Performance verification of spectral and panchromatic modules of the MOMS-02 sensor flown aboard STS-55/D2-mission

Abstract

A second generation instrument of the MOMS (Modular Optoelectronic Multispectral/Stereo Scanner) was flown in the frame of the German D2 mission aboard Space Shuttle flight STS-55. The newly designed sensor provides multispectral coverage in 4 bands including the visible and near-infrared range. In addition, MOMS-02 is equipped with a three line along track stereo device recording for/aft and nadir panchromatic data. During the mission (April to May 1993) approximately 7 mio. km/sup 2/ of data have been recorded in 7 different modes from a mean altitude of 296 km resulting in a GIFOV of 4.5/spl times/4.5 m/sup 2/ in the nadir panchromatic and 13.5/spl times/13.5 m/sup 2/ in the panchromatic for/aft and multispectral bands. MOMS-02 data of distinct test-sites, recorded at different conditions have been investigated on its quantitative and qualitative performance. Different algorithms are used for estimating entropy, signal to noise ratio, point spread function and interband correlation. The results are related to complementary LANDSAT TM and SPOT HRV data sets. The first impression of the raw data was quite positive as compared to the data of the pilot system MOMS-01. Recognizable image distortions could be related to electronic malfunctions and/or to lack of power, shielding and thermal (heating-up) influences. These problems are identified and will he solved for future missions by change of electronic parts and supply of a sufficient thermal environment. The entropy, SNR and PSF performances an comparable to the operational sensors. However, MOMS band 3 is slightly weaker in its performance especially in the SNR. The reason for this was found in electronic malfunctions and may also be related to the band width design that is about 10 nm narrower than the nominal (originally defined) one. Results of the correlation analysis confirm the new arrangement of the band centers and widths. An improvement in spectral dynamic of about 10-15% versus a broad banded design could be estimated.<>