Back to list of UTIG presentations at Fall Agu

J.W. Holt, D.D. Blankenship, M.E. Peters, S.D. Kempf, D.L. Morse

Mapping water in its various forms is perhaps the most fundamental of the various Mars exploration objectives, and the most critical in the search for signs of present or past life. Upcoming missions to Mars will employ radar sounding from orbital platforms and surface rovers in order to map subsurface ice and liquid water. The recent identification of features which exhibit morphologies consistent with ice/rock mixtures, near-surface ice bodies and near-surface liquid water point to the need for appropriate terrestrial analogs. Radar propagation models for similar features on Earth where the important physical properties can be readily determined will be crucial for interpreting data from Mars. Climatic, hydrological, and geological conditions in the McMurdo Dry Valleys of Antarctica are analogous in many ways to those on Mars, and many ice-related features in the Dry Valleys may have direct morphologic and compositional counterparts on Mars.

We collected roughly 1,000 line-km of airborne radar data over permafrost, subsurface ice bodies, rock/ice glaciers, frozen saline lakes, and glacial deposits in the Dry Valleys, primarily in Taylor and Beacon Valleys. These features have direct relevance to future Mars missions. The data were collected with multiple systems including a chirped 52.5 - 67.5 MHz coherent radar operating at 750 W and 8 kW peak power (with multiple receivers) and 1 - 2 microsecond pulse length, and a 60 MHz pulsed continuous-wave, incoherent radar operating at 8 kW peak power with 60 ns and 250 ns pulse lengths. These data are suitable for the implementation of advanced pulse compression algorithms and SAR focusing. Preliminary results indicate penetration of permafrost and massive subsurface ice bodies in Taylor Valley, and a rock glacier in Beacon Valley. The comparison of different radar configurations and parallel tracks where they are available will be utilized to further constrain our interpretations and to develop radar propagation models.