GaoFen-1 Performance and Status After Nine Years on Orbit

Gaofen-1 is a new generation long-life small remote sensing satellite in China. It has been observing the earth for more than nine years after being launched into 645 km sun-synchronous orbit on Apr. 26, 2013. It is worth mentioning that Gaofen-1 is a novel satellite with 2 high resolution cameras (PMS1 and PMS2) and 4 wide swath cameras (WFV1 to WFV4). Two PMS cameras can provide PAN 2 m and 4 bands 8 m images with 69 km total swath. 4 WFV cameras can acquire 4 bands 16 m images with 842 km total swath. During 9 years in orbit, what changes in the performance of remote sensors and the satellite health status have been concerned. This paper writes from satellite evolution of orbit, main subsystems of platform, and so on. Some important events and operations are mentioned. Some improvements of payload are introduced. In particular, the yaw 90° radiometric calibration (side-slither radiometric calibration), TDI stage and gain adjusting, and focus adjustment to ensure the imaging quality are shown. The 9-year change of radiometric calibration coefficient from the ground system is introduced. At last, in order to ensure the illumination condition of remote sensor imaging, the experience of satellite orbit inclination maneuver to changing the local descending node time (>10:00AM) is introduced. All efforts are made to ensure that the satellite has a good condition. All the analysis results show that the satellite works in good status and its excellent performance shows that it will continue to running well in the future.