Influence of lossy data compression on satellite for terrain elevation measurement

PRISM, a panchromatic stereomatic sensor with 2.5 m resolution, is planed to be launched in 2003. Because the observing data rate of PRISM is very high, lossy data compression will be applied on board the satellite in order to decrease the downlink data rate to ground receiving stations. The object of this study is to evaluate influences of the lossy data compression, atmospheric effects and S/N of the sensor for terrain elevation measurement. As the results, the following conclusions were given. Firstly, low S/N increases mean elevation error under the restriction that forward/backward viewing vectors converge within two pixels. Secondly, data compression and the turbid atmosphere decrease the mean elevation error, preferably. Thirdly, a data compression ratio of 1/6 is recommended for the practical operation of PRISM. In this case, the mean elevation error ⩽3 m can be achieved without relation of atmospheric condition and S/N