CERES FM5 Instrument Pre-launch Calibration for NPP Mission
1. Pre-launch Characterization of the CERES Flight Model 5 (FM5) Instrument on NPP S. Thomas a , K. J. Priestley b , M. Shankar a , N. P. Smith a , M. G. Timcoe a a. Science Systems and Applications Inc (SSAI) b. NASA Langley Research Center Hampton, Virginia
3. CERES Instruments Broadband scanning Radiometers measuring Reflected Solar and Emitted Longwave Radiation. Six CERES Instruments built by Northrop Grumman Aerospace Systems (NGAS) at Redondo Beach, CA. FLIGHT MODEL 5 (FM5): NPP Spacecraft Sun synchronous polar orbit with 1:30 PM equatorial crossing. Altitude: 825 KM Proposed Launch: October 2011 Four Sets are Operational on EOS Spacecraft Flight Models 1 & 2 (FM1 & FM2) – TERRA Flight Models 3 & 4 (FM3 & FM4) - AQUA
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5. FLIGHT CALIBRATION SYSTEMS Internal Calibration Module Total & Window: Anodized Aluminum Blackbody sources Shortwave: Evacuated Quartz Tungsten Lamp Mirror Attenuator Mosaic (MAM) Total & SW Sensors: Solar Diffuser Plate Nickel substrate with Aluminum coated spherical cavities
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7. CERES Pre-Launch Calibration Pre-launch Calibrations were performed at the Northrop Grumman Radiometric Calibration Facility (RCF). Four calibrations were performed on CERES FM5 instrument after it was fabricated. March 1999 February 2000 October 2006 Sept. –Oct. 2008 Completed hot acceptance tests. During cold acceptance testing, calibration was stopped due to carousel problems. Tests done in hot and cold acceptance temperatures. Calibration tests done only in hot acceptance temperatures. Full calibration tests in hot and cold acceptance temperatures. 14 days 9 days 11 days 33 days
13. Calibrations using On-board Sources Sensor performance was evaluated using Internal calibration module sources (ICM) throughout test period. The response changes between ground and start-of-mission calibrations will be used as Ground to Flight corrections for radiometric gains.
14. CONCLUSION The final pre-launch vacuum characterization of CERES FM5 instrument was performed in September 2008. Total and Window sensor gains determined by the NFBB is 8.577 counts/Wm-2 and 10.495 counts/Wm-2 respectively. The shortwave sensor gain derived using the SWRS and TACR is 10.105 counts/Wm-2. Spectral response for sensors were derived using the SWRS/TACR and optical component measurements in < 3 micron and FTS measurements in > 3 micron region. ICM calibrations provide a transfer standard for the pre-launch determined radiometric gains to flight.
