Ww. Lu et Mp. Gough, ADAPTIVE COSINE TRANSFORM CODING FOR COMPRESSION OF MARS-96 ELISMA INSTRUMENT DATA, Microprocessors and microsystems, 19(5), 1995, pp. 277-282
Mars-96 ELISMA is a scientific project designed to measure the electri
c and magnetic fields around Mars when the Russian spacecraft Mars-96
orbits the planet. The data rate of the on-board ELISMA instruments wi
ll reach a figure which is about five times the telemetry-rate allocat
ed to them. To overcome this problem, a coding was designed to compres
s the data for the telemetry. This coding combines an adaptive cosine
transform with marginal analysis. Data from the instruments are divide
d into blocks with each block converted by the cosine transform into c
oefficients. The marginal analysis method is performed on the coeffici
ents to achieve a bit allocation vector specifying the level of the su
bsequent Lloyd-Max quantization of the coefficients. This paper descri
bes the coding algorithm and also shows simulation results for the com
pression of geophysical data.