TY - GEN
T1 - Lessons learned from WHISPER relaxation sounder in ten years of CLUSTER mission
AU - Décréau, P. M.E.
AU - Trotignon, J. G.
AU - Canu, P.
AU - Kougblenou, S.
AU - Lointier, G.
AU - Rauch, J. L.
AU - Vallières, X.
PY - 2011/11/21
Y1 - 2011/11/21
N2 - The four WHISPER instruments, part of the Wave Experiment Consortium on board the multi satellite CLUSTER mission, include each a relaxation sounder aimed to measure with a good precision and reliability the frequency positions of Fp, electron plasma frequency, and of Fce, electron gyro-frequency. Those quantities give access to electron density and intensity of magnetic field, key parameters defining local plasma regime. WHISPER sounder's design and realization, based on the expertise provided by successful missions operated in late seventies and eighties (GEOS, ISEE, Viking), is characterized by use of a processor devoted to on board frequency analysis via FFT. This choice makes those relaxation sounders unique of their kind, allowing in particular a complete plasma diagnostic to be made in only 1.5 s, almost one order of magnitude faster than in the past. The CLUSTER mission itself is unique, by its multi-point capability, and by its orbit, which along the mission allowed exploring a large variety of key regions of the magnetosphere. We present in this paper a few examples of WHISPER instrument behaviour and results, exploring in particular magnetosheath, polar cap, outer and inner plasmasphere. In the latter region, Fp and Fce frequency values are far above the working frequency range of the instrument. This range, however, includes the lower hybrid frequency, Flh, which shows up as a clear resonance triggered by the sounder, and allows measurement of Ne whenever Fp/Fce < 1.
AB - The four WHISPER instruments, part of the Wave Experiment Consortium on board the multi satellite CLUSTER mission, include each a relaxation sounder aimed to measure with a good precision and reliability the frequency positions of Fp, electron plasma frequency, and of Fce, electron gyro-frequency. Those quantities give access to electron density and intensity of magnetic field, key parameters defining local plasma regime. WHISPER sounder's design and realization, based on the expertise provided by successful missions operated in late seventies and eighties (GEOS, ISEE, Viking), is characterized by use of a processor devoted to on board frequency analysis via FFT. This choice makes those relaxation sounders unique of their kind, allowing in particular a complete plasma diagnostic to be made in only 1.5 s, almost one order of magnitude faster than in the past. The CLUSTER mission itself is unique, by its multi-point capability, and by its orbit, which along the mission allowed exploring a large variety of key regions of the magnetosphere. We present in this paper a few examples of WHISPER instrument behaviour and results, exploring in particular magnetosheath, polar cap, outer and inner plasmasphere. In the latter region, Fp and Fce frequency values are far above the working frequency range of the instrument. This range, however, includes the lower hybrid frequency, Flh, which shows up as a clear resonance triggered by the sounder, and allows measurement of Ne whenever Fp/Fce < 1.
U2 - 10.1109/URSIGASS.2011.6051119
DO - 10.1109/URSIGASS.2011.6051119
M3 - Conference contribution
AN - SCOPUS:81255129059
SN - 9781424451173
T3 - 2011 30th URSI General Assembly and Scientific Symposium, URSIGASS 2011
BT - 2011 30th URSI General Assembly and Scientific Symposium, URSIGASS 2011
T2 - 2011 30th URSI General Assembly and Scientific Symposium, URSIGASS 2011
Y2 - 13 August 2011 through 20 August 2011
ER -