CCD Noise Effect on Data Transmission Efficiency of Onboard Lossless-Compressed Remote Sensing Images
It has to be aware that remote sensing images need to be encoded onboard using lossless compression method if all information of the image is required to be fully conserved for ground use. Also, to acquire as much onboard data as possible during one available pass of the satellite, it is necessary to consider efficiency of onboard data compression and transmission between satellite and ground segment. However, noise inevitably induced from CCD when the image is captured will affect efficiency of data compression and transmission. Therefore, main CCD noises and their effect on transmission of lossless-compressed Beijing-1 panchromatic images were investigated in this paper. It is proved that CCD noise should be considered adequately if requiring increasing lossless compression ratio and data transmission efficiency. It is further indicated that shot and readout noise modeled as Poisson noise and, thermal and dark-current noise modeled as Gaussian noise are principle factors for data transmission efficiency; impulse noise induced by CCD detector malfunctions has the least effect on data transmission efficiency. Finally, a FPGA-based model of noise suppression is proposed for future development of onboard data processing system. Keywords-charge-coupled device (CCD); Beijing-1; noise; lossless compression; compression ratio (CR); data transmission efficiency (DTE)