Combined Bundle Adjustment of Moc Stereo Images and Mola Altimetry Data for Precise Mars Topographic Mapping

Launched in 1996, Mars Global Surveyor (MGS) carries two types of mapping equipments: Mars Orbiter Laser Altimeter (MOLA) and Mar Orbiter Camera (MOC). MOLA collects accurate laser altimetry data over the Mars surface, while MOC acquires high resolution images. In the process of MOLA registration to MOC images, a certain systematic shift was reported in previous studies. This shift may possibly be attributed to time drift when determining the MOC image orientation. To correct such mis-registration and obtain accurate point determination, a bundle adjustment is developed and implemented in this paper. This is a generalized combined adjustment for images collected by pushbroom cameras. Primary participants in this process are MOLA ground points and ranges, MOC image orientation data, and tie points collected on MOC stereo images. As the outcome of the bundle adjustment, we obtain refined MOLA ground points, ground position of tie points, refined MOC image orientation, and an accurate and consistent registration between MOC images and MOLA data. The refined outcome can then be used to generate local and high resolution digital elevation model.