Performance and First Measurements of the MEDA Wind Sensor of NASAs Mars 2020 Mission at Jezero Crater, Mars

The Mars Environmental Meteorological Station (MEDA)1 is a payload instrument of the Mars2020 rover. The MEDA sensor suite includes measurement of wind speed and direction. The wind sensor (WS) is composed of two booms (WS1 and WS2) located on the Remote Sensing Mast. One of the booms (WS2) had a deployable system activated in sol 9 in order to double its length and hence reduce the rover and Remote Sensing Mast wind flow perturbation once deployed; the other boom (WS1) is shorter and has a fixed length. Both Wind Sensors and calibration models have undergone a detailed electronic characterization as well as a thorough calibration campaign in a dedicated facility specially built for this purpose. This campaign has two purposes: verify the performances of both sensors and acquire a complete calibration file to be used in the data retrieval process. Once on Mars, the Wind Sensor began an extensive commissioning phase, acquiring data at a frequency of 2Hz: initially tuning the electronic parameters so as to achieve continuous non-saturated measurements throughout the sol, and then fine-tuned to maximize the sensors signal/noise at all times. The sensors operational temperatures dynamically adapt to the ambient conditions using an automatic onboard algorithm. During the first sols, the measurements focused on the middle hours of the sol to characterize wind conditions for expected flight times of the M2020 helicopter Ingenuity. After this period, WS measurement periods have been based on science requirements and rover operational constraints. For the first 100 sols after landing at Jezero Crater during the local spring, the wind daily cycle has been measured and analyzed, distinguishing three periods: morning (0 8/10), midsol (8/10- 16/18) and evening (16/18 23) with clear differences between them in wind direction and speed, as well as in general gustiness or stability. These measurements will be discussed in the scope of the sensors capabilities (in accuracy, range and resolution), also considering its limitations analyzing and taking into account the perturbation of the rover body and elements on the measured flow as well as the effect of the varying rover orientation and speed. [1] Rodriguez-Manfredi et al. (2021), SSR, 217(48).