System design of X-band Communication Link for future Spaceborne SAR Mission

摘要

The spaceborne Synthetic Aperture Radar(SAR) is an image acquisition system, using reflected microwave signal from the Earth and has been used in diverse applications in disaster management, change detection, military surveillance and so on. SAR technology has improved significantly in recent years, providing X-band high resolution images that are comparable to that of modern optical sensor images. Spaceborne SAR sensors such as TerraSAR-X, COSMO-SkyMed, along with KOMPSAT-5 have made it possible to obtain high resolution SAR images. But, the increased resolution and dynamic swath coverage lead to the generation of huge amount of data volume on-board. As a result, there rises a strong demand for a high speed X-band down link communication system to deliver acquired image data to the ground station. In this paper, spaceborne SAR mission design is carried out and simulations are performed to estimate the required data storage from the latest spaceborne missions. Initially conventional SAR Imaging modes are considered to calculate the required data link during Strip, Scan, Spotlight mode operations. As the future SAR missions are expected to include further complicated SAR missions modes, TOPS,SS(Sliding Spot) modes will be exploited in terms of coverage area constrained by limited downlink rate. The required data rate to a ground station will be increased drastically due to the simultaneous enhancement of both image resolution and coverage. In this paper, we perform diverse SAR mission simulations to analyze the relationship between X-band data link and future SAR missions.