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Shortwave Spectroradiometer (SWS) Earth Science Division - NASA Ames Research Center • 2006 On April 27, 2006 the Atmospheric Radiation Group installed the Shortwave Spectroradiometer (SWS) at the Department of Energy Atmospheric Radiation Measurement Climate Research Facility (ACRF) in north central Oklahoma. The development of the SWS is supported by a grant from the Department of Energy. It joins other ground instruments at the ACRF Southern Great Plains (SGP) site to observe cloud formation processes and their influence on radiative transfer. This contributes to advancing scientific knowledge of the Earth systems. The Shortwave Spectroradiometer design came from our highly successful airborne Solar Spectral Flux Radiometer (SSFR). The SWS measures the absolute visible and near infrared spectral radiance (units of watts per meter square per nanometer per steradian) of the zenith directly above the instrument. It is a moderate resolution sensor comprised of two Zeiss spectrometers (MMS 1 NIR enhanced and NIR-PGS 2.2) for visible and near-infrared detection in the wavelength range 300 – 2200 nm. The sampling frequency is 1 Hz. The spectral resolution is 8 nm for the MMS 1 NIR and 12 nm for the NIR-PGS 2.2. The light collector has a narrow field of view (1.4° ) collimator at the front end of a high-grade custom-made fiber optic bundle. Its operation is autonomous and capable of daily day-time measurement of at least 12 hours. Data uploading is done hourly via the internet to the archive at the Pacific Northwest National Lab (PNNL) in Richland, WA. SWS control and data monitoring can be done remotely from Ames. The SWS measurements can be used to: a. Retrieve cloud optical depth, particle size and cloud water path. b. Test the cloud optical depth retrieval for overcast and broken cloud fields. c. Validation/comparison with SGP surface remote sensors and future cloud intensive operational period (IOP) campaigns. d. Multivariate analysis to derive information content in hyper spectral data sets and to improve cloud retrieval algorithm development. e. Compare with radiative transfer models for testing and validating retrieval procedures. Peter Pilewskie (formerly with NASA Ames) of the University of Colorado in Boulder is the instrument mentor. http://www.arm.gov/instruments/instrument.php?id=sws Light Collector on Top of Optical Trailer Shortwave Spectrometer in Operation

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Shortwave Spectroradiometer (SWS)

Earth Science Division - NASA Ames Research Center • 2006

On April 27, 2006 the Atmospheric Radiation Group installed theShortwave Spectroradiometer (SWS) at the Department of EnergyAtmospheric Radiation Measurement Climate Research Facility(ACRF) in north central Oklahoma. The development of the SWS issupported by a grant from the Department of Energy. It joins otherground instruments at the ACRF Southern Great Plains (SGP) site toobserve cloud formation processes and their influence on radiativetransfer. This contributes to advancing scientific knowledge of theEarth systems.

The Shortwave Spectroradiometer design came from our highlysuccessful airborne Solar Spectral Flux Radiometer (SSFR). The SWSmeasures the absolute visible and near infrared spectral radiance(units of watts per meter square per nanometer per steradian) of thezenith directly above the instrument. It is a moderate resolutionsensor comprised of two Zeiss spectrometers (MMS 1 NIR enhancedand NIR-PGS 2.2) for visible and near-infrared detection in thewavelength range 300 – 2200 nm. The sampling frequency is 1 Hz.The spectral resolution is 8 nm for the MMS 1 NIR and 12 nm for theNIR-PGS 2.2. The light collector has a narrow field of view (1.4°)collimator at the front end of a high-grade custom-made fiber opticbundle. Its operation is autonomous and capable of daily day-timemeasurement of at least 12 hours. Data uploading is done hourly viathe internet to the archive at the Pacific Northwest National Lab(PNNL) in Richland, WA. SWS control and data monitoring can bedone remotely from Ames.

The SWS measurements can be used to:

a. Retrieve cloud optical depth, particle size and cloud water path.b. Test the cloud optical depth retrieval for overcast and broken cloud

fields.c. Validation/comparison with SGP surface remote sensors and future

cloud intensive operational period (IOP) campaigns.d. Multivariate analysis to derive information content in hyper

spectral data sets and to improve cloud retrieval algorithm development.

e. Compare with radiative transfer models for testing and validating retrieval procedures.

Peter Pilewskie (formerly with NASA Ames) of the University ofColorado in Boulder is the instrument mentor.

http://www.arm.gov/instruments/instrument.php?id=sws

Light Collector on Top of Optical Trailer

Shortwave Spectrometer in Operation

Shortwave Spectroradiometer (SWS)

Points of Contact:Warren J. GoreProject Co-Principal Investigator650-604-5533, [email protected]

Shortwave Spectroradiometer comparison with Total Sky Imager on 20 Sep 2006 under cirrus skycondition

SWS Spectrum at 1905 UTC

SWS Full-day Image

Total Sky Imager