Geometric performance of the small satellite CE-SAT-IE carrying an optical sensor derived from the COTS camera Canon EOS R5

Abstract. The CE-SAT-IE is a small optical satellite developed by Canon Electronics Inc. (CE). It is equipped with an optical frame sensor derived from a commercial off-the-shelf (COTS) camera, the Canon EOS R5, which observes ground images from an altitude of 670 km with a ground sampling distance (GSD) of 0.8 m. This article reports initial results on the geometric calibration and validation of the sensor using ground control points (GCPs), as well as on generating a digital surface model (DSM) from images acquired during in-track multi-view stereo observations. The image distortion specific to the same rolling shutter as the EOS R5 is calibrated in addition to the conventional interior camera parameters, resulting in GCP residuals with standard deviations below one pixel. The exterior parameters are calibrated to improve the direct absolute geolocation accuracy by estimating the fixed sensor alignment, and the result shows that it is around 50-60 m in standard deviations on the ground. Multiple DSMs are generated from selected pairs of different B/Hs in the multi-view stereo images. These are stacked to improve quality, and the height accuracy is estimated at 3.9 m root mean square (RMS), using the aerial light detection and ranging (LiDAR) data as the reference.