Radar techniques to study subsurfaces and interiors of the solar system objects.

• Main Author: Kofman, Wlodek
• Other Authors: Laboratoire de Planétologie de Grenoble (LPG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
• Format: Conference Object
• Language: English
• Published: HAL CCSD 2007
• Subjects: Ice; permafrost
• Online Access: https://insu.hal.science/insu-00359730

abstract P14B-01 INVITED International audience The radar techniques are widely used in the planetary exploration to map the surfaces. The observations from Earth or from spacecrafts were developed during the last decades. However, the idea to use this technique to study the subsurface started to develop during the last 10-15 years. The ability of the radio waves to penetrate the ice, permafrost and arid surface was at the origins of the development of the Ground Penetrating Radars (GPR) with a large number of the scientific work and industrial applications on Earth. The measurements from the surface can not replace the global mapping from orbiting platforms. In this presentation, on the example of MARSIS radar on the Mars Express mission measurements we evaluate the general capabilities of radar sounders for planetary exploration. The CONSERT is the experiment on board of the ROSETTA mission that will provide information about the deep interior of the comet (Kofman et al, 1998, 2007). The CONSERT instrument is an original concept of spaceborne transmission radar based on the propagation throughout the nucleus while the classical radars are based on the reflection. In this experiment, an electromagnetic signal is transmitted between the lander, located on the comet surface, and the orbiter. The transmitted signal will be measured as a function of time and as a function of the relative position of the orbiter and the lander for a number of orbits. Any signal that has propagated through the medium contains information concerning this medium. With a sufficient number of orbits one will be able to obtain many cuts of the interior of the comet and therefore to build up a tomographic image of the interior. On the CONSERT experiment example we discuss the main advantages and difficulties of the techniques using radiowaves to study the interior of asteroids and comets. The capacity of radar technique to do the tomography of the interior of the asteroids and comets is emphasized.