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First Results of Mars Express—ExoMars Trace Gas Orbiter Mutual Radio Occultation
Cardesín-Moinelo, Alejandro; Wilson, Colin; Witasse, Olivier +10 more
Spacecraft-to-spacecraft radio occultations experiments are being conducted at Mars between Mars Express (MEX) and Trace Gas Orbiter (TGO), the first ever extensive inter-spacecraft occultations at a planet other than Earth. Here we present results from the first 83 such occultations, conducted between 2 Nov 2020 and 5th of July 2023. Of these, 44…
Tropospheric Delay Calibration System Performance During the First Two BepiColombo Solar Conjunctions
Cappuccio, Paolo; Iess, Luciano; Tortora, Paolo +8 more
Media propagation delay and delay-rate induced by the water vapor within the Earth's troposphere represent one of the main error sources for radiometric measurements in deep space. In preparation for the BepiColombo and JUICE missions, the European Space Agency has installed and operates the prototype of a tropospheric delay calibration system (TD…
The Phase Response of a Rough Rectangular Facet for Radar Sounder Simulations of Both Coherent and Incoherent Scattering
Gerekos, C.; Haynes, M. S.; Schroeder, D. M. +1 more
With radar sounders, coherent backscattering simulations from global planetary digital elevation models (DEMs) typically display a deficit in diffuse clutter, which is mainly due to the implicit assumption that roughness at scales below the resolution of the DEM is absent. Indeed, while polynomial approximations of the phase evolution across the f…
Analysis of Two Selected Solar Events in 2011 and 2015 With Mars Express Radio Occultation Data
Witasse, Olivier; Sánchez-Cano, Beatriz; Karatekin, Ozgur +3 more
The temporal behavior of the Martian ionosphere is highly variable due to various dynamic processes including space weather events. Here, we study the effect of solar flares and coronal mass ejections (CMEs) on the Martian ionosphere for two selected solar events in 2011 and 2015, using the publicly available Mars EXpress (MEX) radio occultation (…
Martian Lander Radio Science Data Calibration for Mars Troposphere
Le Maistre, S.
The tropospheric propagation effect is one of several sources of error in radio science measurements. Systematically calibrated for the Earth troposphere disturbances, the ranging and Doppler data provided by the Martian landers have not been corrected so far for Mars troposphere effects. These effects were considered negligible because the Mars a…
ExoMars Schiaparelli Direct-to-Earth Observation using GMRT
Asmar, S. W.; De, K.; Gupta, Y. +3 more
During the ExoMars Schiaparelli separation event on 16 October 2016 and Entry, Descent, and Landing (EDL) events 3 days later, the Giant Metrewave Radio Telescope (GMRT) near Pune, India, was used to directly observe UHF transmissions from the Schiaparelli lander as they arrive at Earth. The Doppler shift of the carrier frequency was measured and …
Electrostatic Potential Radiated by a Pulsating Charge in a Two-Electron Temperature Plasma
Henri, P.; Wattieaux, G.; Béghin, C. +2 more
Mutual impedance experiments have been developed to constrain the plasma bulk properties, such as density and temperature, of ionospheric and later space plasmas, through the electric coupling between an emitter and a receiver electric antennas. So far, the analytical modeling of such instruments has enabled to treat ionospheric plasmas, where cha…
CLUSIM: A Synthetic Aperture Radar Clutter Simulator for Planetary Exploration
Sánchez-Cano, B.; Witasse, O.; Orosei, R. +1 more
In this paper we present the CLUtter SIMulator (CLUSIM), a special program simulating radar side echoes from rough planetary surfaces using realistic topography data sets. A numerical model of realistic topography of the Martian surface, based on Mars Orbiter Laser Altimeter data, is developed. A specially developed computer routine for evaluation…
Particle-in-cell modeling of spacecraft-plasma interaction effects on double-probe electric field measurements
Miyake, Y.; Usui, H.
The double-probe technique, commonly used for electric field measurements in magnetospheric plasmas, is susceptible to environmental perturbations caused by spacecraft-plasma interactions. To better model the interactions, we have extended the existing particle-in-cell simulation technique so that it accepts very small spacecraft structures, such …
The processing of electron density profiles from the Mars Express MARSIS topside sounder
Gurnett, D. A.; Morgan, D. D.; Witasse, O. +3 more
here present a manual for the reduction of data from ionograms obtained from the Mars Express MARSIS Active Ionospheric Sounding topside radar sounder. Sample data are presented with the procedure for processing them explained as simply as possible. We discuss the uncertainties inherent in the measurements as well as systematic problems with the d…