Journal article
Juno model rheometry and simulation
Radio science, Vol.51(10), pp.1627-1635
10/01/2016
DOI: 10.1002/2016RS005954
Abstract
The experiment Waves aboard the Juno spacecraft, which will arrive at its target planet Jupiter in 2016, was devised to study the plasma and radio waves of the Jovian magnetosphere. We analyzed the Waves antennas, which consist of two nonparallel monopoles operated as a dipole. For this investigation we applied two independent methods: the experimental technique, rheometry, which is based on a downscaled model of the spacecraft to measure the antenna properties in an electrolytic tank and numerical simulations, based on commercial computer codes, from which the quantities of interest (antenna impedances and effective length vectors) are calculated. In this article we focus on the results for the low-frequency range up to about 4 MHz, where the antenna system is in the quasi-static regime. Our findings show that there is a significant deviation of the effective length vectors from the physical monopole directions, caused by the presence of the conducting spacecraft body. The effective axes of the antenna monopoles are offset from the mechanical axes by more than 30 degrees, and effective lengths show a reduction to about 60% of the antenna rod lengths. The antennas' mutual capacitances are small compared to the self-capacitances, and the latter are almost the same for the two monopoles. The overall performance of the antennas in dipole configuration is very stable throughout the frequency range up to about 4-5 MHz and therefore can be regarded as the upper frequency bound below which the presented quasi-static results are applicable.
Details
- Title: Subtitle
- Juno model rheometry and simulation
- Creators
- Manfred Sampl - Austrian Academy of SciencesWolfgang Macher - Space Research InstituteThomas Oswald - Space Research InstituteDirk Plettemeier - TU DresdenHelmut O. Rucker - Austrian Academy of SciencesWilliam S. Kurth - University of Iowa
- Resource Type
- Journal article
- Publication Details
- Radio science, Vol.51(10), pp.1627-1635
- Publisher
- Amer Geophysical Union
- DOI
- 10.1002/2016RS005954
- ISSN
- 0048-6604
- eISSN
- 1944-799X
- Number of pages
- 9
- Grant note
- 828273 / Austrian Research Promotion Agency (FFG)
- Language
- English
- Date published
- 10/01/2016
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984455270202771
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