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Simulations In Support Of Mars Polar Motion Estimation Using Radio Data From Multiple Landers.
https://publi2-as.oma.be/record/6919
Goli, M.Sat, 09 Mar 2024 16:45:40 GMThttps://publi2-as.oma.be/record/69192023Mars interior structure and spin state from InSight's RISE radio-science experiment.
https://publi2-as.oma.be/record/6918
Le Maistre, S.Sat, 09 Mar 2024 16:44:18 GMThttps://publi2-as.oma.be/record/69182023Detection of the Liquid Core Signature in Mars Nutations from InSight-RISE Data: Implications for Mars Interior Structure.
https://publi2-as.oma.be/record/6894
Le Maistre, S.Sat, 09 Mar 2024 15:54:26 GMThttps://publi2-as.oma.be/record/68942023Detection of the Liquid Core Signature in Mars Nutations from InSight-RISE Data: Implications for Mars Interior Structure.
https://publi2-as.oma.be/record/6861
Le Maistre, S.Wed, 06 Mar 2024 08:42:04 GMThttps://publi2-as.oma.be/record/68612023 Librations of the Galilean satellites
https://publi2-as.oma.be/record/6757
Van Hoolst, TimMon, 05 Feb 2024 15:57:03 GMThttps://publi2-as.oma.be/record/67572023Simulations In Support Of Mars Polar Motion Estimation Using Radio Data From Multiple Landers
https://publi2-as.oma.be/record/6649
The polar motion of Mars is defined as the movement of the rotation axis with respect to a fixed frame tied to the crust. Composed of annual, seasonal and free wobble periods, it provides information on the atmospheric dynamics and seasonal mass exchanges, as well as on the interior structure, making it an attractive study target for investigations using radiometric data. We investigate the uncertainties associated with Mars pole motion (PM) parameters estimation using Doppler, Range and Same-Beam Interferometry (SBI) observables between multiple landers on the surface of Mars and the Deep Space Network (DSN) on Earth. We use the MONTE astrodynamics and measurement simulation suite from JPL to evaluate the improvement enabled by combining data from multiple landers, identify the optimal mission architectures for PM estimation, and analyze them by considering the influence of respective mission parameters on the estimation uncertainty. In particular, we consider the effects of absolute and relative locations of the landers, observation scheduling considerations, and noise level. We re-evaluate the possibility of estimating the polar motion using data from landers in proximity to the equator, and apply our considerations to existing past, present and future missions such as InSight or the planned Mars Sample Return lander. We also consider the possible improvement in the estimation of the period of the pole’s free Chandler Wobble, which has recently been detected for the first time using orbiter radio tracking (Konopliv et al 2020).Goli, MartaWed, 24 Jan 2024 15:03:38 GMThttps://publi2-as.oma.be/record/66492023Simulations In Support Of Mars Polar Motion Estimation Using Radio Data From Multiple Landers.
https://publi2-as.oma.be/record/6623
The polar motion of Mars is defined as the movement of the rotation axis with respect to a fixed frame tied to the crust. Composed of annual, seasonal and free wobble periods, it provides information on the atmospheric dynamics and seasonal mass exchanges, as well as on the interior structure, making it an attractive study target for investigations using radiometric data. We investigate the uncertainties associated with Mars pole motion (PM) parameters estimation using Doppler, Range and Same-Beam Interferometry (SBI) observables between multiple landers on the surface of Mars and the Deep Space Network (DSN) on Earth. We use the MONTE astrodynamics and measurement simulation suite from JPL to evaluate the improvement enabled by combining data from multiple landers, identify the optimal mission architectures for PM estimation, and analyze them by considering the influence of respective mission parameters on the estimation uncertainty. In particular, we consider the effects of absolute and relative locations of the landers, observation scheduling considerations, and noise level. We re-evaluate the possibility of estimating the polar motion using data from landers in proximity to the equator, and apply our considerations to existing past, present and future missions such as InSight or the planned Mars Sample Return lander. We also consider the possible improvement in the estimation of the period of the pole’s free Chandler Wobble, which has recently been detected for the first time using orbiter radio tracking (Konopliv et al 2020).Goli, Marta Tue, 23 Jan 2024 08:51:27 GMThttps://publi2-as.oma.be/record/66232023Mars Interior Structure and Spin State from InSight’s RISE Radio-Science Experiment (Invited)
https://publi2-as.oma.be/record/6609
Fundamental properties of the interior structure and atmosphere dynamics of Mars can be obtained by precisely measuring its rotation and orientation. We report here the results of 4 years of monitoring the rotation of Mars with the RISE instrument on InSight. Le Maistre, S.Mon, 22 Jan 2024 14:15:50 GMThttps://publi2-as.oma.be/record/66092023DETECTION OF THE LIQUID CORE SIGNATURE IN MARS NUTATIONS FROM INSIGHT-RISE DATA: IMPLICATIONS FOR MARS INTERIOR STRUCTURE
https://publi2-as.oma.be/record/6599
Le Maistre, Sébastien Mon, 22 Jan 2024 11:00:18 GMThttps://publi2-as.oma.be/record/65992023Mars rotational elements: how to build an "IAU" solution from Euler angles determination?
https://publi2-as.oma.be/record/6598
Yseboodt, M.Mon, 22 Jan 2024 10:46:18 GMThttps://publi2-as.oma.be/record/65982023The precession and nutations of a rigid Mars, a semi-analytical model
https://publi2-as.oma.be/record/6597
Baland, R.-M.Mon, 22 Jan 2024 10:43:41 GMThttps://publi2-as.oma.be/record/65972023Mars rotational elements and their quadratic behavior
https://publi2-as.oma.be/record/6595
In order to describe the orientation of the spin axis of Mars, the radioscience community commonly uses Euler angles, with obliquity and node longitude defined with respect to the planet mean orbit at epoch. The IAU Working Group on Cartographic Coordinates and Rotational Elements (WGCCRE) uses the right ascension and declination angles, the equatorial coordinates orienting the planet with respect to the Earth equator in J2000. In both sets of coordinates, a third angle, which has a diurnal periodicity, is used to position the prime meridian. The usual way to transform Euler angles into IAU angles is to numerically evaluate the IAU angles over a given time interval with the help of spherical geometry, then to perform a frequency analysis on the so-obtained time series (e.g. Jacobson 2010, Kuchynka et al. 2014 and Jacobson et al. 2018 for Mars). Unfortunately, such a method does not take into account the physical meaning of the planet’s rotational dynamics, which relies on well-known periodicities governed by the celestial mechanics. We explain the analytical expressions to precisely transform one set of angles into the other in the case of Mars. Each angle is modeled by the sum of a quadratic polynomial, a periodic series (nutation or rotation variations) and a Poisson series (a periodic series with amplitudes changing linearly with time). The targeted precision of the transformation is 0.1 mas for each angle on an interval of about 30 years before and after J2000. Even when no quadratic terms exist in a Mars rotation model expressed with Euler angles, the corresponding model with IAU angles does have quadratic terms coming from the transformation. Current IAU-like solutions present very long period signals that result from the absence of a quadratic term in the model used. Such a long period signal has an amplitude, a phase and a frequency specifically chosen to mimic the quadratic behavior over an interval of a few decades around J2000. Adding a long period modulation instead of a quadratic term largely and artificially alters the angle values at J2000 as well as their rates. We compare the solutions of different authors, including the change in the rotation angle value.Yseboodt, M.Mon, 22 Jan 2024 10:33:47 GMThttps://publi2-as.oma.be/record/65952023La mission JUICE À la découverte des lunes de glace de Jupiter
https://publi2-as.oma.be/record/6517
Yseboodt, MarieTue, 07 Nov 2023 14:51:14 GMThttps://publi2-as.oma.be/record/65172023De JUICE-missie
https://publi2-as.oma.be/record/6516
Yseboodt, MarieTue, 07 Nov 2023 14:49:20 GMThttps://publi2-as.oma.be/record/65162023Mars orientation and rotation angles
https://publi2-as.oma.be/record/6515
The rotation and orientation of Mars is commonly described using two different sets of angles, namely (1) the Euler angles with respect to the Mars orbit plane and (2) the right ascension, declination, and prime meridian location angles with respect to the Earth equator at J2000 (as adopted by the IAU). We propose a formulation for both these sets of angles, which consists of the sum of a second degree polynomial and of periodic and Poisson series. Such a formulation is shown here to enable accurate (and physically sound) transformation from one set of angles to the other. The transformation formulas are provided and discussed in this paper. In particular, we point that the quadratic and Poisson terms are key ingredients to reach a transformation precision of 0.1 mas, even 30 years away from the reference epoch of the rotation model (e.g., J2000). Such a precision is required to accurately determine the smaller and smaller geophysical signals observed in the high-accuracy data acquired from the surface of Mars. In addition, we present good practices to build an accurate Martian rotation model over a long time span ( years around J2000) or over a shorter one (e.g., lifetime of a space mission). We recommend to consider the J2000 mean orbit of Mars as the reference plane for Euler angles. An accurate rotation model should make use of up-to-date models for the rigid (this study) and liquid (Le Maistre et al., Nature 619, 733–737 (2023)) nutations, relativistic corrections in rotation (Baland et al., Astron. Astrophys. 670, A29 (2023)), and polar motion induced by the external torque (this study). Our transformation model and recommendations can be used to define the future IAU solution for the rotation and orientation of Mars using right ascension, declination, and prime meridian location. In particular, thanks to its quadratic terms, our transformation model does not introduce arbitrary and non-physical terms of very long period and large amplitudes, thus providing unbiased values of the rates and epoch values of the angles.Yseboodt, MarieTue, 07 Nov 2023 14:46:15 GMThttps://publi2-as.oma.be/record/65152023Spin state and deep interior structure of Mars from InSight radio tracking
https://publi2-as.oma.be/record/6500
Rivoldini, Attilio Fri, 29 Sep 2023 10:04:26 GMThttps://publi2-as.oma.be/record/65002023Spin state and deep interior structure of Mars from InSight radio tracking
https://publi2-as.oma.be/record/6491
Knowledge of the interior structure and atmosphere of Mars is essential to understanding how the planet has formed and evolved. A major obstacle to investigations of planetary interiors, however, is that they are not directly accessible. Most of the geophysical data provide global information that cannot be separated into contributions from the core, the mantle and the crust. The NASA InSight mission changed this situation by providing high-quality seismic and lander radio science data1,2. Here we use the InSight's radio science data to determine fundamental properties of the core, mantle and atmosphere of Mars. By precisely measuring the rotation of the planet, we detected a resonance with a normal mode that allowed us to characterize the core and mantle separately. For an entirely solid mantle, we found that the liquid core has a radius of 1,835 $\pm$55 km and a mean density of 5,955--6,290 kg m−3, and that the increase in density at the core--mantle boundary is 1,690--2,110 kg m−3. Our analysis of InSight's radio tracking data argues against the existence of a solid inner core and reveals the shape of the core, indicating that there are internal mass anomalies deep within the mantle. We also find evidence of a slow acceleration in the Martian rotation rate, which could be the result of a long-term trend either in the internal dynamics of Mars or in its atmosphere and ice caps.Le Maistre, SébastienWed, 30 Aug 2023 14:47:14 GMThttps://publi2-as.oma.be/record/64912023RISE status
https://publi2-as.oma.be/record/6285
Le Maistre, S.Tue, 31 Jan 2023 14:23:25 GMThttps://publi2-as.oma.be/record/62852022The deep interior of Mars from nutation measured by InSight RISE.
https://publi2-as.oma.be/record/6243
Le Maistre, SébastienFri, 27 Jan 2023 12:59:22 GMThttps://publi2-as.oma.be/record/62432022Mars rotational elements: how to explain the long period terms in the IAU standard?
https://publi2-as.oma.be/record/6238
Yseboodt, MarieFri, 27 Jan 2023 11:39:57 GMThttps://publi2-as.oma.be/record/62382022Relativistic variations in Mars rotation
https://publi2-as.oma.be/record/6237
Baland, Rose-MarieFri, 27 Jan 2023 11:37:06 GMThttps://publi2-as.oma.be/record/62372022Relativistic contributions to the rotation of Mars
https://publi2-as.oma.be/record/6236
Context: The orientation and rotation of Mars, which can be described by a set of Euler angles, is estimated from radioscience data and is then used to infer Mars internal properties. The data are analyzed using a modeling expressed within the Barycentric Celestial Reference System (BCRS). Aims: We provide new and more accurate (to the 0.1 mas level) estimations of the relativistic corrections to be included in the BCRS model of the orientation and rotation of Mars to avoid a misinterpretation of the data. Methods: There are two types of relativistic contributions in Mars rotation and orientation: (i) those that directly impact the Euler angles and (ii) those resulting from the time transformation between a local Mars reference frame and BCRS. The former correspond essentially to the geodetic effect. We compute them assuming that Mars evolves on a Keplerian orbit. As for the latter, we compute the effect of the time transformation and compare the rotation angle corrections obtained using realistic orbits as described by ephemerides. Results: The relativistic correction in longitude comes mainly from the geodetic effect and results in the geodetic precession (6.754mas/yr) and the geodetic annual nutation (0.565 mas amplitude). For the rotation angle, the correction is dominated by the effect of the time transformation. The main annual, semi-annual, and ter-annual terms have amplitudes of 166.954 mas, 7.783 mas, and 0.544mas, respectively. The amplitude of the annual term differs by about 9 mas from the estimate usually considered by the community. We identify new terms at the Mars-Jupiter and Mars-Saturn synodic periods (0.567 mas and 0.102 mas amplitude) that are relevant considering the current level of uncertainty of the measurements, as well as a contribution to the rotation rate (7.3088 mas/day). There is no significant correction that applies to the obliquity. Baland, Rose-MarieFri, 27 Jan 2023 11:24:26 GMThttps://publi2-as.oma.be/record/62362023LaRa Instrument for planetary exploration.
https://publi2-as.oma.be/record/5997
Umit, E.Thu, 29 Dec 2022 14:58:09 GMThttps://publi2-as.oma.be/record/59972022LaRa, an X-band coherent transponder ready to fly.
https://publi2-as.oma.be/record/5993
Le Maistre, S.Thu, 29 Dec 2022 14:51:33 GMThttps://publi2-as.oma.be/record/59932022Spin state and deep interior structure of Mars from InSight radio tracking.
https://publi2-as.oma.be/record/5975
Rivoldini, A.Thu, 29 Dec 2022 13:50:03 GMThttps://publi2-as.oma.be/record/59752022