Ref: POSTER-2022-0004

Martian Rotation and Orientation Angles: transformation between the Euler angles and the Earth equatorial coordinates

Yseboodt, Marie ; Baland, Rose-Marie ; Le Maistre, Sebastien ; Dehant, Veronique

Poster presented at Multi-scale (time and mass) dynamics of space objects, IAU symposium, online on 2021-10-18

Abstract: Mars rotation models are regularly updated based on the precise radioscience data coming from Martian orbiters and landers and new theoretical developments. Two precise radio-science experiments are ongoing or will arrive soon: the RISE experiment on board the InSight mission (Folkner et al., 2018) and the future LaRa experiment on ExoMars 2022 (Dehant et al., 2020). Two different sets of angles are commonly used in the rotation matrix transforming the coordinates from the body frame to an inertial frame: the Euler angles versus the IAU formulation with the Earth equatorial coordinates. We present the transformations between the 2 sets. We compute the initial values of the angles, their temporal drift (diurnal rate or precession rate) and their quadratic term, and their periodic variations (nutations and length-of-day LOD variations). The objective is to have a rotation matrix difference smaller than less than 1 mas. The improvements proposed in the transformations mostly affect the rotation angle (or LOD) variations and the quadratic terms.

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Royal Observatory of Belgium > Reference Systems & Planetology
Conference Contributions & Seminars > Posters

 Record created 2022-01-25, last modified 2022-01-25