Pre-launch instrument characterization results and in-orbit verification plan of GCOM-C/SGLI

摘要

The Global Change Observation Mission (GCOM) aims to establish and demonstrate a global, long-term satellite-observing system to measure essential geophysical parameters to facilitate understanding the global water circulation and climate change, and eventually contribute to improving future climate projection through a collaborative framework with climate model institutions. GCOM consists of two polar orbiting satellite observing systems, GCOM-W (Water) and GCOM-C (Climate). The first satellite, GCOM-W with Advance Microwave Radiometer -2 (AMSR-2), was already launched in 2012 and has been observing continuously. The follower satellite, GCOM-C with Second Generation Global Imager (SGLI), will be launched in Japanese fiscal year 2017. SGLI enables a new generation of operational moderate resolution-imaging capabilities following the legacy of the GLI on ADEOS-Ⅱ (Advanced Earth Observing Satellite-Ⅱ) satellite. The SGLI empowers surface and atmospheric measurements related to the carbon cycle and radiation budget, with two radiometers of Visible and Near Infrared Radiometer (VNR) and Infrared Scanning Radiometer (IRS) which perform a wide-band (380nm-12μm) optical observation not only with as wide as 1150-1400km FOV (field of view) but also with as high as 250-500m resolution. Also, polarization and along-track slant view observation are quite characteristic of SGLI, providing the sensor data records for more than 28 standard products and 23 research products including clouds, aerosols, ocean color, vegetation, snow and ice, and other applications. Sensor instrument proto-flight tests including optical characterization tests such as radiometric and geometric were completed, and satellite system proto-flight tests have finished including thermal vacuum, vibration and acoustic test. In this paper, the pre-launch phase instrument characterization of SGLI flight model and status of GCOM-C satellite system flight model along with the overview of them will be described. Especially we focus on the pre-launch geometric and radiometric performance test results, in-orbit calibration activities and methodologies: VNR's on-board calibrator, IRS's on-board calibrator and calibration maneuver, and in-orbit verification plan during a commissioning phase lasting approximately 3 months.