STUDY ON THE SYSTEM MODULATION TRANSFER FUNCTION OF HIGH-RESOLUTION OPTICAL IMAGING SENSOR

摘要

Scene structures of a sharp knife-edge with step target were used in the estimation experiments to predict the system MTF of such high-resolution optical imaging sensor as the AVNIR sensor. Finding optimal candidate target from observing the display of profile for the gray level of Earth observation images taken by the AVNIR sensor is very difficult, error-prone and tedious work. Using a newly developed automatic target detection method, we looked for near-optimum sharp knife-edge with step target in the AVNIR operational images. Estimated results of AVNIR's MTF characteristics using AVNIR imagery near Roger Dry Lake, CA, USA are presented. Investigations for the effect of atmospheric degradation are also conducted using the atmospherically corrected observation imagery. Atmospheric corrected EIFOVs values are improved by 1% to 10% over uncorrected cases. EIFOVs values are estimated to be about 18 meters for Mu bands. The values of MTF at the Nyquist frequency exceeded 0.26 for Mu bands. Considering the effect of digital sampling and resampling(reconstruction) during ground processing, the estimated spatial resolution characteristics seem reasonable compared with prelaunch test data.