Publications

The Magellan spacecraft went into Venus orbit in 1990 and by 1992 had made three complete cycles of polar orbits, each cycle covering the full range of longitudes. During this time the spacecraft obtained synthetic aperture radar (SAR) images of >96% of the planet at a resolution of 75 m/pixel. Images taken with a decreased look angle from vertical, primarily during Cycle 3, provide...

In this abstract we report on our initial experiences performing stereotopographic mapping of Mars with high-resolution images from the Mars Global Surveyor Mars Orbiter Camera Narrow-Angle subsystem (MGS MOC-NA; [1]). Accurate topographic information, and, in particular, high-resolution digital elevation models (DEMs) are of intense interest at all phases of Mars exploration and...

During the Clementine Mission both oblique and vertical multispectral images were collected. The oblique and vertical images from a single spectral band collected during the same orbit form a stereo pair that can be used to derive the topography. These stereo pairs were used to derive the topography of an area surrounding the lunar South Pole (90°S - 64°S latitude) and North Pole (90°N -...

In 2003, NASA is planning to send two robotic rover vehicles to explore the surface of Mars. The spacecraft will land on airbags in different, carefully chosen locations. The search for evidence indicating conditions favorable for past or present life will be a high priority. Each rover will carry a total of ten cameras of five various types. There will be a stereo pair of color...

The United States Geological Survey (USGS) in Flagstaff, Arizona is producing a Web-based, user-friendly interface that integrates powerful Geographic Information Systems (GIS) statistical and spatial relational tools for analyses of planetary datasets. The interface, known as “Planetary Interactive GIS-on-the-Web Analyzable Database” (PIGWAD), provides database support for the research...

An international flotilla of spacecraft are to be sent to Mars over the next decade in an effort to understand the planet's geology and climate history, and to determine whether some form of life ever started there. At least two spacecraft will be sent at each launch opportunity, and at times up to four spacecraft may be operating simultaneously at the planet.

The USGS is producing digital elevation models (DEM) and topographic maps of Mars at scales of 1:250,000 to 1:1,000,000. The initial source material will be Viking Orbiter images, with a later transition to Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) when stereo coverage from that source is available for topographic mapping. The digital terrain models and topographic maps...

An important theme of our work is the synergistic use of a variety of geodetic, cartographic, and photogrammetric software packages. The USGS digital cartographic software system ISIS provides most of the processing capability needed for planimetric mapping tasks such as our revision of the global digital image mosaic of Mars (MDIM). The geodetic control network on which this mosaic is...

The enormous pre-Nectarian South Pole-Aitken (SPA) basin represents a geophysically and compositionally unique region on the Moon. We present and analyze the mineralogical diversity across this basin and discuss the implications for basin evolution. Rock types are derived from Clementine multispectral data based on diagnostic characteristics of ferrous absorptions in fresh materials...

No abstract available.

The Mars Global Surveyor thermal emission spectrometer has made observations of Mars' north polar region for nearly a full martian year. Measurements of bolometric emission and reflectance, as well as brightness temperatures in specific bands synthesized from thermal radiance spectra, are used to track the behavior of surface and atmospheric temperatures, the distribution of condensed...

In the 1970s, Mariner and Viking spacecraft observations of the north polar region of Mars revealed polar brightness temperatures that were significantly below the expected kinetic temperatures for CO2 sublimation. For the past few decades, the scientific community has speculated as to the nature of these Martian polar cold spots. Thermal Emission Spectrometer (TES) thermal spectral data...