Sensor Orientation for High-resolution Satellite Imagery

An investigation into the use of alternative sensor orientation models and their applicability for block adjustment of high-resolution satellite imagery is reported. Ikonos Geo imagery has been employed in the investigation, and since the explicit camera model and precise exterior orientation information required to apply conventional collinearity-based models is not provided with Ikonos data, alternative sensor orientation models are needed. The orientation models considered here are bias-corrected rational functions (with vendor-supplied rational polynomial coefficients) and the affine projection model. Test results arising from the application of the alternative image orientation/triangulation models within two multi-strip, stereo blocks of Geo imagery are reported. These results confirm that Geo imagery can yield three-dimensional geopositioning to pixel and even sub-pixel accuracy over areas of coverage extending well beyond the nominal single scene area for Ikonos. The accuracy achieved is not only consistent with expectations for rigorous sensor orientation models, but is also readily attainable in practice with only a small number of high-quality ground control points.