3D Radargrammetric Modeling of Radarsat-2 Ultra-Fine and Polarimetric Modes
Thierry Toutin(1) and Rene Chenier(1)
(1) Canada Centre for Remote Sensing, 588 Booth Street, K1A 0Y7, Canada
The geometry and the accuracy of the three-dimensional (3-D) cartographic localisation of RADARSAT-2 images are being evaluated as part of the Canadian Space Agency’s Science and Operational Applications Research program. In a first step, the Toutin’s 3-D physical model, previously developed for Radarsat-1, was adapted to Radarsat-2 sensor and applied to two ultra-fine mode and polarimetric stereo-images acquired over an area in Beauport, Quebec. THe first experiments were performed for the ultra-fine mode. The 3-D modeling was computed with ground control points and the planimetric and altimetric localisation were evaluated with different checked data: (1) the root mean square errors computed over independent check points are 1 m in planimetry and 2 m in elevation; (2) the error from the overlay of the two quasi-epipolar images is less than 0.25 m; (3) the error from the comparison of the two ortho-images is less than 1 m; and (4) the comparison with 1-m accurate ortho-photos is less than 1 m. The main result deduced from the relative error between the quasi-epipolaris images is that the internal accuracy of Toutin’s 3-D radargrammetric model is better than 20 cm. Because all results and validations are in agreement and because the checked data error is included in these evaluations, it give a high level of confidence that the 2-D geometric localization and restitution accuracy is 2 m in planimetry while the 3-D geometric localization and stereo-restitution accuracy is 1 m in planimetry and 2 m in elevation.
Other accuracy evaluation will be presented at the Workshop using better ground data (DGPS points). but also the polarimetric fine mode will be processed and evaluated