LROC Stereo Data — Results of Initial Analysis

Edmundson, D. Harbour, E. Howington-Kraus, R. Li, A. McEwen, S. Mattson, Z. Moratto, J. Oberst, M. Rosiek, F. Scholten, T. Tran, M. Robinson, and the LROC Team. Carl Sagan Center at the SETI Institute; NASA Ames Research Center, Mail Stop 245-3 (Bldg. N245), Moffett Field, CA, USA (Ross.A.Beyer@nasa.gov); Astrogeology Science Center, United States Geological Survey; Ohio State University; The University of Arizona; German Aerospace Center (DLR), Institute of Planetary Research; Technical University Berlin; and Arizona State University. http://lroc.sese. asu.edu The Lunar Reconnaissance Orbiter Camera (LROC) [1, 2] is currently capturing multiple overlapping images in order to derive digital terrain models (DTMs) of the lunar surface [3]. There are already ∼ 200 narrow angle camera (NAC) stereo sets with ground scales between 1.5 and 0.5 m/pixel which can be used to create DTMs. The LROC team has representatives from six different groups (ASU, DLR/TUB, NASA Ames, OSU, U of A, and the USGS) using four different methods for creating terrain models. All of these groups have been able to process LROC images to create DTMs. Models have been made of many locales, but all groups have made models of the Apollo landing sites, as they contain useful landmarks for absolute positioning [4–6], are of operational and scientific interest as ground truth sites, and are of general interest due to their historical importance. This analysis by different groups using different techniques on similar data allows an important initial comparison of derived camera parameters and an assessment of LROC DTM quality. Deriving DTMs of areas that include positioning landmarks [5] allows us to tie together various LRO and other lunar datasets, and to assist the Lunar Mapping and Modeling Project (LMMP) [7] in deriving DTMs and controlled mosaics of the Constellation Program’s 50 regions of interest [8]. The USGS group has geodetically controlled and created DTMs from stereo pairs of images near the Apollo 16 landing site, and from a stereo triplet of images at the Apollo 15 site. Software and procedures have been developed and are being refined, which use the BAE Systems SOCET SET R © [9] system in conjunction with the USGS ISIS software (http://isis.astrogeology. usgs.gov). An important aspect of this work is that the auxiliary software and procedures are being made available to other groups who are working with these software tools, including ASU [10], U of A, and NASA Ames. As LROC images are delivered to the PDS, other SOCET SET users will benefit from this work, as well. The USGS group is investigating methods to choose the best images for mapping, geodetically control such images to absolute lunar coordinates, and mask shadowed areas. The OSU group uses Orbital Mapper, a software system they developed to analyze data from orbital pushbroom imaging sensors, which has proved successful in mapping the Martian surface with HiRISE stereo pairs [11]. With this system, the OSU team built a terrain model covering the Apollo 16 landing site. Terrain editing was performed manually using the Leica Photogrammetry Suite 9.3 to improve the mapping quality.