Geo-atmospheric processing of airborne imaging spectrometry data. Part 1: parametric orthorectification

An operational orthorectification solution in support of the combined geometric and radiometric processing of currently available imaging spectrometry data is presented. The described parametric geocoding procedure (PARGE) strictly considers the aircraft and terrain geometry parameters and uses a forward transformation algorithm to create orthorectified imaging spectrometry cubes. The implementation principles, the auxiliary data calibration strategies, and the workflow of the currently applied processor are discussed. The major error sources of the approach are identified, and possibilities are shown how to make the most out of the available auxiliary data Inertial Navigation System/Global Positioning System (INS/GPS) parameters. Results on HyMap and AVIRIS imaging spectrometry data show an absolute accuracy in the range of 1-3 pixels for this kind of imagery. The combination of PARGE with an atmospheric correction procedure is shown in part 2 to this paper. The depicted geo-atmospheric workflow is proposed as a standard processing approach for available and future imaging spectrometry data.