Bundle Adjustment of Mars Hirise Orbiter Stereo Images Based on the Rigorous Sensor Model

Launched in August 2005, the Mars Reconnaissance Orbiter (MRO)’s primary goal is to obtain detailed morphologic information on the Martian surface using its onboard HiRISE sensor with a 0.3-meter ground resolution. However, inconsistencies between HiRISE stereo images must be removed based on the rigorous sensor model for the best level of accuracy. The new rigorous sensor model is developed specially for HiRISE due to its unusual complex camera design so that the mosaic of multiple image strips could be processed simultaneously under a uniform sensor model. A bundle adjustment (BA) based on this rigorous sensor model is implemented on two stereo pairs covering Husband Hill and Victoria Crater. After BA, the significantly reduced back projection residuals indicate that the inconsistencies are removed and the refined exterior orientation parameters are ready for mapping the Martian surface. Furthermore, 4 ground points measured from geo-registered Spirit rover images are incorporated into the BA as ground control points. Reduced inconsistencies on ground features between orbital intersection and measurements from rover images after BA indicate the mapping potential of orbital-ground integration. Small motions of the spacecraft around its nominal pointing, called jitter, has been detected on HiRISE trajectory data. The topographic effect of jitter is evaluated in this paper. Though its effect is insignificant when mapping small areas, further investigation needs to be performed so that the effect can be removed or reduced when mapping large areas.