Simulation Research about HJ-1C SAR Wind Mapping Capability

Abstract

Synthetic aperture radar (SAR) on aboard Chinese Huan Jing (HJ)-1C satellite has been planed to be launched in 2010. The satellite will fly in a sun-synchronous polar orbit of about 500-km altitude. SAR will operate in S band with HH polarization. Its image mode has the incidence angles 25°and 47°at the near and far sides of the swath respectively. SAR image has a spatial resolution of 20 m with a swath of 100 km. Here, the sea surface wind mapping capability of the SAR in the Chinese Coastal Region has been examined using M4S radar imaging model developed by Romeiser et al. The model is based on Bragg scattering theory in a composite surface model expansion. It accounts for contributions of the full ocean wave spectrum to the radar backscatter from ocean surface. The model reproduces absolute normalized radar cross section (NRCS) values for wide ranges of wind speeds. The model results of HJ-1C SAR have been compared with the model results of Envisat and Radarsat SAR signals. It shows that HJ-1C SAR is as good as both Envisat ASAR and Radarsat SAR at sea surface wind mapping Capability.