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Ann. Geophys., 23, 207-220, 2005
www.ann-geophys.net/23/207/2005/
© European Geosciences Union 2005
Range imaging observations of PMSE using the EISCAT VHF radar: Phase calibration and first results
J. R. Fernandez1, R. D. Palmer1,5, P. B. Chilson2, I. Häggström3, and M. T. Rietveld4
1Department of Electrical Engineering, University of Nebraska, Lincoln, NE 68588-0511, USA
2CIRES–University of Colorado and NOAA Environmental Technology Laboratory, Boulder, CO 80305-3328, USA
3EISCAT Scientific Association, Box 164, S-98123 Kiruna, Sweden
4Max–Planck-Institut für Aeronomie, 37191 Katlenburg–Lindau, Germany
5Now with the School of Meteorology, University of Oklahoma, Norman, OK 73019, USA
Abstract. A novel phase calibration technique for use with the
multiple-frequency Range IMaging (RIM) technique is introduced based
on genetic algorithms. The method is used on data collected with the
European Incoherent SCATter (EISCAT) VHF radar during a 2002
experiment with the goal of characterizing the vertical structure of
Polar Mesosphere Summer Echoes (PMSE) over northern Norway. For typical
Doppler measurements, the initial phases of the transmitter and
receiver are not required to be the same. The EISCAT receiver systems
exploit this fact, allowing a multi-static configuration. However,
the RIM method relies on the small phase differences between closely
spaced frequencies. As a result, the high-resolution images produced
by the RIM method can be significantly degraded if not properly
calibrated. Using an enhanced numerical radar simulator, in which
data from multiple sampling volumes are simultaneously generated, the
proposed calibration method is validated. Subsequently, the method is
applied to preliminary data from the EISCAT radar, providing first
results of RIM images of PMSE. Data using conventional
analysis techniques, and confirmed by RIM, reveal an often-observed double-layer structure
with higher stability in the lower layer. Moreover,
vertical velocity oscillations exhibit a clear correlation with the apparent motion of the
layers shown in the echo power plots.
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