Lidar Dust Devil Measurements for Future Mars Atmospheric Studies

Lidar (laser radar) measurements of dust devils have been carried out in the desert near Tucson. These investigations were made during a field test program of the MATADOR project, which is aimed at developing instrumentation for eventual atmospheric measurements from a Mars lander platform. It is well known that dust devils contribute significantly to the properties of both the atmosphere and the surface of Mars. Lidar offers the potential to remotely observe these complex dynamical structures with high spatial and temporal resolution. Such a lidar on Mars could provide important new information on dust devils and deliver an early warning of the potential hazard from an approaching dust devil. Two lidar systems were used in the field test program to obtain information on terrestrial dust devil properties and to provide quantitative information on lidar capabilities for similar applications on Mars. One system utilized a low prf, Nd:Yag laser source with slow manual pointing. The second system used a 2 kHz Nd:glass source with high-speed scanning to provide 3-D spatial information on dust devil structure. The results obtained show clearly the lidar capabilities to detect dust devils out to ranges of the order of 5 km and to obtain detailed quantitative information on their structure and motion. This paper will describe the instrumentation used and present an overview of the results obtained.