Customer and partner spotlight | December 2007
The U.S. Geological Survey (USGS) Astrogeology team employs photogrammetric technology to study and map geologic features of the solar system
The USGS is the primary producer of digital and hardcopy planetary maps in the U.S. Its
Astrogeology team, based in Flagstaff, Arizona, studies the properties and evolution of
planets and their satellites, asteroids, and comets. Using images and samples collected
by spacecraft expeditions, USGS researchers analyze and measure soil, water, terrain,
atmospheric conditions, and other properties that characterize solar system objects. Results
of these studies are used to construct topographic, geologic, and thematic maps, globes,
digital elevation models (DEMs), and 3D flythrough simulations to support geophysical
studies, education, and the planning and operation of subsequent missions.
model on the right, based on a single High-Resolution Imagining Science Experiment (HiRISE) camera stereo pair, contains approximately the same number of height points, spaced 1m apart. Using SOCET SET, its production required 60 hours of automated matching and 90 hours of interactive quality control and editing. The model shows debris flows associated with the central peak of the Mojave crater. Modern digital processing methods, including SOCET SET, make it practical to process gigabytes of image data for an individual research project.
USGS staff are involved in all stages of the planetary exploration and mapping process — in many cases they help to design, build, and test innovative new camera systems. Once images and supporting data are safely on Earth, they must be catalogued, processed into map products, and delivered to the customer. Ultimately, products go to NASA’s Planetary Data System, where they are archived for future users, but the immediate customer is often a team running another mission, urgently in need of maps to plan its next day, week, or year of exploration. Flexibility and efficiency of the mapping software are therefore key concerns.
The USGS has chosen an approach that makes synergistic use of both public domain
software written in-house, as well as commercial photogrammetric software. It uses
BAE Systems’ SOCET SET to accomplish its planetary mapping tasks, and its own system,
Integrated Software for Imagers and Spectrometers (ISIS), provides an end-to-end capability
for processing planetary images into orthophoto mosaics for use as base maps. By writing
the software in-house, the USGS maintains the flexibility to read, decompress, calibrate, and
model data geometrically from each new sensor as it becomes available.