|
|
 |
|
|
Ann. Geophys., 14, 1473-1479, 1996
www.ann-geophys.net/14/1473/1996/
© European Geosciences Union 1996
Alternating-code experiment for plasma-line studies
P. Guio1, N. Bjørnå1, and W. Kofman2
1The Auroral Observatory, University of Tromsø, Tromsø, N-9037 Norway
2CEPHAG Domaine Universitaire, BP 46, St-Martin-D'hères, F-38402 France
Abstract. We present results of the first plasma-line
measurement of the incoherent spectrum using the alternating-code technique with
the EISCAT VHF radar. This technique, which has earlier mostly been used to
measure high-resolution E-region ion-line spectra, turned out to be a very good
alternative to other techniques for plasma-line measurements. The experiment
provides simultaneous measurement of the ion line and downshifted and upshifted
plasma-line spectra with an altitude resolution of 3 km and a temporal
resolution of 10 s. The measurements are taken around the peak of the F region,
but not necessarily at the peak itself, as is the case with the long-pulse
technique. The condition for success is that the scale height should be large
enough such that the backscattered signal from the range extent of one gate
falls inside the receiver filter. The data are analysed and the results are
combined with the results of the ion-line data analysis to estimate electron
mean drift velocity and thereafter electric currents along the line of sight of
the radar using both the standard dispersion relation assuming a Maxwellian
electron velocity distribution and the more recent model including a heat-flow
correction term.
Full Article in PDF (538 KB) |
|
|
