SOME NEW GRASS MODULES TO ORTHORECTIFY HIGH-RESOLUTION SATELLITE IMAGES
Orthorectification is an important feature for high-resolution pushbroom satellite images (such as those provided by Quickbird, Ikonos, Geo-Eye satellites). This process is required to correct deformations due to morphology and sensor view, in order to allow registering of other carthographic information on top of remote sensing data. Until now, Grass missed modules to perfom this important step in satellite image processing. This presentation deals with the description of a group of new native modules usable to orthorectify by forward Rational Functions Model and Rational Polynomial Coefficients as provided by vendors with their images. The RFM is a reasonable approximation of the world-to-image trasformation required to perform rectification, starting from an available DEM, the image and RPCs as available for most common modern pushbroom sensors.
Both model, modules and some experimental results are presented. Future work will be concentrated on rigorous models and improving the provided modules to use also additional ground control points when available.
Francesco Lovergine - CNR