GEOMETRIC INTEGRATION OF NOAA AVHRR AND SPOT DATA - LOW RESOLUTION EFFECTIVE PARAMETERS FROM HIGH-RESOLUTION DATA

Integration appears to be a key for efficient exploitation of data acquired by operating satellites. In this paper we mainly consider geometric aspects and take advantage of information available from ephemeris data, combined with a few ground control points, in order to carry out the geometric combination of NOAA AVHRR and SPOT images by means of orbital models for each satellite. We reconstruct the conditions of observation and determine the common observed areas between the SPOT image pixels and each low resolution AVHRR pixel. The determination of effective parameters, at low spatial resolution, from high spatial resolution data takes into account overlapping effects between adjacent pixels, and pixel size and shape variations with viewing angle for AVHRR data. An application to surface temperature mapping of a selected heterogeneous area is presented by incorporating a high spatial resolution emissivity map derived from SPOT data with NOAA AVHRR thermal data.