Fully Controlled 6 Meters per Pixel Mosaic of Mars's South Polar Region

Abstract

The Mars Reconnaissance Orbiter (MRO) spacecraft has been in operation around Mars since March 2006. The Context Camera (CTX), aboard MRO, has returned over 110,000 images of Mars at ≈5–6 m/px, providing nearly global coverage. Based on our work, reconstruction of MRO's orbit and camera pointing from ground tracking are offset from the Mars global coordinate system, with the 95th percentile of test points offset by ≈850 m, corresponding to ≈150 CTX pixels. While the original level of accuracy is potentially useful for some applications, providing relative control (image-to-image) and absolute or full control (image-to-ground reference) greatly improves the utility of the data. As a proof-of-concept, we have fully controlled all usable images of Mars Chart 30, Mare Australe, which is poleward of 65°S. This represents 4.7% of Mars's surface area and comprises 9,652 images (≈8% of the CTX catalog as of PDS release #48). The control was produced through a mixture of automated code and manual adjustment and validation, and mosaics were produced with manual input to provide a useful product with the best, most consistent images on top. The data—mosaics and updated SPICE kernels—are available to the community through NASA's Planetary Data System (PDS) Imaging and Cartography Annex. The workflow developed for this product is applicable to the remainder of Mars and other planetary bodies.