Image and spectral image compression for four experiments on the ROSETTA and Mars Express missions of ESA

Statistics – Applications

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

1

Scientific paper

The output rates of imaging scientific experiments on planetary missions far exceed the few 10 kbits/s provided by X or Ka band downlink. This severely restricts the duration and frequency of observations. Space applications present specific constraints for compression methods: space qualified ROM and fast RAM chips have limited capacity and large power requirements. Real time compression is therefore preferable (no large local data buffer) but requires a large processing throughput. Wavelet compression provides a fast and efficient method for lossy data compression, when combined with tree- coding algorithms such as that of Said and Pearlman. We have developed such an algorithm for four instruments on ROSETTA (ESA cometary rendez-vous mission) and Mars Express (ESA Mars Orbiter and Lander mission), building on the experience from two experiments on CASSINI and MARS 96 for which lossless compression was implemented. Modern Digital Signal Processors using a pipeline architecture provide the required high computing capability. The Said-Pearlman tree-coding algorithm has been optimized for speed and code size by reducing branching and bit manipulation, which are very costly in terms of processor cycles. Written in C with a few assembly language modules, the implementation on a DSP of this new version of the Said-Pearlman algorithm provides a processing capability of 500 kdata/s (imaging), which is adequate for our applications. Compression ratios of at least 10 can be achieved with acceptable data quality.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Image and spectral image compression for four experiments on the ROSETTA and Mars Express missions of ESA does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Image and spectral image compression for four experiments on the ROSETTA and Mars Express missions of ESA, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Image and spectral image compression for four experiments on the ROSETTA and Mars Express missions of ESA will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1160730

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.