Build Your Own Topographic Model: a Photogrammetry Guest Facility for Planetary Researchers

The United States Geological Survey (USGS) and NASA have jointly established a guest facility in Flagstaff, Arizona, at which NASA-supported planetary scientists will be able to collect high resolution digital topographic data from a wide variety of stereo images in support of their research objectives. The facility has been established with funding from the NASA Planetary Major Equipment (PME) Program. Training and assistance of guest users by the photogrammetrists of the USGS is supported by the NASA Planetary Geology and Geophysics (PG&G) Planetary Cartography Program. Travel expenses for attending training and making use of the facility will be the responsibility of the individual guest users. Researchers wishing to make use of the stereo mapping guest facility should contact the first author with a brief summary of their research goals, measurement needs, and schedule as described below. Background: Topographic information is a requisite for nearly every phase of research on planetary surfaces, as well as an essential tool for planning and operating spacecraft missions. Where available, laser altimetry provides the gold standard for global topographic information because of its unexcelled absolute accuracy. Mars Orbiter Laser Altimeter measurements [1] of the 1990s revolutionized both the geodesy/cartography of Mars and the study of martian geologic features, and the Lunar Orbiter Laser Altimeter is poised to make a similar impact on lunar science [2], but the applicability of these data sets to the study of small surface features is limited by their cross-track spacing, which can be several km. Stereo provides height estimates every few pixels, so images of modest resolution (e.g., tens to hundreds of m) can fill the gaps left by laser altimetry. High resolution images (e.g., MRO HiRISE, with 0.25–0.3 m pixel scale [3]) yield topographic data with vertical precision on the order of a meter or better, comparable to the altimeter measurements. Altimetric data for bodies other than the Moon and Mars are much more limited or nonexistent, so stereo imaging is usually the best available source of topographic information.