A Rigorous Model and DEM Generation for SPOT5-HRS

This paper describes a new model developed at UCL for along track stereo sensors. The model is tested on SPOT HRS data provided under the SPOT Assessment Project (SAP) set up by CNES and ISPRS. The SPOT HRS data has been used to test a new sensor model for along track satellite data, and to generate a DEM using the Leica Photogrammetry Suite (LPS). The model described in this paper uses the collinearity equations in combination with astrodynamics. The main and fundamental point during the development of this model was to benefit from acquisition in the same orbit. The collinearity equations are modified to model the characteristics of a pushbroom scanner and the number of exterior orientation parameters. The state vector at the origin point of each image is computed. The results of testing the model with HRS data show that the model provides a stable, accurate and rigorous solution. The solution for the orientation from the LPS gives similar results to the new model and generates a DEM of a mountainous area which is within the expected accuracy of SPOT HRS data. The model can be used for any along track satellite sensor.