Science.gov

Sample records for instrument calibration reduction

  1. 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

  2. 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.

  3. 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.

  4. Optimal calibration of instrumented treadmills using an instrumented pole.

    PubMed

    Sloot, L H; Houdijk, H; van der Krogt, M M; Harlaar, J

    2016-08-01

    Calibration of instrumented treadmills is imperative for accurate measurement of ground reaction forces and center of pressure (COP). A protocol using an instrumented pole has been shown to considerably increase force and COP accuracy. This study examined how this protocol can be further optimized to maximize accuracy, by varying the measurement time and number of spots, using nonlinear approaches to calculate the calibration matrix and by correcting for potential inhomogeneity in the distribution of COP errors across the treadmill's surface. The accuracy increased with addition of spots and correction for the inhomogeneous distribution across the belt surface, decreased with reduction of measurement time, and did not improve by including nonlinear terms. Most of these methods improved the overall accuracy only to a limited extent, suggesting that the maximal accuracy is approached given the treadmill's inherent mechanical limitations. However, both correction for position dependence of the accuracy as well as its optimization within the walking area are found to be valuable additions to the standard calibration process. PMID:27180211

  5. Microfabricated field calibration assembly for analytical instruments

    DOEpatents

    Robinson, Alex L.; Manginell, Ronald P.; Moorman, Matthew W.; Rodacy, Philip J.; Simonson, Robert J.

    2011-03-29

    A microfabricated field calibration assembly for use in calibrating analytical instruments and sensor systems. The assembly comprises a circuit board comprising one or more resistively heatable microbridge elements, an interface device that enables addressable heating of the microbridge elements, and, in some embodiments, a means for positioning the circuit board within an inlet structure of an analytical instrument or sensor system.

  6. Strain Gauge Balance Calibration and Data Reduction at NASA Langley Research Center

    NASA Technical Reports Server (NTRS)

    Ferris, A. T. Judy

    1999-01-01

    This paper will cover the standard force balance calibration and data reduction techniques used at Langley Research Center. It will cover balance axes definition, balance type, calibration instrumentation, traceability of standards to NIST, calibration loading procedures, balance calibration mathematical model, calibration data reduction techniques, balance accuracy reporting, and calibration frequency.

  7. HESP: Instrument control, calibration and pipeline development

    NASA Astrophysics Data System (ADS)

    Anantha, Ch.; Roy, Jayashree; Mahesh, P. K.; Parihar, P. S.; Sangal, A. K.; Sriram, S.; Anand, M. N.; Anupama, G. C.; Giridhar, S.; Prabhu, T. P.; Sivarani, T.; Sundararajan, M. S.

    Hanle Echelle SPectrograph (HESP) is a fibre-fed, high resolution (R = 30,000 and 60,000) spectrograph being developed for the 2m HCT telescope at IAO, Hanle. The major components of the instrument are a) Cassegrain unit b) Spectrometer instrument. An instrument control system interacting with a guiding unit at Cassegrain interface as well as handling spectrograph functions is being developed. An on-axis auto-guiding using the spill-over angular ring around the input pinhole is also being developed. The stellar light from the Cassegrain unit is taken to the spectrograph using an optical fiber which is being characterized for spectral transmission, focal ratio degradation and scrambling properties. The design of the thermal enclosure and thermal control for the spectrograph housing is presented. A data pipeline for the entire Echelle spectral reduction is being developed. We also plan to implement an instrument physical model based calibration into the main data pipeline and in the maintenance and quality control operations.

  8. 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).

  9. 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.

  10. 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.

  11. 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.

  12. The PREMOS/PICARD instrument calibration

    NASA Astrophysics Data System (ADS)

    Schmutz, Werner; Fehlmann, André; Hülsen, Gregor; Meindl, Peter; Winkler, Rainer; Thuillier, Gérard; Blattner, Peter; Buisson, François; Egorova, Tatiana; Finsterle, Wolfgang; Fox, Nigel; Gröbner, Julian; Hochedez, Jean-François; Koller, Silvio; Meftah, Mustapha; Meisonnier, Mireille; Nyeki, Stephan; Pfiffner, Daniel; Roth, Hansjörg; Rozanov, Eugene; Spescha, Marcel; Wehrli, Christoph; Werner, Lutz; Wyss, Jules U.

    2009-08-01

    PREMOS is a space experiment scheduled to fly on the French solar mission PICARD. The experiment comprises filter radiometers and absolute radiometers to measure the spectral and total solar irradiance. The aim of PREMOS is to contribute to the long term monitoring of the total solar irradiance, to use irradiance observations for 'nowcasting' the state of the terrestrial middle atmosphere and to provide long term sensitivity calibration for the solar imaging instrument SODISM on PICARD. In this paper we describe the calibration of the instruments. The filter radiometer channels in the visible and near IR were characterized at PMOD/WRC and the UV channels were calibrated at PTB Berlin. The absolute radiometers were compared with the World Radiometric Reference at PMOD/WRC and a power calibration relative to a primary cryogenic radiometer standard was performed in vacuum and air at NPL.

  13. 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).

  14. 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. PMID:19044397

  15. 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.

  16. Calibration facility for environment dosimetry instruments

    SciTech Connect

    Bercea, Sorin; Celarel, Aurelia; Cenusa, Constantin

    2013-12-16

    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{sup −9} - 10{sup −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.

  17. NASA airborne satellite instrumentation calibrator (NASIC) technical reference

    NASA Technical Reports Server (NTRS)

    Ward, John L.; Mcintire, Gerry

    1993-01-01

    The NASA Satellite Instrumentation Calibrator (NASIC) is a visible and near-infrared spectrometer used to calibrate various satellite instruments by underflying those instruments in a NASA ER-2 aircraft. The calibration instrument's hardware and software are documented. The design, operation, and function of an Ebert-Fastie monochronomator, which by means of a moveable diffraction grating, becomes a visible and near-infrared spectrometer used to calibrate satellite-borne instruments by high altitude underflights in the NASA ER-2.

  18. 10 CFR 35.61 - Calibration of survey instruments.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... § 35.61 Calibration of survey instruments. (a) A licensee shall calibrate the survey instruments used to show compliance with this part and 10 CFR Part 20 before first use, annually, and following a... 10 Energy 1 2013-01-01 2013-01-01 false Calibration of survey instruments. 35.61 Section...

  19. On-orbit instrument calibration of CALET

    NASA Astrophysics Data System (ADS)

    Javaid, Amir; Calet Collaboration

    2015-04-01

    The CALorimetric Electron Telescope (CALET) is a high-energy cosmic ray experiment which will be placed on the International Space Station in 2015. Primary goals of CALET are measurement of cosmic ray electron spectra from 1 GeV to 20 TeV, gamma rays from 10 GeV to 10 TeV, and protons and nuclei from 10 GeV up to 1000 TeV. The detector consists of three main components: a Charge Detector (CHD), Imaging Calorimeter (IMC), and Total Absorption Calorimeter (TASC). As CALET is going to work in the ISS orbit space environment, it needs to be calibrated while it is in orbit. Penetrating non-showering protons and helium nuclei are prime candidates for instrument calibration, as they provide a known energy signal for calibrating the detector response. In the present paper, we discuss estimation of CALET's detector efficiency to protons and helium nuclei. Included is a discussion of different galactic cosmic ray and trapped proton models used for flux calculation and simulations performed for detector geometric area and trigger rate calculation. This paper also discusses the importance of the albedo proton flux for the CALET detector calibration. This research was supported by NASA at Louisiana State University under Grant Number NNX11AE01G.

  20. 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.

  1. 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.

  2. Onboard calibration status of the ASTER instrument

    NASA Astrophysics Data System (ADS)

    Sakuma, Fumihiro; Kikuchi, Masakuni; Inada, Hitomi; Akagi, Shigeki; Ono, Hidehiko

    2012-11-01

    The ASTER Instrument is one of the five sensors on the NASA's Terra satellite on orbit since December 1999. ASTER consists of three radiometers, VNIR, SWIR and TIR whose spatial resolutions are 15 m, 30 m and 90 m, respectively. Unfortunately SWIR stopped taking images since May 2008 due to the offset rise caused by the detector temperature rise, but VNIR and TIR are taking Earth images of good quality. VNIR and TIR experienced responsivity degradation while SWIR showed little change. Band 1 (0.56 μm) decreased most among three VNIR bands and 30 % in twelve years. Band 12 (9.1 μm) decreased 40 % and most among five TIR bands. There are some discussions of the causes of the responsivity degradation of VNIR and TIR. Possible causes are contamination accretion by silicone outgas, thruster plume and plasma interaction. We marked hydrazine which comes out unburned in the thruster plume during the inclination adjust maneuver (IAM). Hydrazine has the absorption spectra corresponding to the TIR responsivity degradation in the infrared region. We studied the IAM effect on the ASTER by allocating the additional onboard calibration activities just before and after the IAM while the normal onboard calibration activity is operated once in 49 days. This experiment was carried out three times in fiscal year 2011.

  3. 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.

  4. 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.

  5. Pressure instrument calibration reaps SPC benefits

    SciTech Connect

    Kegel, T.M.

    1995-12-01

    Calibration laboratories are faced with the need to become accredited or registered to one or more quality standards. One requirement common to all of these standards is the need to have in place a measurement assurance program. What is a measurement assurance program? Brian Belanger, in Measurement Assurance Programs: Part 1, describes it as a {open_quotes}quality assurance program for a measurement process that quantifies the total uncertainty of the measurements (both random and systematic components of error) with respect to national or designated standards and demonstrates that the total uncertainty is sufficiently small to meet the user`s requirements.{close_quotes} Rolf Schumacher is more specific in Measurement Assurance in Your Own Laboratory. He states, {open_quotes}Measurement assurance is the application of broad quality control principles to measurements of calibrations.{close_quotes} Here, the focus is on one important part of any measurement assurance program: implementation of statistical process control (SPC). Paraphrasing Juran`s Quality Control Handbook, a process is in statistical control if the only observed variations are those that can be attributed to random causes. Conversely, a process that exhibits variations due to assignable causes is not in a state of statistical control. Finally, Carrol Croarkin states, {open_quotes}In the measurement assurance context the measurement algorithm including instrumentation, reference standards and operator interactions is the process that is to be controlled, and its direct product is the measurement per se. The measurements are assumed to be valid if the measurement algorithm is operating in a state of control.{close_quotes} Implicit in this statement is the important fact that an out-of-control process cannot produce valid measurements. 7 figs.

  6. 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

  7. 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.

  8. 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.

  9. Calibration procedure for Slocum glider deployed optical instruments.

    PubMed

    Cetinić, Ivona; Toro-Farmer, Gerardo; Ragan, Matthew; Oberg, Carl; Jones, Burton H

    2009-08-31

    Recent developments in the field of the autonomous underwater vehicles allow the wide usage of these platforms as part of scientific experiments, monitoring campaigns and more. The vehicles are often equipped with sensors measuring temperature, conductivity, chlorophyll a fluorescence (Chl a), colored dissolved organic matter (CDOM) fluorescence, phycoerithrin (PE) fluorescence and spectral volume scattering function at 117 degrees, providing users with high resolution, real time data. However, calibration of these instruments can be problematic. Most in situ calibrations are performed by deploying complementary instrument packages or water samplers in the proximity of the glider. Laboratory calibrations of the mounted sensors are difficult due to the placement of the instruments within the body of the vehicle. For the laboratory calibrations of the Slocum glider instruments we developed a small calibration chamber where we can perform precise calibrations of the optical instruments aboard our glider, as well as sensors from other deployment platforms. These procedures enable us to obtain pre- and post-deployment calibrations for optical fluorescence instruments, which may differ due to the biofouling and other physical damage that can occur during long-term glider deployments. We found that biofouling caused significant changes in the calibration scaling factors of fluorescent sensors, suggesting the need for consistent and repetitive calibrations for gliders as proposed in this paper. PMID:19724540

  10. Evaluation, comparison and calibration of oceanographic instruments

    SciTech Connect

    Not Available

    1985-01-01

    This book reviews oceanographic instrumentation. The parameters for which instrumentation is reviewed are limited to those where continuous monitoring is possible. The discussion is also limited to parameters of interest to physical oceanography and ocean engineering. Specific instruments reviewed include: meterological sensors and instruments; wave sensors; ocean current sensors; pressure sensors; and CTD sensors. Various types of oceanographic measurements are also evaluated.

  11. IECM calibration and data reduction requirements

    NASA Technical Reports Server (NTRS)

    Wills, F. D.; Davis, C. W.

    1981-01-01

    The induced environment contamination monitor (IECM) tape recorder format, as it relates to the ouput of meaningful data from the IECM instrument, is explained. Eight-bit words (or bytes) generate numbers that represent voltage levels of electronic detection probes for each experiment. This information is amalgamated by the IECM Data Acquisition and Control System (DACS). In some cases bits represent certain status situations concerning an experiment, such as whether a valve is opened or closed. Voltages are transformed into meaningful physical phenomena through equations of calibration. Data formats and plots are generated as requested for each IECM experimenter.

  12. Status of Terra and Aqua MODIS Instrument Operation and Calibration

    NASA Astrophysics Data System (ADS)

    Xiong, X.; Wenny, B. N.; Sun, J.; Angal, A.; Salomonson, V. V.

    2013-12-01

    Terra and Aqua MODIS have successfully operated for more than 13 and 11 years since their respective launches in 1999 and 2002. Nearly 40 data products, developed for studies of the earth's land, ocean, and atmosphere, have been routinely generated from calibrated and geo-located MODIS observations and widely distributed to the science and user community. MODIS on-orbit calibration is performed by a set of on-board calibrators, which include a solar diffuser for the reflective solar bands calibration and a blackbody for the thermal emissive bands calibration. MODIS on-board calibrators are regularly operated to monitor on-orbit changes in sensor responses and key performance parameters, such as radiometric calibration coefficients. Since launch, extensive instrument calibration and characterization activities have been scheduled and executed by the MODIS Characterization Support Team (MCST). This presentation provides an overview of both Terra and Aqua MODIS instrument status, their on-orbit operation and calibration activities, and overall long-term performance. It reports calibration improvements (algorithms and look-up tables) made in the latest MODIS data collection (C6). Lessons learned from both Terra and Aqua MODIS and their applications to the S-NPP VIIRS on-orbit calibration are also discussed.

  13. Physical calibration of instruments for the detection of transients

    NASA Astrophysics Data System (ADS)

    Vedrenne, G.; Zenchenko, V. M.; Kuznetsov, A. V.; Niel, M.; Hurley, K.; Chambon, G.; Estulin, I. V.

    The present study describes the ground calibration of the Sneg-2MP (Prognoz 6) and Sneg-2MZ (Venera 11 and 12) instruments for the detection of gamma-ray transients. The basic calibration characteristics are examined including the precision of the time scale of the instrument and the determination of the energy spectrum of events. The construction of the matrix of transition to the electron spectrum is considered along with the calculation of the photon spectrum.

  14. IOT Overview: Calibrations of the VLTI Instruments (MIDI and AMBER)

    NASA Astrophysics Data System (ADS)

    Morel, S.; Rantakyrö, F.; Rivinius, T.; Stefl, S.; Hummel, C.; Brillant, S.; Schöller, M.; Percheron, I.; Wittkowski, M.; Richichi, A.; Ballester, P.

    We present here a short review of the calibration processes that are currently applied to the instruments AMBER and MIDI of the VLTI (Very Large Telescope Interferometer) at Paranal. We first introduce the general principles to calibrate the raw data (the "visibilities") that have been measured by long-baseline optical interferometry. Then, we focus on the specific case of the scientific operation of the VLTI instruments. We explain the criteria that have been used to select calibrator stars for the observations with the VLTI instruments, as well as the routine internal calibration techniques. Among these techniques, the "P2VM" (Pixel-to-Visibility Matrix) in the case of AMBER is explained. Also, the daily monitoring of AMBER and MIDI, that has recently been implemented, is shortly introduced.

  15. Calibration procedure for the polarimetric instrument for Solar Eclipse-98

    NASA Astrophysics Data System (ADS)

    Elmore, David F.; Card, G. L.; Lecinski, A. R.; Lites, Bruce W.; Streander, Kim V.; Tomczyk, Steven

    2000-12-01

    We describe a ground-based eclipse instrument for measuring solar coronal polarization brightness and intensity, and the calibration procedures for this instrument. We present coronal measurements from the February 26, 1998 total solar eclipse observed at Curacao, N.A.. The instrument employs a liquid crystal variable retarder for analysis of coronal broad band linear polarization and collects data on an array detector spanning a 6.5 solar radius field of view. Polarization calibration of the liquid crystal variable retarder utilizes the tangential orientation of coronal polarization to calculate retardance values.

  16. GRACE KBR and Accelerometer Data Reduction and Calibration

    NASA Technical Reports Server (NTRS)

    Rowlands, David D.; Lutheke, Scott B.; Klosko, Steven M.; Lemoine, Frank G.; Williams, Terry A.

    2004-01-01

    The Gravity Recovery and Climate Experiment (GRACE), launched on March 17, 2002, represents the state-of-the-art in geodetic observations of the static and time varying components of the Earth's geopotential field. The fundamental measurement used to observe gravity is the inter-satellite range and range rate between two coplanar, low altitude satellites obtained from a K-band ranging (KBR) system. In addition to the K-band ranging system, each satellite possess a Super-STAR Accelerometer, a GPS receiver/antenna package, Star Cameras and a Laser Retro Reflector (LRR) to complete the compliment of science instruments. The GRACE project has now released two years of Level 1B data derived from the science instruments and sensors. An integral component of our time variable gravity research is the reduction, calibration and analyses of these Level 1B data. In particular we have analyzed several months of K-band ranging (KBR1B), accelerometry (ACC1B) and GPS navigation (GNAV1B) data. Accelerometer calibration and KBR data reduction methodology and results will be presented. We discuss the impact of these analyses on the recovery of time variable gravity.

  17. Planck-LFI: Instrument Design and Ground Calibration Strategy

    NASA Astrophysics Data System (ADS)

    Bersanelli, M.; Aja, B.; Artal, E.; Balasini, M.; Baldan, G.; Battaglia, P.; Bernardino, T.; Bhandari, P.; Blackhurst, E.; Boschini, L.; Bowman, R.; Burigana, C.; Butler, R. C.; Cappellini, B.; Cavaliere, F.; Colombo, F.; Cuttaia, F.; Davis, R.; Dupac, X.; Edgeley, J.; D'Arcangelo, O.; de La Fuente, L.; de Rosa, A.; Ferrari, F.; Figini, L.; Fogliani, S.; Franceschet, C.; Franceschi, E.; Jukkala, P.; Gaier, T.; Galtress, A.; Garavaglia, S.; Gomez-Renasco, F.; Guzzi, P.; Herreros, J. M.; Hoyland, R.; Huges, N.; Kettle, D.; Kilpel, V. H.; Laaninen, M.; Lapolla, M.; Lawrence, C. R.; Lawson, D.; Leonardi, R.; Leutenegger, P.; Levin, S.; Lilje, P. B.; Lubin, P. M.; Maino, D.; Malaspina, M.; Mandolesi, N.; Mari, G.; Maris, M.; Martinez-Gonzalez, E.; Mediavilla, A.; Meinhold, P.; Mennella, A.; Miccolis, M.; Morgante, G.; Nash, A.; Nesti, R.; Pagan, L.; Paine, C.; Pascual, J. P.; Pasian, F.; Pecora, M.; Pezzati, S.; Pospieszalski, M.; Platania, P.; Prina, M.; Rebolo, R.; Roddis, N.; Sabatini, N.; Sandri, M.; Salmon, M. J.; Seiffert, M.; Silvestri, R.; Simonetto, A.; Smoot, G. F.; Sozzi, C.; Stringhetti, L.; Terenzi, L.; Tomasi, M.; Tuovinen, J.; Valenziano, L.; Varis, J.; Villa, F.; Wade, L.; Wilkinson, A.; Winder, F.; Zacchei, A.

    2005-09-01

    The ESA Planck satellite is designed to achieve precision imaging of the Cosmic Microwave Background with an unprecedented combination of angular resolution, sensitivity, spectral range and sky coverage. The Low Frequency Instrument is one of two complementary instruments, and covers 30, 44, and 70 GHz with an array of wideband pseudo-correlation, cryogenic radiometers. Advanced qualification models of the radiometer chains and of the instrument electronics have been manufactured, tested and integrated into the LFI Qualification Model. The main radiometer calibration, RF tuning and performance characterization is carried out at a single radiometer chain level, and then verified at instrument integrated level in dedicated cryofacilities. Here we describe the main requirements and instrument design, and we summarize the radiometer calibration strategy optimised during the qualification activity in view of the LFI Flight Model campaign.

  18. Status of MODIS Instruments and Future Calibration Improvements

    NASA Astrophysics Data System (ADS)

    Xiong, X.; Angal, A.; Wu, A.; Salomonson, V. V.

    2015-12-01

    MODIS is one of the key instruments currently operated on two major missions for the NASA's Earth Observing System (EOS) program: Terra and Aqua launched in 1999 and 2002, respectively. Nearly 40 data products have been routinely generated from both Terra and Aqua MODIS observations and widely distributed to the science community and users worldwide for their studies of the earth's system and changes in its geophysical properties. To date, each MODIS instrument operation remains nominal and its on-board calibrators (OBC) continue to function satisfactorily. On a regular basis, MODIS reflective solar bands (RSB) calibration is performed by a solar diffuser (SD) and a solar diffuser stability monitor (SDSM). For the thermal emissive bands (TEB), an on-board blackbody (BB) provides a scan-by-scan calibration reference. Since launch, extensive calibration and characterization activities have been scheduled and implemented by the MODIS Characterization Support Team (MCST) to produce and update calibration look-up tables (LUT). This presentation provides an overview of both Terra and Aqua MODIS instrument status, their on-orbit operation and calibration activities, and radiometric, spectral, and spatial performance. It describes calibration changes (algorithms and look-up tables) made for the MODIS Level 1B (L1B) data collection 6 (C6) and discusses remaining challenging issues and ongoing effort for future improvements. As expected, lessons from both Terra and Aqua MODIS have benefitted and will continue to help the S-NPP and JPSS VIIRS instruments in terms of on-orbit operation strategies and calibration enhancements.

  19. 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.

  20. 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.

  1. Accuracies of Incoming Radiation: Calibrations of Total Solar Irradiance Instruments

    NASA Astrophysics Data System (ADS)

    Kopp, G.; Harber, D.; Heuerman, K.

    2009-04-01

    All of the energy tracked by the GEWEX Radiative Flux Assessment and the driving energy for Earth climate is incident at the top of the Earth's atmosphere as solar radiation. The total solar irradiance (TSI) has been monitored continually for over 30 years from space. Continuity of these measurements has enabled the creation of composite time series from which the radiative forcing inputs to climate models are derived and solar forcing sensitivities are determined. None of the ten spaceborne TSI instruments contributing to the solar climate data record have been calibrated or validated end-to-end for irradiance accuracy under flight-like conditions, and calibration inaccuracies contribute to seemingly large offsets between the TSI values reported by each instrument. The newest of the flight TSI instruments, the SOlar Radiation and Climate Experiment (SORCE) Total Irradiance Monitor (TIM), measures lower solar irradiance than prior instruments. I will review the accuracies of flight TSI instruments, discuss possible causes for the offsets between them, and describe a recently built calibration facility to improve the accuracies of future TSI instruments. The TSI Radiometer Facility (TRF) enables end-to-end comparisons of TSI instruments to a NIST-calibrated cryogenic radiometer. For the first time, TSI instruments can be validated directly against a cryogenic radiometer under flight-like conditions for measuring irradiance (rather than merely optical power) at solar power levels while under vacuum. The TRF not only validates TSI instrument accuracy, but also can help diagnose the causes of offsets between different instruments. This facility recently validated the accuracy of the TIM to be launched this year on NASA's Glory mission, establishing a baseline that can link the Glory/TIM to future TSI instruments via this ground-based comparison. Similar tests on the TRF with a ground-based SORCE/TIM support the lower TSI values measured by the SORCE flight unit. These

  2. Traceable Micro-Force Sensor for Instrumented Indentation Calibration

    SciTech Connect

    Smith, D T; Shaw, G A; Seugling, R M; Xiang, D; Pratt, J R

    2007-04-02

    Instrumented indentation testing (IIT), commonly referred to as nanoindentation when small forces are used, is a popular technique for determining the mechanical properties of small volumes of material. Sample preparation is relatively easy, usually requiring only that a smooth surface of the material to be tested be accessible to a contact probe, and instruments that combine sophisticated automation with straightforward user interfaces are available commercially from several manufacturers. In addition, documentary standards are now becoming available from both the International Standards Organization (ISO 14577) and ASTM International (E28 WK382) that define test methods and standard practices for IIT, and will allow the technique to be used to produce material property data that can be used in product specifications. These standards also define the required level of accuracy of the force data produced by IIT instruments, as well as methods to verify that accuracy. For forces below 10 mN, these requirements can be difficult to meet, particularly for instrument owners who need to verify the performance of their instrument as it is installed at their site. In this paper, we describe the development, performance and application of an SI-traceable force sensor system for potential use in the field calibration of commercial IIT instruments. The force sensor itself, based on an elastically deforming capacitance gauge, is small enough to mount in a commercial instrument as if it were a test specimen, and is used in conjunction with an ultra-high accuracy capacitance bridge. The sensor system is calibrated with NIST-traceable masses over the range 5.0 {micro}N through 5.0 mN. We will present data on its accuracy and precision, as well its potential application to the verification of force in commercial instrumented indentation instruments.

  3. 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.

  4. 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.

  5. Automatic calibration and correction for intelligent measuring instruments

    NASA Astrophysics Data System (ADS)

    Xu, Zhen-Gao; Yang, Shunian; Li, Zhu

    1993-09-01

    A microprocessor-controlled measuring system model is described in this paper . This system which consists of a sliding guide with a linear motion slide plate a linear inductosyn the signal processing circuit and the microprocessor system can be used on some machine tools such as the lathe the milling machine the drilling machine etc. to take measurements of the absolute displacement of slide plates in process. In order to maintain the expectant accuracy in measurement over a long time it is necessary for the measuring system to be calibrated and corrected periodically . The mathematical models used to approximate the error curve are developed. By utilizing the computing ability of microprocessor the automatic calibration and correction for intelligent instruments can be realized conveniently and an expectant accuracy can be maintained in the period between two successive auto-calibrations.

  6. 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.

  7. Solar-Stellar Irradiance Comparison Experiment 1. II - Instrument calibrations

    NASA Technical Reports Server (NTRS)

    Woods, Thomas N.; Rottman, Gary J.; Ucker, Gregory J.

    1993-01-01

    The science objective for the Solar-Stellar Irradiance Comparison Experiment (SOLSTICE) is to accurately measure the full disk solar spectral irradiance in the ultraviolet (UV) spectral region over a long time period. The SOLSTICE design was driven by the requirement for long-term, precise solar photometry conducted from space. The SOLSTICE 1 is on the Upper Atmosphere Research Satellite (UARS), launched in September 1991 with the possibility for a 10-year operational mission. The in-flight calibration for SOLSTICE to meet its primary objective is the routine measurements of the UV radiation from a set of early-type stars, using the identical optical elements employed for the solar observations. The extensive preflight calibrations of the instrument have yielded a precise characterization of the three SOLSTICE channels. Details of the preflight and in-flight SOLSTICE calibrations are discussed in this paper.

  8. 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.

  9. 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.

  10. 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.

  11. 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...

  12. 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. 35.2061 Section 35.2061 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL Records § 35.2061 Records of radiation survey instrument calibrations. A licensee shall maintain a record of radiation survey instrument calibrations...

  13. 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...

  14. 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...

  15. 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...

  16. 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.

  17. 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.

  18. Calibration and testing of the Planck-LFI QM instrument

    NASA Astrophysics Data System (ADS)

    Mennella, A.; Aja, B.; Artal, E.; Balasini, M.; Baldan, G.; Battaglia, P.; Bernardino, T.; Bersanelli, M.; Blackhurst, E.; Boschini, L.; Burigana, C.; Butler, R. C.; Cappellini, B.; Colombo, F.; Cuttaia, F.; D'Arcangelo, O.; Donzelli, S.; Davis, R.; De La Fuente, L.; Ferrari, F.; Figini, L.; Fogliani, S.; Franceschet, C.; Franceschi, E.; Gaier, T.; Galeotta, S.; Garavaglia, S.; Gregorio, A.; Guerrini, M.; Hoyland, R.; Hughes, N.; Jukkala, P.; Kettle, D.; Laaninen, M.; Lapolla, P. M.; Lawson, D.; Leonardi, R.; Leutenegger, P.; Mari, G.; Meinhold, P.; Miccolis, M.; Maino, D.; Malaspina, M.; Mandolesi, N.; Maris, M.; Martinez-Gonzalez, E.; Morgante, G.; Pagan, L.; Pasian, F.; Platania, P.; Pecora, M.; Pezzati, S.; Popa, L.; Poutanen, T.; Pospieszalski, M.; Roddis, N.; Salmon, M.; Sandri, M.; Silvestri, R.; Simonetto, A.; Sozzi, C.; Stringhetti, L.; Terenzi, L.; Tomasi, M.; Tuovinen, J.; Valenziano, L.; Varis, J.; Villa, F.; Wilkinson, A.; Winder, F.; Zacchei, A.

    2006-06-01

    In this paper we present the test results of the qualification model (QM) of the LFI instrument, which is being developed as part of the ESA Planck satellite. In particular we discuss the calibration plan which has defined the main requirements of the radiometric tests and of the experimental setups. Then we describe how these requirements have been implemented in the custom-developed cryo-facilities and present the main results. We conclude with a discussion of the lessons learned for the testing of the LFI Flight Model (FM).

  19. Gemini Planet Imager observational calibrations I: Overview of the GPI data reduction pipeline

    NASA Astrophysics Data System (ADS)

    Perrin, Marshall D.; Maire, Jérôme; Ingraham, Patrick; Savransky, Dmitry; Millar-Blanchaer, Max; Wolff, Schuyler G.; Ruffio, Jean-Baptiste; Wang, Jason J.; Draper, Zachary H.; Sadakuni, Naru; Marois, Christian; Rajan, Abhijith; Fitzgerald, Michael P.; Macintosh, Bruce; Graham, James R.; Doyon, René; Larkin, James E.; Chilcote, Jeffrey K.; Goodsell, Stephen J.; Palmer, David W.; Labrie, Kathleen; Beaulieu, Mathilde; De Rosa, Robert J.; Greenbaum, Alexandra Z.; Hartung, Markus; Hibon, Pascale; Konopacky, Quinn; Lafreniere, David; Lavigne, Jean-Francois; Marchis, Franck; Patience, Jenny; Pueyo, Laurent; Rantakyrö, Fredrik T.; Soummer, Rémi; Sivaramakrishnan, Anand; Thomas, Sandrine; Ward-Duong, Kimberly; Wiktorowicz, Sloane

    2014-07-01

    The Gemini Planet Imager (GPI) has as its science instrument an infrared integral field spectrograph/polarimeter (IFS). Integral field spectrographs are scientificially powerful but require sophisticated data reduction systems. For GPI to achieve its scientific goals of exoplanet and disk characterization, IFS data must be reconstructed into high quality astrometrically and photometrically accurate datacubes in both spectral and polarization modes, via flexible software that is usable by the broad Gemini community. The data reduction pipeline developed by the GPI instrument team to meet these needs is now publicly available following GPI's commissioning. This paper, the first of a series, provides a broad overview of GPI data reduction, summarizes key steps, and presents the overall software framework and implementation. Subsequent papers describe in more detail the algorithms necessary for calibrating GPI data. The GPI data reduction pipeline is open source, available from planetimager.org, and will continue to be enhanced throughout the life of the instrument. It implements an extensive suite of task primitives that can be assembled into reduction recipes to produce calibrated datasets ready for scientific analysis. Angular, spectral, and polarimetric differential imaging are supported. Graphical tools automate the production and editing of recipes, an integrated calibration database manages reference files, and an interactive data viewer customized for high contrast imaging allows for exploration and manipulation of data.

  20. Integrated imaging instrument for self-calibrated fluorescence protein microarrays

    NASA Astrophysics Data System (ADS)

    Reddington, A. P.; Monroe, M. R.; Ünlü, M. S.

    2013-10-01

    Protein microarrays, or multiplexed and high-throughput assays, monitor multiple protein binding events to facilitate the understanding of disease progression and cell physiology. Fluorescence imaging is a popular method to detect proteins captured by immobilized probes with high sensitivity and specificity. Reliability of fluorescence assays depends on achieving minimal inter- and intra-assay probe immobilization variation, an ongoing challenge for protein microarrays. Therefore, it is desirable to establish a label-free method to quantify the probe density prior to target incubation to calibrate the fluorescence readout. Previously, a silicon oxide on silicon chip design was introduced to enhance the fluorescence signal and enable interferometric imaging to self-calibrate the signal with the immobilized probe density. In this paper, an integrated interferometric reflectance imaging sensor and wide-field fluorescence instrument is introduced for sensitive and calibrated microarray measurements. This platform is able to analyze a 2.5 mm × 3.4 mm area, or 200 spots (100 μm diameter with 200 μm pitch), in a single field-of-view.

  1. 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.

  2. Instrument calibration and data processing systems of Gaia

    NASA Astrophysics Data System (ADS)

    Castañeda-Pons, J.; Torra, J.; Fabricius, C.

    2013-05-01

    The Gaia mission will provide unprecedented positional and velocity measurements of about one billion stars in our Galaxy and throughout the local group. The data processing system is an integral and critical part of the mission. We are developing the Initial Data Treatment system, which will process the raw data arriving from the satellite in near-real-time. It will provide a first estimation of the satellite attitude, the image parameters, and a first cross-match with the Gaia catalogue. We are also developing the Intermediate Data Updating system, which calibrates the instrument response and refines image parameters and cross-match by running on the complete set of raw data, once or twice a year during the mission. Such massive re-processing needs a super-computer such as MareNostrum, where it is planned to run the system. In this paper we describe these data processing systems and the preliminary tests and results obtained with simulated data.

  3. Results of the use of an automated electrical measuring instrument calibration system

    NASA Astrophysics Data System (ADS)

    Barbier, Pierre

    A system for calibrating digital multimeter and stimulus generators was developed. Software was written for fully automated machines, nonautomated instruments with digital output, and entirely manual machines. The advantages in terms of calibration quality, productivity, and operator motivation are stressed.

  4. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2010-10-01

    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 as 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 a 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-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. Here we describe the laser-based calibration and the traditional broad-band sourcebased 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.

  6. 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.

  7. The Challenge of Data Reduction for Multiple Instruments on the Stratospheric Observatory for Infrared Astronomy (SOFIA)

    NASA Astrophysics Data System (ADS)

    Charcos-Llorens, M. V.; Krzaczek, R.; Shuping, R. Y.; Lin, L.

    2011-07-01

    SOFIA, the Stratospheric Observatory For Infrared Astronomy, presents a number of interesting challenges for the development of a data reduction environment which, at its initial phase, will have to incorporate pipelines from seven different instruments developed by organizations around the world. Therefore, the SOFIA data reduction software must run code which has been developed in a variety of dissimilar environments, e.g., IDL, Python, Java, C++. Moreover, we anticipate this diversity will only increase in future generations of instrumentation. We investigated three distinctly different situations for performing pipelined data reduction in SOFIA: (1) automated data reduction after data archival at the end of a mission, (2) re-pipelining of science data with updated calibrations or optimum parameters, and (3) the interactive user-driven local execution and analysis of data reduction by an investigator. These different modes would traditionally result in very different software implementations of algorithms used by each instrument team, in effect tripling the amount of data reduction software that would need to be maintained by SOFIA. We present here a unique approach for enfolding all the instrument-specific data reduction software in the observatory framework and verifies the needs for all three reduction scenarios as well as the standard visualization tools. The SOFIA data reduction structure would host the different algorithms and techniques that the instrument teams develop in their own programming language and operating system. Ideally, duplication of software is minimized across the system because instrument teams can draw on software solutions and techniques previously delivered to SOFIA by other instruments. With this approach, we minimize the effort for analyzing and developing new software reduction pipelines for future generation instruments. We also explore the potential benefits of this approach in the portability of the software to an ever

  8. Measurement reduction for mutual coupling calibration in DOA estimation

    NASA Astrophysics Data System (ADS)

    Aksoy, Taylan; Tuncer, T. Engin

    2012-01-01

    Mutual coupling is an important source of error in antenna arrays that should be compensated for super resolution direction-of-arrival (DOA) algorithms, such as Multiple Signal Classification (MUSIC) algorithm. A crucial step in array calibration is the determination of the mutual coupling coefficients for the antenna array. In this paper, a system theoretic approach is presented for the mutual coupling characterization of antenna arrays. The comprehension and implementation of this approach is simple leading to further advantages in calibration measurement reduction. In this context, a measurement reduction method for antenna arrays with omni-directional and identical elements is proposed which is based on the symmetry planes in the array geometry. The proposed method significantly decreases the number of measurements during the calibration process. This method is evaluated using different array types whose responses and the mutual coupling characteristics are obtained through numerical electromagnetic simulations. It is shown that a single calibration measurement is sufficient for uniform circular arrays. Certain important and interesting characteristics observed during the experiments are outlined.

  9. Cross-Calibration of the GOES-R SUVI with On-Orbit Solar EUV Instruments

    NASA Astrophysics Data System (ADS)

    Darnel, Jonathan; Seaton, Daniel B.

    2016-05-01

    Maintaining the calibration of on-orbit instruments has always been a challenge, but one which is crucial for the accuracy of the data record. This challenge is magnified for solar Extreme UltraViolet (EUV) instruments. Absolute calibration is out of the question as stable and known sources of EUV irradiance are not practical in on-orbit environments. This leaves relative calibration against other solar EUV instruments whose calibration has been well tracked. The need for such cross-calibration efforts is especially acute for an instrument like the Solar Ultraviolet Imager (SUVI), which will fly on the GOES-R spacecraft later this year and is expected to provide two decades of solar observation between four identical instruments. Not only must calibration between the four instruments in the SUVI line be maintained, but the relative calibration between SUVI and both present day imagers like SDO/AIA and PROBA2/SWAP and future instruments yet to be developed must be established as well. We present the methodology developed using current on-orbit solar EUV instruments in order to maintain the calibration of the SUVI instruments.

  10. Calibration of combined bending-torsion fatigue reliability data reduction

    NASA Technical Reports Server (NTRS)

    Kececioglu, D.; Mcconnell, J. B.

    1969-01-01

    The combined bending-torsion fatigue reliability research machines are described. Three such machines are presently in operation. The calibration of these machines is presented in depth. Fatigue data generated with these machines for SAE 4340 steel grooved specimens subjected to reversed bending and steady torque loading are given. The data reduction procedure is presented. Finally, some comments are made about notch sensitivity and stress concentration as applied to combined fatigue.

  11. 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.

  12. 10 CFR 35.61 - Calibration of survey instruments.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... to show compliance with this part and 10 CFR Part 20 before first use, annually, and following a 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, 2014 CFR

    2014-01-01

    ... to show compliance with this part and 10 CFR part 20 before first use, annually, and following a 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. 10 CFR 35.61 - Calibration of survey instruments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... to show compliance with this part and 10 CFR Part 20 before first use, annually, and following a 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...

  15. Calibration Interval Adjustment of a Measuring Instrument in Industries During Long-term Use

    NASA Astrophysics Data System (ADS)

    Natalinova, N.; Ilina, N.; Frantcuzskaia, E.

    2016-06-01

    Calibration interval adjustment of measuring instruments is one of the urgent tasks in industries. The article represents the calibration interval calculation of the potentiometer PCB-4P according to the verifications for the 4 year period of the Metrological Department in the aviation plant. The calibration interval is shown to be increased according to the calculation of its reliability and stability of metrological characteristics.

  16. 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.

  17. 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.

  18. 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.

  19. Improving RR Lyrae Distance Indicators Through Instrumentation, Observation, and Calibration

    NASA Astrophysics Data System (ADS)

    Klein, Christopher Robert

    Due to technological limitations and peculiarities of Nature, classes of astronomical distance indicators are applicable only in specific distance ranges. The Cosmic Distance Ladder is the framework by which we link together distance indicators, climbing from one rung to the next, in order to measure physical distance on an absolute scale. The object of this dissertation is one category of distance indicators, called RR Lyrae pulsating variable stars, which has commanded substantial scientific study for more than a century. RR Lyrae stars are low mass (M ≈ 0.7 Msol), old (age > 1010 yr) Population II objects that are found mixed in with any stellar population of requisite age. They are unstable to radial harmonic oscillations (pulsations) because of their specific mass, metallicity content, and interior composition. It has been empirically determined, and theoretically justified, that the pulsation periods of individual RR Lyrae stars are correlated with their intrinsic luminosity; hereafter referred to as the RR Lyrae period--luminosity relation. Thus, if one can measure the period of a star (a relatively straightforward task given sufficient observations), then one can use that star as a standard candle and infer its distance. The work in this dissertation is aimed at improving our understanding of the period--luminosity relation of RR Lyrae stars, and particularly at improving the precision of RR Lyrae distance measurements. By leveraging (and advancing) new observational facilities, gathering an abundance of new classical observations, and developing new statistical methods to combine a wealth of multi-wavelength data, this goal has been accomplished. In this dissertation I describe the involved methodology and report distances to a calibration sample of 134 RR Lyrae stars with a median fractional distance error of 0.66 per cent. In the following chapters I describe the arc of this research. First, I present an instrumentation development project that

  20. Transfer of Calibration for barley quality from dispersive intrument to fourier transform near-infrared instrument

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study deals with transferring the near-infrared (NIR) calibration models for quality assessment of barley between two instruments with different resolutions and number of data points, a Fourier transform instrument (master) and a dispersive instrument (slave). A file of spectra from 206 ground ...

  1. 40 CFR 92.117 - Gas meter or flow instrumentation calibration, particulate measurement.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Gas meter or flow instrumentation... ENGINES Test Procedures § 92.117 Gas meter or flow instrumentation calibration, particulate measurement. (a) Sampling for particulate emissions requires the use of gas meters or flow instrumentation...

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

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Gas meter or flow instrumentation... ENGINES Test Procedures § 92.117 Gas meter or flow instrumentation calibration, particulate measurement. (a) Sampling for particulate emissions requires the use of gas meters or flow instrumentation...

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

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Gas meter or flow instrumentation... ENGINES Test Procedures § 92.117 Gas meter or flow instrumentation calibration, particulate measurement. (a) Sampling for particulate emissions requires the use of gas meters or flow instrumentation...

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

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Gas meter or flow instrumentation... ENGINES Test Procedures § 92.117 Gas meter or flow instrumentation calibration, particulate measurement. (a) Sampling for particulate emissions requires the use of gas meters or flow instrumentation...

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

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Gas meter or flow instrumentation... ENGINES Test Procedures § 92.117 Gas meter or flow instrumentation calibration, particulate measurement. (a) Sampling for particulate emissions requires the use of gas meters or flow instrumentation...

  6. Use of rotating pinholes and reticles for calibration of cloud droplet instrumentation

    NASA Technical Reports Server (NTRS)

    Hovenac, Edward A.; Hirleman, E. Dan

    1991-01-01

    Calibration devices for the Forward Scattering Spectrometer Probe (FSSP) and the Optical Array Probe (OAP) were developed. The device used with the FSSP is a rotating pinhole calibrator. It utilizes light diffracted by a pinhole of a known diameter to simulate scattered light from a water droplet. This device can be used to calibrate the FSSP, measure the FSSP's optical collection angles and for instrument alignment and troubleshooting. The device used with the OAP is a rotating reticle calibrator. Chrome disks of a known diameter on the reticle are used for calibration of the OAP and for determining the OAP's response to out-of-focus particles in the probe volume.

  7. On-ground calibration of the BEPICOLOMBO/SIMBIO-SYS at instrument level

    NASA Astrophysics Data System (ADS)

    Rodriguez-Ferreira, J.; Poulet, F.; Eng, P.; Longval, Y.; Dassas, K.; Arondel, A.; Langevin, Y.; Capaccioni, F.; Filacchione, G.; Palumbo, P.; Cremonese, G.; Dami, M.

    2012-04-01

    The Mercury Planetary Orbiter/BepiColombo carries an integrated suite of instruments, the Spectrometer and Imagers for MPO BepiColombo-Integrated Observatory SYStem (SIMBIO-SYS). SIMBIO-SYS has 3 channels: a stereo imaging system (STC), a high-resolution imager (HRIC) and a visible-near-infrared imaging spectrometer (VIHI). SIMBIO-SYS will scan the surface of Mercury with these three channels and determine the physical, morphological and compositional properties of the entire planet. Before integration on the S/C, an on-ground calibration at the channels and at the instrument levels will be performed so as to describe the instrumental responses as a function of various parameters that might evolve while the instruments will be operating [1]. The Institut d'Astrophysique Spatiale (IAS) is responsible for the on-ground instrument calibration at the instrument level. During the 4 weeks of calibration campaign planned for June 2012, the instrument will be maintained in a mechanical and thermal environment simulating the space conditions. Four Optical stimuli (QTH lamp, Integrating Sphere, BlackBody with variable temperature from 50 to 1200°C and Monochromator), are placed over an optical bench to illuminate the four channels so as to make the radiometric calibration, straylight monitoring, as well as spectral proofing based on laboratory mineral samples. The instrument will be mounted on a hexapod placed inside a thermal vacuum chamber during the calibration campaign. The hexapod will move the channels within the well-characterized incoming beam. We will present the key activities of the preparation of this calibration: the derivation of the instrument radiometric model, the implementation of the optical, mechanical and software interfaces of the calibration assembly, the characterization of the optical bench and the definition of the calibration procedures.

  8. Planck pre-launch status: Low Frequency Instrument calibration and expected scientific performance

    NASA Astrophysics Data System (ADS)

    Mennella, A.; Bersanelli, M.; Butler, R. C.; Cuttaia, F.; D'Arcangelo, O.; Davis, R. J.; Frailis, M.; Galeotta, S.; Gregorio, A.; Lawrence, C. R.; Leonardi, R.; Lowe, S. R.; Mandolesi, N.; Maris, M.; Meinhold, P.; Mendes, L.; Morgante, G.; Sandri, M.; Stringhetti, L.; Terenzi, L.; Tomasi, M.; Valenziano, L.; Villa, F.; Zacchei, A.; Zonca, A.; Balasini, M.; Franceschet, C.; Battaglia, P.; Lapolla, P. M.; Leutenegger, P.; Miccolis, M.; Pagan, L.; Silvestri, R.; Aja, B.; Artal, E.; Baldan, G.; Bastia, P.; Bernardino, T.; Boschini, L.; Cafagna, G.; Cappellini, B.; Cavaliere, F.; Colombo, F.; de La Fuente, L.; Edgeley, J.; Falvella, M. C.; Ferrari, F.; Fogliani, S.; Franceschi, E.; Gaier, T.; Gomez, F.; Herreros, J. M.; Hildebrandt, S.; Hoyland, R.; Hughes, N.; Jukkala, P.; Kettle, D.; Laaninen, M.; Lawson, D.; Leahy, P.; Levin, S.; Lilje, P. B.; Maino, D.; Malaspina, M.; Manzato, P.; Marti-Canales, J.; Martinez-Gonzalez, E.; Mediavilla, A.; Pasian, F.; Pascual, J. P.; Pecora, M.; Peres-Cuevas, L.; Platania, P.; Pospieszalsky, M.; Poutanen, T.; Rebolo, R.; Roddis, N.; Salmon, M.; Seiffert, M.; Simonetto, A.; Sozzi, C.; Tauber, J.; Tuovinen, J.; Varis, J.; Wilkinson, A.; Winder, F.

    2010-09-01

    We present the calibration and scientific performance parameters of the Planck Low Frequency Instrument (LFI) measured during the ground cryogenic test campaign. These parameters characterise the instrument response and constitute our optimal pre-launch knowledge of the LFI scientific performance. The LFI shows excellent 1/f stability and rejection of instrumental systematic effects; its measured noise performance shows that LFI is the most sensitive instrument of its kind. The calibration parameters will be updated during flight operations until the end of the mission.

  9. THE STANDARD CALIBRATION INSTRUMENT AUTOMATION SYSTEM FOR THE ATOMIC ABSORPTION SPECTROPHOTOMETER. PART III: PROGRAM DOCUMENTATION

    EPA Science Inventory

    This report contains complete documentation for the 15 programs and 11 data files of the EPA Atomic Absorption Instrument Automation System. The system incorporates the following major features: (1) multipoint calibration using first, second, or third degree regression or linear ...

  10. The GEMS X-Ray Polarlimeter: Instrument Concpet and Calibration Requirements

    NASA Technical Reports Server (NTRS)

    Jahoda, Keith

    2010-01-01

    The instrument and detector concepts for the Gravity and Extreme Magnetism Small Explorer (GEMS) X-ray polarimetry mission will be presented. The calibration requirements for astrophysical X-ray polarimeters in general and GEMS in particular will be discussed.

  11. Development of NIR calibration for determining quality of barley as a fuel ethanol source and calibration transfer between instruments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recently there has been growing interest in using barley as a feedstock for fuel ethanol in the U.S. This study focused on potential of near infrared (NIR) spectroscopy for quality evaluation of barley as a rapid and non-destructive analytical method and calibration transfer between two instrument...

  12. 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,

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

    DOE PAGESBeta

    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 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

  14. 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.

  15. 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. PMID:26836861

  16. 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.

  17. 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.

  18. Absolute calibration of Landsat instruments using the moon.

    USGS Publications Warehouse

    Kieffer, H.H.; Wildey, R.L.

    1985-01-01

    A lunar observation by Landsat could provide improved radiometric and geometric calibration of both the Thematic Mapper and the Multispectral Scanner in terms of absolute radiometry, determination of the modulation transfer function, and sensitivity to scattered light. A pitch of the spacecraft would be required. -Authors

  19. 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.

  20. Peak exposures in aluminium potrooms: instrument development and field calibration.

    PubMed

    Carter, Stephanie R; Seixas, Noah S; Thompson, Mary Lou; Yost, Michael G

    2004-11-01

    Aluminium smelter potrooms are unique in that workplace exposures to hydrogen fluoride (HF), sulfur dioxide (SO2), and particulate matter occur simultaneously for some tasks. The peak exposures to these contaminants are of increasing interest in discovering the etiology of respiratory health effects. While a variety of direct-reading instruments are available for sulfur dioxide and particulate matter, only a few exist for hydrogen fluoride. The sensors in these HF instruments have a cross-sensitivity to sulfur dioxide making it difficult to monitor HF in an environment that also contains SO2. To overcome this problem, we assessed the simultaneous use of two electrochemical instruments: one with a SO2 sensor that does not respond to HF and the second with a hydrogen fluoride sensor that responds to both HF and SO2 in a 1 : 1 ratio, termed 'total acid gas'. The difference in the response between the two instruments should indicate the HF concentration: [HF + SO2] minus SO2 equals HF. The performance characteristics of this sampling train were evaluated in the laboratory through the generation of both HF and SO2 with permeation tubes. The response and recovery times for the SO2 only instrument were acceptable (6 and 15 s, respectively), but the "total acid gas" instrument exhibited both slow response and slow recovery approaching three and six min. The association between the traditional integrated filter sampling method and the direct-reading instrument for SO2 is 0.80 (Spearman's rho). The use of the digital filter strengthens the association between the HF direct-reading instrument and the integrated samples from 0.41 to 0.68. PMID:15536509

  1. 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.

  2. The Dynamic Torque Calibration Unit: An instrument for the characterization of bearings used in gimbal applications

    NASA Technical Reports Server (NTRS)

    Jandura, Louise

    1991-01-01

    The Dynamic Torque Calibration Unit (DTCU), an instrument for the characterization of duplex ball bearing pairs used in gimbal applications, was designed and built. The design and operation of the unit are described. Preliminary data from the instrument are presented to illustrate the kinds of experiments that can be performed with the DTCU.

  3. Automatic calibration system for analog instruments based on DSP and CCD sensor

    NASA Astrophysics Data System (ADS)

    Lan, Jinhui; Wei, Xiangqin; Bai, Zhenlong

    2008-12-01

    Currently, the calibration work of analog measurement instruments is mainly completed by manual and there are many problems waiting for being solved. In this paper, an automatic calibration system (ACS) based on Digital Signal Processor (DSP) and Charge Coupled Device (CCD) sensor is developed and a real-time calibration algorithm is presented. In the ACS, TI DM643 DSP processes the data received by CCD sensor and the outcome is displayed on Liquid Crystal Display (LCD) screen. For the algorithm, pointer region is firstly extracted for improving calibration speed. And then a math model of the pointer is built to thin the pointer and determine the instrument's reading. Through numbers of experiments, the time of once reading is no more than 20 milliseconds while it needs several seconds if it is done manually. At the same time, the error of the instrument's reading satisfies the request of the instruments. It is proven that the automatic calibration system can effectively accomplish the calibration work of the analog measurement instruments.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Earth observation sensor calibration using a global instrumented and automated network of test sites (GIANTS)

    NASA Astrophysics Data System (ADS)

    Teillet, Phil M.; Thome, Kurtis J.; Fox, Nigel P.; Morisette, Jeffrey T.

    2001-12-01

    Calibration is critical for useful long-term data records, as well as independent data quality control. However, in the context of Earth observation sensors, post-launch calibration and the associated quality assurance perspective are far from operational. This paper explores the possibility of establishing a global instrumented and automated network of test sites (GIANTS) for post-launch radiometric calibration of Earth observation sensors. It is proposed that a small number of well-instrumented benchmark test sites and data sets for calibration be supported. A core set of sensors, measurements, and protocols would be standardized across all participating test sites and the measurement data sets would undergo identical processing at a central secretariat. The network would provide calibration information to supplement or substitute for on-board calibration, would reduce the effort required by individual agencies, and would provide consistency for cross-platform studies. Central to the GIANTS concept is the use of automation, communication, coordination, visibility, and education, all of which can be facilitated by greater use of advanced in-situ sensor and telecommunication technologies. The goal is to help ensure that the resources devoted to remote sensing calibration benefit the intended user community and facilitate the development of new calibration methodologies (research and development) and future specialists (education and training).

  9. 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. PMID:18784780

  10. 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.

  11. 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.

  12. 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

  13. 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

  14. 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.

  15. 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.

  16. Development of Long-term Datasets from Satellite BUV Instruments: The "Soft" Calibration Approach

    NASA Technical Reports Server (NTRS)

    Bhartia, Pawan K.; Taylor, Steven; Jaross, Glen

    2005-01-01

    The first BUV instrument was launched in April 1970 on NASA's Nimbus4 satellite. More than a dozen instruments, broadly based on the same principle, but using very different technologies, have been launched in the last 35 years on NASA, NOAA, Japanese and European satellites. In this paper we describe the basic principles of the "soft" calibration approach that we have successfully applied to the data from many of these instruments to produce a consistent long-term record of total ozone, ozone profile and aerosols. This approach is based on using accurate radiative transfer models and assumed/known properties of the atmosphere in ultraviolet to derive calibration parameters. Although the accuracy of the results inevitably depends upon how well the assumed atmospheric properties are known, the technique has several built-in cross- checks that improve the robustness of the method. To develop further confidence in the data the soft calibration technique can be combined with data collected from few well- calibrated ground-based instruments. We will use examples from past and present BUV instruments to show how the method works.

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

    SciTech Connect

    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.

  18. 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.

  19. Inertial Sensor Error Reduction through Calibration and Sensor Fusion.

    PubMed

    Lambrecht, Stefan; Nogueira, Samuel L; Bortole, Magdo; Siqueira, Adriano A G; Terra, Marco H; Rocon, Eduardo; Pons, José L

    2016-01-01

    This paper presents the comparison between cooperative and local Kalman Filters (KF) for estimating the absolute segment angle, under two calibration conditions. A simplified calibration, that can be replicated in most laboratories; and a complex calibration, similar to that applied by commercial vendors. The cooperative filters use information from either all inertial sensors attached to the body, Matricial KF; or use information from the inertial sensors and the potentiometers of an exoskeleton, Markovian KF. A one minute walking trial of a subject walking with a 6-DoF exoskeleton was used to assess the absolute segment angle of the trunk, thigh, shank, and foot. The results indicate that regardless of the segment and filter applied, the more complex calibration always results in a significantly better performance compared to the simplified calibration. The interaction between filter and calibration suggests that when the quality of the calibration is unknown the Markovian KF is recommended. Applying the complex calibration, the Matricial and Markovian KF perform similarly, with average RMSE below 1.22 degrees. Cooperative KFs perform better or at least equally good as Local KF, we therefore recommend to use cooperative KFs instead of local KFs for control or analysis of walking. PMID:26901198

  20. Inertial Sensor Error Reduction through Calibration and Sensor Fusion

    PubMed Central

    Lambrecht, Stefan; Nogueira, Samuel L.; Bortole, Magdo; Siqueira, Adriano A. G.; Terra, Marco H.; Rocon, Eduardo; Pons, José L.

    2016-01-01

    This paper presents the comparison between cooperative and local Kalman Filters (KF) for estimating the absolute segment angle, under two calibration conditions. A simplified calibration, that can be replicated in most laboratories; and a complex calibration, similar to that applied by commercial vendors. The cooperative filters use information from either all inertial sensors attached to the body, Matricial KF; or use information from the inertial sensors and the potentiometers of an exoskeleton, Markovian KF. A one minute walking trial of a subject walking with a 6-DoF exoskeleton was used to assess the absolute segment angle of the trunk, thigh, shank, and foot. The results indicate that regardless of the segment and filter applied, the more complex calibration always results in a significantly better performance compared to the simplified calibration. The interaction between filter and calibration suggests that when the quality of the calibration is unknown the Markovian KF is recommended. Applying the complex calibration, the Matricial and Markovian KF perform similarly, with average RMSE below 1.22 degrees. Cooperative KFs perform better or at least equally good as Local KF, we therefore recommend to use cooperative KFs instead of local KFs for control or analysis of walking. PMID:26901198

  1. Smos Instrument Performance and Calibration after 4 Years and 6 Months in Orbit

    NASA Astrophysics Data System (ADS)

    Martin-Neira, Manuel; Corbella, Ignasi; Torres, Francesc; Kainulainen, Juha; Oliva, Roger; Closa, Josep; Cabot, François; Khazaal, Ali; Anterrieu, Eric; Barbosa, Jose; Gutierrez, Antonio; Freitas, Sofia; Tenerelli, Joe; Martin-Porqueras, Fernando; Díez-García, Raul; Fauste, Jorge; Delwart, Steven; Crapolicchio, Raffaele; Suess, Martin

    2014-05-01

    cancellation algorithms, including or not the limited set of Sun acquisition responses which are available. The reduction of the spatial ripple and the residual land-sea contamination will require further understanding of fundamental image reconstruction issues as well as more elaborated ways to compute and apply the Ocean Target Transformation. Finally, the mitigation of the temporal variations will be attempted using a more sophisticated model of the front-end losses of the receivers, applied to the current instrument configuration as well as to the so called ALL-LICEF mode. An overview of the results of the second mission reprocessing at Level-1 and the progress achieved in both calibration and image reconstruction by April 2014, as anticipated above, will be presented in this contribution.

  2. 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.

  3. 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

  4. The GEMS X-Ray Polarimeter: Instrument Concept and Calibration Requirements

    NASA Technical Reports Server (NTRS)

    Jahoda, Keith

    2010-01-01

    The instrument and detector concepts for the Gravity and Extreme Magnetism Small Explorer (GEMS) X-ray polarimetry mission will be presente d. The calibration requirements for astrophysical X-ray polarimeters in general and GEMS in particular will be discussed.

  5. Calibration sources for the soft x-ray spectrometer instrument on ASTRO-H

    NASA Astrophysics Data System (ADS)

    de Vries, C. P.; Lowes, P.; den Herder, J. W.; Aarts, H.; Haas, D.; Mitsuda, K.; Yamasaki, N. Y.; Kelley, R.; Kilbourne, C.; Gendreau, K.

    2012-09-01

    The SXS instrument is the Soft X-ray micro-calorimeter Spectrometer planned for the Japanese ASTRO-H satellite, scheduled to be launched in 2014. In this paper we describe the X-ray calibration sources used in this instrument. These sources use light sensitive photo-cathodes to generate electrons, which in turn generate the X-rays. This design has the unique property to allow for fast discrete pulsations of the generated X-rays. This enables the energy scale calibration of the instrument simultaneously with astronomical observations, without adding to the background in the astronomical data. Flight-model sources have been made, and a number of them have been operating in the past several months to monitor their behaviour. Here we report on the characterisation and performance of these sources. In addition, we will elaborate on the nature and expected accuracy of the energy calibration, in relation to the expected stability of the instrument, given the calibration source strength and its mode of operation.

  6. 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.

  7. 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.

  8. 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.

  9. Viking lander camera geometry calibration report. Volume 1: Test methods and data reduction techniques

    NASA Technical Reports Server (NTRS)

    Wolf, M. B.

    1981-01-01

    The determination and removal of instrument signature from Viking Lander camera geometric data are described. All tests conducted as well as a listing of the final database (calibration constants) used to remove instrument signature from Viking Lander flight images are included. The theory of the geometric aberrations inherent in the Viking Lander camera is explored.

  10. 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

    ... calibration; particulate, methanol, and formaldehyde measurement. 86.1320-90 Section 86.1320-90 Protection of... instrumentation calibration; particulate, methanol, and formaldehyde measurement. (a) Sampling for particulate, methanol and formaldehyde emissions requires the use of gas meters or flow instrumentation to...

  11. 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

    ... calibration; particulate, methanol, and formaldehyde measurement. 86.1320-90 Section 86.1320-90 Protection of... instrumentation calibration; particulate, methanol, and formaldehyde measurement. (a) Sampling for particulate, methanol and formaldehyde emissions requires the use of gas meters or flow instrumentation to...

  12. 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... MEDICAL USE OF BYPRODUCT MATERIAL Records § 35.2060 Records of calibrations of instruments used to measure the activity of unsealed byproduct material. A licensee shall maintain a record of...

  13. 10 CFR 35.2060 - Records of calibrations of instruments used to measure the activity of unsealed byproduct material.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Records of calibrations of instruments used to measure the... MEDICAL USE OF BYPRODUCT MATERIAL Records § 35.2060 Records of calibrations of instruments used to measure the activity of unsealed byproduct material. A licensee shall maintain a record of...

  14. 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... MEDICAL USE OF BYPRODUCT MATERIAL Records § 35.2060 Records of calibrations of instruments used to measure the activity of unsealed byproduct material. A licensee shall maintain a record of...

  15. 10 CFR 35.2060 - Records of calibrations of instruments used to measure the activity of unsealed byproduct material.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Records of calibrations of instruments used to measure the... MEDICAL USE OF BYPRODUCT MATERIAL Records § 35.2060 Records of calibrations of instruments used to measure the activity of unsealed byproduct material. A licensee shall maintain a record of...

  16. 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... MEDICAL USE OF BYPRODUCT MATERIAL Records § 35.2060 Records of calibrations of instruments used to measure the activity of unsealed byproduct material. A licensee shall maintain a record of...

  17. Detailed Calibration of SphinX instrument at the Palermo XACT facility of INAF-OAPA

    NASA Astrophysics Data System (ADS)

    Szymon, Gburek; Collura, Alfonso; Barbera, Marco; Reale, Fabio; Sylwester, Janusz; Kowalinski, Miroslaw; Bakala, Jaroslaw; Kordylewski, Zbigniew; Plocieniak, Stefan; Podgorski, Piotr; Trzebinski, Witold; Varisco, Salvatore

    The Solar photometer in X-rays (SphinX) experiment is scheduled for launch late summer 2008 on-board the Russian CORONAS-Photon satellite. SphinX will use three silicon PIN diode detectors with selected effective areas in order to record solar spectra in the X-ray energy range 0.3-15 keV with unprecedented temporal and medium energy resolution. High sensitivity and large dynamic range of the SphinX instrument will give for the first time possibility of observing solar soft X-ray variability from the weakest levels, ten times below present thresholds, to the largest X20+ flares. We present the results of the ground X-ray calibrations of the SphinX instrument performed at the X-ray Astronomy Calibration and Testing (XACT) facility of INAF-OAPA. The calibrations were essential for determination of SphinX detector energy resolution and efficiency. We describe the ground tests instrumental set-up, adopted measurement techniques and present results of the calibration data analysis.

  18. 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.

  19. 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.

  20. 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.

  1. Instrument calibration.

    PubMed

    Padden, Harvey

    2002-05-01

    The main thing to remember is that measurement uncertainty must encompass everything from NIST to the final laboratory result. Every source of error along the way must be accounted for. Our vendors do much of it for us, but we must make sure they are doing their job properly. We must make certain our vendors have performed rigorous uncertainty analyses and are performing in accordance with them. ISO 9001-2000 and 17,025 accreditations can eventually help offer us assurance in this area. PMID:12037906

  2. The measurement of linear and angular displacements in prototype aircraft - Instrumentation, calibration and operational accuracy

    NASA Astrophysics Data System (ADS)

    Storm van Leeuwen, Sam

    The design and development of angular displacement transducers for flight test instrumentation systems are considered. Calibration tools, developed to meet the accuracy requirements, allowed in situ calibration with short turn around times. The design of the control surface deflection measurement channels for the Fokker 100 prototype aircraft is discussed in detail. It is demonstrated that a bellows coupling provides accurate results, and that the levers and push-pull rod drive mechanisms perform well. The results suggest that a complex mechanical drive mechanism reduces the system accuracy.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. The MICROSCOPE space mission and the inflight calibration approach for its instrument

    NASA Astrophysics Data System (ADS)

    Levy, A.; Touboul, P.; Rodrigues, M.; Métris, G.; Robert, A.

    2010-12-01

    MICROSCOPE is a fundamental physics space mission which aims at testing the Equivalence Principle (EP) with an accuracy of 10-15. The gravitational signal is measured precisely by a differential electrostatic accelerometer which includes two cylindrical test masses made of different materials. The accelerometer is on-board a drag-free micro-satellite which is controlled either Earth pointing or rotating about the normal to the orbital plane with a very stable angular velocity.The expected accuracy of the EP test could be limited by the inaccurate a priori knowledge of the instrument physical parameters associated to the instrument environment on-board the satellite. These parameters are partially measured or estimated by means of ground tests or during the integration of the instrument on the satellite. However, these evaluations are not sufficient and an in-orbit calibration is therefore needed to finely characterize the instrument and to correct the measurements.After the overall presentation of the MICROSCOPE mission and its scientific goal, this paper will focus on the accelerometer and will describe the specific procedures proposed for the in-flight instrument calibration.

  8. 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.

  9. 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.

  10. Calibrating system errors of large scale three-dimensional profile measurement instruments by subaperture stitching method.

    PubMed

    Dong, Zhichao; Cheng, Haobo; Feng, Yunpeng; Su, Jingshi; Wu, Hengyu; Tam, Hon-Yuen

    2015-07-01

    This study presents a subaperture stitching method to calibrate system errors of several ∼2  m large scale 3D profile measurement instruments (PMIs). The calibration process was carried out by measuring a Φ460  mm standard flat sample multiple times at different sites of the PMI with a length gauge; then the subaperture data were stitched together using a sequential or simultaneous stitching algorithm that minimizes the inconsistency (i.e., difference) of the discrete data in the overlapped areas. The system error can be used to compensate the measurement results of not only large flats, but also spheres and aspheres. The feasibility of the calibration was validated by measuring a Φ1070  mm aspheric mirror, which can raise the measurement accuracy of PMIs and provide more reliable 3D surface profiles for guiding grinding, lapping, and even initial polishing processes. PMID:26193139

  11. In-flight calibration and verification of the Planck-LFI instrument

    NASA Astrophysics Data System (ADS)

    Gregorio, A.; Cuttaia, F.; Mennella, A.; Bersanelli, M.; Maris, M.; Meinhold, P.; Sandri, M.; Terenzi, L.; Tomasi, M.; Villa, F.; Frailis, M.; Morgante, G.; Pearson, D.; Zacchei, A.; Battaglia, P.; Butler, R. C.; Davis, R.; Franceschet, C.; Franceschi, E.; Galeotta, S.; Leonardi, R.; Lowe, S.; Mandolesi, N.; Melot, F.; Mendes, L.; Stassi, P.; Stringhetti, L.; Tavagnacco, D.; Zonca, A.; Wilkinson, A.; Wilson, P.; Charra, M.; Maciaszek, T.; Foley, S.; Watson, C. J.; Casale, M.; Laureijs, R.; Tauber, J.; Texier, D.; Baker, M.; Perez Cuevas, L.; Krassenburg, M.; Rihet, P.

    2013-07-01

    In this paper we discuss the Planck-LFI in-flight calibration campaign. After a brief overview of the ground test campaigns, we describe in detail the calibration and performance verification (CPV) phase, carried out in space during and just after the cool-down of LFI. We discuss in detail the functionality verification, the tuning of the front-end and warm electronics, the preliminary performance assessment and the thermal susceptibility tests. The logic, sequence, goals and results of the in-flight tests are discussed. All the calibration activities were successfully carried out and the instrument response was comparable to the one observed on ground. For some channels the in-flight tuning activity allowed us to improve significantly the noise performance.

  12. Prelaunch Photogrammetric Calibration of Russian Satellite Elektro-L Imagery Instruments

    NASA Astrophysics Data System (ADS)

    Gektin, U. M.; Egoshkin, N. A.; Eremeev, V. V.; Kuznetcov, A. E.; Kochergin, A. M.

    2016-06-01

    Technology of prelaunch geometric calibration of multispectral imagery instruments of Russian geostationary satellites "Elektro-L" No.1 and No.2 is considered. Circular control points are used as a test field. Its geometrical model is developed to take distortions in the collimator optical system into account. Multiple observations of a test field at different angles is used to cover the full visual field of a geostationary sensor. New algorithm of circular control point detection is developed and adapted to complex geometry of geostationary imagery. It is capable of processing images formed as a set of separate scans. Under calibration, sensor design parameters and also the law of scanning mirror motion are specified. The paper contains results of the technology approval under prelaunch calibration of MSU-GS sensors for geostationary operational meteorological satellites (GOMS) "Elektro-L" No.1 and No.2.

  13. Automatic releveling of calibration stands for wind tunnel force and moment measurement instrumentation

    NASA Technical Reports Server (NTRS)

    Perazza, Manuel Rodriguez

    1995-01-01

    Wind tunnel force and moment measuring instrumentation at NASA LaRC are calibrated by applying NIST certified dead loads, to generate forces and moments in three orthogonal axes, in twenty five percent increments, up to full-load and down to no-load in a nine point continuous procedure, using specially built calibration stands. The measuring instruments deflect upon the application of loads. These deflections must be cancelled to minimize loading interactions. The older calibration stands, integrated with AC induction motors, or DC motors, have provisions for manually releveling the loading point after each load. A newer stand, with integrated DC stepper motors, relevels automatically under software control. It was proposed to extend automation to the old stands. An algorithm to control the unwieldy induction motors to relevel a calibration stand, to within two arcseconds of horizontal direction automatically, was developed. The system developed uses coasting prediction and load adaptation in a general type robust stability control configuration with noncoincidental feedback. Automatic releveling cuts the releveling time to approximately half of the time required to do it manually. The principal constraint for shorter times is the time constant of the angular position feedback transducer.

  14. 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.

  15. Calibration of passive remote observing optical and microwave instrumentation; Proceedings of the Meeting, Orlando, FL, Apr. 3-5, 1991

    NASA Technical Reports Server (NTRS)

    Guenther, Bruce W. (Editor)

    1991-01-01

    Various papers on the calibration of passive remote observing optical and microwave instrumentation are presented. Individual topics addressed include: on-board calibration device for a wide field-of-view instrument, calibration for the medium-resolution imaging spectrometer, cryogenic radiometers and intensity-stabilized lasers for EOS radiometric calibrations, radiometric stability of the Shuttle-borne solar backscatter ultraviolet spectrometer, ratioing radiometer for use with a solar diffuser, requirements of a solar diffuser and measurements of some candidate materials, reflectance stability analysis of Spectralon diffuse calibration panels, stray light effects on calibrations using a solar diffuser, radiometric calibration of SPOT 23 HRVs, surface and aerosol models for use in radiative transfer codes. Also addressed are: calibrated intercepts for solar radiometers used in remote sensor calibration, radiometric calibration of an airborne multispectral scanner, in-flight calibration of a helicopter-mounted Daedalus multispectral scanner, technique for improving the calibration of large-area sphere sources, remote colorimetry and its applications, spatial sampling errors for a satellite-borne scanning radiometer, calibration of EOS multispectral imaging sensors and solar irradiance variability.

  16. 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.

  17. 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.

  18. TES-based microcalorimeter for future X-ray astronomy missions. Software development for instrument calibration

    NASA Astrophysics Data System (ADS)

    Fraga-Encinas, R.; Cobo, B.; Ceballos, M.; Schuurmans, J.; van der Kuur, J.; Carrera, F.; Barcons, X.

    2013-05-01

    The XMS (X-ray Microcalorimeter Spectrometer) is an instrument prototype with imaging capability in X-rays and high-spectral resolution. This instrument is a microcalorimeter based on transition edge sensors. As part of the Spanish contribution to the advancement of the XMS, we present the work carried out by the X-ray astronomy group at the Instituto de Física de Cantabria in collaboration with The Netherlands Institute for Space Research. The main work hereby presented includes the development and testing of software for this prototype with the purpose of instrument calibration and characterization, X-ray pulse detection and energy resolution calculations (Bergmann 2004, Tekst. Proefschrift Universiteit Utrecht; Boyce et al. 1999, Proc SPIE 3765; Den Herder et al. 2011, SRON-XMS-RP-2011-033; ATHENA Assessment Study Report, ESA/SRE(2011)17)

  19. Planck pre-launch status: Calibration of the Low Frequency Instrument flight model radiometers

    NASA Astrophysics Data System (ADS)

    Villa, F.; Terenzi, L.; Sandri, M.; Meinhold, P.; Poutanen, T.; Battaglia, P.; Franceschet, C.; Hughes, N.; Laaninen, M.; Lapolla, P.; Bersanelli, M.; Butler, R. C.; Cuttaia, F.; D'Arcangelo, O.; Frailis, M.; Franceschi, E.; Galeotta, S.; Gregorio, A.; Leonardi, R.; Lowe, S. R.; Mandolesi, N.; Maris, M.; Mendes, L.; Mennella, A.; Morgante, G.; Stringhetti, L.; Tomasi, M.; Valenziano, L.; Zacchei, A.; Zonca, A.; Aja, B.; Artal, E.; Balasini, M.; Bernardino, T.; Blackhurst, E.; Boschini, L.; Cappellini, B.; Cavaliere, F.; Colin, A.; Colombo, F.; Davis, R. J.; de La Fuente, L.; Edgeley, J.; Gaier, T.; Galtress, A.; Hoyland, R.; Jukkala, P.; Kettle, D.; Kilpia, V.-H.; Lawrence, C. R.; Lawson, D.; Leahy, J. P.; Leutenegger, P.; Levin, S.; Maino, D.; Malaspina, M.; Mediavilla, A.; Miccolis, M.; Pagan, L.; Pascual, J. P.; Pasian, F.; Pecora, M.; Pospieszalski, M.; Roddis, N.; Salmon, M. J.; Seiffert, M.; Silvestri, R.; Simonetto, A.; Sjoman, P.; Sozzi, C.; Tuovinen, J.; Varis, J.; Wilkinson, A.; Winder, F.

    2010-09-01

    The Low Frequency Instrument (LFI) on-board the ESA Planck satellite carries eleven radiometer subsystems, called radiometer chain assemblies (RCAs), each composed of a pair of pseudo-correlation receivers. We describe the on-ground calibration campaign performed to qualify the flight model RCAs and to measure their pre-launch performances. Each RCA was calibrated in a dedicated flight-like cryogenic environment with the radiometer front-end cooled to 20 K and the back-end at 300 K, and with an external input load cooled to 4 K. A matched load simulating a blackbody at different temperatures was placed in front of the sky horn to derive basic radiometer properties such as noise temperature, gain, and noise performance, e.g. 1/f noise. The spectral response of each detector was measured as was their susceptibility to thermal variation. All eleven LFI RCAs were calibrated. Instrumental parameters measured in these tests, such as noise temperature, bandwidth, radiometer isolation, and linearity, provide essential inputs to the Planck-LFI data analysis.

  20. Solar Probe Plus: Motor Controllers Design for Manipulator for Calibration Purposes of SPAN-A and SPAN-B Instruments

    NASA Astrophysics Data System (ADS)

    Juache Aguilar, K.

    2015-12-01

    In preparation for the 2018 launch of Solar Probe Plus, and for the pre-flight tests of the SWEAP package, the instrument manipulator has been updated and modernized. Calibration of the Electrostatic Analyzers (ESA) is the critical last stop before launching instruments into space. The current method of controlling the instrument manipulator requires a dedicated computer, operating system, and power supplies. A novel solution integrates the power supplies, data acquisition, motor controller, and commanding microcontroller into one small enclosure. The system will also include software integration that communicates via Ethernet with electrical ground support equipment (EGSE) for full scripting automation during instrument calibration.

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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

    ... calibration; particulate, methanol and formaldehyde measurement. 86.120-94 Section 86.120-94 Protection of... 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...

  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

    ... calibration; particulate, methanol and formaldehyde measurement. 86.120-94 Section 86.120-94 Protection of... 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...

  7. 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.

  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 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.

  10. Inter-instrument calibration using magnetic field data from Flux Gate Magnetometer (FGM) and Electron Drift Instrument (EDI) onboard Cluster

    NASA Astrophysics Data System (ADS)

    Nakamura, R.; Plaschke, F.; Teubenbacher, R.; Giner, L.; Baumjohann, W.; Magnes, W.; Steller, M.; Torbert, R. B.; Vaith, H.; Chutter, M.; Fornaçon, K.-H.; Glassmeier, K.-H.; Carr, C.

    2013-07-01

    We compare the magnetic field data obtained from the Flux-Gate Magnetometer (FGM) and the magnetic field data deduced from the gyration time of electrons measured by the Electron Drift Instrument (EDI) onboard Cluster to determine the spin axis offset of the FGM measurements. Data are used from orbits with their apogees in the magnetotail, when the magnetic field magnitude was between about 20 nT and 500 nT. Offset determination with the EDI-FGM comparison method is of particular interest for these orbits, because no data from solar wind are available in such orbits to apply the usual calibration methods using the Alfvén waves. In this paper, we examine the effects of the different measurement conditions, such as direction of the magnetic field relative to the spin plane and field magnitude in determining the FGM spin-axis offset, and also take into account the time-of-flight offset of the EDI measurements. It is shown that the method works best when the magnetic field magnitude is less than about 128 nT and when the magnetic field is aligned near the spin-axis direction. A remaining spin-axis offset of about 0.4 ~ 0.6 nT was observed between July and October 2003. Using multi-point multi-instrument measurements by Cluster we further demonstrate the importance of the accurate determination of the spin-axis offset when estimating the magnetic field gradient.

  11. An integrated development facility for the calibration of low-energy charged particle flight instrumentation

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    A system was developed for the calibration and development of thermal ion instrumentation. The system provides an extended beam with usable current rates, approx. 1 pA/sq cm, at beam energies as low as 1 eV, with much higher values available with increasing energy. A tandem electrostatic and variable geometry magnetic mirror configuration within the ion source optimizes the use of the ionizing electrons. The system is integrated under microcomputer control to allow automatic control and monitoring of the beam energy and composition and the mass and angle-dependent response of the instrument under test. The system is pumped by a combination of carbon vane and cryogenic sorption roughing pumps and ion and liquid helium operating pumps.

  12. 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.

  13. 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

    ... 40 Protection of Environment 19 2014-07-01 2014-07-01 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...

  14. 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

    ... 40 Protection of Environment 19 2012-07-01 2012-07-01 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...

  15. 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

    ... 40 Protection of Environment 19 2013-07-01 2013-07-01 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...

  16. 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

    ... 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 direct measurements performed in accordance with § 35.63, a licensee shall possess and use instrumentation to...

  17. 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

    ... 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 direct measurements performed in accordance with § 35.63, a licensee shall possess and use instrumentation to...

  18. 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

    ... 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 direct measurements performed in accordance with § 35.63, a licensee shall possess and use instrumentation to...

  19. 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

    ... 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 direct measurements performed in accordance with § 35.63, a licensee shall possess and use instrumentation to...

  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

    ... 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 direct measurements performed in accordance with § 35.63, a licensee shall possess and use instrumentation to...

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. Self-calibrating power angle instrument: Volume 1, A functional overview: Final report

    SciTech Connect

    Demcko, J.A.; Chrysty, J.P.

    1989-08-01

    This report provides functional documentation of the development of a second generation electronic power angle instrument (PAI) for synchronous machines. The first generation device, also developed by EPRI funded research, proved the viability of the measurement concept but required human intervention for recalibration each time an input quantity was removed or the instrument power supply was lost. Loss of input intelligence also occurs each time a synchronous motor or generator is removed from service, thereby forcing additional recalibrations. The self-calibrating PAI automatically recalibrates itself for any contingency and as its predecessor, provides accurate low cost steady state and transient power angle measurements for both synchronous motors and generators. The report covering EPRI sponsored research project RP2591-1 includes a detailed PAI functional block diagram description as well as autocal PAI performance specification as measured in the lab. Several ancillary equipments were developed in support of the autocal project. These include an infrared optoprobe which replaces toothed wheel PAI input, an optoelectronic probe and tooth wheel test bed, and an electronic turbine generator simulator for PAI functional test and calibration. 24 figs.

  6. Flux-gate magnetometer spin axis offset calibration using the electron drift instrument

    NASA Astrophysics Data System (ADS)

    Plaschke, Ferdinand; Nakamura, Rumi; Leinweber, Hannes K.; Chutter, Mark; Vaith, Hans; Baumjohann, Wolfgang; Steller, Manfred; Magnes, Werner

    2014-10-01

    Spin-stabilization of spacecraft immensely supports the in-flight calibration of on-board flux-gate magnetometers (FGMs). From 12 calibration parameters in total, 8 can be easily obtained by spectral analysis. From the remaining 4, the spin axis offset is known to be particularly variable. It is usually determined by analysis of Alfvénic fluctuations that are embedded in the solar wind. In the absence of solar wind observations, the spin axis offset may be obtained by comparison of FGM and electron drift instrument (EDI) measurements. The aim of our study is to develop methods that are readily usable for routine FGM spin axis offset calibration with EDI. This paper represents a major step forward in this direction. We improve an existing method to determine FGM spin axis offsets from EDI time-of-flight measurements by providing it with a comprehensive error analysis. In addition, we introduce a new, complementary method that uses EDI beam direction data instead of time-of-flight data. Using Cluster data, we show that both methods yield similarly accurate results, which are comparable yet more stable than those from a commonly used solar wind-based method.

  7. A fully Bayesian method for jointly fitting instrumental calibration and X-ray spectral models

    SciTech Connect

    Xu, Jin; Yu, Yaming; Van Dyk, David A.; Kashyap, Vinay L.; Siemiginowska, Aneta; Drake, Jeremy; Ratzlaff, Pete; Connors, Alanna; Meng, Xiao-Li E-mail: yamingy@ics.uci.edu E-mail: vkashyap@cfa.harvard.edu E-mail: jdrake@cfa.harvard.edu E-mail: meng@stat.harvard.edu

    2014-10-20

    Owing to a lack of robust principled methods, systematic instrumental uncertainties have generally been ignored in astrophysical data analysis despite wide recognition of the importance of including them. Ignoring calibration uncertainty can cause bias in the estimation of source model parameters and can lead to underestimation of the variance of these estimates. We previously introduced a pragmatic Bayesian method to address this problem. The method is 'pragmatic' in that it introduced an ad hoc technique that simplified computation by neglecting the potential information in the data for narrowing the uncertainty for the calibration product. Following that work, we use a principal component analysis to efficiently represent the uncertainty of the effective area of an X-ray (or γ-ray) telescope. Here, however, we leverage this representation to enable a principled, fully Bayesian method that coherently accounts for the calibration uncertainty in high-energy spectral analysis. In this setting, the method is compared with standard analysis techniques and the pragmatic Bayesian method. The advantage of the fully Bayesian method is that it allows the data to provide information not only for estimation of the source parameters but also for the calibration product—here the effective area, conditional on the adopted spectral model. In this way, it can yield more accurate and efficient estimates of the source parameters along with valid estimates of their uncertainty. Provided that the source spectrum can be accurately described by a parameterized model, this method allows rigorous inference about the effective area by quantifying which possible curves are most consistent with the data.

  8. 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.

  9. 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

  10. VIRTIS-H: an infrared spectrometer for the ROSETTA mission - instrumental simulator and calibration process

    NASA Astrophysics Data System (ADS)

    Frederique Jacquinod, Sophie; Reess, Jean-Michel; Erard, Stéphane; Leyrat, Cédric; Bockelee-Morvan, Dominique; Drossart, Pierre; Henry, Florence; Semery, Alain

    2015-08-01

    Virtis-H is the high spectral resolution channel of the VIRTIS Imaging Spectrometer on board the Rosetta spacecraft, devoted to the in-orbit remote sensing study of comet 67P/Churyumov-Gerasimenko. The Virtis-H channel is a cross-dispersion spectrometer in the spectral range 2-5µm with a resolution between 1200 and 3000. Its design consists in an afocal telescope-collimator off-axis parabola mirrors, a prism-grating system performing the cross-dispersion, and a three-lens objective imaging the entrance slit on a 438 x 270 HgCdTe array from Raytheon / IRCOE. Temperature control of the instrument is ensured by a radiator, to keep the spectrometer temperature at around 130 K, and by cryocoolers to lower the infrared detectors focal planes down to 80 K. At each recorded image, a full spectrum of the observed scene is reconstructed allowing the study of the fine spectral details of the coma and the cometary nucleus. The instrument technical specifications have been verified in the laboratory at channel level. A simulator of the Virtis-H channel has been developed to verify the compliance of the instrument performances. Furthermore, this simulator is used to prepare the comet observations and to estimate upper-limit detection of minor gaseous species and signal to noise ratio.The VIRTIS-H data are processed through the so-called pipeline CALIBROS, which uses a dual approach based on on-ground calibration data and Cruise flight observations of the asteroid 21 Lutetia. The calibrated spectra are produced in radiance (W/m2/sr/µm). Another part of the pipeline is devoted to geometric computations and projection of the field of view on the target, based on the SPICE library (NAIF) and ESA trajectory kernels. The pipeline products are directly stored in PDS format to be ingested in ESA / PSA public archive for long-term preservation and distribution.The comparison between the calibrated spectra and the simulated spectra shows a good compliance and allows being confident in

  11. 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.

  12. 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.

  13. NPOESS Preparatory Project (NPP) instrument characterization and calibration, and products validation: an integrated strategy in preparation for NPOESS new generation of environmental satellites

    NASA Astrophysics Data System (ADS)

    Mango, Stephen A.; Murphy, Robert E.; Ouaidrari, Hassan; Menzel, W. Paul

    2003-04-01

    This paper presents the strategy designed by the government team, IPO and NASA, for the NPOESS Preparatory Project (NPP) instrument characterization and calibration, and product validation, in preparation for the NPOESS operational system. NPP is a risk reduction mission for NPOESS, managed by the IPO and NASA. NPP will carry three (3) instruments, VIIRS, CrIS and ATMS, and an Instrument of Opportunity to be announced soon. Responsibilities will be shared between government and industry participants to ensure high performance at all system levels. This will include provision of the sensor pre-launch characterization and post-launch calibration procedures, definition of validation approaches for all NPP products, and identification of the resources and assets required to achieve these activities. This calibration and validation plan will benefit greatly from the validation efforts and infrastructure of several existing programs at the national and international scale. The synergy between the SSPR system integrator and the government team, IPO and NASA, will build the foundation for interactions that will lead to better sensors, better algorithms, and better ground data systems.

  14. 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.

  15. Jefferson Lab Hall A Beamline Instrumentation and Calibration for GMP experiment

    NASA Astrophysics Data System (ADS)

    Gautam, Thir Narayan

    2015-10-01

    The nucleon electromagnetic form factors characterize the distributions of electric charge and magnetization current inside the nucleon and thus reflect the internal structure determined by Quantum Chromodynamics. The GMp experiment is a first experiment run in Hall A at Jefferson Lab after the upgrade to double the beam energy with the goal to precisely measure electron-proton elastic cross section in the Q2 range of 7 to 17 GeV2 with an accuracy of better than 2%; several time better than existing data at the highest Q2. In order to achieve this accuracy, a determination of the accumulated beam charge of better than 0.5% is required. The new 12 GeV beamline was commissioned during the spring of 2015, with the main instrumentation consisting of beam charge and position monitors. In this talk, the procedures and the results of the calibrations of these beamline components will be presented.

  16. 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.

  17. Calibration measurements on the DEPFET Detectors for the MIXS instrument on BepiColombo

    NASA Astrophysics Data System (ADS)

    Majewski, P.; Aschauer, F.; Aschauer, S.; Bähr, A.; Bergbauer, B.; Hilchenbach, M.; Krumrey, M.; Laubis, C.; Lauf, T.; Lechner, P.; Lutz, G.; Scholze, F.; Soltau, H.; Stefanescu, A.; Strüder, L.; Treis, J.

    2014-11-01

    The Mercury Imaging X-ray Spectrometer (MIXS) will be launched on board of the 5th ESA cornerstone mission BepiColombo. The two channel instrument MIXS is dedicated to the exploration of the elemental composition of the mercurian surface by imaging x-ray spectroscopy of the elemental fluorescence lines. One of the main scientific goals of MIXS is to provide spatially resolved elemental abundance maps of key rock-forming elements. MIXS will be the successor of the XRS instrument, which is currently orbiting Mercury on board of NASAs satellite MESSENGER. MIXS will provide unprecedented spectral and spatial resolution due to its innovative detector and optics concepts. The MIXS target energy band ranges from 0.5 to 7 keV and allows to directly access the Fe-L line at 0.7 keV, which was not accessible to previous missions. In addition, the high spectroscopic resolution of FWHM ≤ 200 eV at the reference energy of 1 keV after one year in Mercury orbit, allows to separate the x-ray fluorescence emission lines of important elements like Mg (1.25 keV) and Al (1.49 keV) without the need for any filter. The detectors for the energy and spatially resolved detection of x-rays for both channels are identical DEPFET (DEpleted P-channel FET) active pixel detectors. We report on the calibration of the MIXS flight and flight spare detector modules at the PTB (Physikalisch-Technische Bundesanstalt) beamlines at the BESSY II synchrotron radiation facility. Each detector was calibrated at least at 10 discrete energies in the energy range from 0.5 to 10 keV. The excellent spectroscopic performance of all three detector modules was verified.

  18. Direct liquid deposition calibration method for trace cyclotrimethylenetrinitramine using thermal desorption instrumentation.

    PubMed

    Field, Christopher R; Lubrano, Adam L; Rogers, Duane A; Giordano, Braden C; Collins, Greg E

    2013-03-22

    A simple method for establishing calibration curves with sorbent-filled thermal desorption tubes has been demonstrated for nitroaromatic and nitramine vapor samples using a thermal desorption system with a cooled inlet system (TDS-CIS), which was coupled to a gas chromatograph (GC) with an electron capture detector (ECD). The method relies upon the direct liquid deposition of standard solutions onto the glass frit at the head of sorbent-filled thermal desorption tubes. Linear calibration results and ideal system conditions for the TDS-CIS-GC-ECD were established for mixtures containing both cyclotrimethylenetrinitramine, a.k.a. RDX, and 2,4,6-trinitrotoluene (TNT). Because of the chemical characteristics of RDX, a higher TDS-CIS flow rate relative to the optimized approach for TNT was required for efficient RDX desorption. Simultaneous quantitation of TNT and RDX using the direct liquid deposition method with optimized instrumentation parameters for RDX were compared to results from a standard split/splitless GC inlet and a CIS. PMID:23415141

  19. 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).

  20. Calibration activities on the BepiColombo High-Resolution Channel (HRIC) of SIMBIO-SYS instrument

    NASA Astrophysics Data System (ADS)

    Della Corte, V.; Zusi, M.; Palumbo, P.; Baroni, M.; Ficai Veltroni, I.; Flamini, E.; Mugnuolo, R.

    2015-10-01

    HRIC (High Resolution Imaging Channel) is the high resolution channel of the SIMBIO-SYS instrument on- board the ESA BepiColombo Mission. Calibration activities were performed at SelexES premises in spring- summer 2014 in order to check for Channel performances (radiometric performances, quality image and geometrical performances) and to obtain data necessary to setup a calibration pipeline necessary to process the raw images acquired by the channel when in operative scenario.

  1. 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.

  2. 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.

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

    PubMed

    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. PMID:26827320

  4. 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

  5. A new algorithm for five-hole probe calibration, data reduction, and uncertainty analysis

    NASA Technical Reports Server (NTRS)

    Reichert, Bruce A.; Wendt, Bruce J.

    1994-01-01

    A new algorithm for five-hole probe calibration and data reduction using a non-nulling method is developed. The significant features of the algorithm are: (1) two components of the unit vector in the flow direction replace pitch and yaw angles as flow direction variables; and (2) symmetry rules are developed that greatly simplify Taylor's series representations of the calibration data. In data reduction, four pressure coefficients allow total pressure, static pressure, and flow direction to be calculated directly. The new algorithm's simplicity permits an analytical treatment of the propagation of uncertainty in five-hole probe measurement. The objectives of the uncertainty analysis are to quantify uncertainty of five-hole results (e.g., total pressure, static pressure, and flow direction) and determine the dependence of the result uncertainty on the uncertainty of all underlying experimental and calibration measurands. This study outlines a general procedure that other researchers may use to determine five-hole probe result uncertainty and provides guidance to improve measurement technique. The new algorithm is applied to calibrate and reduce data from a rake of five-hole probes. Here, ten individual probes are mounted on a single probe shaft and used simultaneously. Use of this probe is made practical by the simplicity afforded by this algorithm.

  6. 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.

  7. Pressure dependent calibration of the OH and HOx channels of a FAGE HOx instrument using the Highly Instrumented Reactor for Atmospheric Chemistry (HIRAC)

    NASA Astrophysics Data System (ADS)

    Winiberg, F. A. F.; Smith, S. C.; Bejan, I.; Brumby, C. A.; Ingham, T.; Malkin, T. L.; Orr, S. C.; Heard, D. E.; Seakins, P. W.

    2014-07-01

    The calibration of field instruments used to measure concentrations of OH and HO2 worldwide have traditionally relied on a single method utilising the photolysis of water vapour in air in a flow tube at atmospheric pressure. Here the calibration of two FAGE (Fluorescence Assay by Gaseous Expansion) apparatuses designed for HOx (OH and HO2) measurements have been investigated as a function of external pressure and temperature, using two different laser systems. The conventional method of generating known concentrations of HOx from H2O vapour photolysis in a turbulent flowtube impinging just outside the FAGE sample inlet has been used to study instrument sensitivity as a function of internal fluorescence cell pressure (1.8-3.8 mbar). An increase in the calibration constants COH and CHO2 with pressure was observed and an empirical linear regression of the data was used to describe the trends, with ΔCOH = (17 ± 11)% and ΔCHO2 = (31.6 ± 4.4)% increase per mbar air (uncertainties quoted to 2σ). Presented here are the first direct measurements of the FAGE calibration constants as a function of external pressure (440-1000 mbar) in a controlled environment using the University of Leeds HIRAC chamber (Highly Instrumented Reactor for Atmospheric Chemistry). Two methods were used: the temporal decay of hydrocarbons for calibration of OH, and the kinetics of the second-order recombination of HO2 for HO2 calibrations. Over comparable conditions for the FAGE cell, the two alternative methods are in good agreement with the conventional method, with the average ratio of calibration factors (conventional : alternative) across the entire pressure range COH(conv)/COH(alt) = 1.19 ± 0.26 and CHO2(conv)/CHO2(alt) = 0.96 ± 0.18 (2σ). These alternative calibration methods currently have comparable systematic uncertainties than the conventional method: ~28% and ~41% for the alternative OH and HO2 calibration methods respectively compared to 35% for the H2O vapour photolysis method

  8. Pressure-dependent calibration of the OH and HO2 channels of a FAGE HOx instrument using the Highly Instrumented Reactor for Atmospheric Chemistry (HIRAC)

    NASA Astrophysics Data System (ADS)

    Winiberg, F. A. F.; Smith, S. C.; Bejan, I.; Brumby, C. A.; Ingham, T.; Malkin, T. L.; Orr, S. C.; Heard, D. E.; Seakins, P. W.

    2015-02-01

    The calibration of field instruments used to measure concentrations of OH and HO2 worldwide has traditionally relied on a single method utilising the photolysis of water vapour in air in a flow tube at atmospheric pressure. Here the calibration of two FAGE (fluorescence assay by gaseous expansion) apparatuses designed for HOx (OH and HO2) measurements have been investigated as a function of external pressure using two different laser systems. The conventional method of generating known concentrations of HOx from H2O vapour photolysis in a turbulent flow tube impinging just outside the FAGE sample inlet has been used to study instrument sensitivity as a function of internal fluorescence cell pressure (1.8-3.8 mbar). An increase in the calibration constants CHO and CHO2 with pressure was observed, and an empirical linear regression of the data was used to describe the trends, with ΔCHO = (17 ± 11) % and ΔCHO2 = (31.6 ± 4.4)% increase per millibar air (uncertainties quoted to 2σ). Presented here are the first direct measurements of the FAGE calibration constants as a function of external pressure (440-1000 mbar) in a controlled environment using the University of Leeds HIRAC chamber (Highly Instrumented Reactor for Atmospheric Chemistry). Two methods were used: the temporal decay of hydrocarbons for calibration of OH, and the kinetics of the second-order recombination of HO2 for HO2 calibrations. Over comparable conditions for the FAGE cell, the two alternative methods are in good agreement with the conventional method, with the average ratio of calibration factors (conventional : alternative) across the entire pressure range, COH(conv)/COH(alt) = 1.19 ± 0.26 and CHO2(conv)/CHO2(alt) = 0.96 ± 0.18 (2σ). These alternative calibration methods currently have comparable systematic uncertainties to the conventional method: ~ 28% and ~ 41% for the alternative OH and HO2 calibration methods respectively compared to 35% for the H2O vapour photolysis method; ways in

  9. Precision calibration and systematic error reduction in the long trace profiler

    SciTech Connect

    Qian, Shinan; Sostero, Giovanni; Takacs, Peter Z.

    2000-01-01

    The long trace profiler (LTP) has become the instrument of choice for surface figure testing and slope error measurement of mirrors used for synchrotron radiation and x-ray astronomy optics. In order to achieve highly accurate measurements with the LTP, systematic errors need to be reduced by precise angle calibration and accurate focal plane position adjustment. A self-scanning method is presented to adjust the focal plane position of the detector with high precision by use of a pentaprism scanning technique. The focal plane position can be set to better than 0.25 mm for a 1250-mm-focal-length Fourier-transform lens using this technique. The use of a 0.03-arcsec-resolution theodolite combined with the sensitivity of the LTP detector system can be used to calibrate the angular linearity error very precisely. Some suggestions are introduced for reducing the system error. With these precision calibration techniques, accuracy in the measurement of figure and slope error on meter-long mirrors is now at a level of about 1 {mu}rad rms over the whole testing range of the LTP. (c) 2000 Society of Photo-Optical Instrumentation Engineers.

  10. 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.

  11. 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

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

    PubMed

    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

  13. 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

  14. 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

  15. 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.

  16. Calibration

    NASA Astrophysics Data System (ADS)

    Kunze, Hans-Joachim

    Commercial spectrographic systems are usually supplied with some wave-length calibration, but it is essential that the experimenter performs his own calibration for reliable measurements. A number of sources emitting well-known emission lines are available, and the best values of their wavelengths may be taken from data banks accessible on the internet. Data have been critically evaluated for many decades by the National Institute of Standards and Technology (NIST) of the USA [13], see also p. 3. Special data bases have been established by the astronomy and fusion communities (Appendix B).

  17. 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).

  18. Data reduction and astrometric calibration of a starshade test using real starlight

    NASA Astrophysics Data System (ADS)

    Jordan, Ian J. E.; Henze, Paul; Cash, Webster C.; Soummer, Remi; Regan, Michael W.; Westminster Astronomical Society, New Worlds

    2015-01-01

    Calibration of data obtained during 2011-2013 for a ground-based optically scaled starshade alignment sensing test is discussed. The equipment included a 3.7-cm starshade-occulter in front of a coelostat at separations of up to 90-metres from a small telescope. Various stellar and planetary sources were observed. Astrometric reduction of images was challenged by variable horizontal refraction and wavefront distortion during occultations and between images which introduced uncertainty in localizing the occulter. Guider software issues were an additional complication in the reduction process and are discussed. The changing conditions during each observing session necessitate careful tagging of different datasets for appropriate treatment in the reduction pipeline. The techniques for handling the data are described along with astrometric results.

  19. 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).

  20. A New Radiometric Calibration Paradigm for the OMPS Nadir Total Column and Profile Instruments

    NASA Technical Reports Server (NTRS)

    Heath, Donald; Georgiew, Georgi

    2011-01-01

    A fused silica Mie Scattering Diffuser (MSD) has been developed at Ball Aerospace & Technology Corp. that has measured characteristics which could be used to increase the accuracy of the spectral albedo calibration of the Ozone Mapping and Profiler Suite (OMPS) Nadir ozone total column and profile instrument by almost an order of magnitude. Measurements have been made of the optical characteristics on both natural and synthetic forms of fused silica MSDs. Preliminary measurements suggest that MSDs are useable in the solar reflective wavelength region from 250 nm to 3.7 m. To date synthetic and natural MSDs have been irradiated for 60 hours of UV radiation from a solar simulator, and synthetic MSDs have been irradiated with increasing doses of Co-60 gamma rays at 30, 500 krads up to 1.5 Mrads, and 30 krads of 200 MeV protons. The principal effects have been small loses in transmittance at wavelengths < 350 nm. The high energy particle irradiation measurements were provided by Neal Nickles and Dean Spieth.

  1. RadBallTM Technology Testing in the Savannah River Site's Health Physics Instrument Calibration Laboratory

    NASA Astrophysics Data System (ADS)

    Farfán, Eduardo B.; Foley, Trevor Q.; Jannik, G. Timothy; Harpring, Larry J.; Gordon, John R.; Blessing, Ronald; Rusty Coleman, J.; Holmes, Christopher J.; Oldham, Mark; Adamovics, John; Stanley, Steven J.

    2010-11-01

    The UK'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 RadBallTM, 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 UK and facilities of the Savannah River National Laboratory (SRNL). This paper summarizes the tests completed at SRNL Health Physics Instrument Calibration Laboratory (HPICL).

  2. RadBall Technology Testing in the Savannah River Site's Health Physics Instrument Calibration Laboratory.

    PubMed

    Farfán, Eduardo B; Foley, Trevor Q; Jannik, G Timothy; Harpring, Larry J; Gordon, John R; Blessing, Ronald; Coleman, J Rusty; Holmes, Christopher J; Oldham, Mark; Adamovics, John; Stanley, Steven J

    2010-01-01

    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(™), 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 RadBall(™) 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). PMID:21617738

  3. Calibration of the San Marco airglow-solar spectrometer instrument in the extreme ultraviolet

    NASA Astrophysics Data System (ADS)

    Worden, John; Woods, Thomas N.; Rottman, Gary J.; Schmidtke, Gerhard; Tai, Hongsheng; Doll, Harry G.; Solomon, Stanley C.

    1996-02-01

    The San Marco 5 carried the airglow-solar spectrometer instrument (ASSI). This 18-channel spectrometer measured the solar and terrestrial radiation in the wavelength region between 20 and 700 nm for 9 months in 1988. The ASSI extreme ultraviolet (EUV) channels showed significant sensitivity changes during the mission. The sensitivity changes of the EUV channels are quantified by comparing ASSI solar EUV irradiance measurements to the solar EUV irradiance derived from a solar proxy model. A sensitivity change model is developed that shows that exponential curves can adequately describe the sensitivity changes of the ASSI optics and detectors. The November 10 calibration parameters and the sensitivity change model can be used to derive the EUV terrestrial airglow brightness for the time period of the ASSI mission. Analysis of the solar Lyman-(alpha) irradiance measured by the ASSI, the solar mesospheric explorer (SME), and the upper atmosphere research satellite has led to a revised Lyman-(alpha) irradiance for the San Marco mission. For example, the ASSI November 10, 1988, Lyman-(alpha) measurement is 5.3 X 1011 photons cm-2 s-1 versus the reported SME measurement of 3.35 X 1011 photons cm-2 s-1.

  4. 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

  5. Pressure Dependent OH and HO2 Calibration of the Fluorescence Assay by Gas Expansion (FAGE) Instrument Using the Highly Instrumented Reactor for Atmospheric Chemistry (HIRAC)

    NASA Astrophysics Data System (ADS)

    Winiberg, F.; Smith, S. C.; Seakins, P.

    2012-12-01

    The hydroxyl (OH) and hydroperoxy (HO2) radical are very important tropospheric radical species. The balance between OH and HO2 (the HOx cycle) can give understanding of localised atmospheric composition. OH and HO2 is measured in both ground and aircraft based campaigns using FAGE. Calibration of this non-absolute fluorescence technique is traditionally achieved by H2O photolysis. Operation of FAGE at varying pressure can affect the instrument sensitivity to HOx due to internal fluorescence cell pressure changes. These are traditionally accounted by varying the inlet pinhole size of the instrument, however this may alter the gas expansion and hence the instrument sensitivity to OH and HO2 (COH and CHO2 respectively). Presented here are the initial results from independent OH and HO2 pressure dependent calibration methods using the stainless steel HIRAC chamber, which can operate at various pressures (0.1 - 1 bar). The OH calibration method uses the loss rate of a well characterised hydrocarbon upon reaction with OH to infer the OH concentration measured by FAGE in the HIRAC chamber. A photolytic OH source ((CH3)3COOH) was used and all reactants were measured using calibrated GC-FID and FTIR. For HO2 calibrations, formaldehyde, HCHO, is photolysed (λ < 300 nm) in the presence of O2 to form 2HO2 to steady state, and the post-photolysis HO2 decay is monitored using FAGE. The decay is a function of the second order HO2 self-reaction, for which the rate is well known. As [HO2] = SHO2 x CHO2 (where SHO2 is the FAGE HO2 signal), the second order rate equation can be rearranged and a plot of 1/SHO2 vs. time yields CHO2. Preliminary experiments for the OH calibration method show discrepancies between traditional and hydrocarbon decay techniques. This is thought to be due to as yet unknown OH loss processes and conditioning of the HIRAC chamber. For the HO2 pressure dependent calibrations were in good agreement with traditional methods validating the widely used

  6. Investigations into Cost Reductions of X-band Instrumentation

    SciTech Connect

    Van Winkle, D.; Dolgashev, V.A.; Fox, J.D.; Tantawi, S.G.; /SLAC

    2009-05-15

    The prohibitive costs of commercial test equipment for making fast and accurate pulsed phase and amplitude measurements at X-Band result in decreased productivity due to shortages of shared equipment across the test laboratory. In addition, most current set-ups rely on the use of pulsed power heads which do not allow for the measurement of phase thereby limiting the flexibility of available measurements. In this paper, we investigate less expensive in-house designed instrumentation based upon commercial satellite down converters and widely available logarithmic detector amplifiers and phase detectors. The techniques are used to measure X-Band pulses with widths of 50 ns to 10's of usec. We expect a dynamic range of 30-40 dB with accuracies of better than +/- 0.1 dB and +/- 1 degree of phase. We show preliminary results of the built and tested modules. Block diagrams of the down conversion scheme, and the architecture of a multi-signal X-band RF monitor and measurement system is illustrated. Measured results, and possible modifications and upgrades are presented.

  7. Reduction of Helicity-Dependent Instrumental Laser Intensity Asymmetries

    NASA Astrophysics Data System (ADS)

    Burtwistle, Samantha; Dreiling, Joan; Gay, Timothy

    2014-05-01

    We present a new optical system that greatly reduces helicity-dependent instrumental intensity asymmetries. The optical setup is similar to that described in Fabrikant et al., where two beams with orthogonal linear polarizations are sent through a chopper, allowing only one beam to pass through the optical system at a time. The two temporally-separated beams are then spatially recombined. We now use a system, with a second active polarization changing element, that is analogous to that described in Gay and Dunning, which compensates for false asymmetries in Mott polarimetry. In our setup, the orthogonal linear polarizations are now circularly polarized by a Pockels cell switching between a retardance of + λ /4 and - λ/4 at the same frequency as the chopper, but with a 90-degree phase shift. Using this method, we have been able to control the standard deviation of the mean of our asymmetries, as measured by a photodiode with lock-in signal processing, to 3*10-8.

  8. Stress Reduction in Adjacent Level Discs via Dynamic Instrumentation: A Finite Element Analysis

    PubMed Central

    Castellvi, Antonio E.; Huang, Hao; Vestgaarden, Tov; Saigal, Sunil; Pienkowski, David

    2007-01-01

    Background Conventional (rigid) fusion instrumentation is believed to accelerate the degeneration of adjacent discs by increasing stresses caused by motion discontinuity. Fusion instrumentation that employs reduced rod stiffness and increased axial motion, or dynamic instrumentation, may partially alleviate this problem, but the effects of this instrumentation on the stresses in the adjacent disc are unknown. We used a finiteelement model to calculate and compare the stresses in the adjacent-level disc that are induced by rigid and dynamic posterior lumbar fusion instrumentation. Methods A 3-dimensional finite-element model of the lumbar spine was obtained that simulated flexion and extension. The L5–S1 segment of this model was fused, and the L4–L5 segment was fixed with rigid or dynamic instrumentation. The mechanical properties of the dynamic instrumentation were determined by laboratory testing and then used in the finite-element model. Peak stresses in the lumbar discs were calculated and compared. Results The reduced-stiffness component of the dynamic instrumentation was associated with a 1% to 2% reduction in peak compressive stresses in the adjacent-level disc (at 45° flexion), and the increased axial motion component of this instrumentation reduced peak disc stress by 8% to 9%. Areas of disc tissue exposed to 80% of peak stresses of 6.17 MPa were 47% less for discs adjacent to dynamic instrumentation than for those adjacent to rigid instrumentation. Conclusions Reduced stiffness and increased axial motion of dynamic posterior lumbar fusion instrumentation designs result in an approximately 10% cumulative stress reduction for each flexion cycle. The effect of this stress reduction over many cycles may be substantial. Clinical Relevance The cumulative effect of this reduced amplitude and distribution of peak stresses in the adjacent disc may partially alleviate the problem of adjacent-level disc degeneration. PMID:25802582

  9. Calibration of an instrumented treadmill using a precision-controlled device with artificial neural network-based error corrections.

    PubMed

    Hsieh, Hong-Jung; Lin, Hsiu-Chen; Lu, Hsuan-Lun; Chen, Ting-Yi; Lu, Tung-Wu

    2016-03-01

    Instrumented treadmills (ITs) are used to measure reaction forces (RF) and center of pressure (COP) movements for gait and balance assessment. Regular in situ calibration is essential to ensure their accuracy and to identify conditions when a factory re-calibration is needed. The current study aimed to develop and calibrate in situ an IT using a portable, precision-controlled calibration device with an artificial neural network (ANN)-based correction method. The calibration device was used to apply static and dynamic calibrating loads to the surface of the IT at 189 and 25 grid-points, respectively, at four belt speeds (0, 4, 6 and 8 km/h) without the need of a preset template. Part of the applied and measured RF and COP were used to train a threelayered, back-propagation ANN model while the rest of the data were used to evaluate the performance of the ANN. The percent errors of Fz and errors of the Px and Py were significantly decreased from a maximum of -1.15%, -1.64 mm and -0.73 mm to 0.02%, 0.02 mm and 0.03 mm during static calibration, respectively. During dynamic calibration, the corresponding values were decreasing from -3.65%, 2.58 mm and -4.92 mm to 0.30%, -0.14 mm and -0.47 mm, respectively. The results suggest that the calibration device and associated ANN will be useful for correcting measurement errors in vertical loads and COP for ITs. PMID:26979909

  10. Calibration and instrumental line shape characterization of a set of portable FTIR spectrometers for detecting greenhouse gas emissions

    NASA Astrophysics Data System (ADS)

    Frey, M.; Hase, F.; Blumenstock, T.; Groß, J.; Kiel, M.; Mengistu Tsidu, G.; Schäfer, K.; Sha, M. K.; Orphal, J.

    2015-07-01

    A comprehensive calibration procedure for mobile, low-resolution, solar-absorption FTIR spectrometers, used for greenhouse gases observations, is developed. These instruments commend themselves for campaign use and deployment at remote sites. The instrumental line shape (ILS) of each spectrometer has been thoroughly characterized by analyzing the shape of H2O signatures in open path spectra. A setup for the external source is suggested and the invariance of derived ILS parameters with regard to chosen path length is demonstrated. The instrumental line shape characteristics of all spectrometers were found to be close to nominal. Side-by-side solar observations before and after a campaign, which involved shipping of all spectrometers to a selected target site and back, are applied for verifying the temporal invariability of instrumental characteristics and for deriving intercalibration factors for XCO2 and XCH4, which take into account residual differences of instrumental characteristics. An excellent level of agreement and stability was found between the different spectrometers: the uncorrected biases in XCO2 and XCH4 are smaller than 0.01 and 0.15 %, respectively, and the drifts are smaller than 0.005 and 0.035 %. As an additional sensitive demonstration of the instrumental performance we show the excellent agreement of ground pressure values obtained from the total column measurements of O2 and barometric records. We find a calibration factor of 0.9700 for the spectroscopic measurements in comparison to the barometric records and a very small scatter between the individual spectrometers (0.02 %). As a final calibration step, using a co-located TCCON (Total Carbon Column Observation Network) spectrometer as a reference, a common scaling factor has been derived for the XCO2 and XCH4 products, which ensures that the records are traceable to the WMO in situ scale.

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. Error budget for a calibration demonstration system for the reflected solar instrument for the climate absolute radiance and refractivity observatory

    NASA Astrophysics Data System (ADS)

    Thome, Kurtis; McCorkel, Joel; McAndrew, Brendan

    2013-09-01

    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.

  16. 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.

  17. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

    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 MoS2 to demonstrate the technique. Carbon and single crystal MoS2 had friction coefficients of μ = 0.20 ± 0.04 and μ = 0.006 ± 0.001, respectively, against an integrated Si probe. Against a glass colloidal sphere, MoS2 had a friction coefficient of μ = 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).

  19. Auxiliary instruments for the absolute calibration of the ASTRI SST-2M prototype for the Cherenkov Telescope Array

    NASA Astrophysics Data System (ADS)

    Maccarone, Maria C.; Segreto, Alberto; Catalano, Osvaldo; La Rosa, Giovanni; Russo, Francesco; Sottile, Giuseppe; Gargano, Carmelo; Biondo, Benedetto; Fiorini, Mauro; Incorvaia, Salvatore; Toso, Giorgio

    2014-08-01

    ASTRI SST-2M is the end-to-end prototype telescope under development by the Italian National Institute of Astrophysics, INAF, proposed for the investigation of the highest-energy gamma-ray band in the framework of the Cherenkov Telescope Array, CTA. The ASTRI SST-2M prototype will be installed in Italy at the INAF station located at Serra La Nave on Mount Etna during Fall 2014. The calibration and scientific validation phase will start soon after. The calibration of a Cherenkov telescope includes several items and tools. The ASTRI SST- 2M camera is equipped with an internal fiber illumination system that allows to perform the relative calibration through monitoring of gain and efficiency variations of each pixel. The absolute calibration of the overall system, including optics, will take advantage from auxiliary instrumentation, namely UVscope and UVSiPM, two small-aperture multi-pixels photon detectors NIST calibrated in lab. During commissioning phase, to measure the main features of ASTRI SST-2M, as its overall spectral response, the main telescope and the auxiliary UVscope-UVSiPM will be illuminated simultaneously by a spatially uniform flux generated by a ground-based light source, named Illuminator, placed at a distance of few hundreds meters. Periodically, during clear nights, the flux profiles of a reference star tracked simultaneously by ASTRI SST-2M and UVscope-UVSiPM will allow to evaluate the total atmospheric attenuation and the absolute calibration constant of the ASTRI SST-2M prototype. In this contribution we describe the auxiliary UVscope-UVSiPM and Illuminator sub-system together with an overview of the end-to-end calibration procedure foreseen for the ASTRI SST-2M telescope prototype.

  20. Instrumental correction of the uneven PMT aging effect on the calibration constant of a water vapor Raman lidar

    NASA Astrophysics Data System (ADS)

    Simeonov, Valentin; Fastig, Shlomo; Haefele, Alexander; Martucci, Giovanni; Calpini, Bertrand

    2015-04-01

    The water vapor profile derived from Raman lidar measurements is obtained from the ratio of water vapor to nitrogen Raman-shifted returns. The proportionality factor converting the signal ratio to water vapor/air mixing ratio is referred to as lidar calibration constant. The calibration constant is a function of the water vapor and nitrogen Raman cross sections and the efficiencies of the respective Raman channels including the photomultiplier tubes (PMT) efficiencies. Unequal, gradual changes in the water vapor and nitrogen channels PMT efficiencies due to aging effects lead to steady alteration of the calibration constant. This effect has been observed during the seven- year continuous operation of the RAman Lidar for Meteorological Observations (RALMO)1. A more detailed research2, has shown that the calibration constant change is more pronounced during summer time, which is explained by the higher daylight exposure of the PMTs during this period. Periodical recalibration of the lidar with radiosonde measurements is used to correct the calibration constant. This approach, however, induces additional systematic errors due to the nature of the calibration procedure and because of sonde-to-sonde accuracy variations. The systematic errors could induce artefacts leading to an incorrect interpretation of certain data points in the framework of climatological studies. To resolve this problem we developed a new, instrumental method for automated correction of the lidar calibration constant. By this method, the change in the water vapor and the nitrogen PMTs efficiencies are estimated from the PMTs responses measured when they are illuminated simultaneously by a single stabilized LED light source. A correction factor is deduced from the ratio of the signals of the two photomultipliers. The correction measurements are taken automatically once daily before midnight. The correction is applied when the correction factor exceeds a predefined threshold for several days. The

  1. 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

  2. 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

  3. 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.

  4. 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.

  5. Laboratory Calibration and Flight Validation of an Aircraft Based Instrument to Measure Water Isotopes in the Upper Troposphere and Lower Stratosphere.

    NASA Astrophysics Data System (ADS)

    St. Clair, J. M.; Hanisco, T. F.; Anderson, J. G.

    2004-12-01

    The relative abundance of the hydrogen isotopes of water, H2O and HDO, is a sensitive indicator of the condensation history of air in the near-tropopause region. The observations of the isotopes present a particular challenge because of the very high probability of sampling artifacts in the detection of water vapor itself and the certainty that the isotopes bear those same errors. We have developed a fluorescence-based instrument that has the sensitivity to measure the relative abundance of H2O and HDO without the sampling artifacts associated with large sampling volumes. The instrument combines a new water photolysis system with our pre-existing instrument for laser induced fluorescence detection of OH. Water is photolyzed with an excimer lamp source at 172;nm, producing ground state OH and OD radicals that are detected with state selective laser induced fluorescence at 287;nm. The experiment has three notable characteristics. The first is the high sensitivity afforded by laser induced fluorescence detection. At stratospheric mixing ratios of H2O (4;ppm at 50;mbar), the relative abundance of H2O and HDO can be measured with a S/N > 12 in a 16;s acquisition cycle. The second is a reduction in the exchange of water isotopes on surfaces within the instrument: the OH and OD radicals are removed with near unity efficiency after collisions with walls in the system and are not detected. The third is a rigorous laboratory evaluation of artifacts in the sampling of water vapor and its isotopes, and an empirical demonstration of the instrument's capabilities. The instrument layout and unique detection scheme virtually eliminates the possibility of contamination and resulting measurement hysteresis. These characteristics enable an independent validation of the absorption-based water isotope instruments in situ. Laboratory calibration will be discussed in depth, and data will be presented from recent test flights where the laser induced fluorescence instrument was flown

  6. 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.

  7. 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.

  8. Uncertainty on differential measurements and its reduction using the calibration by comparison method

    NASA Astrophysics Data System (ADS)

    Ospina, José; Canuto, Enrico

    2008-08-01

    The paper deals with the uncertainty of differential measurements, obtained from the subtraction of a pair of absolute measurements. It is shown that if the same sensor is used to perform both measurements, a model of the sensor will reveal a correlation component between the uncertainty of each absolute measurement, reducing the uncertainty on its subtraction. The procedure followed is based on the Gauss-Markov estimation method, showing that differential measurement uncertainty vanishes when the gradient to be measured is zero. If the two absolute measurements are to be performed using different sensors, a calibration by comparison between them will result in a similar uncertainty reduction. Finally, a simulated example based on commercially available thermistor data is included.

  9. 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

  10. Calibration between color camera and 3D LIDAR instruments with a polygonal planar board.

    PubMed

    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