PRISM On-Orbit Geometric Calibration and DSM Performance

The Panchromatic Remote-sensing Instrument for Stereo Mapping (PRISM) carried by the Advanced Land-Observing Satellite was designed to generate worldwide topographic data with its high-resolution and stereoscopic observation. For this objective, the on-orbit geometric performance of PRISM sensors has been widely assessed and calibrated since the launch in January 2006 as an activity of the calibration and validation team of the Japan Aerospace Exploration Agency´s Earth Observation Research Center. This ongoing activity has generated various geometric performance data over two and a half years of on-orbit operation. A suite of geometric model parameters was calibrated to express the geometric characteristics of the PRISM sensors. These include static interior parameters (charge-coupled device camera parameters) and dynamic exterior parameters (orbit data, attitude data, and sensor alignment). The interior parameters were calibrated using test-field self-calibration with test sites of dense ground control points (GCPs). The exterior parameters were calibrated by adaptive orientation with test sites of worldwide GCPs. These parameters are correlated to the direct geolocation accuracy of the PRISM sensors and are monitored and validated to maintain performance. The performance of the digital surface model (DSM) derived from these geometric model parameters was analyzed. The detailed characteristics of the triangulation results were analyzed by GCPs, and the height accuracy was evaluated based on comparisons with high-accuracy high-resolution reference DSM data sets derived from Lidar and aerial photo matching of various terrain features.