Capabilities of the New Moroccan Satellite Mohammed-VI for Planimetric and Altimetric Mapping

The new Moroccan remote sensing program is composed from two identical satellites named Mohammed-VI (a and B), which operates in panchromatic, visible and near-infrared wavelengths, and provides a multi-swath ability under different angles for stereo imaging. The present paper assesses the capability of these satellites to create 3D stereo model, to retrieve DEM, and to derivate orthorectified images from multispectral data. To achieve these, along-track pair of stereo-images were preprocessed radiometrically and atmospherically, and processed using the Leica Photogrammetry Suite (LPS) module based on digital photogrammetry principles. A field survey was organized and a total of 21 GCPs were measured using a DGPS for stereo model calibration, as well as for verification and validation purposes (i.e. absolute accuracies evaluation for planimetric and altimetric coordinates). The results obtained shows that the orientation operations were achieved with similar accuracies as DGPS GCPs used for the model calibration. The overall obtained RMSE, using 14 checking points, are ±0.20 m and ±0.61 m for planimetry and altimetry, respectively. However, these accuracies are significantly influenced by topographic variations. Indeed, errors are larger for areas with high altitudes and strong slopes, yielding an RMSE of ±0.80 m and ±1.50 m for planimetry and altimetry, respectively. Whereas, significant accuracies improvement is observed for flat areas in the plain, or low to medium-relief areas with indulgent slopes, achieving an RMSE of ±0.04 m for planimetry and ±0.10 m for altimetry. Accordingly, these new satellites enable definitely several large-scale applications requiring high planimetric and altimetric accuracies, such as urban and topographic mapping, civil engineering planning, city modeling, etc.