebula, R. P.

    1996-01-01

    This report describes an improved instrument characterization used for the Version 7 processing of the Nimbus-7 Total Ozone Mapping Spectrometer (TOMS) data record. An improved internal calibration technique referred to as spectral discrimination is used to provide long-term calibration precision of +/- 1%/decade in total column ozone amount. A revised wavelength scale results in a day one calibration that agrees with other satellite and ground-based measurements of total ozone, while a wavelength independent adjustment of the initial radiometric calibration constants provides good agreement with surface reflectivity measured by other satellite-borne ultraviolet measurements. The impact of other aspects of the Nimbus-7 TOMS instrument performance are also discussed. The Version 7 data should be used in all future studies involving the Nimbus-7 TOMS measurements of ozone. The data are available through the NASA Goddard Space Flight Center's Distributive Active Archive Center (DAAC).

  12. DIRBE External Calibrator (DEC)

    NASA Technical Reports Server (NTRS)

    Wyatt, Clair L.; Thurgood, V. Alan; Allred, Glenn D.

    1987-01-01

    Under NASA Contract No. NAS5-28185, the Center for Space Engineering at Utah State University has produced a calibration instrument for the Diffuse Infrared Background Experiment (DIRBE). DIRBE is one of the instruments aboard the Cosmic Background Experiment Observatory (COBE). The calibration instrument is referred to as the DEC (Dirbe External Calibrator). DEC produces a steerable, infrared beam of controlled spectral content and intensity and with selectable point source or diffuse source characteristics, that can be directed into the DIRBE to map fields and determine response characteristics. This report discusses the design of the DEC instrument, its operation and characteristics, and provides an analysis of the systems capabilities and performance.

  13. Assessing the Impact of Retreat Mechanisms in a Simple Antarctic Ice Sheet Model Using Bayesian Calibration

    PubMed Central

    Shaffer, Gary; Pollard, David; Guan, Yawen; Wong, Tony E.; Forest, Chris E.; Keller, Klaus

    2017-01-01

    The response of the Antarctic ice sheet (AIS) to changing climate forcings is an important driver of sea-level changes. Anthropogenic climate change may drive a sizeable AIS tipping point response with subsequent increases in coastal flooding risks. Many studies analyzing flood risks use simple models to project the future responses of AIS and its sea-level contributions. These analyses have provided important new insights, but they are often silent on the effects of potentially important processes such as Marine Ice Sheet Instability (MISI) or Marine Ice Cliff Instability (MICI). These approximations can be well justified and result in more parsimonious and transparent model structures. This raises the question of how this approximation impacts hindcasts and projections. Here, we calibrate a previously published and relatively simple AIS model, which neglects the effects of MICI and regional characteristics, using a combination of observational constraints and a Bayesian inversion method. Specifically, we approximate the effects of missing MICI by comparing our results to those from expert assessments with more realistic models and quantify the bias during the last interglacial when MICI may have been triggered. Our results suggest that the model can approximate the process of MISI and reproduce the projected median melt from some previous expert assessments in the year 2100. Yet, our mean hindcast is roughly 3/4 of the observed data during the last interglacial period and our mean projection is roughly 1/6 and 1/10 of the mean from a model accounting for MICI in the year 2100. These results suggest that missing MICI and/or regional characteristics can lead to a low-bias during warming period AIS melting and hence a potential low-bias in projected sea levels and flood risks. PMID:28081273

  14. Assessing the Impact of Retreat Mechanisms in a Simple Antarctic Ice Sheet Model Using Bayesian Calibration.

    PubMed

    Ruckert, Kelsey L; Shaffer, Gary; Pollard, David; Guan, Yawen; Wong, Tony E; Forest, Chris E; Keller, Klaus

    2017-01-01

    The response of the Antarctic ice sheet (AIS) to changing climate forcings is an important driver of sea-level changes. Anthropogenic climate change may drive a sizeable AIS tipping point response with subsequent increases in coastal flooding risks. Many studies analyzing flood risks use simple models to project the future responses of AIS and its sea-level contributions. These analyses have provided important new insights, but they are often silent on the effects of potentially important processes such as Marine Ice Sheet Instability (MISI) or Marine Ice Cliff Instability (MICI). These approximations can be well justified and result in more parsimonious and transparent model structures. This raises the question of how this approximation impacts hindcasts and projections. Here, we calibrate a previously published and relatively simple AIS model, which neglects the effects of MICI and regional characteristics, using a combination of observational constraints and a Bayesian inversion method. Specifically, we approximate the effects of missing MICI by comparing our results to those from expert assessments with more realistic models and quantify the bias during the last interglacial when MICI may have been triggered. Our results suggest that the model can approximate the process of MISI and reproduce the projected median melt from some previous expert assessments in the year 2100. Yet, our mean hindcast is roughly 3/4 of the observed data during the last interglacial period and our mean projection is roughly 1/6 and 1/10 of the mean from a model accounting for MICI in the year 2100. These results suggest that missing MICI and/or regional characteristics can lead to a low-bias during warming period AIS melting and hence a potential low-bias in projected sea levels and flood risks.

  15. Analysis of health-related quality-of-life instruments measuring the impact of bariatric surgery: systematic review of the instruments used and their content validity.

    PubMed

    Tayyem, Raed; Ali, Abdulmajid; Atkinson, John; Martin, Colin R

    2011-01-01

    The worldwide prevalence of obesity has been steadily rising, reaching alarming levels. Obesity, particularly morbid obesity, carries significant health risks to the lives of affected patients, including physical, psychological, and social co-morbidities. Bariatric surgery provides the only effective and sustainable approach to treat morbid obesity and reverse its adverse effects. The reduction in well-being due to poor health in obesity may have adverse effects on health-related quality of life (HR-QOL). There are numerous studies reporting HR-QOL in bariatric patients; however, there is a paucity of studies examining the psychometric properties of the HR-QOL instruments used. The main aim of this review is to identify the instruments used in assessing HR-QOL in bariatric patients and evaluate their content validity. We believe that this is the first systematic review of its kind to look in depth at various generic- and obesity-specific HR-QOL instruments that were used in bariatric surgery, and to analyze their content validity. A systematic and structured search of Ovid databases (1980-2009) was conducted using terms synonymous with bariatric surgery, combined with terms synonymous with HR-QOL instruments. A total of 112 relevant studies were identified, detailing the use of eight generic, nine obesity-specific, and numerous other condition-specific instruments. A conceptual framework comprising 20 domains pertinent to bariatric surgery and morbid obesity was proposed, against which the identified generic- and obesity-specific instruments were assessed. The results of this assessment showed that neither the generic nor the specific instruments were adequate instruments in terms of content validity. Given the lack of adequate HR-QOL instruments in the rapidly developing field of bariatric surgery, we suggest building a new bariatric-specific instrument informed by the proposed framework, which will then enable clinicians to assess the full impact of morbid

  16. Design and Calibration of a Raman Spectrometer for use in a Laser Spectroscopy Instrument Intended to Analyze Martian Surface and Atmospheric Characteristics for NASA

    NASA Technical Reports Server (NTRS)

    Lucas, John F.; Hornef, James

    2016-01-01

    This project's goal is the design of a Raman spectroscopy instrument to be utilized by NASA in an integrated spectroscopy strategy that will include Laser-Induced Breakdown Spectroscopy (LIBS) and Laser-Induced Florescence Spectroscopy (LIFS) for molecule and element identification on Mars Europa, and various asteroids. The instrument is to be down scaled from a dedicated rover mounted instrument into a compact unit with the same capabilities and accuracy as the larger instrument. The focus for this design is a spectrometer that utilizes Raman spectroscopy. The spectrometer has a calculated range of 218 nm wavelength spectrum with a resolution of 1.23 nm. To filter out the laser source wavelength of 532 nm the spectrometer design utilizes a 532 nm wavelength dichroic mirror and a 532 nm wavelength notch filter. The remaining scatter signal is concentrated by a 20 x microscopic objective through a 25-micron vertical slit into a 5mm diameter, 1cm focal length double concave focusing lens. The light is then diffracted by a 1600 Lines per Millimeter (L/mm) dual holographic transmission grating. This spectrum signal is captured by a 1-inch diameter double convex 3 cm focal length capture lens. An Intensified Charge Couple Device (ICCD) is placed within the initial focal cone of the capture lens and the Raman signal captured is to be analyzed through spectroscopy imaging software. This combination allows for accurate Raman spectroscopy to be achieved. The components for the spectrometer have been bench tested in a series of prototype developments based on theoretical calculations, alignment, and scaling strategies. The mounting platform is 2.5 cm wide by 8.8 cm long by 7 cm height. This platform has been tested and calibrated with various sources such as a neon light source and ruby crystal. This platform is intended to be enclosed in a ruggedized enclosure for mounting on a rover platform. The size and functionality of the Raman spectrometer allows for the rover to

  17. The Impact of a School Loaner-Instrument Program on the Attitudes and Achievement of Low-Income Music Students

    ERIC Educational Resources Information Center

    Ester, Don; Turner, Kristin

    2009-01-01

    The purpose of this study was to investigate the impact of a public school loaner-instrument program on the attitudes and achievement of low-income students in an urban environment. Socioeconomic Status (SES) and Instrument Status served as independent variables. Participants (N = 245) completed surveys at the beginning and end of the school year,…

  18. Science impact of MODIS C5 calibration degradation and C6+ improvements

    NASA Astrophysics Data System (ADS)

    Lyapustin, A.; Wang, Y.; Xiong, X.; Meister, G.; Platnick, S.; Levy, R.; Franz, B.; Korkin, S.; Hilker, T.; Tucker, J.; Hall, F.; Sellers, P.; Wu, A.; Angal, A.

    2014-07-01

    The Collection 6 (C6) MODIS land and atmosphere datasets are scheduled for release in 2014. C6 contains significant revisions of the calibration approach to account for sensor aging. This analysis documents the presence of systematic temporal trends in the visible and near-infrared (500 m) bands of the Collection 5 (C5) MODIS Terra, and to lesser extent, in MODIS Aqua geophysical datasets. Sensor degradation is largest in the Blue band (B3) of the MODIS sensor on Terra and decreases with wavelength. Calibration degradation causes negative global trends in multiple MODIS C5 products including the dark target algorithm's aerosol optical depth over land and Ångström Exponent over the ocean, global liquid water and ice cloud optical thickness, as well as surface reflectance and vegetation indices, including the normalized difference vegetation index (NDVI) and enhanced vegetation index (EVI). As the C5 production will be maintained for another year in parallel with C6, one objective of this paper is to raise awareness of the calibration-related trends for the broad MODIS user community. The new C6 calibration approach removes major calibrations trends in the Level 1B (L1B) data. This paper also introduces an enhanced C6+ calibration of the MODIS dataset which includes an additional polarization correction (PC) to compensate for the increased polarization sensitivity of MODIS Terra since about 2007, as well as de-trending and Terra-Aqua cross-calibration over quasi-stable desert calibration sites. The PC algorithm, developed by the MODIS ocean biology processing group (OBPG), removes residual scan angle, mirror side and seasonal biases from aerosol and surface reflectance (SR) records along with spectral distortions of SR. Using the Multi-Angle Implementation of Atmospheric Correction (MAIAC) algorithm over deserts, we have also developed a de-trending and cross-calibration method which removes residual decadal trends on the order of several tenths of one percent of

  19. Scientific impact of MODIS C5 calibration degradation and C6+ improvements

    NASA Astrophysics Data System (ADS)

    Lyapustin, A.; Wang, Y.; Xiong, X.; Meister, G.; Platnick, S.; Levy, R.; Franz, B.; Korkin, S.; Hilker, T.; Tucker, J.; Hall, F.; Sellers, P.; Wu, A.; Angal, A.

    2014-12-01

    The Collection 6 (C6) MODIS (Moderate Resolution Imaging Spectroradiometer) land and atmosphere data sets are scheduled for release in 2014. C6 contains significant revisions of the calibration approach to account for sensor aging. This analysis documents the presence of systematic temporal trends in the visible and near-infrared (500 m) bands of the Collection 5 (C5) MODIS Terra and, to lesser extent, in MODIS Aqua geophysical data sets. Sensor degradation is largest in the blue band (B3) of the MODIS sensor on Terra and decreases with wavelength. Calibration degradation causes negative global trends in multiple MODIS C5 products including the dark target algorithm's aerosol optical depth over land and Ångström exponent over the ocean, global liquid water and ice cloud optical thickness, as well as surface reflectance and vegetation indices, including the normalized difference vegetation index (NDVI) and enhanced vegetation index (EVI). As the C5 production will be maintained for another year in parallel with C6, one objective of this paper is to raise awareness of the calibration-related trends for the broad MODIS user community. The new C6 calibration approach removes major calibrations trends in the Level 1B (L1B) data. This paper also introduces an enhanced C6+ calibration of the MODIS data set which includes an additional polarization correction (PC) to compensate for the increased polarization sensitivity of MODIS Terra since about 2007, as well as detrending and Terra-Aqua cross-calibration over quasi-stable desert calibration sites. The PC algorithm, developed by the MODIS ocean biology processing group (OBPG), removes residual scan angle, mirror side and seasonal biases from aerosol and surface reflectance (SR) records along with spectral distortions of SR. Using the multiangle implementation of atmospheric correction (MAIAC) algorithm over deserts, we have also developed a detrending and cross-calibration method which removes residual decadal trends on

  20. Scientific Impact of MODIS C5 Calibration Degradation and C6+ Improvements

    NASA Technical Reports Server (NTRS)

    Lyapustin, A.; Wang, Y.; Xiong, X.; Meister, G.; Platnick, S.; Levy, R.; Franz, B.; Korkin, S.; Hilker, T.; Tucker, J.; Hall, F.; Sellers, P.; Wu, A.; Angal, A.

    2014-01-01

    The Collection 6 (C6) MODIS (Moderate Resolution Imaging Spectroradiometer) land and atmosphere data sets are scheduled for release in 2014. C6 contains significant revisions of the calibration approach to account for sensor aging. This analysis documents the presence of systematic temporal trends in the visible and near-infrared (500 m) bands of the Collection 5 (C5) MODIS Terra and, to lesser extent, in MODIS Aqua geophysical data sets. Sensor degradation is largest in the blue band (B3) of the MODIS sensor on Terra and decreases with wavelength. Calibration degradation causes negative global trends in multiple MODIS C5 products including the dark target algorithm's aerosol optical depth over land and Ångstrom exponent over the ocean, global liquid water and ice cloud optical thickness, as well as surface reflectance and vegetation indices, including the normalized difference vegetation index (NDVI) and enhanced vegetation index (EVI). As the C5 production will be maintained for another year in parallel with C6, one objective of this paper is to raise awareness of the calibration-related trends for the broad MODIS user community. The new C6 calibration approach removes major calibrations trends in the Level 1B (L1B) data. This paper also introduces an enhanced C6C calibration of the MODIS data set which includes an additional polarization correction (PC) to compensate for the increased polarization sensitivity of MODIS Terra since about 2007, as well as detrending and Terra- Aqua cross-calibration over quasi-stable desert calibration sites. The PC algorithm, developed by the MODIS ocean biology processing group (OBPG), removes residual scan angle, mirror side and seasonal biases from aerosol and surface reflectance (SR) records along with spectral distortions of SR. Using the multiangle implementation of atmospheric correction (MAIAC) algorithm over deserts, we have also developed a detrending and cross-calibration method which removes residual decadal trends on

  1. Monitoring of Refractory Wall recession using high temperature impact echo instrumentation

    SciTech Connect

    University of Dayton

    2004-04-30

    Regression of refractory linings of furnaces occurs due to a variety of mechanisms. The specific mechanism selected for investigation during this program is the regression of refractories which are in direct contact with a liquid corrodant. Examples include the melting of glass, the production of pig iron and steel, and the melting of aluminum. The rates of regression to a wall thickness which requires reline or extensive reconstruction vary widely, from less than a year to over ten years depending on the specific service environment. This program investigated the feasibility of measuring refractory wall thickness with an impact-echo method while at operating temperature (wall temperatures exceeding 500 C). The impact-echo method uses the impact of a small sphere with the surface of the test object to send a stress wave into the object. In a plate-like structure, the stress wave reflects back to the front surface, reverberating in the structure and causing a periodic surface displacement whose frequency is inversely proportional to the thickness of the test object. Impact-echo testing was chosen because it requires access to only one side of the test object and could be performed during the operation of a refractory structure. Commercially-available impact-echo instrumentation is available for room temperature use for a variety of tests on concrete. The enabling technology for this work was to use a high-temperature piezoelectric material, aluminum nitride, as the receiving sensor for the stress waves, allowing its use on refractories during furnace operation.

  2. Inherent calibration of a novel LED-CE-DOAS instrument to measure iodine oxide, glyoxal, methyl glyoxal, nitrogen dioxide, water vapour and aerosol extinction in open cavity mode

    NASA Astrophysics Data System (ADS)

    Thalman, R.; Volkamer, R.

    2010-06-01

    The combination of Cavity Enhanced Absorption Spectroscopy (CEAS) with broad-band light sources (e.g. Light-Emitting Diodes, LEDs) lends itself to the application of cavity enhanced Differential Optical Absorption Spectroscopy (CE-DOAS) to perform sensitive and selective point measurements of multiple trace gases and aerosol extinction with a single instrument. In contrast to other broad-band CEAS techniques, CE-DOAS relies only on the measurement of relative intensity changes, i.e. does not require knowledge of the light intensity in the absence of trace gases and aerosols (I0). We have built a prototype LED-CE-DOAS instrument in the blue spectral range (420-490 nm) to measure nitrogen dioxide (NO2), glyoxal (CHOCHO), methyl glyoxal (CH3COCHO), iodine oxide (IO), water vapour (H2O) and oxygen dimers (O4). We demonstrate the first CEAS detection of methyl glyoxal, and the first CE-DOAS detection of CHOCHO and IO. A further innovation consists in the measurement of extinction losses from the cavity, e.g. due to aerosols, at two wavelengths by observing O4 (477 nm) and H2O (443 nm) and measuring the pressure, relative humidity and temperature independently. This approach is demonstrated by experiments where laboratory aerosols of known size and refractive index were generated and their extinction measured. The measured extinctions were then compared to the theoretical extinctions calculated using Mie theory (3-7×10-7 cm-1). Excellent agreement is found from both the O4 and H2O retrievals. This enables the first inherently calibrated CEAS measurement in open cavity mode (mirrors facing the open atmosphere), and eliminates the need for sampling lines to supply air to the cavity, and/or keep the cavity enclosed and aerosol free. Measurements in open cavity mode are demonstrated for CHOCHO, CH3COCHO, NO2, H2O and aerosol extinction at 477 nm and 443 nm. Our prototype LED-CE-DOAS provides a low cost, yet research grade innovative instrument for applications in simulation

  3. Discrimination slope and integrated discrimination improvement - properties, relationships and impact of calibration.

    PubMed

    Pencina, Michael J; Fine, Jason P; D'Agostino, Ralph B

    2016-10-03

    Discrimination slope, defined as the slope of a linear regression of predicted probabilities of event derived from a prognostic model on the binary event status, has recently gained popularity as a measure of model performance. It is as a building block for the integrated discrimination improvement that equals the difference in discrimination slopes between the two models being compared. Several authors have pointed out that it does not make sense to apply the integrated discrimination improvement and discrimination slope when working with mis-calibrated models, whereas others have raised concerns about the ability of improving discrimination slope without adding new information. In this paper, we show that under certain assumptions the discrimination slope is asymptotically related to two other R-squared measures, one of which is a rescaled version of the Brier score, known to be proper. Furthermore, we illustrate how a simple recalibration makes the slope equal to the rescaled Brier R-squared metric. We also show that the discrimination slope can be interpreted as a measure of reduction in expected regret for the Gini-Brier regret function. Using theoretical and practical examples, we illustrate how all of these metrics are affected by different levels of model mis-calibration. In particular, we demonstrate that simple recalibration ascertaining calibration in-the-large and calibration slope equal to 1 are not sufficient to correct for some forms of mis-calibration. We conclude that R-squared metrics, including the discrimination slope, offer an attractive choice for quantifying model performance as long as one accounts for their sensitivity to model calibration. Copyright © 2016 John Wiley & Sons, Ltd.

  4. MODIS On-orbit Calibration: Key Issues and Approaches

    NASA Technical Reports Server (NTRS)

    Xiong, Xian-Xiong; Sun, J.; Chiang, K.; Che, N.; Barnes, W.

    2004-01-01

    MODIS, one of the key instruments for the NASA's Earth Observing System (EOS), is currently operating on both the Terra and Aqua spacecraft making continuous observations in 36 spectral bands from 0.4 to 14.4 micrometers. A complete suite of on-board calibrators (OBC) have been designed for the instruments' on-orbit calibration and characterization, including a solar diffuser (SD) and solar diffuser stability monitor (SDSM) system for the radiometric calibration of the 20 reflective solar bands (RSB), a blackbody (BB) for the radiometric calibration of the 16 thermal emissive bands (TEZB), and a spectro-radiometric calibration assembly (SRCA) for the sensors' spatial and spectral characterization. The task of continuously performing high quality on-orbit calibration and characterization of all 36 spectral bands with a total of 490 detectors located on four focal plane assemblies is extremely challenging. The use of a large two-sided paddle wheel scan mirror with a +/- 55 deg scan angle range and a retractable pinhole attenuation screen in front of the SD panel for calibrating the high gain bands have resulted in additional unanticipated complexity. In this paper, we describe some of the key issues in the Terra and Aqua MODIS on-orbit calibration and characterization, and discuss the methods developed to solve these problems or to reduce their impact on the Level 1B calibration algorithms. Instrument performance and current issues are also presented.

  5. Dust Impact Monitor DIM onboard Rosetta/Philae: Calibration experiments with ice particles as cometary analogue materials

    NASA Astrophysics Data System (ADS)

    Krüger, H.; Albin, T.; Flandes, A.; Fischer, H.; Hirn, A.; Loose, A.; Seidensticker, K.; Arnold, W.

    2014-07-01

    The Rosetta lander spacecraft Philae will land on the nucleus surface of comet 67P/Churyumov-Gerasimenko in November 2014. Philae is equipped with the Dust Impact Monitor (DIM). DIM is part of the SESAME instrument package onboard Philae and employs piezoelectric PZT sensors to detect impacts by sub-millimetre and millimetre-sized ice and dust particles that are emitted from the nucleus and transported into the cometary coma by the escaping gas flow. DIM will measure fluxes, impact directions, as well as the speed and size of the impacting particles. We studied the performance of DIM based on impact experiments and compared the measurements with the sensor's expected theoretical behaviour as derived from the Hertz theory of elastic impacts. We simulated impacts onto the DIM sensor with spherical ice particles with radii of approximately 0.7 mm and porous particles of other materials with radii up to 4 mm. Impact speeds range up to 2 m s^{-1}. Cometary grains on ballistic trajectories will have impact speeds below the escape speed from the nucleus surface (approximately 1.5 m s^{-1}), thus the impact speeds achievable by our experiments cover the range expected at the comet. Our results show that the signal strength and the contact durations measured with the DIM PZT sensors can be well approximated by the Hertz contact mechanics.

  6. Environmental impact assessment (EIA): an overlooked instrument for sustainable development in Pakistan.

    PubMed

    Saeed, Rashid; Sattar, Ayesha; Iqbal, Zafar; Imran, Muhammad; Nadeem, Raziya

    2012-04-01

    Environmental impact assessment (EIA) is a policy tool used for evaluating a project proposal from physical and socioeconomic environmental perspectives. Its aim is to reduce the impact of development on environment, hence, ensuring environmental sustainability. It is mandatory to submit an Environmental Impact Statement before starting a mega project as required by Environmental Protection Act of 1997 and Environmental Policy of Pakistan. Public consultation plays a key role in an EIA system, identifying the likely aspects and impacts of a development activity. This aspect has been ignored in effective enactment of environmental legislation in Pakistan. Sufficient legislative instruments are there to support EIA system in the country but the agencies responsible for the enforcement of environmental regulations have failed to do so. The current research gives an insight into the actual status of EIA system in Pakistan along with the feedback of EIA specialists and university teachers of the concerned departments. A new index has been devised on the basis of questionnaire response to work out the overall performance of EIA system in Pakistan or any other country. The weaknesses and deficiencies of each EIA stage have been worked out for Pakistan and elaborated with the help of the controversial Zero point Interchange Project in the capital city of Pakistan.

  7. Calibration of PS09, PS10, and PS11 trans-Alaska pipeline system strong-motion instruments, with acceleration, velocity, and displacement records of the Denali fault earthquake, 03 November 2002

    USGS Publications Warehouse

    Evans, John R.; Jensen, E. Gray; Sell, Russell; Stephens, Christopher D.; Nyman, Douglas J.; Hamilton, Robert C.; Hager, William C.

    2006-01-01

    In September, 2003, the Alyeska Pipeline Service Company (APSC) and the U.S. Geological Survey (USGS) embarked on a joint effort to extract, test, and calibrate the accelerometers, amplifiers, and bandpass filters from the earthquake monitoring systems (EMS) at Pump Stations 09, 10, and 11 of the Trans-Alaska Pipeline System (TAPS). These were the three closest strong-motion seismographs to the Denali fault when it ruptured in the MW 7.9 earthquake of 03 November 2002 (22:12:41 UTC). The surface rupture is only 3.0 km from PS10 and 55.5 km from PS09 but PS11 is 124.2 km away from a small rupture splay and 126.9 km from the main trace. Here we briefly describe precision calibration results for all three instruments. Included with this report is a link to the seismograms reprocessed using these new calibrations: http://nsmp.wr.usgs.gov/data_sets/20021103_2212_taps.html Calibration information in this paper applies at the time of the Denali fault earthquake (03 November 2002), but not necessarily at other times because equipment at these stations is changed by APSC personnel at irregular intervals. In particular, the equipment at PS09, PS10, and PS11 was changed by our joint crew in September, 2003, so that we could perform these calibrations. The equipment stayed the same from at least the time of the earthquake until that retrieval, and these calibrations apply for that interval.

  8. SNLS calibrations

    NASA Astrophysics Data System (ADS)

    Regnault, N.

    2015-08-01

    The Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) is a massive imaging survey, conducted between 2003 and 2008, with the MegaCam instrument, mounted on the CFHT-3.6-m telescope. With a 1 degree wide focal plane, made of 36 2048 × 4612 sensors totalling 340 megapixels, MegaCam was at the time the largest imager on the sky. The Supernova Legacy Survey (SNLS) uses the cadenced observations of the 4 deg2 wide "DEEP" layer of the CFHTLS to search and follow-up Type Ia supernovae (SNe Ia) and study the acceleration of the cosmic expansion. The reduction and calibration of the CFHTLS/SNLS datasets has posed a series of challenges. In what follows, we give a brief account of the photometric calibration work that has been performed on the SNLS data over the last decade.

  9. Instrumented impact properties of zircaloy-oxygen and zircaloy-hydrogen alloys

    SciTech Connect

    Garde, A.M.; Kassner, T.F.

    1980-04-01

    Instrumented-impact tests were performed on subsize Charpy speciments of Zircaloy-2 and -4 with up to approx. 1.3 wt % oxygen and approx. 2500 wt ppM hydrogen at temperatures between 373 and 823/sup 0/K. Self-consistent criteria for the ductile-to-brittle transition, based upon a total absorbed energy of approx. 1.3 x 10/sup 4/ J/m/sup 2/, a dynamic fracture toughness of approx. 10 MPa.m/sup 1/2/, and a ductility index of approx. 0, were established relative to the temperature and oxygen concentration of the transformed BETA-phase material. The effect of hydrogen concentration and hydride morphology, produced by cooling Zircaloy-2 specimens through the temperature range of the BETA ..-->.. ..cap alpha..' = hydride phase transformation at approx. 0.3 and 3 K/s, on the impact properties was determined at temperatures between 373 and 673 K. On an atom fraction basis, oxygen has a greater effect than hydrogen on the impact properties of Zircaloy at temperatures between approx. 400 and 600 K. 34 figures.

  10. SNR 1E 0102.2-7219 as an X-ray calibration standard in the 0.5-1.0 keV bandpass and its application to the CCD instruments aboard Chandra, Suzaku, Swift and XMM-Newton

    NASA Astrophysics Data System (ADS)

    Plucinsky, Paul P.; Beardmore, Andrew P.; Foster, Adam; Haberl, Frank; Miller, Eric D.; Pollock, Andrew M. T.; Sembay, Steve

    2017-01-01

    Context. The flight calibration of the spectral response of charge-coupled device (CCD) instruments below 1.5 keV is difficult in general because of the lack of strong lines in the on-board calibration sources typically available. This calibration is also a function of time due to the effects of radiation damage on the CCDs and/or the accumulation of a contamination layer on the filters or CCDs. Aims: We desire a simple comparison of the absolute effective areas of the current generation of CCD instruments onboard the following observatories: Chandra ACIS-S3, XMM-Newton (EPIC-MOS and EPIC-pn), Suzaku XIS, and Swift XRT and a straightforward comparison of the time-dependent response of these instruments across their respective mission lifetimes. Methods: We have been using 1E 0102.2-7219, the brightest supernova remnant in the Small Magellanic Cloud, to evaluate and modify the response models of these instruments. 1E 0102.2-7219 has strong lines of O, Ne, and Mg below 1.5 keV and little or no Fe emission to complicate the spectrum. The spectrum of 1E 0102.2-7219 has been well-characterized using the RGS gratings instrument on XMM-Newton and the HETG gratings instrument on Chandra. As part of the activities of the International Astronomical Consortium for High Energy Calibration (IACHEC), we have developed a standard spectral model for 1E 0102.2-7219 and fit this model to the spectra extracted from the CCD instruments. The model is empirical in that it includes Gaussians for the identified lines, an absorption component in the Galaxy, another absorption component in the SMC, and two thermal continuum components with different temperatures. In our fits, the model is highly constrained in that only the normalizations of the four brightest lines/line complexes (the O vii Heα triplet, O viii Lyα line, the Ne ix Heα triplet, and the Ne x Lyα line) and an overall normalization are allowed to vary, while all other components are fixed. We adopted this approach to

  11. Impact of Calibrated Land Surface Model Parameters on the Accuracy and Uncertainty of Land-Atmosphere Coupling in WRF Simulations

    NASA Technical Reports Server (NTRS)

    Santanello, Joseph A., Jr.; Kumar, Sujay V.; Peters-Lidard, Christa D.; Harrison, Ken; Zhou, Shujia

    2012-01-01

    Land-atmosphere (L-A) interactions play a critical role in determining the diurnal evolution of both planetary boundary layer (PBL) and land surface temperature and moisture budgets, as well as controlling feedbacks with clouds and precipitation that lead to the persistence of dry and wet regimes. Recent efforts to quantify the strength of L-A coupling in prediction models have produced diagnostics that integrate across both the land and PBL components of the system. In this study, we examine the impact of improved specification of land surface states, anomalies, and fluxes on coupled WRF forecasts during the summers of extreme dry (2006) and wet (2007) land surface conditions in the U.S. Southern Great Plains. The improved land initialization and surface flux parameterizations are obtained through the use of a new optimization and uncertainty estimation module in NASA's Land Information System (LIS-OPT/UE), whereby parameter sets are calibrated in the Noah land surface model and classified according to a land cover and soil type mapping of the observation sites to the full model domain. The impact of calibrated parameters on the a) spinup of the land surface used as initial conditions, and b) heat and moisture states and fluxes of the coupled WRF simulations are then assessed in terms of ambient weather and land-atmosphere coupling along with measures of uncertainty propagation into the forecasts. In addition, the sensitivity of this approach to the period of calibration (dry, wet, average) is investigated. Finally, tradeoffs of computational tractability and scientific validity, and the potential for combining this approach with satellite remote sensing data are also discussed.

  12. [Survey and analysis of radiation safety management systems at medical institutions--second report: radiation measurement, calibration of radiation survey meters, and periodic check of installations, equipment, and protection instruments].

    PubMed

    Ohba, Hisateru; Ogasawara, Katsuhiko; Aburano, Tamio

    2006-01-20

    We carried out a questionnaire survey to determine the actual situation of radiation safety management measures in all medical institutions in Japan that had nuclear medicine facilities. The questionnaire consisted of questions concerning the evaluation of shielding capacity; radiation measurement; periodic checks of installations, equipment, and protection instruments; and the calibration of radiation survey meters. The analysis was undertaken according to region, type of establishment, and number of beds. The overall response rate was 60 percent. For the evaluation of shielding capacity, the outsourcing rate was 53 percent of the total. For the radiation measurements of "leakage radiation dose and radioactive contamination" and "contamination of radioactive substances in the air," the outsourcing rates were 28 percent and 35 percent of the total, respectively (p<0.001, according to region and establishment). For the periodic check of radiation protection instruments, the implementation rate was 98 percent, and the outsourcing rate was 32 percent for radiation survey meters and 47 percent for lead aprons. The non-implemented rate for calibration of radiation survey meters was 25 percent of the total (p<0.001, according to region and establishment). The outsourcing rate for calibration of radiation survey meters accounted for 87 percent of the total, and of these medical institutions, 72 percent undertook annual calibration. The implementation rate for patient exposure measurement was 20 percent of the total (p<0.001, according to number of beds), and of these medical institutions 46 percent recorded measurement outcome.

  13. β-adrenergic impact underlies the effect of mood and hedonic instrumentality on effort-related cardiovascular response.

    PubMed

    Silvestrini, Nicolas; Gendolla, Guido H E

    2011-05-01

    After habituation, participants were first induced into negative vs. positive moods and performed then an attention task with either low vs. high hedonic instrumentality of success. In the high-instrumentality condition participants expected to see a funny movie after success and an unpleasant movie after failure; in the low-instrumentality condition participants expected an unpleasant movie after success and a pleasant movie after failure. Effort-related cardiovascular response (ICG, blood pressure) was assessed during mood inductions and task performance. As predicted by the mood-behavior-model (Gendolla, 2000), responses of cardiac pre-ejection period (PEP) and systolic blood pressure were stronger in the high-instrumentality/negative-mood condition than in the other three cells. Here the high hedonic instrumentality of success justified the high effort that was perceived as necessary in a negative mood. Moreover, the PEP effects indicate that cardiovascular response was driven by beta-adrenergic impact on the heart rather than by vascular adjustments.

  14. Construction and operation of an improved radiation calibration facility at Brookhaven National Laboratory. Environmental assessment

    SciTech Connect

    1994-10-01

    Calibration of instruments used to detect and measure ionizing radiation has been conducted over the last 20 years at Brookhaven National Laboratory`s (BNL) Radiation Calibration Facility, Building 348. Growth of research facilities, projects in progress, and more stringent Department of Energy (DOE) orders which involve exposure to nuclear radiation have placed substantial burdens on the existing radiation calibration facility. The facility currently does not meet the requirements of DOE Order 5480.4 or American National Standards Institute (ANSI) N323-1978, which establish calibration methods for portable radiation protection instruments used in the detection and measurement of levels of ionizing radiation fields or levels of radioactive surface contaminations. Failure to comply with this standard could mean instrumentation is not being calibrated to necessary levels of sensitivity. The Laboratory has also recently obtained a new neutron source and gamma beam irradiator which can not be made operational at existing facilities because of geometry and shielding inadequacies. These sources are needed to perform routine periodic calibrations of radiation detecting instruments used by scientific and technical personnel and to meet BNL`s substantial increase in demand for radiation monitoring capabilities. To place these new sources into operation, it is proposed to construct an addition to the existing radiation calibration facility that would house all calibration sources and bring BNL calibration activities into compliance with DOE and ANSI standards. The purpose of this assessment is to identify potential significant environmental impacts associated with the construction and operation of an improved radiation calibration facility at BNL.

  15. A deadtime model for the calibration of impact sensors with an application to a modified miniphone sensor

    NASA Astrophysics Data System (ADS)

    Yurk, Brian P.; Hansen, Edward C.; Hazle, Dean

    2013-12-01

    Due to deadtime effects, undercounting by aeolian impact sensors is present at all sediment flux levels. During a short time interval following an impact (the deadtime), an impact sensor is unable to detect new impacts. The degree of undercounting increases with increasing flux so that the sensor eventually becomes saturated. We develop an undercounting model for aeolian impact sensors that accounts for deadtime. This model was applied to field data obtained using a miniphone sensor modified from Ellis et al. (2009). The modified miniphone is inexpensive ($75.00 USD per pair, including datalogging) and easy to assemble. A protective layer of foil increases longevity at the probable expense of sensitivity. Modified Wilson and Cooke (MWAC) sand traps were paired with modified miniphones (MM) for intervals of up to 50 min during two winter storms along the coast of Lake Michigan. Sand from each MWAC was sieved, and the masses were fit to a continuous density function to estimate grain counts. MM deployed for cumulative periods of up to 200 showed no evidence of signal degradation. Fitting a deadtime model to the MM/MWAC data yielded a R2 value of 0.9766. While short segments of the response curve can be approximated by a linear fit, linear models will fail if applied much beyond the experimental conditions at which they were calibrated. The deadtime curve is based on a more realistic model of how impact sensors work and should give a better approximation of aeolian sand flux over a broader range of impact rates.

  16. Should different impact assessment instruments be integrated? Evidence from English spatial planning

    SciTech Connect

    Tajima, Ryo; Fischer, Thomas B.

    2013-07-15

    This paper aims at providing empirical evidence to the question as to whether integration of different instruments is achieving its aim in supporting sustainable decision making, focusing on SEA inclusive sustainability appraisal (SA) and other impact assessments (IAs) currently used in English spatial planning. Usage of IAs in addition to SA is established and an analysis of the integration approach (in terms of process, output, and assessor) as well as its effectiveness is conducted. It is found that while integration enhances effectiveness to some extent, too much integration, especially in terms of the procedural element, appears to diminish the overall effectiveness of each IA in influencing decisions as they become captured by the balancing function of SA. -- Highlights: ► The usage of different impact assessments in English spatial planning is clarified. ► The relationship between integration approach and effectiveness is analyzed. ► Results suggest that integration does not necessarily lead to more sustainable decisions. ► Careful consideration is recommended upon process integration.

  17. Improved Detection System Description and New Method for Accurate Calibration of Micro-Channel Plate Based Instruments and Its Use in the Fast Plasma Investigation on NASA's Magnetospheric MultiScale Mission

    NASA Technical Reports Server (NTRS)

    Gliese, U.; Avanov, L. A.; Barrie, A. C.; Kujawski, J. T.; Mariano, A. J.; Tucker, C. J.; Chornay, D. J.; Cao, N. T.; Gershman, D. J.; Dorelli, J. C.; Zeuch, M. A.; Pollock, C. J.; Jacques, A. D.

    2015-01-01

    The Fast Plasma Investigation (FPI) on NASAs Magnetospheric MultiScale (MMS) mission employs 16 Dual Electron Spectrometers (DESs) and 16 Dual Ion Spectrometers (DISs) with 4 of each type on each of 4 spacecraft to enable fast (30 ms for electrons; 150 ms for ions) and spatially differentiated measurements of the full 3D particle velocity distributions. This approach presents a new and challenging aspect to the calibration and operation of these instruments on ground and in flight. The response uniformity, the reliability of their calibration and the approach to handling any temporal evolution of these calibrated characteristics all assume enhanced importance in this application, where we attempt to understand the meaning of particle distributions within the ion and electron diffusion regions of magnetically reconnecting plasmas. Traditionally, the micro-channel plate (MCP) based detection systems for electrostatic particle spectrometers have been calibrated using the plateau curve technique. In this, a fixed detection threshold is set. The detection system count rate is then measured as a function of MCP voltage to determine the MCP voltage that ensures the count rate has reached a constant value independent of further variation in the MCP voltage. This is achieved when most of the MCP pulse height distribution (PHD) is located at higher values (larger pulses) than the detection system discrimination threshold. This method is adequate in single-channel detection systems and in multi-channel detection systems with very low crosstalk between channels. However, in dense multi-channel systems, it can be inadequate. Furthermore, it fails to fully describe the behavior of the detection system and individually characterize each of its fundamental parameters. To improve this situation, we have developed a detailed phenomenological description of the detection system, its behavior and its signal, crosstalk and noise sources. Based on this, we have devised a new detection

  18. Spatial patterns of substantial climate impact from anthropogenic aerosols in the early instrumental period

    NASA Astrophysics Data System (ADS)

    Undorf, Sabine; Bollasina, Massimo; Hegerl, Gabriele

    2016-04-01

    While many aspects of climate variation in the early instrumental period (1860-1950) are still unexplained, for instance the early twentieth-century warming from the 1910s to the 1940s, the role of anthropogenic aerosols in this period has been overlooked. Yet, the period is also an interesting case study to isolate aerosol impacts since it is characterised by the increase of North American and especially European aerosol emissions concurrently with negligible Asian emissions and relatively low carbon dioxide concentrations. We thus analyse the spatial and temporal patterns of aerosol impact for this period in available observations (NOAA 20th-century reanalysis, etc.) and historical single-forcing and all-forcing experiments with state-of-the-art CMIP5 models. We make use of coupled empirical orthogonal functions (EOFs) applied to surface temperature -the most reliable variable in observations- and different aerosol indicating variables such as aerosol optical depth and short-wave downward radiation, some of which include aerosol indirect effects. The principal components of the most important EOFs are then regressed onto sea level pressure, winds, and other variables to identify associated circulation patterns. A decomposition into multi-decadal and longer time scales is performed by filtering the data prior to the analysis. Our analysis reveals both statistically significant local and non-local aerosol impact and identifies circulation states associated with the temperature response. The results are consistent across different aerosol variables, and show a strong non-local response as well as specific differences between time scales. We find a distinctive circulation pattern which strongly resembles observations and might explain the observed early twentieth century warming in the Arctic.

  19. Single-impact calibrated electromagnetic tightening of long-life bolted joints in aviation structures

    NASA Astrophysics Data System (ADS)

    Firsov, V. A.; Bekhmet'ev, V. I.

    The general design and operation of a newly developed electromagnetic impact driver for the assembly of aviation structures is described. The electromagnetic impact driver makes it possible to considerably improve the precision of bolt torquing during the assembly. To test the performance of the new tool, M6 bolts of 16KhSN steel (tensile strength 120 +/- 10 kg/sq mm) were tightened by a manual torque wrench and by the electromagnetic impact driver. It is shown that the scatter of bolt elongation during the tightening by the impact driver is a factor of 3-5 less than in the case of manual torquing, which corresponds to a torque precision of 1.5-2 percent.

  20. JPSS-1 VIIRS reflective solar band on-orbit calibration performance impacts due to SWIR nonlinearity artifacts

    NASA Astrophysics Data System (ADS)

    Moyer, D.; De Luccia, F.; Haas, E.

    2016-10-01

    The Joint Polar Satellite System 1 (JPSS-1) is the follow on mission to the Suomi-National Polar-orbiting Partnership (SNPP) and provides critical weather and global climate products to the user community. A primary sensor on both JPSS-1 and S-NPP is the Visible-Infrared Imaging Radiometer Suite (VIIRS) with the Reflective Solar Band (RSB), Thermal Emissive Band (TEB) and Day Night Band (DNB) imagery providing a diverse spectral range of Earth observations. These VIIRS observation are radiometrically calibrated within the Sensor Data Records (SDRs) for use in Environmental Data Record (EDR) products such as Ocean Color/Chlorophyll (OCC) and Sea Surface Temperature (SST). Spectrally the VIIRS sensor can be broken down into 4 groups: the Visible Near Infra-Red (VNIR), Short-Wave Infra-Red (SWIR), Mid- Wave Infra-Red (MWIR) and Long-Wave Infra-Red (LWIR). The SWIR spectral bands on JPSS-1 VIIRS have a nonlinear response at low light levels affecting the calibration quality where Earth scenes are dark (like oceans). This anomalous behavior was not present on S-NPP VIIRS and will be a unique feature of the JPSS-1 VIIRS sensor. This paper will show the behavior of the SWIR response non-linearity on JPSS-1 VIIRS and potential mitigation approaches to limit its impact on the SDR and EDR products.

  1. Sandia WIPP calibration traceability

    SciTech Connect

    Schuhen, M.D.; Dean, T.A.

    1996-05-01

    This report summarizes the work performed to establish calibration traceability for the instrumentation used by Sandia National Laboratories at the Waste Isolation Pilot Plant (WIPP) during testing from 1980-1985. Identifying the calibration traceability is an important part of establishing a pedigree for the data and is part of the qualification of existing data. In general, the requirement states that the calibration of Measuring and Test equipment must have a valid relationship to nationally recognized standards or the basis for the calibration must be documented. Sandia recognized that just establishing calibration traceability would not necessarily mean that all QA requirements were met during the certification of test instrumentation. To address this concern, the assessment was expanded to include various activities.

  2. Reliability and construct validity of the Instrument to Measure the Impact of Valve Heart Disease on the Patient's Daily Life

    PubMed Central

    dos Anjos, Daniela Brianne Martins; Rodrigues, Roberta Cunha Matheus; Padilha, Kátia Melissa; Pedrosa, Rafaela Batista dos Santos; Gallani, Maria Cecília Bueno Jayme

    2016-01-01

    ABSTRACT Objective: evaluate the practicality, acceptability and the floor and ceiling effects, estimate the reliability and verify the convergent construct's validity with the instrument called the Heart Valve Disease Impact on daily life (IDCV) of the valve disease in patients with mitral and or aortic heart valve disease. Method: data was obtained from 86 heart valve disease patients through 3 phases: a face to face interview for a socio-demographic and clinic characterization and then other two done through phone calls of the interviewed patients for application of the instrument (test and repeat test). Results: as for the practicality and acceptability, the instrument was applied with an average time of 9,9 minutes and with 110% of responses, respectively. Ceiling and floor effects observed for all domains, especially floor effect. Reliability was tested using the test - repeating pattern to give evidence of temporal stability of the measurement. Significant negative correlations with moderate to strong magnitude were found between the score of the generic question about the impact of the disease and the scores of IDCV, which points to the validity of the instrument convergent construct. Conclusion: the instrument to measure the impact of valve heart disease on the patient's daily life showed evidence of reliability and validity when applied to patients with heart valve disease. PMID:27992024

  3. MIRO Calibration Switch Mechanism

    NASA Technical Reports Server (NTRS)

    Suchman, Jason; Salinas, Yuki; Kubo, Holly

    2001-01-01

    The Jet Propulsion Laboratory has designed, analyzed, built, and tested a calibration switch mechanism for the MIRO instrument on the ROSETTA spacecraft. MIRO is the Microwave Instrument for the Rosetta Orbiter; this instrument hopes to investigate the origin of the solar system by studying the origin of comets. Specifically, the instrument will be the first to use submillimeter and millimeter wave heterodyne receivers to remotely examine the P-54 Wirtanen comet. In order to calibrate the instrument, it needs to view a hot and cold target. The purpose of the mechanism is to divert the instrument's field of view from the hot target, to the cold target, and then back into space. This cycle is to be repeated every 30 minutes for the duration of the 1.5 year mission. The paper describes the development of the mechanism, as well as analysis and testing techniques.

  4. A Pilot Project to Develop Instruments for an Impact Study of Wisconsin State University - River Falls. Final Report.

    ERIC Educational Resources Information Center

    Wyman, Walker D.

    This report briefly discusses the development of a survey instrument that will be used for an impact study of Wisconsin State University at River Falls. The questionnaire will be sent to 9,000 living graduates for whom addresses are available. Two books relevant to the study are briefly summarized. Both are entitled "They Went to…

  5. Aquarius Whole Range Calibration: Celestial Sky, Ocean, and Land Targets

    NASA Technical Reports Server (NTRS)

    Dinnat, Emmanuel P.; Le Vine, David M.; Bindlish, Rajat; Piepmeier, Jeffrey R.; Brown, Shannon T.

    2014-01-01

    Aquarius is a spaceborne instrument that uses L-band radiometers to monitor sea surface salinity globally. Other applications of its data over land and the cryosphere are being developed. Combining its measurements with existing and upcoming L-band sensors will allow for long term studies. For that purpose, the radiometers calibration is critical. Aquarius measurements are currently calibrated over the oceans. They have been found too cold at the low end (celestial sky) of the brightness temperature scale, and too warm at the warm end (land and ice). We assess the impact of the antenna pattern model on the biases and propose a correction. We re-calibrate Aquarius measurements using the corrected antenna pattern and measurements over the Sky and oceans. The performances of the new calibration are evaluated using measurements over well instrument land sites.

  6. Multi-Target Calibration with a VIC Hydrologic Model: Impacts of Climate Change and Risk Assessment in the Colorado River Basin

    NASA Astrophysics Data System (ADS)

    Wi, S.; Isenstein, L.; Yang, Y. C. E.; Brown, C.

    2015-12-01

    The Variable Infiltration Capacity (VIC) model is applied to the headwaters of the Arkansas River (Colorado Springs) in the USA for the purpose of water supply evaluation. Modeling the hydrologic regime of the Arkansas River is a challenge due to the large number of diversions and regulations that might impact the natural streamflow. Since the Arkansas River headwaters are snow-melt dominated, a snow cover dataset can provide additional information during the model calibration process. Remote sensing snow data have been successfully used in previous studies coupled with hydrologic modeling to improve calibration results. Using the daily snow data acquired from the Moderate Resolution Imaging Spectroradiometer (MODIS) satellite, and this study tests different calibration schemes to determine the most suitable calibration target(s) for the Colorado Springs. First, the VIC model is calibrated to streamflow and snow alone, and then a mutli-objective optimization is utilized to calibrate the model to streamflow and snow simultaneously. A well calibrated hydrologic model can be employed particularly for climate change assessments to inform decision makers about water availability and water supply under different climate conditions. This study will provide such information to Colorado Springs in which development in terms of water supply is expected to grow considerably; increases in demands are projected to be 28% higher than the present demands (approximately 102 billion gallons) by the year 2050.

  7. ALTEA calibration

    NASA Astrophysics Data System (ADS)

    Zaconte, V.; Altea Team

    The ALTEA project is aimed at studying the possible functional damages to the Central Nervous System (CNS) due to particle radiation in space environment. The project is an international and multi-disciplinary collaboration. The ALTEA facility is an helmet-shaped device that will study concurrently the passage of cosmic radiation through the brain, the functional status of the visual system and the electrophysiological dynamics of the cortical activity. The basic instrumentation is composed by six active particle telescopes, one ElectroEncephaloGraph (EEG), a visual stimulator and a pushbutton. The telescopes are able to detect the passage of each particle measuring its energy, trajectory and released energy into the brain and identifying nuclear species. The EEG and the Visual Stimulator are able to measure the functional status of the visual system, the cortical electrophysiological activity, and to look for a correlation between incident particles, brain activity and Light Flash perceptions. These basic instruments can be used separately or in any combination, permitting several different experiments. ALTEA is scheduled to fly in the International Space Station (ISS) in November, 15th 2004. In this paper the calibration of the Flight Model of the silicon telescopes (Silicon Detector Units - SDUs) will be shown. These measures have been taken at the GSI heavy ion accelerator in Darmstadt. First calibration has been taken out in November 2003 on the SDU-FM1 using C nuclei at different energies: 100, 150, 400 and 600 Mev/n. We performed a complete beam scan of the SDU-FM1 to check functionality and homogeneity of all strips of silicon detector planes, for each beam energy we collected data to achieve good statistics and finally we put two different thickness of Aluminium and Plexiglas in front of the detector in order to study fragmentations. This test has been carried out with a Test Equipment to simulate the Digital Acquisition Unit (DAU). We are scheduled to

  8. An experimental study of airbag impact to the orbit using an instrumented Hybrid III headform.

    PubMed

    Duma, S M; Kress, T A; Porta, D J; Martin, P G; Simmons, R J; Alexander, C L

    1997-01-01

    This paper provides the results from an experimental study intended to assess airbag impact to the orbit. Twenty-seven airbags were deployed onto an instrumented Hybrid III headform. Seven different types of airbags were used that included tethered and nontethered, light to heavy nylon weaves, and different coating types. The airbags were deployed via a pneumatic deployment system. Seven individual force transducers, each having a 2.25 cm2 contact area, were placed on the right orbital region to evaluate the force patterns. The midpoint of the two ocular regions of the headform was positioned 12.5 cm above and 15.0 cm away from the center of the airbag, a position determined from previous airbag deployments to yield the highest leading edge velocity. The average maximum force per sensor ranged from 15.4 N to 63.6 N, and peak pressure ranged from 68 kPa to 282 kPa. The upper center of the orbit presented the highest values while the center of the orbit recorded the lowest values, a comparison that was proven to be statistically significant. For this configuration, the maximum force on the ocular region was found to be independent of the presence of a tether or the maximum internal airbag pressure.

  9. The Impact of Gait Disability on the Calibration of Accelerometer Output in Adults with Multiple Sclerosis

    PubMed Central

    Weikert, Madeline; Dlugonski, Deirdre; Suh, Yoojin; Fernhall, Bo

    2011-01-01

    Accelerometer activity counts have been correlated with energy expenditure during treadmill walking among ambulatory adults with multiple sclerosis (MS). This study examined the effects of gait disability on 1) the association between rates of energy expenditure and accelerometer output in overground walking and 2) the calibration of accelerometer output for quantifying time spent in moderate-to-vigorous physical activity (MVPA) in people with MS. The sample consisted of 24 individuals with MS, of whom 10 reported gait disability based on Patient-Determined Disease Steps (PDDS) scores. The participants undertook three 6-minute periods of overground walking while wearing an accelerometer and a portable metabolic unit (K4b2, Cosmed, Rome, Italy). In the first period of walking, the participants walked at a self-selected, comfortable speed. In the two subsequent walking periods, participants walked at speeds above and below (±0.5 mph) the comfortable walking speed, respectively. Strong linear relationships were observed between rates of accelerometer activity counts and energy expenditure during walking in the overall sample (R2 = 0.90) and subsamples with (R2 = 0.88) and without gait disability (R2 = 0.91). The slope of the relationship was significantly steeper in the subsample with gait disability (β= 0.0049) than in the subsample without gait disability (β= 0.0026). The difference in slopes resulted in a significantly lower cut-point for MVPA (1886 vs. 2717 counts/min) in those with gait disability. These findings provide a metabolic cut-point for quantifying time spent in MVPA in people with MS, both with and without gait disability. PMID:24453722

  10. The impact of clinical use on the torsional behavior of Reciproc and WaveOne instruments

    PubMed Central

    de MAGALHÃES, Rafael Rodrigues Soares; BRAGA, Lígia Carolina Moreira; PEREIRA, Érika Sales Joviano; PEIXOTO, Isabella Faria da Cunha; BUONO, Vicente Tadeu Lopes; BAHIA, Maria Guiomar de Azevedo

    2016-01-01

    ABSTRACT Torsional overload is a fracture representative parameter for instruments in single-file techniques. Objective The aim of this study was to assess the influence of clinical use, in vivo, on the torsional behavior of Reciproc and WaveOne instruments considering the possibility that they degraded with use. Material and Methods Diameter at each millimeter, pitch length, and area at 3 mm from the tip were determined for both types of instruments. Twenty-four instruments, size 25, 0.08 taper, of each system were divided into two groups (n=12 each): Control Group (CG), in which new Reciproc (RC) and WaveOne Primary (WO) instruments were tested in torsion until rupture based on ISO 3630-1; and Experimental Group (EG), in which each new instrument was clinically used to clean and shape the root canals of one molar. After clinical use, the instruments were analyzed using optical and scanning electron microscopy and subsequently tested in torsion until fracture. Data were analyzed using one-way analysis of variance at a=.05. Results WO instruments showed significantly higher mean values of cross-sectional area A3 (P=0.000) and smaller pitch lengths than RC instruments with no statistically significant differences in the diameter at D3 (P=0.521). No significant differences in torsional resistance between the RC and WO new instruments (P=0.134) were found. The clinical use resulted in a tendency of reduction in the maximum torque of the analyzed instruments but no statistically significant difference was observed between them (P=0.327). During the preparation of the root canals, two fractured RC instruments and longitudinal and transversal cracks in RC and WO instruments were observed through SEM analysis. Conclusion After clinical use, no statistically significant reduction in the torsional resistance was observed. PMID:27556200

  11. Modeller subjectivity and calibration impacts on hydrological model applications: an event-based comparison for a road-adjacent catchment in south-east Norway.

    PubMed

    Kalantari, Zahra; Lyon, Steve W; Jansson, Per-Erik; Stolte, Jannes; French, Helen K; Folkeson, Lennart; Sassner, Mona

    2015-01-01

    Identifying a 'best' performing hydrologic model in a practical sense is difficult due to the potential influences of modeller subjectivity on, for example, calibration procedure and parameter selection. This is especially true for model applications at the event scale where the prevailing catchment conditions can have a strong impact on apparent model performance and suitability. In this study, two lumped models (CoupModel and HBV) and two physically-based distributed models (LISEM and MIKE SHE) were applied to a small catchment upstream of a road in south-eastern Norway. All models were calibrated to a single event representing typical winter conditions in the region and then applied to various other winter events to investigate the potential impact of calibration period and methodology on model performance. Peak flow and event-based hydrographs were simulated differently by all models leading to differences in apparent model performance under this application. In this case-study, the lumped models appeared to be better suited for hydrological events that differed from the calibration event (i.e., events when runoff was generated from rain on non-frozen soils rather than from rain and snowmelt on frozen soil) while the more physical-based approaches appeared better suited during snowmelt and frozen soil conditions more consistent with the event-specific calibration. This was due to the combination of variations in subsurface conditions over the eight events considered, the subsequent ability of the models to represent the impact of the conditions (particularly when subsurface conditions varied greatly from the calibration event), and the different approaches adopted to calibrate the models. These results indicate that hydrologic models may not only need to be selected on a case-by-case basis but also have their performance evaluated on an application-by-application basis since how a model is applied can be equally important as inherent model structure.

  12. Fast calibration of gas flowmeters

    NASA Technical Reports Server (NTRS)

    Lisle, R. V.; Wilson, T. L.

    1981-01-01

    Digital unit automates calibration sequence using calculator IC and programmable read-only memory to solve calibration equations. Infrared sensors start and stop calibration sequence. Instrument calibrates mass flowmeters or rotameters where flow measurement is based on mass or volume. This automatic control reduces operator time by 80 percent. Solid-state components are very reliable, and digital character allows system accuracy to be determined primarily by accuracy of transducers.

  13. Impact of Moderate Blast Exposures on Thrombin Biomarkers Assessed by Calibrated Automated Thrombography in Rats

    PubMed Central

    Serebruany, Victor L.; Svetlov, Artem; Hayes, Ronald L.

    2013-01-01

    Abstract Severe blast exposures are frequently complicated with fatal intracranial hemorrhages. However, many more sustain low level blasts without tissue damage detectable by brain imaging. To investigate effects of nonlethal blast on thrombin-related biomarkers, rats were subjected to two different types of head-directed blast: 1) moderate “composite” blast with strong head acceleration or 2) moderate primary blast, without head acceleration. Thrombin generation (TG) ex vivo after blast was studied by calibrated automated thrombography (CAT). In the same blood samples, we assessed maximal concentration of TG (TGmax), start time, peak time, mean time, and concentrations of protein markers for vascular/hemostatic dysfunctions: integrin α/β, soluble endothelial selectin (sE-selectin), soluble intercellular cell adhesion molecule-1 (sICAM-1), and matrix metalloproteinases (MMP)-2, MMP-8, and MMP-13. Blast remarkably affected all TG indices. In animals exposed to “composite” blast, TGmax peaked at 6 h (∼4.5-fold vs. control), sustained at day 1 (∼3.8-fold increase), and declined to a 2-fold increase over control at day 7 post-blast. After primary blast, TGmax also rose to ∼4.2-fold of control at 6 h, dropped to ∼1.7-fold of control at day 1, and then exhibited a slight secondary increase at 2-fold of control at day 7. Other TG indices did not differ significantly between two types of blast exposure. The changes were also observed in other microvascular/inflammatory/hemostatic biomarkers. Integrin α/β and sICAM-1 levels were elevated after both “composite” and primary blast at 6 h, 1 day, and 7 days. sE-selectin exhibited near normal levels after “composite” blast, but increased significantly at 7 days after primary blast; MMP-2, MMP-8, and MMP-13 slightly rose after “composite” blast and significantly increased (∼2-4-fold) after primary blast. In summary, CAT may have a clinical diagnostic utility in combination with selected

  14. Forecasting the impact of an 1859-calibre superstorm on satellite resources

    NASA Astrophysics Data System (ADS)

    Odenwald, Sten; Green, James; Taylor, William

    2006-01-01

    We have developed simple models to assess the economic impacts to the current satellite resource caused by the worst-case scenario of a hypothetical superstorm event occurring during the next sunspot cycle. Although the consequences may be severe, our worse-case scenario does not include the complete failure of the entire 937 operating satellites in the current population, which have a replacement value of ˜170-230 billion, and supporting a ˜90 billion/year industry. Our estimates suggest a potential economic loss of <70 billion for lost revenue (˜44 billion) and satellite replacement for GEO satellites (˜24 billion) caused by a 'once a century' single storm similar to the 1859 superstorm. We estimate that 80 satellites (LEO, MEO, and GEO) may be disabled as a consequence of a superstorm event. Additional impacts may include the failure of many of the GPS, GLONASS, and Galileo satellite systems in MEO. Approximately 97 LEO satellites, which normally would not have re-entered for many decades, may prematurely de-orbit by ca 2021 as a result of the temporarily increased atmospheric drag caused by a superstorm event occurring in ca. 2012. The 100 billion International Space Station may lose significant altitude, placing it in critical need for re-boosting by an amount potentially outside the range of typical Space Shuttle operations, which are in any case scheduled to end in 2010. Currently, the ability to forecast extreme particle events and coronal mass ejections, or predict their fluences and geoseverity in the 24-h prior to the event, appears to be no better than 50/50. Our analysis of economic impacts is a first attempt at estimation whose approach will suggest ways in which better estimates may eventually be obtained.

  15. A model of union participation: the impact of perceived union support, union instrumentality, and union loyalty.

    PubMed

    Tetrick, Lois E; Shore, Lynn M; McClurg, Lucy Newton; Vandenberg, Robert J

    2007-05-01

    Perceived union support and union instrumentality have been shown to uniquely predict union loyalty. This study was the first to explicitly examine the relation between perceived union support and union instrumentality. Surveys were completed by 273 union members and 29 union stewards. A comparison of 2 models, 1 based on organizational support theory and 1 based on union participation theories, found that the model based on organizational support theory, in which union instrumentality was an antecedent to perceived union support and led to union loyalty and subsequently union participation, best fit the data. The model based on union participation theories, in which perceived union support was an antecedent of union instrumentality and led to union loyalty and subsequently union participation, was not supported. Union instrumentality was related to union commitment, but the relation was completely mediated by perceived union support.

  16. NASA 2014 The Hyperspectral Infrared Imager (HyspIRI) - Science Impact of Deploying Instruments on Separate Platforms

    NASA Technical Reports Server (NTRS)

    Turpie, Kevin; Veraverbeke, Sander; Wright, Robert; Anderson, Martha; Prakash, Anupma; Quattrochi, Dale

    2014-01-01

    The Hyperspectral Infrared Imager (HyspIRI) mission was recommended for implementation by the 2007 report from the U.S. National Research Council Earth Science and Applications from Space: National Imperatives for the Next Decade and Beyond, also known as the Earth Science Decadal Survey. The HyspIRI mission is science driven and will address a set of science questions identified by the Decadal Survey and broader science community. The mission includes a visible shortwave infrared (VSWIR) imaging spectrometer, a multispectral thermal infrared (TIR) imager and an intelligent payload module (IPM). The IPM enables on-board processing and direct broadcast for those applications with short latency requirements. The science questions are organized as VSWIR-only, TIR-only and Combined science questions, the latter requiring data from both instruments. In order to prepare for the mission NASA is undertaking pre-phase A studies to determine the optimum mission implementation, in particular, cost and risk reduction activities. Each year the HyspIRI project is provided with feedback from NASA Headquarters on the pre-phase A activities in the form of a guidance letter which outlines the work that should be undertaken the subsequent year. The 2013 guidance letter included a recommendation to undertake a study to determine the science impact of deploying the instruments from separate spacecraft in sun synchronous orbits with various time separations and deploying both instruments on the International Space Station (ISS). This report summarizes the results from that study. The approach taken was to evaluate the impact on the combined science questions of time separations between the VSWIR and TIR data of <3 minutes, <1 week and a few months as well as deploying both instruments on the ISS. Note the impact was only evaluated for the combined science questions which require data from both instruments (VSWIR and TIR). The study concluded the impact of a separation of <3 minutes was

  17. Update of the Photometric Calibration of the LASCO-C2 Coronagraph Using Stars

    NASA Astrophysics Data System (ADS)

    Colaninno, Robin; Howard, Russell

    2015-04-01

    We present an update to the photometric calibration of the LASCO-C2 coronagraph onboard the SOHO spacecraft. We obtained the new calibration using data from the beginning of the mission in 1996 until 2013. We re-examined the LASCO-C2 photometric calibration by comparing the past three calibrations and the present calibration with the goal of validating an in-flight calibration. We find a photometric calibration factor (PCF) that is very similar to the factor recently published in Gardès, Lamy, and Llebaria (Solar Phys. 283, 667, 2013), which calculated a calibration between 1996 and 2009. The average of our PCF between 1999 and 2009 is the same, within our margin of error, as the average given by Gardès, Lamy, and Llebaria (Solar Phys. 283, 667, 2013) during the same time period. However, we find a different evolution of the calibration over the lifetime of the LASCO-C2 instrument compared with past results. We find that the sensitivity of the instrument is decreasing by a constant 0.20 [±0.03] % per year. We also find no significant difference in the signal degradation before and after the SOHO interruption. We discuss the effects of this new PCF on the calibrated data set and the potential impact on scientific results derived from the previous calibration.

  18. Update of the Photometric Calibration of the LASCO-C2 Coronagraph Using Stars

    NASA Astrophysics Data System (ADS)

    Colaninno, R. C.; Howard, R. A.

    2015-03-01

    We present an update to the photometric calibration of the LASCO-C2 coronagraph onboard the SOHO spacecraft. We obtained the new calibration using data from the beginning of the mission in 1996 until 2013. We re-examined the LASCO-C2 photometric calibration by comparing the past three calibrations and the present calibration with the goal of validating an in-flight calibration. We find a photometric calibration factor (PCF) that is very similar to the factor recently published in Gardès, Lamy, and Llebaria ( Solar Phys. 283, 667, 2013), which calculated a calibration between 1996 and 2009. The average of our PCF between 1999 and 2009 is the same, within our margin of error, as the average given by Gardès, Lamy, and Llebaria ( Solar Phys. 283, 667, 2013) during the same time period. However, we find a different evolution of the calibration over the lifetime of the LASCO-C2 instrument compared with past results. We find that the sensitivity of the instrument is decreasing by a constant 0.20 [±0.03] % per year. We also find no significant difference in the signal degradation before and after the SOHO interruption. We discuss the effects of this new PCF on the calibrated data set and the potential impact on scientific results derived from the previous calibration.

  19. Update of the Photometric Calibration of the LASCO-C2 Coronagraph Using Stars.

    PubMed

    Colaninno, R C; Howard, R A

    We present an update to the photometric calibration of the LASCO-C2 coronagraph onboard the SOHO spacecraft. We obtained the new calibration using data from the beginning of the mission in 1996 until 2013. We re-examined the LASCO-C2 photometric calibration by comparing the past three calibrations and the present calibration with the goal of validating an in-flight calibration. We find a photometric calibration factor (PCF) that is very similar to the factor recently published in Gardès, Lamy, and Llebaria (Solar Phys.283, 667, 2013), which calculated a calibration between 1996 and 2009. The average of our PCF between 1999 and 2009 is the same, within our margin of error, as the average given by Gardès, Lamy, and Llebaria (Solar Phys.283, 667, 2013) during the same time period. However, we find a different evolution of the calibration over the lifetime of the LASCO-C2 instrument compared with past results. We find that the sensitivity of the instrument is decreasing by a constant 0.20 [±0.03] % per year. We also find no significant difference in the signal degradation before and after the SOHO interruption. We discuss the effects of this new PCF on the calibrated data set and the potential impact on scientific results derived from the previous calibration.

  20. On-Orbit Performance of MODIS On-Board Calibrators

    NASA Technical Reports Server (NTRS)

    Xiong, X.; Che, N.; Chiang, K.; Esposito, J.; Barnes, William; Guenther, B.; Zukor, Dorothy J. (Technical Monitor)

    2001-01-01

    The Terra MODIS (Moderate Resolution Imaging Spectroradiometer) was launched on December 18, 1999 and acquired the first scene data on February 24, 2000. It has 36 spectral bands covering spectral range from 0.41 to 14.2 microns and provides spatial resolutions of 250 (2 bands), 500 (5 bands), and 1000 m at Nadir. The instrument on-orbit calibration and characterization are determined and monitored through the use of a number of on-board calibrators (OBC). Radiometric calibration for the reflective solar bands (B1-B19, B26), from VIS (visible) to SWIR (short wavelength infrared) (0.41 to 2.1 microns), uses a Spectralon (tm) solar diffuser (SD) and a solar diffuser stability monitor (SDSM). For the thermal emissive bands (B20-B25, B27-B36), from MWIR (medium wavelength infrared) to LWIR (long wavelength infrared) (3.75 to 14.2 micron), a V-grooved flat panel blackbody is used. The instrument spectral for the VIS to SWIR bands and spatial co-registration characterizations for all bands are monitored on-orbit by the spectral radiometric calibration assembly (SRCA). In this report, we discuss the application and performance of the key MODIS on-board calibrators and their impacts on the instrument system calibration and characterization.

  1. Forecasting the Impact of an 1859-calibre Superstorm on Satellite Resources

    NASA Technical Reports Server (NTRS)

    Odenwald, Sten; Green, James; Taylor, William

    2005-01-01

    We have assembled a database of operational satellites in orbit as of 2004, and have developed a series of simple models to assess the economic impacts to this resource caused by various scenarios of superstorm events possible during the next sunspot cycle between 2010 and 2014. Despite the apparent robustness of our satellite assets against the kinds of storms we have encountered during the satellite era, our models suggest a potential economic loss exceeding $10(exp 11) for satellite replacement and lost profitability caused by a once a century single storm similar to the 1859 superstorm. From a combination of power system and attitude control system (the most vulnerable) failures, we estimate that 80 satellites (LEO, MEO, GEO) may be disabled as a consequence of a superstorm event. Additional consequences may include the failure of many of the GPS, GLONASS and Galileo satellite systems in MEO. Approximately 98 LEO satellites that normally would not have re-entered for many decades, may prematurely de-orbit in ca 2021 as a result of the temporarily increased atmospheric drag caused by the superstorm event occurring in 2012. The $10(exp 11) International Space Station may lose at least 15 kilometers of altitude, placing it in critical need for re-boosting by an amount that is potentially outside the range of typical Space Shuttle operations during the previous solar maximum in ca 2000, and at a time when NASA plans to decommission the Space Shuttle. Several LEO satellites will unexpectedly be placed on orbits that enter the ISS zone of avoidance, requiring some action by ground personnel and ISS astronauts to avoid close encounters. Radiation effects on astronauts have also been considered and could include a range of possibilities from acute radiation sickness for astronauts inside spacecraft, to near-lethal doses during EVAs. The specifics depends very sensitively on the spectral hardness of the accompanying SPE event. Currently, the ability to forecast extreme

  2. Design and Lessons Learned on the Development of a Cryogenic Pupil Select Mechanism used in the Testing and Calibration of the Integrated Science Instrument Module (ISIM) on the James Webb Space Telescope (JWST)

    NASA Technical Reports Server (NTRS)

    Mitchell, Alissa; Capon, Thomas; Guzek, Jeffrey; Hakun, Claef; Haney, Paul; Koca, Corina

    2014-01-01

    Calibration and testing of the instruments on the Integrated Science Instrument Module (ISIM) of the James Webb Space Telescope (JWST) is being performed by the use of a cryogenic, full-field, optical simulator that was constructed for this purpose. The Pupil Select Mechanism (PSM) assembly is one of several mechanisms and optical elements that compose the Optical Telescope Element SIMulator, or OSIM. The PSM allows for several optical elements to be inserted into the optical plane of OSIM, introducing a variety of aberrations, distortions, obscurations, and other calibration states into the pupil plane. The following discussion focuses on the details of the design evolution, analysis, build, and test of this mechanism along with the challenges associated with creating a sub arc-minute positioning mechanism operating in an extreme cryogenic environment. In addition, difficult challenges in the control system design will be discussed including the incorporation of closed-loop feedback control into a system that was designed to operate in an open-loop fashion.

  3. Design and Lessons Learned on the Development of a Cryogenic Pupil Select Mechanism Used in the Testing and Calibration of the Integrated Science Instrument Module (ISIM) on the James Webb Space Telescope (JWST)

    NASA Technical Reports Server (NTRS)

    Mitchell, Alissa; Capon, Thomas; Guzek, Jeffrey; Hakun, Claef; Haney, Paul; Koca, Corina

    2014-01-01

    Calibration and testing of the instruments on the Integrated Science Instrument Module (ISIM) of the James Webb Space Telescope (JWST) is being performed by the use of a cryogenic, full-field, optical simulator that was constructed for this purpose. The Pupil Select Mechanism (PSM) assembly is one of several mechanisms and optical elements that compose the Optical Telescope Element SIMulator, or OSIM. The PSM allows for several optical elements to be inserted into the optical plane of OSIM, introducing a variety of aberrations, distortions, obscurations, and other calibration states into the pupil plane. The following discussion focuses on the details of the design evolution, analysis, build, and test of this mechanism along with the challenges associated with creating a sub arc-minute positioning mechanism operating in an extreme cryogenic environment. In addition, difficult challenges in the control system design will be discussed including the incorporation of closed-loop feedback control into a system that was designed to operate in an open-loop fashion.

  4. A Review of Sensor Calibration Monitoring for Calibration Interval Extension in Nuclear Power Plants

    SciTech Connect

    Coble, Jamie B.; Meyer, Ryan M.; Ramuhalli, Pradeep; Bond, Leonard J.; Hashemian, Hash; Shumaker, Brent; Cummins, Dara

    2012-08-31

    Currently in the United States, periodic sensor recalibration is required for all safety-related sensors, typically occurring at every refueling outage, and it has emerged as a critical path item for shortening outage duration in some plants. Online monitoring can be employed to identify those sensors that require calibration, allowing for calibration of only those sensors that need it. International application of calibration monitoring, such as at the Sizewell B plant in United Kingdom, has shown that sensors may operate for eight years, or longer, within calibration tolerances. This issue is expected to also be important as the United States looks to the next generation of reactor designs (such as small modular reactors and advanced concepts), given the anticipated longer refueling cycles, proposed advanced sensors, and digital instrumentation and control systems. The U.S. Nuclear Regulatory Commission (NRC) accepted the general concept of online monitoring for sensor calibration monitoring in 2000, but no U.S. plants have been granted the necessary license amendment to apply it. This report presents a state-of-the-art assessment of online calibration monitoring in the nuclear power industry, including sensors, calibration practice, and online monitoring algorithms. This assessment identifies key research needs and gaps that prohibit integration of the NRC-approved online calibration monitoring system in the U.S. nuclear industry. Several needs are identified, including the quantification of uncertainty in online calibration assessment; accurate determination of calibration acceptance criteria and quantification of the effect of acceptance criteria variability on system performance; and assessment of the feasibility of using virtual sensor estimates to replace identified faulty sensors in order to extend operation to the next convenient maintenance opportunity. Understanding the degradation of sensors and the impact of this degradation on signals is key to

  5. Compact radiometric microwave calibrator

    SciTech Connect

    Fixsen, D. J.; Wollack, E. J.; Kogut, A.; Limon, M.; Mirel, P.; Singal, J.; Fixsen, S. M.

    2006-06-15

    The calibration methods for the ARCADE II instrument are described and the accuracy estimated. The Steelcast coated aluminum cones which comprise the calibrator have a low reflection while maintaining 94% of the absorber volume within 5 mK of the base temperature (modeled). The calibrator demonstrates an absorber with the active part less than one wavelength thick and only marginally larger than the mouth of the largest horn and yet black (less than -40 dB or 0.01% reflection) over five octaves in frequency.

  6. Lidar Calibration Centre

    NASA Astrophysics Data System (ADS)

    Pappalardo, Gelsomina; Freudenthaler, Volker; Nicolae, Doina; Mona, Lucia; Belegante, Livio; D'Amico, Giuseppe

    2016-06-01

    This paper presents the newly established Lidar Calibration Centre, a distributed infrastructure in Europe, whose goal is to offer services for complete characterization and calibration of lidars and ceilometers. Mobile reference lidars, laboratories for testing and characterization of optics and electronics, facilities for inspection and debugging of instruments, as well as for training in good practices are open to users from the scientific community, operational services and private sector. The Lidar Calibration Centre offers support for trans-national access through the EC HORIZON2020 project ACTRIS-2.

  7. Impact of Instrumented Spinal Fusion on the Development of Vertebral Compression Fracture

    PubMed Central

    Chiu, Yen-Chun; Tsai, Tsung-Ting; Yang, Shih-Chieh; Chen, Hung-Shu; Kao, Yu-Hsien; Tu, Yuan-Kun

    2016-01-01

    Abstract Instrumented spinal fusion has become one of the most common surgeries for patients with various spinal disorders. Only few studies have reported subsequent vertebral compression fractures (VCFs) after instrumented spinal fusion. The purpose of this study was to evaluate the risk of new VCFs in patients undergoing instrumented spinal fusion. We obtained claims data from the National Health Insurance Research Database of Taiwan and retrospectively reviewed 6949 patients with instrumented spinal fusion as the spinal fusion cohort. Control subjects were individually matched at a ratio of 10:1 with those of the spinal fusion cohort according to age, sex, and the index day. Comorbidities were classified as those existing before the index day, and these included diabetes mellitus, hypertension, osteoporosis, and cerebrovascular accident. The end of the follow-up period for the analyses was marked on the day new VCFs developed, enrolment in the National Health Insurance was terminated, on the day of death, or until the end of 2012. We used the Cox proportion hazards model to analyze the hazard ratio (HR) for developing new VCFs. Patients with instrumented spinal fusion were significantly more likely to develop new VCFs (1.87% vs .25%, HR: 8.56; P < 0.001). Female, elderly, and osteoporotic patients had a high incidence of new VCFs after spinal fusion. The HR for developing new VCFs after instrumented spinal fusion was higher in patients younger than 65 years than in those 65 years or older (HR: 10.61 vs 8.09). Male patients with instrumented spinal fusion also had a higher HR of developing new VCFs than female patients (men, HR: 26.42; women, HR: 7.53). In our retrospective cohort study, patients who had undergone instrumented spinal fusion surgery exhibited an increased risk of developing new VCFs. Particularly, the HR increased in young (age <65 years) and male patients. PMID:27124040

  8. Calibration of the Malvern particle sizer

    NASA Technical Reports Server (NTRS)

    Dodge, L. G.

    1984-01-01

    A relatively simple technique has been developed to calibrate particle- and droplet-sizing instruments manufactured by Malvern and other similar Fraunhofer diffraction particle-sizing instruments. Measurements of standard reticles using an instrument calibrated in this manner demonstrate the effectiveness of the procedure. In addition, guidelines are presented to avoid errors due to vignetting of the scattered light signal.

  9. Life History Traits and Niche Instability Impact Accuracy and Temporal Transferability for Historically Calibrated Distribution Models of North American Birds

    PubMed Central

    Wogan, Guinevere O. U.

    2016-01-01

    A primary assumption of environmental niche models (ENMs) is that models are both accurate and transferable across geography or time; however, recent work has shown that models may be accurate but not highly transferable. While some of this is due to modeling technique, individual species ecologies may also underlie this phenomenon. Life history traits certainly influence the accuracy of predictive ENMs, but their impact on model transferability is less understood. This study investigated how life history traits influence the predictive accuracy and transferability of ENMs using historically calibrated models for birds. In this study I used historical occurrence and climate data (1950-1990s) to build models for a sample of birds, and then projected them forward to the ‘future’ (1960-1990s). The models were then validated against models generated from occurrence data at that ‘future’ time. Internal and external validation metrics, as well as metrics assessing transferability, and Generalized Linear Models were used to identify life history traits that were significant predictors of accuracy and transferability. This study found that the predictive ability of ENMs differs with regard to life history characteristics such as range, migration, and habitat, and that the rarity versus commonness of a species affects the predicted stability and overlap and hence the transferability of projected models. Projected ENMs with both high accuracy and transferability scores, still sometimes suffered from over- or under- predicted species ranges. Life history traits certainly influenced the accuracy of predictive ENMs for birds, but while aspects of geographic range impact model transferability, the mechanisms underlying this are less understood. PMID:26959979

  10. Improvements of VIIRS and MODIS Solar Diffuser and Lunar Calibration

    NASA Technical Reports Server (NTRS)

    Xiong, Xiaoxiong; Butler, James J.; Lei, Ning; Sun, Junqiang; Fulbright, Jon; Wang, Zhipeng; McIntire, Jeff; Angal, Amit Avinash

    2013-01-01

    Both VIIRS and MODIS instruments use solar diffuser (SD) and lunar observations to calibrate their reflective solar bands (RSB). A solar diffuser stability monitor (SDSM) is used to track the SD on-orbit degradation. On-orbit observations have shown similar wavelength-dependent SD degradation (larger at shorter VIS wavelengths) and SDSM detector response degradation (larger at longer NIR wavelengths) for both VIIRS and MODIS instruments. In general, the MODIS scan mirror has experienced more degradation in the VIS spectral region whereas the VIIRS rotating telescope assembly (RTA) mirrors have seen more degradation in the NIR and SWIR spectral region. Because of this wavelength dependent mirror degradation, the sensor's relative spectral response (RSR) needs to be modulated. Due to differences between the solar and lunar spectral irradiance, the modulated RSR could have different effects on the SD and lunar calibration. In this paper, we identify various factors that should be considered for the improvements of VIIRS and MODIS solar and lunar calibration and examine their potential impact. Specifically, we will characterize and assess the calibration impact due to SD and SDSM attenuation screen transmission (uncertainty), SD BRF uncertainty and onorbit degradation, SDSM detector response degradation, and modulated RSR resulting from the sensor's optics degradation. Also illustrated and discussed in this paper are the calibration strategies implemented in the VIIRS and MODIS SD and lunar calibrations and efforts that could be made for future improvements.

  11. Fiber-matrix integrity, micromorphology and flexural strength of glass fiber posts: Evaluation of the impact of rotary instruments.

    PubMed

    Pereira, Gabriel Kalil Rocha; Lançanova, Mateus; Wandscher, Vinicius Felipe; Kaizer, Osvaldo Bazzan; Limberger, Inácio; Özcan, Mutlu; Valandro, Luiz Felipe

    2015-08-01

    Several rotary instruments have been daily employed on clinic to promote cut aiming to adjust the length of fiber posts to the radicular conduct, but there is no information on the literature about the effects of the different rotary instruments and its impact on the micromorphology of surface and mechanical properties of the glass fiber post. This study aimed the impact of rotary instruments upon fiber-matrix integrity, micromorphology and flexural-strength of glass-fiber posts (GFP). GFP (N=110) were divided into 5 groups: Ctrl: as-received posts, DBc: coarse diamond-bur, DBff: extra-fine diamond-bur, CB: carbide-bur, DD: diamond-disc. Cutting procedures were performed under abundant irrigation. Posts exposed to rotary instruments were then subjected to 2-point inclined loading test (compression 45°) (n=10/group) and 3-point flexural-strength test (n=10/group). Fiber-matrix integrity and micromorphology at the cut surface were analyzed using a SEM (n=2/group). Cutting procedures did not significantly affect the 2-point (51.7±4.3-56.7±5.1 MPa) (p=0.0233) and 3-point flexural-strength (671.5±35.3-709.1±33.1 MPa) (p=0.0968) of the posts (One-way ANOVA and Tukey׳s test). Fiber detachment was observed only at the end point of the cut at the margins of the post. Cut surfaces of the CB group were smoother than those of the other groups. After 3-point flexural strength test, fiber-matrix separation was evident at the tensile side of the post. Rotary instruments tested with simultaneous water-cooling did not affect the resistance of the tested fiber posts but caused disintegration of the fibers from the matrix at the end of the cut, located at the margins.

  12. Calibration Monitor for Dark Energy Experiments

    SciTech Connect

    Kaiser, M. E.

    2009-11-23

    The goal of this program was to design, build, test, and characterize a flight qualified calibration source and monitor for a Dark Energy related experiment: ACCESS - 'Absolute Color Calibration Experiment for Standard Stars'. This calibration source, the On-board Calibration Monitor (OCM), is a key component of our ACCESS spectrophotometric calibration program. The OCM will be flown as part of the ACCESS sub-orbital rocket payload in addition to monitoring instrument sensitivity on the ground. The objective of the OCM is to minimize systematic errors associated with any potential changes in the ACCESS instrument sensitivity. Importantly, the OCM will be used to monitor instrument sensitivity immediately after astronomical observations while the instrument payload is parachuting to the ground. Through monitoring, we can detect, track, characterize, and thus correct for any changes in instrument senstivity over the proposed 5-year duration of the assembled and calibrated instrument.

  13. Low-cost sensors and crowd-sourced data: Observations of siting impacts on a network of air-quality instruments.

    PubMed

    Miskell, Georgia; Salmond, Jennifer; Williams, David E

    2017-01-01

    Low-cost sensors offer the possibility of gathering high temporal and spatial resolution crowd-sourced data-sets that have the potential to revolutionize the ways in which we understand individual and population exposure to air pollution. However, one of the challenges associated with crowd-sourced data ('citizen science'), often from low-cost sensors, is that citizens may use sites strongly affected by local conditions, limiting the wider significance of the data. This paper examines results from a low-cost network measuring ground-level ozone to evaluate the impact of siting on data quality. Locations at both reference stations and at private homes or research centers were used, and thought of as a typical 'crowd-sourced' network. Two instruments were co-located at each site to determine intra-site variability and evaluated by standard performance statistics and local-scale activity logs. The wider application of the data for both regional Inter-site variability was evaluated to show-case the wider value and usefulness of crowd-sourced data. Analysis of intra-site variability showed little differences at most sites (<5ppb). Large differences in intra-site variability were detected when sensors were exposed to direct sunlight (causing thermal variations within the instrument) and proximity to large emission sources. Short-term local activities, such as lawn-mowing, were identifiable in the data, but had minimal impact on standard reporting time-scales, and so did not pose as being significant limitations or errors. Inter-site evaluation demonstrated that dense networks of low-cost sensors can add value to existing networks, with minimal impact on the overall data-set quality. Sensors located in crowd-sourced locations nearby to regulatory analyzers were able to capture similar trends and concentrations, supporting their ability to report on wider conditions. Thus crowd-sourced approaches to monitoring (with suitable calibration and data quality control checks) may

  14. Calibrating Single-Ended Fiber-Optic Raman Spectra Distributed Temperature Sensing Data

    PubMed Central

    Hausner, Mark B.; Suárez, Francisco; Glander, Kenneth E.; van de Giesen, Nick; Selker, John S.; Tyler, Scott W.

    2011-01-01

    Hydrologic research is a very demanding application of fiber-optic distributed temperature sensing (DTS) in terms of precision, accuracy and calibration. The physics behind the most frequently used DTS instruments are considered as they apply to four calibration methods for single-ended DTS installations. The new methods presented are more accurate than the instrument-calibrated data, achieving accuracies on the order of tenths of a degree root mean square error (RMSE) and mean bias. Effects of localized non-uniformities that violate the assumptions of single-ended calibration data are explored and quantified. Experimental design considerations such as selection of integration times or selection of the length of the reference sections are discussed, and the impacts of these considerations on calibrated temperatures are explored in two case studies. PMID:22346676

  15. 13. VIEW FROM COLD CALIBRATION BLOCKHOUSE LOOKING DOWN CONNECTING TUNNEL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. VIEW FROM COLD CALIBRATION BLOCKHOUSE LOOKING DOWN CONNECTING TUNNEL TO COLD CALIBRATION TEST STAND BASEMENT, SHOWING HARD WIRE CONNECTION (INSTRUMENTATION AND CONTROL). - Marshall Space Flight Center, East Test Area, Cold Calibration Test Stand, Huntsville, Madison County, AL

  16. VIIRS On-Orbit Calibration for Ocean Color Data Processing

    NASA Technical Reports Server (NTRS)

    Eplee, Robert E., Jr.; Turpie, Kevin R.; Fireman, Gwyn F.; Meister, Gerhard; Stone, Thomas C.; Patt, Frederick S.; Franz, Bryan; Bailey, Sean W.; Robinson, Wayne D.; McClain, Charles R.

    2012-01-01

    The NASA VIIRS Ocean Science Team (VOST) has the task of evaluating Suomi NPP VIIRS ocean color data for the continuity of the NASA ocean color climate data records. The generation of science quality ocean color data products requires an instrument calibration that is stable over time. Since the VIIRS NIR Degradation Anomaly directly impacts the bands used for atmospheric correction of the ocean color data (Bands M6 and M7), the VOST has adapted the VIIRS on-orbit calibration approach to meet the ocean science requirements. The solar diffuser calibration time series and the solar diffuser stability monitor time series have been used to derive changes in the instrument response and diffuser reflectance over time for bands M1-M11.

  17. 10 years of MS instrumental developments--impact on LC-MS/MS in clinical chemistry.

    PubMed

    Himmelsbach, Markus

    2012-02-01

    The combination of liquid chromatography and mass spectrometry (LC-MS) is a powerful and indispensable analytical tool that is widely applied in many areas of chemistry, medicine, pharmaceutics and biochemistry. In this review recent MS instrumental developments are presented as part of a special issue covering various aspects of liquid chromatography tandem mass spectrometry (LC-MS/MS) in clinical chemistry. Improvements, new inventions as well as new combinations in ion source technology are described focusing on dual or multimode sources and atmospheric pressure photoionization (APPI). Increasing demands regarding sensitivity, accuracy, resolution and both quantitation and identification guarantee on-going improvements in mass analyzer technology. This paper discusses new hybrid MS instruments that can perform novel scan modes as well as high-resolution mass spectrometers (HRMS) that finally seem to be able to overcome, or at least significantly reduce, their weaknesses in quantitative applications. Ion mobility-mass spectrometry (IMMS) itself is not an invention of the last 10 years, but a lot of progress was made within the last decade that reveals the potential benefits of this combination. This is clearly reflected by the increased number of commercially available instruments and the various designs of IMMS are covered in detail in this review. Selected applications for all these instrumental developments are given focusing on the perspective of clinical chemistry.

  18. Calibrating Communication Competencies

    NASA Astrophysics Data System (ADS)

    Surges Tatum, Donna

    2016-11-01

    The Many-faceted Rasch measurement model is used in the creation of a diagnostic instrument by which communication competencies can be calibrated, the severity of observers/raters can be determined, the ability of speakers measured, and comparisons made between various groups.

  19. Data reduction of digitized images processed from calibrated photographic and spectroscopic films obtained from terrestial, rocket and space shuttle telescopic instruments

    NASA Technical Reports Server (NTRS)

    Hammond, Ernest C., Jr.

    1990-01-01

    The Microvax 2 computer, the basic software in VMS, and the Mitsubishi High Speed Disk were received and installed. The digital scanning tunneling microscope is fully installed and operational. A new technique was developed for pseudocolor analysis of the line plot images of a scanning tunneling microscope. Computer studies and mathematical modeling of the empirical data associated with many of the film calibration studies were presented. A gas can follow-up experiment which will be launched in September, on the Space Shuttle STS-50, was prepared and loaded. Papers were presented on the structure of the human hair strand using scanning electron microscopy and x ray analysis and updated research on the annual rings produced by the surf clam of the ocean estuaries of Maryland. Scanning electron microscopic work was conducted by the research team for the study of the Mossbauer and Magnetic Susceptibility Studies on NmNi(4.25)Fe(.85) and its Hydride.

  20. The Impact of Scholastic Instrumental Music and Scholastic Chess Study on the Standardized Test Scores of Students in Grades Three, Four, and Five

    ERIC Educational Resources Information Center

    Martinez, Edwin E.

    2012-01-01

    This study examines the impact of instrumental music study and group chess lessons on the standardized test scores of suburban elementary public school students (grades three through five) in Levittown, New York. The study divides the students into the following groups and compares the standardized test scores of each: a) instrumental music…

  1. Calibration of quasi-static aberrations in exoplanet direct-imaging instruments with a Zernike phase-mask sensor. II. Concept validation with ZELDA on VLT/SPHERE

    NASA Astrophysics Data System (ADS)

    N'Diaye, M.; Vigan, A.; Dohlen, K.; Sauvage, J.-F.; Caillat, A.; Costille, A.; Girard, J. H. V.; Beuzit, J.-L.; Fusco, T.; Blanchard, P.; Le Merrer, J.; Le Mignant, D.; Madec, F.; Moreaux, G.; Mouillet, D.; Puget, P.; Zins, G.

    2016-08-01

    Warm or massive gas giant planets, brown dwarfs, and debris disks around nearby stars are now routinely observed by dedicated high-contrast imaging instruments that are mounted on large, ground-based observatories. These facilities include extreme adaptive optics (ExAO) and state-of-the-art coronagraphy to achieve unprecedented sensitivities for exoplanet detection and their spectral characterization. However, low spatial frequency differential aberrations between the ExAO sensing path and the science path represent critical limitations for the detection of giant planets with a contrast lower than a few 10-6 at very small separations (<0.3'') from their host star. In our previous work, we proposed a wavefront sensor based on Zernike phase-contrast methods to circumvent this problem and measure these quasi-static aberrations at a nanometric level. We present the design, manufacturing, and testing of ZELDA, a prototype that was installed on VLT/SPHERE during its reintegration in Chile. Using the internal light source of the instrument, we first performed measurements in the presence of Zernike or Fourier modes introduced with the deformable mirror. Our experimental results are consistent with the results in simulations, confirming the ability of our sensor to measure small aberrations (<50 nm rms) with nanometric accuracy. Following these results, we corrected the long-lived non-common path aberrations in SPHERE based on ZELDA measurements and estimated a contrast gain of 10 in the coronagraphic image at 0.2'', reaching the raw contrast limit set by the coronagraph in the instrument. In addition to this encouraging result, the simplicity of the design and its phase reconstruction algorithm makes ZELDA an excellent candidate for the online measurements of quasi-static aberrations during the observations. The implementation of a ZELDA-based sensing path on the current and future facilities (ELTs, future space missions) could facilitate the observation of cold gaseous

  2. Planck 2015 results. V. LFI calibration

    NASA Astrophysics Data System (ADS)

    Planck Collaboration; Ade, P. A. R.; Aghanim, N.; Ashdown, M.; Aumont, J.; Baccigalupi, C.; Banday, A. J.; Barreiro, R. B.; Bartolo, N.; Battaglia, P.; Battaner, E.; Benabed, K.; Benoît, A.; Benoit-Lévy, A.; Bernard, J.-P.; Bersanelli, M.; Bielewicz, P.; Bock, J. J.; Bonaldi, A.; Bonavera, L.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Bucher, M.; Burigana, C.; Butler, R. C.; Calabrese, E.; Cardoso, J.-F.; Catalano, A.; Chamballu, A.; Christensen, P. R.; Colombi, S.; Colombo, L. P. L.; Crill, B. P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R. D.; Davis, R. J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Dickinson, C.; Diego, J. M.; Dole, H.; Donzelli, S.; Doré, O.; Douspis, M.; Ducout, A.; Dupac, X.; Efstathiou, G.; Elsner, F.; Enßlin, T. A.; Eriksen, H. K.; Fergusson, J.; Finelli, F.; Forni, O.; Frailis, M.; Franceschi, E.; Frejsel, A.; Galeotta, S.; Galli, S.; Ganga, K.; Giard, M.; Giraud-Héraud, Y.; Gjerløw, E.; González-Nuevo, J.; Górski, K. M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Hansen, F. K.; Hanson, D.; Harrison, D. L.; Henrot-Versillé, S.; Herranz, D.; Hildebrandt, S. R.; Hivon, E.; Hobson, M.; Holmes, W. A.; Hornstrup, A.; Hovest, W.; Huffenberger, K. M.; Hurier, G.; Jaffe, A. H.; Jaffe, T. R.; Juvela, M.; Keihänen, E.; Keskitalo, R.; Kisner, T. S.; Knoche, J.; Krachmalnicoff, N.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lähteenmäki, A.; Lamarre, J.-M.; Lasenby, A.; Lattanzi, M.; Lawrence, C. R.; Leahy, J. P.; Leonardi, R.; Lesgourgues, J.; Levrier, F.; Liguori, M.; Lilje, P. B.; Linden-Vørnle, M.; López-Caniego, M.; Lubin, P. M.; Macías-Pérez, J. F.; Maggio, G.; Maino, D.; Mandolesi, N.; Mangilli, A.; Maris, M.; Martin, P. G.; Martínez-González, E.; Masi, S.; Matarrese, S.; McGehee, P.; Meinhold, P. R.; Melchiorri, A.; Mendes, L.; Mennella, A.; Migliaccio, M.; Mitra, S.; Montier, L.; Morgante, G.; Mortlock, D.; Moss, A.; Munshi, D.; Murphy, J. A.; Naselsky, P.; Nati, F.; Natoli, P.; Netterfield, C. B.; Nørgaard-Nielsen, H. U.; Novikov, D.; Novikov, I.; Paci, F.; Pagano, L.; Pajot, F.; Paoletti, D.; Partridge, B.; Pasian, F.; Patanchon, G.; Pearson, T. J.; Peel, M.; Perdereau, O.; Perotto, L.; Perrotta, F.; Pettorino, V.; Piacentini, F.; Pierpaoli, E.; Pietrobon, D.; Pointecouteau, E.; Polenta, G.; Pratt, G. W.; Prézeau, G.; Prunet, S.; Puget, J.-L.; Rachen, J. P.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Renzi, A.; Rocha, G.; Romelli, E.; Rosset, C.; Rossetti, M.; Roudier, G.; Rubiño-Martín, J. A.; Rusholme, B.; Sandri, M.; Santos, D.; Savelainen, M.; Scott, D.; Seiffert, M. D.; Shellard, E. P. S.; Spencer, L. D.; Stolyarov, V.; Sutton, D.; Suur-Uski, A.-S.; Sygnet, J.-F.; Tauber, J. A.; Tavagnacco, D.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Tuovinen, J.; Türler, M.; Umana, G.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Vassallo, T.; Vielva, P.; Villa, F.; Wade, L. A.; Wandelt, B. D.; Watson, R.; Wehus, I. K.; Wilkinson, A.; Yvon, D.; Zacchei, A.; Zonca, A.

    2016-09-01

    We present a description of the pipeline used to calibrate the Planck Low Frequency Instrument (LFI) timelines into thermodynamic temperatures for the Planck 2015 data release, covering four years of uninterrupted operations. As in the 2013 data release, our calibrator is provided by the spin-synchronous modulation of the cosmic microwave background dipole, but we now use the orbital component, rather than adopting the Wilkinson Microwave Anisotropy Probe (WMAP) solar dipole. This allows our 2015 LFI analysis to provide an independent Solar dipole estimate, which is in excellent agreement with that of HFI and within 1σ (0.3% in amplitude) of the WMAP value. This 0.3% shift in the peak-to-peak dipole temperature from WMAP and a general overhaul of the iterative calibration code increases the overall level of the LFI maps by 0.45% (30 GHz), 0.64% (44 GHz), and 0.82% (70 GHz) in temperature with respect to the 2013 Planck data release, thus reducing the discrepancy with the power spectrum measured by WMAP. We estimate that the LFI calibration uncertainty is now at the level of 0.20% for the 70 GHz map, 0.26% for the 44 GHz map, and 0.35% for the 30 GHz map. We provide a detailed description of the impact of all the changes implemented in the calibration since the previous data release.

  3. INSTRUMENTS AND METHODS OF INVESTIGATION: Deep Impact experiment: possible observable effects

    NASA Astrophysics Data System (ADS)

    Klumov, Boris A.; Kim, V. V.; Lomonosov, I. V.; Sultanov, Valerii G.; Shutov, A. V.; Fortov, Vladimir E.

    2005-07-01

    A hypervelocity collision of a metal impactor and the nucleus of the Tempel 1 comet is to be carried out in July 2005 in the framework of the Deep Impact active experiment in space. This paper discusses certain observable consequences of this impact. Numerical simulation of the impact process made it possible to evaluate the diameter of the impact-produced crater as a function of the initial density and porosity of the cometary nucleus. A substantial part of the shockwave-compressed cometary material that is evaporated at the unloading stage may become heated to temperatures on the order of (1-2)×104 K. A change in the chemical composition of the hot vapor in the process of its expansion was computed using a model elemental composition of the cometary nucleus; this may prove useful for determining the parameters of the flash induced by the impact in the visible optical, UV, IR, and radio wavelength bands.

  4. The Impact of Instrument-Specific Musical Training on Rhythm Perception and Production

    PubMed Central

    Matthews, Tomas E.; Thibodeau, Joseph N. L.; Gunther, Brian P.; Penhune, Virginia B.

    2016-01-01

    Studies comparing musicians and non-musicians have shown that musical training can improve rhythmic perception and production. These findings tell us that training can result in rhythm processing advantages, but they do not tell us whether practicing a particular instrument could lead to specific effects on rhythm perception or production. The current study used a battery of four rhythm perception and production tasks that were designed to test both higher- and lower-level aspects of rhythm processing. Four groups of musicians (drummers, singers, pianists, string players) and a control group of non-musicians were tested. Within-task differences in performance showed that factors such as meter, metrical complexity, tempo, and beat phase significantly affected the ability to perceive and synchronize taps to a rhythm or beat. Musicians showed better performance on all rhythm tasks compared to non-musicians. Interestingly, our results revealed no significant differences between musician groups for the vast majority of task measures. This was despite the fact that all musicians were selected to have the majority of their training on the target instrument, had on average more than 10 years of experience on their instrument, and were currently practicing. These results suggest that general musical experience is more important than specialized musical experience with regards to perception and production of rhythms. PMID:26869969

  5. Planck 2013 results. V. LFI calibration

    NASA Astrophysics Data System (ADS)

    Planck Collaboration; Aghanim, N.; Armitage-Caplan, C.; Arnaud, M.; Ashdown, M.; Atrio-Barandela, F.; Aumont, J.; Baccigalupi, C.; Banday, A. J.; Barreiro, R. B.; Battaner, E.; Benabed, K.; Benoît, A.; Benoit-Lévy, A.; Bernard, J.-P.; Bersanelli, M.; Bielewicz, P.; Bobin, J.; Bock, J. J.; Bonaldi, A.; Bonavera, L.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Bridges, M.; Bucher, M.; Burigana, C.; Butler, R. C.; Cappellini, B.; Cardoso, J.-F.; Catalano, A.; Chamballu, A.; Chen, X.; Chiang, L.-Y.; Christensen, P. R.; Church, S.; Colombi, S.; Colombo, L. P. L.; Crill, B. P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R. D.; Davis, R. J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Dickinson, C.; Diego, J. M.; Dole, H.; Donzelli, S.; Doré, O.; Douspis, M.; Dupac, X.; Efstathiou, G.; Enßlin, T. A.; Eriksen, H. K.; Finelli, F.; Forni, O.; Frailis, M.; Franceschi, E.; Gaier, T. C.; Galeotta, S.; Ganga, K.; Giard, M.; Giardino, G.; Giraud-Héraud, Y.; Gjerløw, E.; González-Nuevo, J.; Górski, K. M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Hansen, F. K.; Hanson, D.; Harrison, D.; Henrot-Versillé, S.; Hernández-Monteagudo, C.; Herranz, D.; Hildebrandt, S. R.; Hivon, E.; Hobson, M.; Holmes, W. A.; Hornstrup, A.; Hovest, W.; Huffenberger, K. M.; Jaffe, A. H.; Jaffe, T. R.; Jewell, J.; Jones, W. C.; Juvela, M.; Kangaslahti, P.; Keihänen, E.; Keskitalo, R.; Kisner, T. S.; Knoche, J.; Knox, L.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lähteenmäki, A.; Lamarre, J.-M.; Lasenby, A.; Laureijs, R. J.; Lawrence, C. R.; Leach, S.; Leahy, J. P.; Leonardi, R.; Lesgourgues, J.; Liguori, M.; Lilje, P. B.; Linden-Vørnle, M.; López-Caniego, M.; Lubin, P. M.; Macías-Pérez, J. F.; Maino, D.; Mandolesi, N.; Maris, M.; Marshall, D. J.; Martin, P. G.; Martínez-González, E.; Masi, S.; Massardi, M.; Matarrese, S.; Matthai, F.; Mazzotta, P.; Meinhold, P. R.; Melchiorri, A.; Mendes, L.; Mennella, A.; Migliaccio, M.; Mitra, S.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Moss, A.; Munshi, D.; Naselsky, P.; Natoli, P.; Netterfield, C. B.; Nørgaard-Nielsen, H. U.; Novikov, D.; Novikov, I.; O'Dwyer, I. J.; Osborne, S.; Paci, F.; Pagano, L.; Paladini, R.; Paoletti, D.; Partridge, B.; Pasian, F.; Patanchon, G.; Pearson, D.; Peel, M.; Perdereau, O.; Perotto, L.; Perrotta, F.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Ponthieu, N.; Popa, L.; Poutanen, T.; Pratt, G. W.; Prézeau, G.; Prunet, S.; Puget, J.-L.; Rachen, J. P.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Ricciardi, S.; Riller, T.; Rocha, G.; Rosset, C.; Rossetti, M.; Roudier, G.; Rubiño-Martín, J. A.; Rusholme, B.; Sandri, M.; Santos, D.; Scott, D.; Seiffert, M. D.; Shellard, E. P. S.; Spencer, L. D.; Starck, J.-L.; Stolyarov, V.; Stompor, R.; Sureau, F.; Sutton, D.; Suur-Uski, A.-S.; Sygnet, J.-F.; Tauber, J. A.; Tavagnacco, D.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Tuovinen, J.; Türler, M.; Umana, G.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Varis, J.; Vielva, P.; Villa, F.; Vittorio, N.; Wade, L. A.; Wandelt, B. D.; Watson, R.; Wilkinson, A.; Yvon, D.; Zacchei, A.; Zonca, A.

    2014-11-01

    We discuss the methods employed to photometrically calibrate the data acquired by the Low Frequency Instrument on Planck. Our calibration is based on a combination of the orbital dipole plus the solar dipole, caused respectively by the motion of the Planck spacecraft with respect to the Sun and by motion of the solar system with respect to the cosmic microwave background (CMB) rest frame. The latter provides a signal of a few mK with the same spectrum as the CMB anisotropies and is visible throughout the mission. In this data releasewe rely on the characterization of the solar dipole as measured by WMAP. We also present preliminary results (at 44 GHz only) on the study of the Orbital Dipole, which agree with the WMAP value of the solar system speed within our uncertainties. We compute the calibration constant for each radiometer roughly once per hour, in order to keep track of changes in the detectors' gain. Since non-idealities in the optical response of the beams proved to be important, we implemented a fast convolution algorithm which considers the full beam response in estimating the signal generated by the dipole. Moreover, in order to further reduce the impact of residual systematics due to sidelobes, we estimated time variations in the calibration constant of the 30 GHz radiometers (the ones with the largest sidelobes) using the signal of an internal reference load at 4 K instead of the CMB dipole. We have estimated the accuracy of the LFI calibration following two strategies: (1) we have run a set of simulations to assess the impact of statistical errors and systematic effects in the instrument and in the calibration procedure; and (2) we have performed a number of internal consistency checks on the data and on the brightness temperature of Jupiter. Errors in the calibration of this Planck/LFI data release are expected to be about 0.6% at 44 and 70 GHz, and 0.8% at 30 GHz. Both these preliminary results at low and high ℓ are consistent with WMAP results

  6. Improved absolute calibration of LOPES measurements and its impact on the comparison with REAS 3.11 and CoREAS simulations

    NASA Astrophysics Data System (ADS)

    Apel, W. D.; Arteaga-Velázquez, J. C.; Bähren, L.; Bekk, K.; Bertaina, M.; Biermann, P. L.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Cantoni, E.; Chiavassa, A.; Daumiller, K.; de Souza, V.; Di Pierro, F.; Doll, P.; Engel, R.; Falcke, H.; Fuchs, B.; Gemmeke, H.; Grupen, C.; Haungs, A.; Heck, D.; Hiller, R.; Hörandel, J. R.; Horneffer, A.; Huber, D.; Huege, T.; Isar, P. G.; Kampert, K.-H.; Kang, D.; Krömer, O.; Kuijpers, J.; Link, K.; Łuczak, P.; Ludwig, M.; Mathes, H. J.; Melissas, M.; Morello, C.; Nehls, S.; Oehlschläger, J.; Palmieri, N.; Pierog, T.; Rautenberg, J.; Rebel, H.; Roth, M.; Rühle, C.; Saftoiu, A.; Schieler, H.; Schmidt, A.; Schoo, S.; Schröder, F. G.; Sima, O.; Toma, G.; Trinchero, G. C.; Weindl, A.; Wochele, J.; Zabierowski, J.; Zensus, J. A.

    2016-02-01

    LOPES was a digital antenna array detecting the radio emission of cosmic-ray air showers. The calibration of the absolute amplitude scale of the measurements was done using an external, commercial reference source, which emits a frequency comb with defined amplitudes. Recently, we obtained improved reference values by the manufacturer of the reference source, which significantly changed the absolute calibration of LOPES. We reanalyzed previously published LOPES measurements, studying the impact of the changed calibration. The main effect is an overall decrease of the LOPES amplitude scale by a factor of 2.6 ± 0.2, affecting all previously published values for measurements of the electric-field strength. This results in a major change in the conclusion of the paper 'Comparing LOPES measurements of air-shower radio emission with REAS 3.11 and CoREAS simulations' published by Apel et al. (2013) : With the revised calibration, LOPES measurements now are compatible with CoREAS simulations, but in tension with REAS 3.11 simulations. Since CoREAS is the latest version of the simulation code incorporating the current state of knowledge on the radio emission of air showers, this new result indicates that the absolute amplitude prediction of current simulations now is in agreement with experimental data.

  7. Instrument calibration and measurement plan for the poorly measured/unmeasured category of highly enriched uranium at Lawrence Livermore National Laboratory

    SciTech Connect

    Glosup, J; Mount, M E

    1999-07-01

    In partial response to a Department of Energy (DOE) request to evaluate the state of measurements of special nuclear material, Lawrence Livermore National Laboratory (LLNL) evaluated and classified all highly enriched uranium (HEU) metal and oxide items in its inventory. Because of a lack of traceable HEU standards, no items were deemed to fit the category of well measured. A subsequent DOE-HQ sponsored survey by New Brunswick Laboratory resulted in their preparation of a set of certified reference material (CRM) standards for HEU oxide (U{sub 3}O{sub 8}) that are projected for delivery during September of 1999. However, CRM standards for HEU metal are neither in preparation nor are they expected to be prepared within the foreseeable future. Consequently, HEU metal working standards must be developed if the poorly measured/unmeasured portion of the LLNL inventory is to be reclassified. This paper describes the approach that LLNL will take to (1) develop a set of HEU metal working standards; (2) develop HEU metal and oxide calibration curves for the passive-active neutron (PAN) shuffler that are functions of mass, enrichment, size, and shape; and (3) reclassify the poorly measured/unmeasured inventory through direct measurement or reprocessing of previously archived data.

  8. Scan pointing calibration for the Mariner Mars 1971 spacecraft

    NASA Technical Reports Server (NTRS)

    Havens, W. F.; Jaivin, G. I.; Pace, G. D.; Virzi, R. A.

    1972-01-01

    The methods used to calibrate the pointing direction of the Mars 71 spacecraft scan platform are described. Accurate calibration was required to meet the pointing accuracy requirements of the scientific instruments mounted on the platform. A detailed ground calibration was combined with an in-flight calibration utilizing narrow angle television pictures of stars. Results of these calibrations are summarized.

  9. Impact of Passive Safety on FHR Instrumentation Systems Design and Classification

    SciTech Connect

    Holcomb, David Eugene

    2015-01-01

    Fluoride salt-cooled high-temperature reactors (FHRs) will rely more extensively on passive safety than earlier reactor classes. 10CFR50 Appendix A, General Design Criteria for Nuclear Power Plants, establishes minimum design requirements to provide reasonable assurance of adequate safety. 10CFR50.69, Risk-Informed Categorization and Treatment of Structures, Systems and Components for Nuclear Power Reactors, provides guidance on how the safety significance of systems, structures, and components (SSCs) should be reflected in their regulatory treatment. The Nuclear Energy Institute (NEI) has provided 10 CFR 50.69 SSC Categorization Guideline (NEI-00-04) that factors in probabilistic risk assessment (PRA) model insights, as well as deterministic insights, through an integrated decision-making panel. Employing the PRA to inform deterministic requirements enables an appropriately balanced, technically sound categorization to be established. No FHR currently has an adequate PRA or set of design basis accidents to enable establishing the safety classification of its SSCs. While all SSCs used to comply with the general design criteria (GDCs) will be safety related, the intent is to limit the instrumentation risk significance through effective design and reliance on inherent passive safety characteristics. For example, FHRs have no safety-significant temperature threshold phenomena, thus enabling the primary and reserve reactivity control systems required by GDC 26 to be passively, thermally triggered at temperatures well below those for which core or primary coolant boundary damage would occur. Moreover, the passive thermal triggering of the primary and reserve shutdown systems may relegate the control rod drive motors to the control system, substantially decreasing the amount of safety-significant wiring needed. Similarly, FHR decay heat removal systems are intended to be running continuously to minimize the amount of safety-significant instrumentation needed to initiate

  10. Impact of optical distortions on fiber positioning in the dark energy spectroscopic instrument

    NASA Astrophysics Data System (ADS)

    Kent, Stephen; Lampton, Michael; Doel, A. Peter; Brooks, David; Miller, Tim; Besuner, Robert; Silber, Joe; Liang, Ming; Sprayberry, David; Baltay, Charles; Rabinowitz, David

    2016-08-01

    The Dark Energy Spectroscopic Instrument, to be located at the prime focus of the Mayall telescope, includes a wide field corrector, a 5000 fiber positioner system, and a fiber view camera. The mapping of the sky to the focal plane, needed to position the fibers accurately, is described in detail. A major challenge is dealing with the large amount of distortion introduced by the optics (of order 10% scale change), including time-dependent non-axisymmetric distortions introduced by the atmospheric dispersion compensator. Solutions are presented to measure or mitigate these effects.

  11. Impact of Distortions on Fiber Position Location in the dark Energy Spectroscopic Instrument

    SciTech Connect

    Kent, Stephen; Lampton, Michael; Doel, A. Peter; Brooks, David; Miller, Tim; Besuner, Robert; Silber, Joe; Liang, Ming; Sprayberry, David; Baltay, Charles; Rabinowitz, David

    2016-01-01

    The Dark Energy Spectroscopic Instrument, to be located at the prime focus of the Mayall telescope, includes a wide field corrector, a 5000 fiber positioner system, and a fiber view camera. The mapping of the sky to the focal plane, needed to position the fibers accurately, is described in detail. A major challenge is dealing with the large amount of distortion introduced by the optics (of order 10% scale change), including time-dependent non-axisymmetric distortions introduced by the atmospheric dispersion compensator. Solutions are presented to measure or mitigate these effects.

  12. [Laser-based radiometric calibration].

    PubMed

    Li, Zhi-gang; Zheng, Yu-quan

    2014-12-01

    Increasingly higher demands are put forward to spectral radiometric calibration accuracy and the development of new tunable laser based spectral radiometric calibration technology is promoted, along with the development of studies of terrestrial remote sensing, aeronautical and astronautical remote sensing, plasma physics, quantitative spectroscopy, etc. Internationally a number of national metrology scientific research institutes have built tunable laser based spectral radiometric calibration facilities in succession, which are traceable to cryogenic radiometers and have low uncertainties for spectral responsivity calibration and characterization of detectors and remote sensing instruments in the UK, the USA, Germany, etc. Among them, the facility for spectral irradiance and radiance responsivity calibrations using uniform sources (SIRCCUS) at the National Institute of Standards and Technology (NIST) in the USA and the Tunable Lasers in Photometry (TULIP) facility at the Physikalisch-Technische Bundesanstalt (PTB) in Germany have more representatives. Compared with lamp-monochromator systems, laser based spectral radiometric calibrations have many advantages, such as narrow spectral bandwidth, high wavelength accuracy, low calibration uncertainty and so on for radiometric calibration applications. In this paper, the development of laser-based spectral radiometric calibration and structures and performances of laser-based radiometric calibration facilities represented by the National Physical Laboratory (NPL) in the UK, NIST and PTB are presented, technical advantages of laser-based spectral radiometric calibration are analyzed, and applications of this technology are further discussed. Laser-based spectral radiometric calibration facilities can be widely used in important system-level radiometric calibration measurements with high accuracy, including radiance temperature, radiance and irradiance calibrations for space remote sensing instruments, and promote the

  13. GTC Photometric Calibration

    NASA Astrophysics Data System (ADS)

    di Cesare, M. A.; Hammersley, P. L.; Rodriguez Espinosa, J. M.

    2006-06-01

    We are currently developing the calibration programme for GTC using techniques similar to the ones use for the space telescope calibration (Hammersley et al. 1998, A&AS, 128, 207; Cohen et al. 1999, AJ, 117, 1864). We are planning to produce a catalogue with calibration stars which are suitable for a 10-m telescope. These sources will be not variable, non binary and do not have infrared excesses if they are to be used in the infrared. The GTC science instruments require photometric calibration between 0.35 and 2.5 microns. The instruments are: OSIRIS (Optical System for Imaging low Resolution Integrated Spectroscopy), ELMER and EMIR (Espectrógrafo Multiobjeto Infrarrojo) and the Acquisition and Guiding boxes (Di Césare, Hammersley, & Rodriguez Espinosa 2005, RevMexAA Ser. Conf., 24, 231). The catalogue will consist of 30 star fields distributed in all of North Hemisphere. We will use fields containing sources over the range 12 to 22 magnitude, and spanning a wide range of spectral types (A to M) for the visible and near infrared. In the poster we will show the method used for selecting these fields and we will present the analysis of the data on the first calibration fields observed.

  14. Impact of instrumental systematic errors on fine-structure constant measurements with quasar spectra

    NASA Astrophysics Data System (ADS)

    Whitmore, Jonathan B.; Murphy, Michael T.

    2015-02-01

    We present a new `supercalibration' technique for measuring systematic distortions in the wavelength scales of high-resolution spectrographs. By comparing spectra of `solar twin' stars or asteroids with a reference laboratory solar spectrum, distortions in the standard thorium-argon calibration can be tracked with ˜10 m s-1 precision over the entire optical wavelength range on scales of both echelle orders (˜50-100 Å) and entire spectrographs arms (˜1000-3000 Å). Using archival spectra from the past 20 yr, we have probed the supercalibration history of the Very Large Telescope-Ultraviolet and Visible Echelle Spectrograph (VLT-UVES) and Keck-High Resolution Echelle Spectrograph (HIRES) spectrographs. We find that systematic errors in their wavelength scales are ubiquitous and substantial, with long-range distortions varying between typically ±200 m s-1 per 1000 Å. We apply a simple model of these distortions to simulated spectra that characterize the large UVES and HIRES quasar samples which previously indicated possible evidence for cosmological variations in the fine-structure constant, α. The spurious deviations in α produced by the model closely match important aspects of the VLT-UVES quasar results at all redshifts and partially explain the HIRES results, though not self-consistently at all redshifts. That is, the apparent ubiquity, size and general characteristics of the distortions are capable of significantly weakening the evidence for variations in α from quasar absorption lines.

  15. Teacher Perceptions Regarding the Instrumental Factors That Impact Their Decisions to Remain in an Urban District

    ERIC Educational Resources Information Center

    Luckett, Tiffany Pointer

    2016-01-01

    The purpose of this study was to examine the factors that impact teachers' decisions to remain teaching in an urban school district. The researcher analyzed survey data provided by the Office of Planning and Accountability for an urban school district in Tennessee. The findings of the study are also discussed as well as any implication for…

  16. Binary logistic regression-Instrument for assessing museum indoor air impact on exhibits.

    PubMed

    Bucur, Elena; Danet, Andrei Florin; Lehr, Carol Blaziu; Lehr, Elena; Nita-Lazar, Mihai

    2017-04-01

    This paper presents a new way to assess the environmental impact on historical artifacts using binary logistic regression. The prediction of the impact on the exhibits during certain pollution scenarios (environmental impact) was calculated by a mathematical model based on the binary logistic regression; it allows the identification of those environmental parameters from a multitude of possible parameters with a significant impact on exhibitions and ranks them according to their severity effect. Air quality (NO2, SO2, O3 and PM2.5) and microclimate parameters (temperature, humidity) monitoring data from a case study conducted within exhibition and storage spaces of the Romanian National Aviation Museum Bucharest have been used for developing and validating the binary logistic regression method and the mathematical model. The logistic regression analysis was used on 794 data combinations (715 to develop of the model and 79 to validate it) by a Statistical Package for Social Sciences (SPSS 20.0). The results from the binary logistic regression analysis demonstrated that from six parameters taken into consideration, four of them present a significant effect upon exhibits in the following order: O3>PM2.5>NO2>humidity followed at a significant distance by the effects of SO2 and temperature. The mathematical model, developed in this study, correctly predicted 95.1 % of the cumulated effect of the environmental parameters upon the exhibits. Moreover, this model could also be used in the decisional process regarding the preventive preservation measures that should be implemented within the exhibition space.

  17. New Instruments for Studying the Impacts of Science Teacher Professional Development

    ERIC Educational Resources Information Center

    Trygstad, Peggy J.; Banilower, Eric R.; Smith, P. Sean; Nelson, Courtney L.

    2014-01-01

    The logic model that implicitly drives most professional development (PD) efforts asserts that PD leads to changes in teacher knowledge and beliefs, which leads to improved classroom practice, and ultimately, better student outcomes. However, efforts to study the impacts of PD programs are often hampered by the scarcity of high-quality…

  18. Metop-BAVHRR IR channel post-launch calibration and verification tests

    NASA Astrophysics Data System (ADS)

    Chang, Tiejun; Wu, Xiangqian; Weng, Fuzhong

    2013-09-01

    Meteorological Operational (METOP)-B spacecraft was launched on September 17, 2012, and the Advanced Very High Resolution Radiometer (AVHRR) IR channels were activated October 18. AVHRR instrument has been tested and characterized pre-launch under thermal vacuum (TV) condition by the instrument vender. The instrument dynamic range, noise equivalent differential temperature (NEDT), and nonlinear response have been characterized in the test. Basing on the TV test data, the calibration coefficients are generated for post-launch. The on-orbit verification tests have been performed to verify the instrument response and performance, including the dynamic range, NEDT, on-board blackbody (BB) temperature, instrument response calibration, and instrument status from the telemetry data. The post-launch Cal/Val test is to improve the calibration accuracy and enhance the L1B data quality. These tests include stray light analysis, instrument gain verification, and uncertainty assessment. The stray light impact on the calibration is estimated as 0.2% for 11 μm channel, 0.3% for 12 μm channel, and 3% for 3.7μm channel. The inter-comparison AVHRR IR channel radiances with the radiance derived from Infrared Atmospheric Sounding Interferometer (IASI) measurement has been performed and the AVHRR bias shoes brightness temperature dependency.

  19. Results and Insights on the Impact of Smoke on Digital Instrumentation and Control

    SciTech Connect

    Tanaka, T. J.; Nowlen, S. P.

    2001-01-31

    Smoke can cause interruptions and upsets in active electronics. Because nuclear power plants are replacing analog with digital instrumentation and control systems, qualification guidelines for new systems are being reviewed for severe environments such as smoke and electromagnetic interference. Active digital systems, individual components, and active circuits have been exposed to smoke in a program sponsored by the U.S. Nuclear Regulatory Commission. The circuits and systems were all monitored during the smoke exposure, indicating any immediate effects of the smoke. The major effect of smoke has been to increase leakage currents (through circuit bridging across contacts and leads) and to cause momentary upsets and failures in digital systems. This report summarizes two previous reports and presents new results from conformal coating, memory chip, and hard drive tests. The report describes practices for mitigation of smoke damage through digital system design, fire barriers, ventilation, fire suppressants, and post fire procedures.

  20. The impact patient-specific instrumentation has had on my practice in the last 5 years.

    PubMed

    Collins, Michael J

    2014-03-01

    I have performed total knee arthroplasty (TKA) using patient- specific instrumentation (PSI) (TRUMATCH® Personalized Solutions, DePuy Synthes Joint Reconstruction, Warsaw, Indiana) since July 2009. Since that time, I have performed over 600 of these procedures, all at the same hospital and all using the same personnel I worked with before I began using PSI. I do not have a physician assistant, but I do have a surgical assistant who scrubs with and assists me on all TKAs. There are a number of reasons why a surgeon may decide to use PSI. This paper discusses the effect PSI has had on my practice in the last 5 years, including my experiences and conclusions.

  1. Antenna Calibration and Measurement Equipment

    NASA Technical Reports Server (NTRS)

    Rochblatt, David J.; Cortes, Manuel Vazquez

    2012-01-01

    A document describes the Antenna Calibration & Measurement Equipment (ACME) system that will provide the Deep Space Network (DSN) with instrumentation enabling a trained RF engineer at each complex to perform antenna calibration measurements and to generate antenna calibration data. This data includes continuous-scan auto-bore-based data acquisition with all-sky data gathering in support of 4th order pointing model generation requirements. Other data includes antenna subreflector focus, system noise temperature and tipping curves, antenna efficiency, reports system linearity, and instrument calibration. The ACME system design is based on the on-the-fly (OTF) mapping technique and architecture. ACME has contributed to the improved RF performance of the DSN by approximately a factor of two. It improved the pointing performances of the DSN antennas and productivity of its personnel and calibration engineers.

  2. Radiance calibration of spherical integrators

    NASA Technical Reports Server (NTRS)

    Mclean, James T.; Guenther, Bruce W.

    1989-01-01

    Techniques for improving the knowledge of the radiance of large area spherical and hemispherical integrating energy sources have been investigated. Such sources are used to calibrate numerous aircraft and spacecraft remote sensing instruments. Comparisons are made between using a standard source based calibration method and a quantum efficient detector (QED) based calibration method. The uncertainty involved in transferring the calibrated values of the point source standard lamp to the extended source is estimated to be 5 to 10 percent. The use of the QED allows an improvement in the uncertainty to 1 to 2 percent for the measurement of absolute radiance from a spherical integrator source.

  3. The Impact II, a Very High-Resolution Quadrupole Time-of-Flight Instrument (QTOF) for Deep Shotgun Proteomics.

    PubMed

    Beck, Scarlet; Michalski, Annette; Raether, Oliver; Lubeck, Markus; Kaspar, Stephanie; Goedecke, Niels; Baessmann, Carsten; Hornburg, Daniel; Meier, Florian; Paron, Igor; Kulak, Nils A; Cox, Juergen; Mann, Matthias

    2015-07-01

    Hybrid quadrupole time-of-flight (QTOF) mass spectrometry is one of the two major principles used in proteomics. Although based on simple fundamentals, it has over the last decades greatly evolved in terms of achievable resolution, mass accuracy, and dynamic range. The Bruker impact platform of QTOF instruments takes advantage of these developments and here we develop and evaluate the impact II for shotgun proteomics applications. Adaption of our heated liquid chromatography system achieved very narrow peptide elution peaks. The impact II is equipped with a new collision cell with both axial and radial ion ejection, more than doubling ion extraction at high tandem MS frequencies. The new reflectron and detector improve resolving power compared with the previous model up to 80%, i.e. to 40,000 at m/z 1222. We analyzed the ion current from the inlet capillary and found very high transmission (>80%) up to the collision cell. Simulation and measurement indicated 60% transfer into the flight tube. We adapted MaxQuant for QTOF data, improving absolute average mass deviations to better than 1.45 ppm. More than 4800 proteins can be identified in a single run of HeLa digest in a 90 min gradient. The workflow achieved high technical reproducibility (R2 > 0.99) and accurate fold change determination in spike-in experiments in complex mixtures. Using label-free quantification we rapidly quantified haploid against diploid yeast and characterized overall proteome differences in mouse cell lines originating from different tissues. Finally, after high pH reversed-phase fractionation we identified 9515 proteins in a triplicate measurement of HeLa peptide mixture and 11,257 proteins in single measurements of cerebellum-the highest proteome coverage reported with a QTOF instrument so far.

  4. The Impact II, a Very High-Resolution Quadrupole Time-of-Flight Instrument (QTOF) for Deep Shotgun Proteomics*

    PubMed Central

    Beck, Scarlet; Michalski, Annette; Raether, Oliver; Lubeck, Markus; Kaspar, Stephanie; Goedecke, Niels; Baessmann, Carsten; Hornburg, Daniel; Meier, Florian; Paron, Igor; Kulak, Nils A.; Cox, Juergen; Mann, Matthias

    2015-01-01

    Hybrid quadrupole time-of-flight (QTOF) mass spectrometry is one of the two major principles used in proteomics. Although based on simple fundamentals, it has over the last decades greatly evolved in terms of achievable resolution, mass accuracy, and dynamic range. The Bruker impact platform of QTOF instruments takes advantage of these developments and here we develop and evaluate the impact II for shotgun proteomics applications. Adaption of our heated liquid chromatography system achieved very narrow peptide elution peaks. The impact II is equipped with a new collision cell with both axial and radial ion ejection, more than doubling ion extraction at high tandem MS frequencies. The new reflectron and detector improve resolving power compared with the previous model up to 80%, i.e. to 40,000 at m/z 1222. We analyzed the ion current from the inlet capillary and found very high transmission (>80%) up to the collision cell. Simulation and measurement indicated 60% transfer into the flight tube. We adapted MaxQuant for QTOF data, improving absolute average mass deviations to better than 1.45 ppm. More than 4800 proteins can be identified in a single run of HeLa digest in a 90 min gradient. The workflow achieved high technical reproducibility (R2 > 0.99) and accurate fold change determination in spike-in experiments in complex mixtures. Using label-free quantification we rapidly quantified haploid against diploid yeast and characterized overall proteome differences in mouse cell lines originating from different tissues. Finally, after high pH reversed-phase fractionation we identified 9515 proteins in a triplicate measurement of HeLa peptide mixture and 11,257 proteins in single measurements of cerebellum—the highest proteome coverage reported with a QTOF instrument so far. PMID:25991688

  5. Impacts of Cross-Platform Vicarious Calibration on the Deep Blue Aerosol Retrievals for Moderate Resolution Imaging Spectroradiometer Aboard Terra

    NASA Technical Reports Server (NTRS)

    Jeong, Myeong-Jae; Hsu, N. Christina; Kwiatkowska, Ewa J.; Franz, Bryan A.; Meister, Gerhard; Salustro, Clare E.

    2012-01-01

    The retrieval of aerosol properties from spaceborne sensors requires highly accurate and precise radiometric measurements, thus placing stringent requirements on sensor calibration and characterization. For the Terra/Moderate Resolution Imaging Spedroradiometer (MODIS), the characteristics of the detectors of certain bands, particularly band 8 [(B8); 412 nm], have changed significantly over time, leading to increased calibration uncertainty. In this paper, we explore a possibility of utilizing a cross-calibration method developed for characterizing the Terral MODIS detectors in the ocean bands by the National Aeronautics and Space Administration Ocean Biology Processing Group to improve aerosol retrieval over bright land surfaces. We found that the Terra/MODIS B8 reflectance corrected using the cross calibration method resulted in significant improvements for the retrieved aerosol optical thickness when compared with that from the Multi-angle Imaging Spectroradiometer, Aqua/MODIS, and the Aerosol Robotic Network. The method reported in this paper is implemented for the operational processing of the Terra/MODIS Deep Blue aerosol products.

  6. Multi-Axis Accelerometer Calibration System

    NASA Technical Reports Server (NTRS)

    Finley, Tom; Parker, Peter

    2010-01-01

    A low-cost, portable, and simplified system has been developed that is suitable for in-situ calibration and/or evaluation of multi-axis inertial measurement instruments. This system overcomes facility restrictions and maintains or improves the calibration quality for users of accelerometer-based instruments with applications in avionics, experimental wind tunnel research, and force balance calibration applications. The apparatus quickly and easily positions a multi-axis accelerometer system into a precisely known orientation suitable for in-situ quality checks and calibration. In addition, the system incorporates powerful and sophisticated statistical methods, known as response surface methodology and statistical quality control. These methods improve calibration quality, reduce calibration time, and allow for increased calibration frequency, which enables the monitoring of instrument stability over time.

  7. A variable acceleration calibration system

    NASA Astrophysics Data System (ADS)

    Johnson, Thomas H.

    2011-12-01

    A variable acceleration calibration system that applies loads using gravitational and centripetal acceleration serves as an alternative, efficient and cost effective method for calibrating internal wind tunnel force balances. Two proof-of-concept variable acceleration calibration systems are designed, fabricated and tested. The NASA UT-36 force balance served as the test balance for the calibration experiments. The variable acceleration calibration systems are shown to be capable of performing three component calibration experiments with an approximate applied load error on the order of 1% of the full scale calibration loads. Sources of error are indentified using experimental design methods and a propagation of uncertainty analysis. Three types of uncertainty are indentified for the systems and are attributed to prediction error, calibration error and pure error. Angular velocity uncertainty is shown to be the largest indentified source of prediction error. The calibration uncertainties using a production variable acceleration based system are shown to be potentially equivalent to current methods. The production quality system can be realized using lighter materials and a more precise instrumentation. Further research is needed to account for balance deflection, forcing effects due to vibration, and large tare loads. A gyroscope measurement technique is shown to be capable of resolving the balance deflection angle calculation. Long term research objectives include a demonstration of a six degree of freedom calibration, and a large capacity balance calibration.

  8. Physicians' decision process for drug prescription and the impact of pharmaceutical marketing mix instruments.

    PubMed

    Campo, Katia; De Staebel, Odette; Gijsbrechts, Els; van Waterschoot, Walter

    2005-01-01

    This paper provides an in-depth, qualitative analysis of the physicians' decision process for drug prescription. Drugs in the considered therapeutic classes are mainly prescribed by specialists, treating patients with obligatory medical insurance, for a prolonged period of time. The research approach is specifically designed to capture the full complexity and sensitive nature of the physician's choice behavior, which appears to be more hybrid and less rational in nature than is often assumed in quantitative, model-based analyses of prescription behavior. Several interesting findings emerge from the analysis: (i) non-compensatory decision rules seem to dominate the decision process, (ii) consideration sets are typically small and change-resistant, (iii) drug cost is not a major issue for most physicians, (iv) detailing remains one of the most powerful pharmaceutical marketing instruments and is highly appreciated as a valuable and quick source of information, and (v) certain types of non-medical marketing incentives (such as free conference participation) may in some situations also influence drug choices.

  9. NASA Metrology and Calibration, 1980

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The proceedings of the fourth annual NASA Metrology and Calibration Workshop are presented. This workshop covered (1) review and assessment of NASA metrology and calibration activities by NASA Headquarters, (2) results of audits by the Office of Inspector General, (3) review of a proposed NASA Equipment Management System, (4) current and planned field center activities, (5) National Bureau of Standards (NBS) calibration services for NASA, (6) review of NBS's Precision Measurement and Test Equipment Project activities, (7) NASA instrument loan pool operations at two centers, (8) mobile cart calibration systems at two centers, (9) calibration intervals and decals, (10) NASA Calibration Capabilities Catalog, and (11) development of plans and objectives for FY 1981. Several papers in this proceedings are slide presentations only.

  10. The impact of the 2005 Gulf hurricanes on pollution emissions as inferred from Ozone Monitoring Instrument (OMI) nitrogen dioxide

    NASA Astrophysics Data System (ADS)

    Yoshida, Yasuko; Duncan, Bryan N.; Retscher, Christian; Pickering, Kenneth E.; Celarier, Edward A.; Joiner, Joanna; Boersma, K. Folkert; Veefkind, J. Pepijn

    2010-04-01

    The impact of Hurricanes Katrina and Rita in 2005 on pollution emissions in the Gulf of Mexico region was investigated using tropospheric column amounts of nitrogen dioxide (NO 2) from the Ozone Monitoring Instrument (OMI) on the NASA Aura satellite. Around New Orleans and coastal Mississippi, we estimate that Katrina caused a 35% reduction in NO x emissions on average in the three weeks after landfall. Hurricane Rita caused a significant reduction (20%) in NO x emissions associated with power generation and intensive oil refining activities near the Texas/Louisiana border. We also found a 43% decrease by these two storms over the eastern Gulf of Mexico Outer Continental Shelf mainly due to the evacuation of and damage to platforms, rigs, and ports associated with oil and natural gas production.

  11. Urban traffic-related determinants of health questionnaire (UTDHQ): an instrument developed for health impact assessments

    PubMed Central

    Nadrian, Haidar; Nedjat, Saharnaz; Taghdisi, Mohammad Hossein; Shojaeizadeh, Davoud

    2014-01-01

    Background: Traffic and transport is a substantial part of a range of economic, social and environmental factors distinguished to have impact on human health. This paper is a report on a preliminary section of a Health Impact Assessment (HIA) on urban traffic and transport initiatives, being conducted in Sanandaj, Iran. In this preliminary study, the psychometric properties of Urban Traffic related Determinants of Health Questionnaire (UTDHQ) were investigated. Methods: Multistage cluster sampling was employed to recruit 476 key informants in Sanandaj from April to June 2013 to participate in the study. The development of UTDHQ began with a comprehensive review of the literature. Then face, content and construct validity as well as reliability were determined. Results: Exploratory Factor Analysis showed optimal reduced solution including 40 items and 8 factors. Three of the factors identified were Physical Environment, Social Environment, Public Services Delivery and Accessibility. UTDHQ demonstrated an appropriate validity, reliability, functionality and simplicity. Conclusion: Despite the need for further studies on UTDHQ, this study showed that it can be a practical and useful tool for conducting HIAs in order to inform decision makers and stakeholders about the health influences of their decisions and measures. PMID:25664285

  12. A calibrated Monte Carlo approach to quantify the impacts of misorientation and different driving forces on texture development

    SciTech Connect

    Liangzhe Zhang; Anthony D. Rollett; Timothy Bartel; Di Wu; Mark T. Lusk

    2012-02-01

    A calibrated Monte Carlo (cMC) approach, which quantifies grain boundary kinetics within a generic setting, is presented. The influence of misorientation is captured by adding a scaling coefficient in the spin flipping probability equation, while the contribution of different driving forces is weighted using a partition function. The calibration process relies on the established parametric links between Monte Carlo (MC) and sharp-interface models. The cMC algorithm quantifies microstructural evolution under complex thermomechanical environments and remedies some of the difficulties associated with conventional MC models. After validation, the cMC approach is applied to quantify the texture development of polycrystalline materials with influences of misorientation and inhomogeneous bulk energy across grain boundaries. The results are in good agreement with theory and experiments.

  13. Comparison of Electrostatic Fins with Piezoelectric Impact Hammer Techniques to Extend Impulse Calibration Range of a Torsional Thrust Stand (Preprint)

    DTIC Science & Technology

    2011-03-23

    plasma electric propulsion devices, it has become necessary to accurately measure their thruster performance (1). Direct thrust measurements are the...pulsed plasma electric propulsion devices, it has become necessary to accurately measure their thruster performance1. Direct thrust measurements are the...calibration systems and can impart maximum impulses has high as 100’s of mNs as required for the direct testing of new pulsed plasma electric propulsion

  14. Impacts of depolarization calibration methods on cloud phase interpretation at Eureka during 2013 and 2014 CRL lidar measurement campaigns

    NASA Astrophysics Data System (ADS)

    McCullough, E. M.; Perro, C. W.; Gamage, S. M.; Hopper, J.; Sica, R. J.; Duck, T.; Walker, K. A.; Drummond, J. R.

    2014-12-01

    The radiative behaviour of clouds is dependent on cloud particle phase. Water droplets can exist in temperatures well below 0° C for extended periods. Lidar depolarization measurements allow liquid and solid states to be differentiated in individual clouds at high spatial-temporal resolution. The 2012, 2013 and 2014 Canadian Arctic ACE Validation Campaigns in Eureka, Nunavut, Canada (80°N, 86°W) provided an opportunity to make extensive depolarization measurements using the CANDAC Rayleigh-Mie-Raman Lidar (CRL) in the troposphere.To date, most calibration methods in the literature are applicable to lidars which do not have non-ideal polarizing optics upstream of the polarizing analyzers in the receiver. We demonstrate a more complete matrix algebra calibration of the CRL to take the extra optics from six upstream lidar channels into account.Differences in depolarization parameter from 2013 and 2014 measurements show the advantage of the more extensive calibration for this lidar compared to the simpler traditional approach. The largest differences are found for depolarization parameter values around d = 0.50 (corresponding to δ = 0.33). Depolarization ratio values of δ = 0.2 to 0.3 are generally taken to be the cutoff between interpretations of ice (higher δ) or water (lower δ), and many CRL measurements lie in this particularly diagnostic range. An uncertainty analysis becomes important when extending the depolarization parameters to interpretation of the clouds in the atmosphere above Eureka.

  15. Using instrumental neutron activation analysis for geochemical analyses of terrestrial impact structures: current analytical procedures at the university of vienna geochemistry activation analysis laboratory.

    PubMed

    Mader, Dieter; Koeberl, Christian

    2009-12-01

    The Instrumental Neutron Activation Analysis Gamma Spectroscopy Laboratory at the Department of Lithospheric Research, University of Vienna, has been upgraded in the year 2006. This paper describes the sample preparation, new instrumentation and data evaluation for hundreds of rock samples of two terrestrial impact structures. The measurement and data evaluation are done by using Genie 2000 and a custom-made batch software for the used analysis sequences.

  16. Metrology - Beyond the Calibration Lab

    NASA Technical Reports Server (NTRS)

    Mimbs, Scott M.

    2008-01-01

    We rely on data from measurements every day; a gas-pump, a speedometer, and a supermarket weight scale are just three examples of measurements we use to make decisions. We generally accept the data from these measurements as "valid." One reason we can accept the data is the "legal metrology" requirements established and regulated by the government in matters of commerce. The measurement data used by NASA, other government agencies, and industry can be critical to decisions which affect everything from economic viability, to mission success, to the security of the nation. Measurement data can even affect life and death decisions. Metrology requirements must adequately provide for risks associated with these decisions. To do this, metrology must be integrated into all aspects of an industry including research, design, testing, and product acceptance. Metrology, the science of measurement, has traditionally focused on the calibration of instruments, and although instrument calibration is vital, it is only a part of the process that assures quality in measurement data. For example, measurements made in research can influence the fundamental premises that establish the design parameters, which then flow down to the manufacturing processes, and eventually impact the final product. Because a breakdown can occur anywhere within this cycle, measurement quality assurance has to be integrated into every part of the life-cycle process starting with the basic research and ending with the final product inspection process. The purpose of this paper is to discuss the role of metrology in the various phases of a product's life-cycle. For simplicity, the cycle will be divided in four broad phases, with discussions centering on metrology within NASA. .

  17. Understanding human visual systems and its impact on our intelligent instruments

    NASA Astrophysics Data System (ADS)

    Strojnik Scholl, Marija; Páez, Gonzalo; Scholl, Michelle K.

    2013-09-01

    We review the evolution of machine vision and comment on the cross-fertilization from the neural sciences onto flourishing fields of neural processing, parallel processing, and associative memory in optical sciences and computing. Then we examine how the intensive efforts in mapping the human brain have been influenced by concepts in computer sciences, control theory, and electronic circuits. We discuss two neural paths that employ the input from the vision sense to determine the navigational options and object recognition. They are ventral temporal pathway for object recognition (what?) and dorsal parietal pathway for navigation (where?), respectively. We describe the reflexive and conscious decision centers in cerebral cortex involved with visual attention and gaze control. Interestingly, these require return path though the midbrain for ocular muscle control. We find that the cognitive psychologists currently study human brain employing low-spatial-resolution fMRI with temporal response on the order of a second. In recent years, the life scientists have concentrated on insect brains to study neural processes. We discuss how reflexive and conscious gaze-control decisions are made in the frontal eye field and inferior parietal lobe, constituting the fronto-parietal attention network. We note that ethical and experiential learnings impact our conscious decisions.

  18. The use of a virtual reality simulator to explore and understand the impact of Linac mis-calibrations

    NASA Astrophysics Data System (ADS)

    Beavis, Andrew W.; Ward, James W.

    2014-03-01

    Purpose: In recent years there has been interest in using Computer Simulation within Medical training. The VERT (Virtual Environment for Radiotherapy Training) system is a Flight Simulator for Radiation Oncology professionals, wherein fundamental concepts, techniques and problematic scenarios can be safely investigated. Methods: The system provides detailed simulations of several Linacs and the ability to display DICOM treatment plans. Patients can be mis-positioned with 'set-up errors' which can be explored visually, dosimetrically and using IGRT. Similarly, a variety of Linac calibration and configuration parameters can be altered manually or randomly via controlled errors in the simulated 3D Linac and its component parts. The implication of these can be investigated by following through a treatment scenario or using QC devices available within a Physics software module. Results: One resultant exercise is a systematic mis-calibration of 'lateral laser height' by 2mm. The offset in patient alignment is easily identified using IGRT and once corrected by reference to the 'in-room monitor'. The dosimetric implication is demonstrated to be 0.4% by setting a dosimetry phantom by the lasers (and ignoring TSD information). Finally, the need for recalibration can be shown by the Laser Alignment Phantom or by reference to the front pointer. Conclusions: The VERT system provides a realistic environment for training and enhancing understanding of radiotherapy concepts and techniques. Linac error conditions can be explored in this context and valuable experience gained in a controlled manner in a compressed period of time.

  19. Operational Land Imager relative radiometric calibration

    NASA Astrophysics Data System (ADS)

    Barsi, Julia A.; Markham, Brian L.

    2015-09-01

    The Operational Land Imager (OLI), on board the Landsat-8 satellite, is a pushbroom sensor with nearly 7000 detectors per band, divided between 14 separate modules. While rigorously characterized prior to launch, the shear number of individual detectors presents a challenge to maintaining the on-orbit relative calibration, such that stripes, bands and other artifacts are minimized in the final image products. On-orbit relative calibration of the OLI is primarily monitored and corrected by observing an on-board primary solar diffuser panel. The panel is the most uniform target available to the OLI, though as observed but the OLI, it has a slope across the field of view due to view angle effects. Just after launch, parameters were derived using the solar diffuser data, to correct for the angular effects across the 14 modules. The residual discontinuities between arrays and the detector-to-detector uniformity continue to be monitored on a weekly basis. The observed variations in the responses to the diffuser panel since launch are thought to be due to real instrument changes. Since launch, the Coastal/Aerosol (CA) and Blue bands have shown the most variation in relative calibration of the VNIR bands, with as much as 0.14% change (3-sigma) between consecutive relative gain estimates. The other VNIR bands (Green, Red and NIR) initially had detectors showing a slow drift of about 0.2% per year, though this stopped after an instrument power cycle about seven months after launch. The SWIR bands also exhibit variability between collects (0.11% 3-sigma) but the larger changes have been where individual detectors' responses change suddenly by as much as 1.5%. The mechanisms behind these changes are not well understood but in order to minimize impact to the users, the OLI relative calibration is updated on a quarterly basis in order to capture changes over time.

  20. Ultraviolet Plume Instrument Calibration and Sensor Assessment

    DTIC Science & Technology

    1993-09-01

    S9. SPONSORING/MONITORING AGENCY NAMEIS) AND ADDRESSIES) 10 . SPONSORING/MONITORING AGENCY REPORT NUMBER Strategic Defense Initiative Organization SDIO...UNCLASSIFIED UL NSN 7640-01-280-6OO htndord Form 205 (Rev. 240) PIoerlbed by ANSI Std 230-1S I i 212-102 I CONTENTS 3EXECUTIVE SUMMARY...measurement accuracy cf .bout 10 . Figure 1 is a - schematic of the LACE satellite. The top boom extends to 150 ft and carries :i 200-lb tip mass for gravity

  1. Impacts of uncertainties in weather and streamflow observations in calibration and evaluation of an elevation distributed HBV-model

    NASA Astrophysics Data System (ADS)

    Engeland, K.; Steinsland, I.; Petersen-Øverleir, A.; Johansen, S.

    2012-04-01

    The aim of this study is to assess the uncertainties in streamflow simulations when uncertainties in both observed inputs (precipitation and temperature) and streamflow observations used in the calibration of the hydrological model are explicitly accounted for. To achieve this goal we applied the elevation distributed HBV model operating on daily time steps to a small catchment in high elevation in Southern Norway where the seasonal snow cover is important. The uncertainties in precipitation inputs were quantified using conditional simulation. This procedure accounts for the uncertainty related to the density of the precipitation network, but neglects uncertainties related to measurement bias/errors and eventual elevation gradients in precipitation. The uncertainties in temperature inputs were quantified using a Bayesian temperature interpolation procedure where the temperature lapse rate is re-estimated every day. The uncertainty in the lapse rate was accounted for whereas the sampling uncertainty related to network density was neglected. For every day a random sample of precipitation and temperature inputs were drawn to be applied as inputs to the hydrologic model. The uncertainties in observed streamflow were assessed based on the uncertainties in the rating curve model. A Bayesian procedure was applied to estimate the probability for rating curve models with 1 to 3 segments and the uncertainties in their parameters. This method neglects uncertainties related to errors in observed water levels. Note that one rating curve was drawn to make one realisation of a whole time series of streamflow, thus the rating curve errors lead to a systematic bias in the streamflow observations. All these uncertainty sources were linked together in both calibration and evaluation of the hydrologic model using a DREAM based MCMC routine. Effects of having less information (e.g. missing one streamflow measurement for defining the rating curve or missing one precipitation station

  2. Apollo 16/AS-511/LM-11 operational calibration curves. Volume 1: Calibration curves for command service module CSM 113

    NASA Technical Reports Server (NTRS)

    Demoss, J. F. (Compiler)

    1971-01-01

    Calibration curves for the Apollo 16 command service module pulse code modulation downlink and onboard display are presented. Subjects discussed are: (1) measurement calibration curve format, (2) measurement identification, (3) multi-mode calibration data summary, (4) pulse code modulation bilevel events listing, and (5) calibration curves for instrumentation downlink and meter link.

  3. Remote-sensing reflectance determinations in the coastal ocean environment: impact of instrumental characteristics and environmental variability.

    PubMed

    Toole, D A; Siegel, D A; Menzies, D W; Neumann, M J; Smith, R C

    2000-01-20

    Three independent ocean color sampling methodologies are compared to assess the potential impact of instrumental characteristics and environmental variability on shipboard remote-sensing reflectance observations from the Santa Barbara Channel, California. Results indicate that under typical field conditions, simultaneous determinations of incident irradiance can vary by 9-18%, upwelling radiance just above the sea surface by 8-18%, and remote-sensing reflectance by 12-24%. Variations in radiometric determinations can be attributed to a variety of environmental factors such as Sun angle, cloud cover, wind speed, and viewing geometry; however, wind speed is isolated as the major source of uncertainty. The above-water approach to estimating water-leaving radiance and remote-sensing reflectance is highly influenced by environmental factors. A model of the role of wind on the reflected sky radiance measured by an above-water sensor illustrates that, for clear-sky conditions and wind speeds greater than 5 m/s, determinations of water-leaving radiance at 490 nm are undercorrected by as much as 60%. A data merging procedure is presented to provide sky radiance correction parameters for above-water remote-sensing reflectance estimates. The merging results are consistent with statistical and model findings and highlight the importance of multiple field measurements in developing quality coastal oceanographic data sets for satellite ocean color algorithm development and validation.

  4. Review of Instrumented Indentation

    PubMed Central

    VanLandingham, Mark R.

    2003-01-01

    Instrumented indentation, also known as depth-sensing indentation or nanoindentation, is increasingly being used to probe the mechanical response of materials from metals and ceramics to polymeric and biological materials. The additional levels of control, sensitivity, and data acquisition offered by instrumented indentation systems have resulted in numerous advances in materials science, particularly regarding fundamental mechanisms of mechanical behavior at micrometer and even sub-micrometer length scales. Continued improvements of instrumented indentation testing towards absolute quantification of a wide range of material properties and behavior will require advances in instrument calibration, measurement protocols, and analysis tools and techniques. In this paper, an overview of instrumented indentation is given with regard to current instrument technology and analysis methods. Research efforts at the National Institute of Standards and Technology (NIST) aimed at improving the related measurement science are discussed. PMID:27413609

  5. Image Calibration

    NASA Technical Reports Server (NTRS)

    Peay, Christopher S.; Palacios, David M.

    2011-01-01

    Calibrate_Image calibrates images obtained from focal plane arrays so that the output image more accurately represents the observed scene. The function takes as input a degraded image along with a flat field image and a dark frame image produced by the focal plane array and outputs a corrected image. The three most prominent sources of image degradation are corrected for: dark current accumulation, gain non-uniformity across the focal plane array, and hot and/or dead pixels in the array. In the corrected output image the dark current is subtracted, the gain variation is equalized, and values for hot and dead pixels are estimated, using bicubic interpolation techniques.

  6. Impact of the angular dependence of the SNPP VIIRS solar diffuser BRDF degradation factor on the radiometric calibration of the reflective solar bands

    NASA Astrophysics Data System (ADS)

    Lei, Ning; Xiong, Xiaoxiong

    2015-09-01

    The Visible Infrared Imaging Radiometer Suite (VIIRS) aboard the Suomi National Polar-orbiting Partnership satellite performs radiometric calibration of its reflective solar bands (RSBs) primarily by observing an onboard solar diffuser (SD). The SD optical scattering property is measured by a bidirectional reflectance distribution function (BRDF). Once on orbit, the BRDF degrades over time and the degradation factor is determined by an onboard solar diffuser stability monitor (SDSM) which observes the Sun and the sunlit SD at almost the same time. We showed in a previous SPIE paper that the BRDF degradation factor is angle dependent. Consequently, due to that the SDSM and the VIIRS telescope SD views have very different angles, applying the BRDF degradation factor determined from the SDSM without any adjustments to the VIIRS RSB calibration can result in large systematic errors. In addition, the BRDF angular dependence impacts the determination of the SD screen transmittance viewed by both the SDSM detectors and the VIIRS telescope. We first use yaw maneuver data to determine the product of the SD attenuation screen transmittance and the BRDF at the initial time (when the BRDF just started to degrade) viewed by the VIIRS telescope, removing the impact of the SD BRDF degradation factor angular dependence over satellite orbits. By attributing the large bumps observed in the initially computed VIIRS detector gains for the M1-M4 bands to the angular dependence of the BRDF degradation factor and matching the computed VIIRS detector gains from the SD and the lunar observations, we find the relation between the BRDF degradation factors in the VIIRS telescope and SDSM SD view directions.

  7. Commodity-Free Calibration

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Commodity-free calibration is a reaction rate calibration technique that does not require the addition of any commodities. This technique is a specific form of the reaction rate technique, where all of the necessary reactants, other than the sample being analyzed, are either inherent in the analyzing system or specifically added or provided to the system for a reason other than calibration. After introduction, the component of interest is exposed to other reactants or flow paths already present in the system. The instrument detector records one of the following to determine the rate of reaction: the increase in the response of the reaction product, a decrease in the signal of the analyte response, or a decrease in the signal from the inherent reactant. With this data, the initial concentration of the analyte is calculated. This type of system can analyze and calibrate simultaneously, reduce the risk of false positives and exposure to toxic vapors, and improve accuracy. Moreover, having an excess of the reactant already present in the system eliminates the need to add commodities, which further reduces cost, logistic problems, and potential contamination. Also, the calculations involved can be simplified by comparison to those of the reaction rate technique. We conducted tests with hypergols as an initial investigation into the feasiblility of the technique.

  8. Stardust interstellar dust calibration: Hydrocode modeling of impacts on Al-1100 foil at velocities up to 300 km s-1 and validation with experimental data

    NASA Astrophysics Data System (ADS)

    Price, Mark C.; Kearsley, Anton T.; Burchell, Mark J.; Howard, Lauren E.; Hillier, Jon K.; Starkey, Natalie A.; Wozniakiewicz, Penny J.; Cole, Mike J.

    2012-04-01

    We present initial results from hydrocode modeling of impacts on Al-1100 foils, undertaken to aid the interstellar preliminary examination (ISPE) phase for the NASA Stardust mission interstellar dust collector tray. We used Ansys' AUTODYN to model impacts of micrometer-scale, and smaller projectiles onto Stardust foil (100 μm thick Al-1100) at velocities up to 300 km s-1. It is thought that impacts onto the interstellar dust collector foils may have been made by a combination of interstellar dust particles (ISP), interplanetary dust particles (IDP) on comet, and asteroid derived orbits, β micrometeoroids, nanometer dust in the solar wind, and spacecraft derived secondary ejecta. The characteristic velocity of the potential impactors thus ranges from <<1 to a few km s-1 (secondary ejecta), approximately 4-25 km s-1 for ISP and IDP, up to hundreds of km s-1 for the nanoscale dust reported by Meyer-Vernet et al. (2009). There are currently no extensive experimental calibrations for the higher velocity conditions, and the main focus of this work was therefore to use hydrocode models to investigate the morphometry of impact craters, as a means to determine an approximate impactor speed, and thus origin. The model was validated against existing experimental data for impact speeds up to approximately 30 km s-1 for particles ranging in density from 2.4 kg m-3 (glass) to 7.8 kg m-3 (iron). Interpolation equations are given to predict the crater depth and diameter for a solid impactor with any diameter between 100 nm and 4 μm and density between 2.4 and 7.8 kg m-3.

  9. Pipeline Calibration for STIS

    NASA Astrophysics Data System (ADS)

    Hodge, P. E.; Hulbert, S. J.; Lindler, D.; Busko, I.; Hsu, J.-C.; Baum, S.; McGrath, M.; Goudfrooij, P.; Shaw, R.; Katsanis, R.; Keener, S.; Bohlin, R.

    The CALSTIS program for calibration of Space Telescope Imaging Spectrograph data in the OPUS pipeline differs in several significant ways from calibration for earlier HST instruments, such as the use of FITS format, computation of error estimates, and association of related exposures. Several steps are now done in the pipeline that previously had to be done off-line by the user, such as cosmic ray rejection and extraction of 1-D spectra. Although the program is linked with IRAF for image and table I/O, it is written in ANSI C rather than SPP, which should make the code more accessible. FITS extension I/O makes use of the new IRAF FITS kernel for images and the HEASARC FITSIO package for tables.

  10. EOS ASTER thermal infrared band vicarious calibration

    NASA Technical Reports Server (NTRS)

    Palluconi, F.; Tonooka, H.; Hook, S.; Abtahi, A.; Alley, R.; Thompson, T.; Hoover, G.; Zadourian, S.

    2001-01-01

    Calibration of the 5 EOS ASTER instrument emission bands (90 m pixels at surface) is being checked during the operational life of the mission using field measurements simultaneous with the image acquisition.

  11. Calibration beads containing luminescent lanthanide ion complexes

    EPA Science Inventory

    The reliability of lanthanide luminescence measurements, by both flow cytometry and digital microscopy, will be enhanced by the availability of narrow-band emitting lanthanide calibration beads. These beads can also be used to characterize spectrographic instruments, including mi...

  12. Measuring the Impact of Students' Social Relations and Values: Validation of the Social-Relational Support for Education Instrument

    ERIC Educational Resources Information Center

    Vickers, Margaret; Finger, Linda; Barker, Katrina; Bodkin-Andrews, Gawaian

    2014-01-01

    A significant body of literature attests to the influence of social contexts on students' engagement with school. A review of this literature led to the construction of a self-report instrument designed to measure Social-Relational Support for Education (SRSE). The conceptual framework underlying the SRSE instrument focuses on the factors that can…

  13. Determining orbital particle parameters of impacts into germanium using morphology analysis and calibration data from hypervelocity impact experiments in the laboratory

    NASA Technical Reports Server (NTRS)

    Paul, Klaus G.

    1995-01-01

    This paper describes the work that is done at the Lehrstuhl fur Raumfahrttechnik (lrt) at the Technische Universitat Munchen to examine particle impacts into germanium surfaces which were flown on board the LDEF satellite. Besides the description of the processing of the samples, a brief overview of the particle launchers at our institute is given together with descriptions of impact morphology of high- and hypervelocity particles into germanium. Since germanium is a brittle, almost glass-like material, the impact morphology may also be interesting for anyone dealing with materials such as optics and solar cells. The main focus of our investigations is to learn about the impacting particle's properties, for example mass, velocity and direction. This is done by examining the morphology, various geometry parameters, crater obliqueness and crater volume.

  14. Simplified Vicarious Radiometric Calibration

    NASA Technical Reports Server (NTRS)

    Stanley, Thomas; Ryan, Robert; Holekamp, Kara; Pagnutti, Mary

    2010-01-01

    A measurement-based radiance estimation approach for vicarious radiometric calibration of spaceborne multispectral remote sensing systems has been developed. This simplified process eliminates the use of radiative transfer codes and reduces the number of atmospheric assumptions required to perform sensor calibrations. Like prior approaches, the simplified method involves the collection of ground truth data coincident with the overpass of the remote sensing system being calibrated, but this approach differs from the prior techniques in both the nature of the data collected and the manner in which the data are processed. In traditional vicarious radiometric calibration, ground truth data are gathered using ground-viewing spectroradiometers and one or more sun photometer( s), among other instruments, located at a ground target area. The measured data from the ground-based instruments are used in radiative transfer models to estimate the top-of-atmosphere (TOA) target radiances at the time of satellite overpass. These TOA radiances are compared with the satellite sensor readings to radiometrically calibrate the sensor. Traditional vicarious radiometric calibration methods require that an atmospheric model be defined such that the ground-based observations of solar transmission and diffuse-to-global ratios are in close agreement with the radiative transfer code estimation of these parameters. This process is labor-intensive and complex, and can be prone to errors. The errors can be compounded because of approximations in the model and inaccurate assumptions about the radiative coupling between the atmosphere and the terrain. The errors can increase the uncertainty of the TOA radiance estimates used to perform the radiometric calibration. In comparison, the simplified approach does not use atmospheric radiative transfer models and involves fewer assumptions concerning the radiative transfer properties of the atmosphere. This new technique uses two neighboring uniform

  15. Shortwave Radiometer Calibration Methods Comparison and Resulting Solar Irradiance Measurement Differences: A User Perspective

    SciTech Connect

    Habte, Aron; Sengupta, Manajit; Andreas, Afshin; Reda, Ibrahim; Robinson, Justin

    2016-11-21

    Banks financing solar energy projects require assurance that these systems will produce the energy predicted. Furthermore, utility planners and grid system operators need to understand the impact of the variable solar resource on solar energy conversion system performance. Accurate solar radiation data sets reduce the expense associated with mitigating performance risk and assist in understanding the impacts of solar resource variability. The accuracy of solar radiation measured by radiometers depends on the instrument performance specification, installation method, calibration procedure, measurement conditions, maintenance practices, location, and environmental conditions. This study addresses the effect of different calibration methods provided by radiometric calibration service providers, such as NREL and manufacturers of radiometers, on the resulting calibration responsivity. Some of these radiometers are calibrated indoors and some outdoors. To establish or understand the differences in calibration methodology, we processed and analyzed field-measured data from these radiometers. This study investigates calibration responsivities provided by NREL's broadband outdoor radiometer calibration (BORCAL) and a few prominent manufacturers. The BORCAL method provides the outdoor calibration responsivity of pyranometers and pyrheliometers at 45 degree solar zenith angle, and as