Finite difference time domain simulation of radar wave propagation through comet nuclei dielectic models

Ruth A. Carley, Essam Heggy

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

The 90 MHz radar-wave experiment, Comet Nucleus Sounding Experiment by Radiowave Transmission (CONSERT), on board the Rosetta mission (ESA, 2004) is expected to probe the nucleus of the comet 67P/ Churyumov-Gerasimenko (67P/C-G) to reveal information on its physical properties, chemical composition, and internal structure. This investigation assesses the potential to recognize lithological structure in the comet nucleus with a radar experiment such as CONSERT. Radar simulations at 90 MHz were performed with a finite difference time domain (FDTD) method. The amplitude and losses of the transmitted and reflected electric field components of an incident radar pulse were evaluated as a function of time. Seven different dielectric models of sections of a hypothetical comet nucleus were used, representative of existing theories of comet nuclei. Values of dielectric constant assigned to these models are based on mixing laws for a porous mixture of ice and meteoritic dust, employing laboratory measured values of relative permittivity for mainly chondritic meteorites. Our results confirm that structural differences such as layers or inclusions are discernable from transmitted and reflected radar signals at 90 MHz, the central frequency of the CONSERT instrument. Such simulations help to constrain the ambiguities that might exist in future radar data associated with the nature of the comet nuclei, whether conglomerate or layered in nature.

Original languageEnglish
Pages (from-to)1085-1095
Number of pages11
JournalMeteoritics and Planetary Science
Volume43
Issue number6
Publication statusPublished - Jun 2008
Externally publishedYes

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ASJC Scopus subject areas

  • Geophysics
  • Space and Planetary Science

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