An improved sheath impedance model for the Van Allen Probes EFW instrument: Effects of the spin axis antenna
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378289%3A_____%2F17%3A00476047" target="_blank" >RIV/68378289:_____/17:00476047 - isvavai.cz</a>
Result on the web
<a href="http://dx.doi.org/10.1002/2016JA023597" target="_blank" >http://dx.doi.org/10.1002/2016JA023597</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1002/2016JA023597" target="_blank" >10.1002/2016JA023597</a>
Alternative languages
Result language
angličtina
Original language name
An improved sheath impedance model for the Van Allen Probes EFW instrument: Effects of the spin axis antenna
Original language description
A technique to quantitatively determine the sheath impedance of the Van Allen Probes Electric Field and Waves (EFW) instrument is presented. This is achieved, for whistler mode waves, through a comparison between the total electric field wave power spectra calculated from magnetic field observations and cold plasma theory and the total electric field wave power measured by the EFW spherical double probes instrument. In a previous study, a simple density-dependent sheath impedance model was developed in order to account for the differences between the observed and calculated wave electric field. The current study builds on this previous work by investigating the remaining discrepancies, identifying their cause, and developing an improved sheath impedance correction. Analysis reveals that anomalous gains are caused by the spin axis antennas measuring too much electric field at specific densities and frequencies. This is accounted for in an improved sheath impedance model by introducing a density-dependent function describing the relative effective length of the probe separation, Leff, in addition to the sheath capacitance and resistance values previously calculated. Leff values vary between between 0.5 and 1.2, with values >1 accounting for the anomalous gains and values <1 accounting for the shorting effect at low densities. Applying this improved sheath impedance model results in a significant increase in the agreement level between observed and calculated electric field power spectra and wave powers over the previous model.
Czech name
—
Czech description
—
Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
—
OECD FORD branch
10305 - Fluids and plasma physics (including surface physics)
Result continuities
Project
<a href="/en/project/LH15304" target="_blank" >LH15304: Implementation of the electromagnetic wave analyzer ELMAVAN for the RESONANCE satellite project, data analysis and interpretation</a><br>
Continuities
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2017
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Journal of Geophysical Research: Space Physics
ISSN
2169-9380
e-ISSN
—
Volume of the periodical
122
Issue of the periodical within the volume
4
Country of publishing house
US - UNITED STATES
Number of pages
10
Pages from-to
4420-4429
UT code for WoS article
000401340800038
EID of the result in the Scopus database
2-s2.0-85017619056