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An Investigation of Aircraft Heaters 25: Use of the Thermopile Radiometer

Description: Report presenting an analysis of the thermopile radiometer as used in the measurement of irradiation and radiant power interchange is given. The theory of the instrument when used to measure irradiation and net radiant power interchange is developed, and the precautions to be observed when using it for these measurements are presented.
Date: April 1945
Creator: Boelter, L. M. K.; Bromberg, R.; Gier, J. T. & Dempster, E. R.
Partner: UNT Libraries Government Documents Department

Report on Broadband Solar Radiometer Inconsistencies at the Atmospheric Radiation (ARM) Southern Great Plains (SGP) Central Facility During the ARM Enhanced Shortwave Experiment (ARESE)

Description: Broadband solar radiometer data collected at the U.S. Department of Energy’s Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) Central Facility during the ARM Enhanced Shortwave Experiment (ARESE) exhibits inconsistencies and inter-calibration offsets. This report examines these problems, and in some cases, suggests error sources and possible solutions. The data discussed here covers the period from September 28, 1995, through October 30, 1995.
Date: June 18, 1996
Creator: Long, CN
Partner: UNT Libraries Government Documents Department

Multi-Filter Rotating Shadowband Radiometers Mentor Report and Baseline Surface Radiation Network Submission Status

Description: There are currently twenty-four Multi-Filter Rotating Shadowband Radiometers (MFRSR) operating within Atmospheric Radiation Measurement (ARM). Eighteen are located within the Southern Great Plains (SGP) region, there is one at each of the North Slope of Alaska (NSA) and Tropical Western Pacific (TWP) sites, and one is part of the instrumentation of the ARM Mobile Facility. At this time there are four sites, all extended facilities within the SGP, that are equipped for a MFRSR but do not have one due to instrument failure and a lack of spare instruments. In addition to the MFRSRs, there are three other MFRSR derived instruments that ARM operates. They are the Multi-Filter Radiometer (MFR), the Normal Incidence Multi-Filter Radiometer (NIMFR) and the Narrow Field of View (NFOV) radiometer. All are essentially just the head of a MFRSR used in innovative ways. The MFR is mounted on a tower and pointed at the surface. At the SGP Central Facility there is one at ten meters and one at twenty-five meters. The NSA has a MFR at each station, both at the ten meter level. ARM operates three NIMFRs; one is at the SGP Central Facility and one at each of the NSA stations. There are two NFOVs, both at the SGP Central Facility. One is a single channel (870) and the other utilizes two channels (673 and 870).
Date: March 18, 2005
Creator: Hodges, G.
Partner: UNT Libraries Government Documents Department

Atmospheric Radiation Measurement Program facilities newsletter, August 2003.

Description: This Monthly newsletter discusses the following topic: New Atmospheric Profiling Instrument Added to SGP CART Suite--A new atmospheric profiling instrument at the SGP CART site is giving researchers an additional useful data stream. The new instrument is a microwave radiometer profiler (MWRP) developed by Radiometrics Corporation.
Date: September 2, 2003
Creator: Holdridge, D.J.
Partner: UNT Libraries Government Documents Department

Microwave Radiometer – 3 Channel (MWR3C) Handbook

Description: The microwave radiometer 3-channel (MWR3C) provides time-series measurements of brightness temperatures from three channels centered at 23.834, 30, and 89 GHz. These three channels are sensitive to the presence of liquid water and precipitable water vapor.
Date: May 4, 2012
Creator: Cadeddu, MP
Partner: UNT Libraries Government Documents Department

Tower Camera Handbook

Description: The tower camera in Barrow provides hourly images of ground surrounding the tower. These images may be used to determine fractional snow cover as winter arrives, for comparison with the albedo that can be calculated from downward-looking radiometers, as well as some indication of present weather. Similarly, during spring time, the camera images show the changes in the ground albedo as the snow melts. The tower images are saved in hourly intervals. In addition, two other cameras, the skydeck camera in Barrow and the piling camera in Atqasuk, show the current conditions at those sites.
Date: January 1, 2005
Creator: Moudry, D
Partner: UNT Libraries Government Documents Department

Microwave Radiometer (MWR) Handbook

Description: The Microwave Radiometer (MWR) provides time-series measurements of column-integrated amounts of water vapor and liquid water. The instrument itself is essentially a sensitive microwave receiver. That is, it is tuned to measure the microwave emissions of the vapor and liquid water molecules in the atmosphere at specific frequencies.
Date: August 1, 2006
Creator: Morris, VR
Partner: UNT Libraries Government Documents Department

Rotating Shadowband Spectroradiometer (RSS) Handbook

Description: The rotating shawdowband spectroradiometer (RSS) implements the same automated shadowbanding technique used by the multifilter rotating shadowband radiometer (MFRSR), and so it too provides spectrally-resolved, direct-normal, diffuse-horizontal, and total-horizontal irradiances, and can be calibrated in situ via Langley regression. The irradiance spectra are measured simultaneously at all spectral elements (pixels) in 360-nm to 1050-nm range.
Date: January 1, 2005
Creator: Kiedron, P.; Schlemmer, J. & Klassen, M.
Partner: UNT Libraries Government Documents Department

Multi-Filter Rotating Shadowband Radiometer (MFRSR) retrievals of total column aerosol, water vapor, and ozone during the Arm Enhanced Shortwave Experiment (ARESE)

Description: The ARESE provided an opportunity to compare MFRSR retrievals of total column aerosol optical depth, total column water vapor, and total column ozone with independent measurements of the same quantities during this campaign in the fall of 1995. MFRSR ozone was compared to ozonesondes that reached altitudes of at least 30 km. MFRSR water vapor was compared to microwave radiometer water vapor on several clear days during the campaign. Aerosol was measured by the ARM MFRSR and the Penn State Reagan sun photometer at high time resolution on a few days of the experiment. Only total column measurements of these constituents were compared. These comparisons were part of an effort to validate MFRSR retrievals that date from 1992. The daily total column aerosol optical depth record since that year illustrates the archival data and the variability of aerosol seasonally and during the decay of the Mt. Pinatubo stratospheric aerosol layer.
Date: December 31, 1996
Creator: Michalsky, J.J.; Min, Qilong & Harrison, L.C.
Partner: UNT Libraries Government Documents Department

Aspects of the quality of data from SGP cart site broadband radiation sensors

Description: This report presents details of the performance of broadband radiometers the the southern Great Plains (SGP) cloud and radiation testbed (CART) site to estimate the uncertainties of irradiance observations. Net radiation is observed with net radiometer in the energy balance Bowen ratio station at the central facility and compared with the net radiation computed as the sum of component irradiances recorded by nearby pyranometers and pyrgeometers. This paper observes the uncertainties of readings from net radiometers which are known to be substantial.
Date: June 1, 1995
Creator: Splitt, M.E. & Wesely, M.L.
Partner: UNT Libraries Government Documents Department

Spectral correction of silicon photodiode solar radiation detectors

Description: The multi-filter rotating shadowband radiometer (MFRSR) is a ground- based instrument that uses a silicon photodiode sensor to measure shortwave global and diffuse horizontal irradiance from which direct normal irradiance is calculated. Besides this multiplexing advantage, silicon sensors are rugged, stable and have a fast time response. On the other hand, silicon sensors are both thermally and spectrally sensitive. They, as do all pyranometric sensors, have an imperfect cosine response, especially at high solar-zenith angles. In the MFRSR two of these problems are solved. The MFRSR`s cosine response is measured and corrected. An automatic heater maintains the MFRSR detector at a constant temperature near 40 {degree}C. This paper describes a correction scheme, based on sky conditions, to account for the remaining spectral bias. The data base for these corrections was collected in Albany, New York, during 1993. The MFRSR and WMO firstclass thermopile instruments were sampled every 15 seconds and 5- minute averages were compared. The differences in time response between silicon and thermopile instruments contributes substantially to the remaining root-mean-square error reported.
Date: December 31, 1994
Creator: Zhou, C. & Michalsky, J.
Partner: UNT Libraries Government Documents Department

Multi-spectral automated rotating shadowband radiometry in the Atmospheric Radiation Measurement (ARM) Program

Description: This paper discusses the work in progress to develop two RSR variants that extend this measurement technique to make measurements at multiple wavelengths. One of these instruments uses independent interference-filter/photodiode detectors to measure any seven wavelength bands chosen between 350 nm and 2.5 {micro}m, and the other uses a prism spectrograph coupled to a Charge-Coupled Device (CCD) array to measure 256 wavelength intervals from 370 nm to 1 {micro}m. These instruments provide spectrally resolved measurements of the direct-normal, total horizontal, and diffuse horizontal irradiances. These parameters of the sky-radiance function are measured using the same detector (for a given wavelength), eliminating the difficulties inherent in comparing these data when they are taken by independent detectors. The data are measured synchronously, and can be measured at intervals as short as 10 seconds if desired, though more normally data are taken at 15 second intervals and averaged over 1 to 5 minutes. Field deployment of the multiple filter instruments has begun, and twelve of these instruments will be deployed this year as part of the United States Department of Energy (DOE) Quantitative Links measurement program. In addition, further development and testing of these instruments is underway as part of the Atmospheric Radiation Measurement Program also sponsored by DOE.
Date: December 31, 1991
Creator: Harrison, L.
Partner: UNT Libraries Government Documents Department

An internal analysis of SGP/CART radiosonde performance during the September 1996 Water Vapor intensive operations period

Description: The September 1996 Water Vapor Intensive Operations Period (IOP) provided an excellent opportunity to investigate further the operational performance of the radiosondes used by ARM at the SGP/CART site. Although many instrument intercomparisons were conducted during the IOP, the lack of an accepted absolute standard makes evaluation of the results difficult. By focusing on information obtained from the radiosondes themselves, with minimal reference to external instruments, we hope to eliminate much of the uncertainty associated with comparing different measurement systems.
Date: September 1, 1997
Creator: Lesht, B.M.
Partner: UNT Libraries Government Documents Department

Tropical Ocean Climate Study (TOCS) and Japan-United States Tropical Ocean Study (JUSTOS) on the R/V KAIYO, 25 Jan to 2 March 1997, to the Tropical Western Pacific Ocean BNL component

Description: The Japanese U.S. Tropical Ocean Study (JUSTOS) cruise on the R/V KAIYO in the Tropical Western Pacific Ocean was a collaborative effort with participants from the Japanese Marine Science and Technology Center (JAMSTEC), the National Center for Atmospheric Research (NCAR), and Brookhaven National Laboratory BNL. This report is a summary of the instruments, measurements, and initial analysis of the BNL portion of the cruise only. It includes a brief description of the instrument system, calibration procedures, problems and resolutions, data collection, processing and data file descriptions. This is a working document, which is meant to provide both a good description of the work and as much information as possible in one place for future analysis.
Date: April 11, 1997
Creator: Reynolds, R. M. & Smith, S.
Partner: UNT Libraries Government Documents Department

Measurement of bidirectional optical properties of complex shading devices

Description: A new method of predicting the solar heat gain through complex fenestration systems involving nonspecular layers such as shades or blinds has been examined in a project jointly sponsored by ASHRAE and DOE. In this method, a scanning radiometer is used to measure the bidirectional radiative transmittance and reflectance of each layer of a fenestration system. The properties of systems containing these layers are then built up computationally from the measured layer properties using a transmission/multiple-reflection calculation. The calculation produces the total directional-hemispherical transmittance of the fenestration system and the layer-by-layer absorptances. These properties are in turn combined with layer-specific measurements of the inward-flowing fractions of absorbed solar energy to produce the overall solar heat gain coefficient. This paper describes the method of measuring the spatially averaged bidirectional optical properties using an automated, large-sample gonioradiometer/photometer, termed a ``Scanning Radiometer.`` Property measurements are presented for one of the most optically complex systems in common use, a venetian blind. These measurements will form the basis for optical system calculations used to test the method of determining performance.
Date: January 1995
Creator: Klems, J. H. & Warner, J. L.
Partner: UNT Libraries Government Documents Department


Description: The WHOI buoy radiometer intercomparison took place during May and June, 2000 at the WHOI facility. The WHOI IMET, JAMSTEC Triton, and NOAA TAO buoy systems were operated from a beach site and the Brookhaven National Laboratory set up two Portable Radiation Package systems (P01 and P02) alongside the WHOI instrumentation on the roof of the Clark Building, about 300 m away. The BNL instruments were named ''P01'' and ''P02'' and were identical. Buoy instruments were all leveled to {+-}1{degree} to horizontal. The purpose of the project was to compare the buoy systems with precision measurements so that any differences in data collection or processing would be evaluated. BNL was pleased to participate so the PRP system could be evaluated as a calibration tool. The Portable Radiation Package is an integral component of the BNL Shipboard Oceanographic and Atmospheric Radiation (SOAR) system. It is designed to make accurate downwelling radiation measurements, including the three solar irradiance components (direct normal, diffuse and global) at six narrowband channels, aerosol optical depth measurements, and broadband longwave and shortwave irradiance measurements.
Date: December 1, 2000
Creator: Reynolds, R. M.; Bartholomew, M. J.; Miller, M. A.; Smith, S. & Edwards, R.
Partner: UNT Libraries Government Documents Department

Progress report of FY 1998 activities: Continued development of an integrated sounding system in support of the DOE/ARM experimental program

Description: Both during September 15-30, 1996 and September 15-October 5, 1997, the Environmental Technology Laboratory (ETL) participated in an experiment at the Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) site that was designed to study many of the ways that ARM is measuring water vapor. These experiments, called the Water Vapor Intensive Operating Periods (WVIOPs), produced some results of significant importance to ARM water vapor measurements. We have spent the major portion of this years activities in analyzing results of these experiments, and improving algorithms for improving the measurement of precipitable water vapor (PWV) from instruments available at ARM. The most important ARM instrument for this measurement continues to be the Microwave Radiometer (MWR). Measurements of water vapor at the North Slope of Alaska and Adjacent Arctic Ocean (NSA/AAO) CART site in Barrow, Alaska, area potential problem because of the difficulty of radiosondes to measure low amounts of vapor during cold and extremely dry conditions. The applicability of MWR scaling to radiosondes is questionable because of the low sensitivity of these instrument during dry conditions. It has been suggested by the ARM Instantaneous Radiative Flux Working Group and others that measurements of brightness temperature around 183 GHz could be used to scale during the coldest and driest periods. However, the millimeter wavelengths are vulnerable to cloud effects from both liquid and ice. We have participated in the planning and will participate in the Millimeter wave Arctic Experiment that will evaluate microwave and millimeter wave radiometers during extremely cold conditions. ETL has tested, both in an experiment at the Boulder Atmospheric Observatory and during the two Water Vapor Intensive Operating Periods in 1996 and 1997, a 5-mm scanning radiometer that measures low-altitude temperature profiles; both profiles of lapse rate and absolute temperature can be measured with the instrument. The technique ...
Date: September 6, 1998
Creator: Westwater, Edgeworth R.; Han, Yong & Leuskiy, Vladimir
Partner: UNT Libraries Government Documents Department

Progress report: Continued development of an integrated sounding system in support of the DOE/ARM experimental program

Description: From January 6 to February 28, 1993, the second phase of the Prototype Radiation Observation Experiment (PROBE) was conducted in Kavieng, Papua New Guinea. Data taken during PROBE included frequent radiosondes, 915 MHz Wind profiler/Radio Acoustic Sounding System (RASS) observations of winds and temperatures, and lidar measurements of cloud-base heights. In addition, a dual-channel Microwave Water Substance Radiometer (MWSR) at 23.87 and 31.65 GHz and a Fourier Transform Infrared Radiometer (FTIR) were operated. The FTIR operated between 500 and 2000 cm{sup -1} and measured some of the first high spectral resolution (1 cm{sup -1}) radiation data taken in the tropics. The microwave radiometer provided continuous measurements with 30-second resolution of precipitable water vapor (PWV) and integrated cloud liquid (ICL), the RASS measured virtual temperature profiles every 30 minutes, and the cloud lidar provided episodic measurements of clouds every minute. The RASS, MWSR, and FTIR data taken during PROBE were compared with radiosonde data. Broadband longwave and shortwave irradiance data and lidar data were used to identify the presence of cirrus clouds and clear conditions. Comparisons were made between measured and calculated radiance during clear conditions, using radiosonde data as input to a Line-By-Line Radiative Transfer Model. Comparisons of RASS-measured virtual temperature with radiosonde data revealed a significant cold bias below 500 m.
Date: September 6, 1996
Creator: Westwater, Edgeworth R.; Gage, Kenneth S.; Han, Yong; Shaw, Joseph A. & Churnside, Jim H.
Partner: UNT Libraries Government Documents Department

CART and GSFC Raman lidar measurements of atmospheric aerosol backscattering and extinction profiles for EOS validation and ARM radiation studies

Description: The aerosol retrieval algorithms used by the Moderate-Resolution Imaging Spectroradiometer (MODIS) and Multi-Angle Imaging SpectroRadiometer (MISR) sensors on the Earth Observing Satellite (EOS) AM-1 platform operate by comparing measured radiances with tabulated radiances that have been computed for specific aerosol models. These aerosol models are based almost entirely on surface and/or column averaged measurements and so may not accurately represent the ambient aerosol properties. Therefore, to validate these EOS algorithms and to determine the effects of aerosols on the clear-sky radiative flux, the authors have begun to evaluate the vertical variability of ambient aerosol properties using the aerosol backscattering and extinction profiles measured by the Cloud and Radiation Testbed (CART) and NASA Goddard Space Flight Center (GSFC) Raman Lidars. Using the procedures developed for the GSFC Scanning Raman Lidar (SRL), the authors have developed and have begun to implement algorithms for the CART Raman Lidar to routinely provide profiles of aerosol extinction and backscattering during both nighttime and daytime operations. Aerosol backscattering and extinction profiles are computed for both lidar systems using data acquired during the 1996 and 1997 Water Vapor Intensive Operating Periods (IOPs). By integrating these aerosol extinction profiles, they derive measurements of aerosol optical thickness and compare these with coincident sun photometer measurements. They also use these measurements to measure the aerosol extinction/backscatter ratio S{sub a} (i.e. lidar ratio). Furthermore, they use the simultaneous water vapor measurements acquired by these Raman lidars to investigate the effects of water vapor on aerosol optical properties.
Date: April 1, 1998
Creator: Ferrare, R.A.; Turner, D.D.; Melfi, S.H.; Evans, K.D.; Whiteman, D.N.; Schwemmer, G. et al.
Partner: UNT Libraries Government Documents Department