GOSAT lunar calibration in two year operation
Abstract
The Greenhouse Gases Observing Satellite (GOSAT) is a Japanese mission to monitor greenhouse gases such as CO_{2} and CH_{4} from space. The GOSAT carries the Fourier Transform Spectrometer (TANSO-FTS) and the Cloud and Aerosol Imager (TANSO-CAI). The FTS has 3 polarized SWIR narrow bands, which are 0.76, 1.6 and 2.0 microns and TIR wide band from 5.5 to 14.3 microns. The FTS observes globally with grid points of 10 km FOV by separate pointing. The CAI is carried 4 radiometers of 0.38, 0.67, 0.87, and 1.60 microns with high spatial resolution of 0.5-1.5 km and wide swath of 1000 km. The GOSAT observes the full moon for the radiometric calibration of the FTS SWIR bands and the CAI by the lunar calibration operation every year. Bottom of the satellite installed the sensors is oriented to the moon before moon rise of the satellite. The initial lunar calibration on orbit just after the launch was operated on March 11 and April 9, 2009. Every year calibrations were operated on April for continuous annual trend and July for corresponding to the Railroad Valley calibration and validation field campaign. In 3rd year operation, the specification of lunar calibration is optimized to observe in phase angle around 7 degrees to avoid the opposition surge and use the lunar model in good accuracy and brightest target. The FTS observes the moon by 0.6 IFOV. The FTS carries a high-resolution monitoring camera for checking the observation target. The moon position in the FTS IFOV is confirmed by the camera image. The CAI observes the moon by 12 pixels of Band 1-3, by 4 pixels of Band 4. The CAI scans the moon in 2 reciprocations with constant scan speed. This presentation shows the sensitivity study using the GOSAT lunar observation in two year operation.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2011
- Bibcode:
- 2011AGUFM.A33C0205S
- Keywords:
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- 0365 ATMOSPHERIC COMPOSITION AND STRUCTURE / Troposphere: composition and chemistry;
- 0394 ATMOSPHERIC COMPOSITION AND STRUCTURE / Instruments and techniques