Mini-MARLI: a small lidar for measuring of atmospheric wind and aerosol profiles from Mars orbit

The Mars science community has identified atmospheric wind measurements as a key objective for a future Mars orbiter. To meet this need we previously developed a prototype of the MARLI lidar to measure the height-resolved wind and aerosol profiles. MARLI is a pulsed 1064-nm direct detection lidar designed for a polar orbit and to be pointed ~30° from nadir. This allows measuring the height resolved Doppler shift caused by wind in the aerosol backscatter. Although our work on MARLI showed it is practical for space, its mass and power are large given NASA’s new emphasis on smaller Mars missions. We have recently developed a newer version called Mini-MARLI. It uses a similar measurement approach but uses a pulsed semiconductor-based laser transmitter that emits near 780 nm and uses more sensitive single photon counting detectors and improved receiver optics. These allow improved wind measurements with lower instrument mass and power. Our measurement model uses several different atmospheric dust distributions. The results for a typical dust distribution show that in the lowest 30 km the wind speed errors are 1-3 m/sec. We are completing the development of a lidar breadboard and plan to use it to demonstrate aerosol and wind profiling measurements from our laboratory.