On the realtime satellite image compression of X-Sat

The transmission of image data acquired by remote sensing missions based on spaceborne platforms is a major bottleneck. It results from limited power on-board, the huge volume of the data, and the number of accessible ground receiving stations. In particular these arguments hold true for small satellites that face additional design constraints in terms of size, mass and cost. To relax the downlink restriction image compression has to be applied. This paper analyses the architecture and requirements for the minisatellite X-Sat and sets them in relation with selected compression algorithms. Due to the realtime nature of the mission, i.e. simultaneous imaging and downlinking, only hardware-based solutions are considered. The investigation addresses the issues of achievable compression ratios and guaranteeing lossless compression.