Finding SEIS North on Mars: Comparisons Between SEIS Sundial, Inertial and Imaging Measurements and Consequences for Seismic Analysis

Autor: D. Savoie, A. Richard, M. Goutaudier, P. Lognonné, K. J. Hurst, J. N. Maki, M. P. Golombek, M. van Driel, J. Clinton, E. Stutzmann, D. Mimoun, W. B. Banerdt, N. R. Williams
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: Earth and Space Science, Vol 8, Iss 3, Pp n/a-n/a (2021)
Druh dokumentu: article
ISSN: 2333-5084
DOI: 10.1029/2020EA001286
Popis: Abstract In this paper, we present the results obtained in the determination of the true north direction on Mars by using a gnomon on the InSight mission and compare the measurements with either the North determination from the Inertial Measurement Unit and imaging analysis. The obtained measurement has been used to populate the SEIS orientation information in the archived SEIS data. Images taken during December 2018 and January 2019 allow to determine the gnomon shadow position and length over a target. By calculating the Sun local coordinates using planetary ephemeris VSOP87, the images are used to estimate the true North direction on the landing site. By using eight different images selected, we obtain the true North direction with an accuracy up to 2.5°, which is confirmed by the IMU and imaging analysis. The true North direction is also confirmed by an image taken near local noon, when the sun crosses the meridian. The North determination precision is then discussed in view of the seismic determination of the back azimuth.
Databáze: Directory of Open Access Journals
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