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1999-2003 Shortwave Characterizations of Earth Radiation Budget Satellite (ERBS)/Earth Radiation Budget Experiment (ERBE) Broadband Active Cavity Radiometer SensorsFrom October 1984 through May 2005, the NASA Earth Radiation Budget Satellite (ERBS/ )/Earth Radiation Budget Experiment (ERBE)ERBE nonscanning active cavity radiometers (ACR) were used to monitor long-term changes in the earth radiation budget components of the incoming total solar irradiance (TSI), earth-reflected TSI, and earth-emitted outgoing longwave radiation (OLR). From September1984 through September 1999, using on-board calibration systems, the ERBS/ERBE ACR sensor response changes, in gains and offsets, were determined from on-orbit calibration sources and from direct observations of the incoming TSI through calibration solar ports at measurement precision levels approaching 0.5 W/sq m , at satellite altitudes. On October 6, 1999, the onboard radiometer calibration system elevation drive failed. Thereafter, special spacecraft maneuvers were performed to observe cold space and the sun in order to define the post-September 1999 geometry of the radiometer measurements, and to determine the October 1999-September 2003 ERBS sensor response changes. Analyses of these special solar and cold space observations indicate that the radiometers were pointing approximately 16 degrees away from the spacecraft nadir and on the anti-solar side of the spacecraft. The special observations indicated that the radiometers responses were stable at precision levels approaching 0.5 W/sq m . In this paper, the measurement geometry determinations and the determinations of the radiometers gain and offset are presented, which will permit the accurate processing of the October 1999 through September 2003 ERBE data products at satellite and top-of-the-atmosphere altitudes.
Document ID
20090026578
Document Type
Conference Paper
Authors
Lee, Robert B., III (National Inst. of Aerospace Hampton, VA, United States)
Smith, George L. (National Inst. of Aerospace Hampton, VA, United States)
Wong, Takmeng (NASA Langley Research Center Hampton, VA, United States)
Date Acquired
August 24, 2013
Publication Date
August 10, 2008
Subject Category
Space Radiation
Report/Patent Number
LF99-6869
Meeting Information
SPIE Optics and Photonics 2008(San Diego, CA)
Funding Number(s)
WBS: WBS 921266.04.07.07
Distribution Limits
Public
Copyright
Other