Frequency domain interferometry mode observations of PMSE using the EISCAT VHF radar

Abstract

Abstract. During the summer of 1997 investigations into the nature of polar mesosphere summer echoes (PMSE) were conducted using the European incoherent scatter (EISCAT) VHF radar in Norway. The radar was operated in a frequency domain interferometry (FDI) mode over a period of two weeks to study the frequency coherence of the returned radar signals. The operating frequencies of the radar were 224.0 and 224.6 MHz. We present the ®rst results from the experiment by discussing two 4-h intervals of data collected over two consecutive nights. During the ®rst of the two days an enhancement of the FDI coherence, which indicates the presence of distinct scattering layers, was found to follow the lower boundary of the PMSE. Indeed, it is not unusual to observe that the coherence values are peaked around the heights corresponding to both the lower-and upper-most boundaries of the PMSE layer and sublayers. A Kelvin±Helmholtz mechanism is oered as one possible explanation for the layering structure. Additionally, our analysis using range-timepseudocolor plots of signal-to-noise ratios, spectrograms of Doppler velocity, and estimates of the positions of individual scattering layers is shown to be consistent with the proposition that upwardly propagating gravity waves can become steepened near the mesopause.

First artificially induced modulation of PMSE using the EISCAT Heating Facility

“…That is, estimates of the backscattered power and the center and spread of the Doppler frequency spectrum were estimated for every data record. A more thorough description of the data analysis method is given in Chilson et al [2000]. For the present analysis, we only consider the zeroth moment of the Doppler spectrum, that is, the backscattered power.…”

A review of Mesosphere–Stratosphere–Troposphere (MST) radar developments and studies, circa 1997–2008

“…The first attempt along these lines for atmospheric/ionospheric signals was by Hysell (1996), who used MEM. Subsequent developments in angular imaging were published by Palmer et al (1998Palmer et al ( , 1999Palmer et al ( , 2001, Luce et al (2001c), and Chilson et al (2001). Parallel developments in range imaging and frequency domain interferometry were presented by Luce et al (1999Luce et al ( , 2000aLuce et al ( ,b, 2001c and Smaïni et al (2002).…”

Coordinated optical and radar image measurements of noctilucent clouds and polar mesospheric summer echoes

“…The PMSE and NLC often exhibit common altitudinal variability and wave-like structures (e.g. Ruster et al, 1996;Ruster, 1997;Czechowsky and Ruster, 1997;Chilson et al, 2001). However, this is not always the case and PMSE have been detected in the absence of NLC (and vice versa).…”