Browsing by Author "Clinton, J."

We provide a general science overview of the seismometer (SEIS) instrument package that comprises the primary payload of the upcoming InSight mission to Mars.

InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) is the next Discovery mission, selected by NASA in 2012. It will be launched in March 2016 for a landing by the end of September 2016. Science operation will start in January 2017. The payload is a complete geophysical observatory, with a seismometer (SEIS), an heat flux experiment (HP3), a geodesy experiment (RISE), a magnetometer and a suite of at-mospheric sensors measuring wind, atmospheric temperature, and pressure. SEIS is the primary instrument of the mission and consists of a 3-axis very-broad-band (VBB) instrument and a 3-axis short period (SP) instrument. Its technical description is detailed in a a compagnon abstract (K.Hurst et al, SSA 2015). SEIS is expected to provide the very first seismic records of Mars. Thus implementation of the science goals is very challenging due to the almost complete lack of information on the deep seismic interior structure of Mars, as well as its level of seismic activity and surface seismic noise. Efforts of the SEIS science team were concentrated in three areas, associated with the challenges of: (i) single-station seismic analysis methodology, performed with data of only one Earth station.We demonstrated the capability to retrieve the origin time and epicentral distance of the events within the accuracy of the shortest surface wave period used and to produce mantle velocity structure relatively close to the Earth reference model (PREM). (ii) pre-launch estimation of the seismic and station-generated noise. This has led to a complete noise model, enabling better estimation of the expected SNR and operational constraints, and to noise reduction strategies using measurements taken by complementary sensors on the lander (especially for pressure and magnetic noise). (iii) estimation of the amplitude and frequency of signals generated not only by quakes but also by other non-seismic sources (impacts, atmospheric hum and Phobos tide).