A miniature laser anemometer for measurement of wind speed and dust suspension on Mars

Suspended dust is a dominant component of the Martian environment. It has a major influence on atmospheric circulation and it is deposited widely over the planetary surface causing a serious hazard to instrumentation. In order to study dust transport, quantification of the wind flow and dust concentration are vital. A simple laser-based anemometer system is presented that is able to measure suspended dust grain velocity and turbulence from a landed spacecraft. This system has advantages over other techniques of wind speed determination in being insensitive to contamination or atmospheric conditions such as temperature, pressure or composition. For the first time it would allow direct measurement of the suspended dust concentration on Mars. A prototype instrument has been constructed and successfully tested in a wind tunnel facility under simulated Martian conditions. The optics are simple in design, light weight and the instrument has low power consumption. It is also robust and the output signal is easily interpreted, producing only a small data volume. Future improvements will be discussed, specifically modification to measure wind direction, the possibility of obtaining information about dust grain size and the construction of a flight model.