A new numerical model of the HF antenna of the Mars Reconnaissance Orbiter's (MRO) Shallow Radar (SHARAD) and first results from a test at a roll

This communication deals with a newly developed electromagnetic model of the Mars Reconnaissance Orbiter Shallow Radar (SHARAD) HF antenna and its interaction with the spacecraft. The model has been developed considering the effect of spacecraft materials and components and the orientation of appendages such as the solar arrays and high-gain antenna. The model appears very useful in designing new operational scenarios of the SHARAD sub-surface sounder, confirming the ability to increase up to 10 dB the signal-to-noise ratio in radar sounding performances by altering the geometry of the observations. We show results from a first test wherein the spacecraft roll angle was set to 120 degrees while obtaining an observation over a ground track previously observed at 0 degrees roll angle, and the expected performance improvement was achieved.