An Update of the Noise Model of the SEIS Seismometer of the InSight Mission To Mars

In order to assess its capability to fulfil the scientific requirements of the InSight mission, the SEIS (Seismic Experiment for Interior Structure) seismometer has been thoroughly studied before its landing and deployment on Mars. In particular, its in situ performance in the seismic bandwidth (0.01 Hz to 1 Hz) was estimated by a model that took in account all the likely noise sources including simulations of environmental noise [Mimoun et al, 2017]. These typically include the impact of the wind, pressure, temperature and magnetic field on the background seismic noise. This study updates this noise model using more than two years of data obtained by the InSight mission at the surface of Mars. Specifically, we use the new environment parameters as measured by the meteorological station onboard InSight (APSS) for atmospheric temperature, pressure, wind and magnetic fields, as well as temperatures at different locations in SEIS collected by monitoring sensors on the instrument. While keeping the same theoretical models developed in [Mimoun et al, 2017], the pre-landing noise predictions are compared to the model predictions with updated environment parameters, and finally to the actual seismic noise observations on Mars. Updating this noise model allows for a better understanding of the signals measured by SEIS, and is an important step in eventual attempts to increase the signal to noise ratio by post-processing techniques. Mimoun, David, et al. "The noise model of the SEIS seismometer of the InSight mission to Mars." Space Science Reviews 211.1 (2017): 383-428.