Proceedings with Extended Abstracts (single PDF file) - Radio ...

equested more investigations on the properties of the range imaging processing, which areregarded necessary before finally reliable applications can be expected to studyatmospheric processes.Jürgen Röttger asked what is turbulence seen by VHF radar. This paper was regarded as afollow-on of the paper by W. Hocking and J. Röttger during MST-9. It recollected the veryearly, partially forgotten, work done as early as in the 1960’s on scattering and reflection ofelectro-magnetic waves from rough surfaces. Most of the present VHF radar echoes can bedescribed as resulting from this mechanism. He also introduced a new approach to analyseVHF radar data in combined spatial-domain frequency-domain measurements (SDI-FDI).This approach just analyses raw data without any assumptions for applying mathematicalmethods and allows most pictorial descriptions the microstructure of VHF radar echoes.There exist limits, though, on the three-dimensional spatial resolution, which are intrinsic tothe used instruments and applied methods. This newly presented technique anyhow seemsto be a means for improved understanding of the echoing irregularities and discriminatingbetween the two (unnatural) extremes, scattering from pure turbulence and specular-typereflection from stratified refractivity gradients. This means that all observational evidencepoints to phenomena, which are existing between these extreme limits.Wayne Hocking, co-authored by S. Franke, N. Mitchell, D. Pancheva, P. Batista, B.Clemesha, B. Fuller, B. Vandepeer, T. Nakamura, T. Tsuda and J. MacDougall, reportedabout a recent global analysis of the mesospheric wind field observed by radars during theSpace Shuttle Columbia accident. He showed that an unusually strong 2-day wave existedwhich, together with a strong diurnal tide in the mesosphere, created a strong wind shear at60 to 65 km altitude. Whether such observations can be of use for applications andforecasting middle atmospheric winds was discussed.A new approach to analyse spaced antenna data was presented by Alexander Praskovsky,co-authored by Eleanor Praskovskaya. Instead using correlation function or spectrumanalysis they implemented the structure function alternatively. They claimed the advantageof this method, which can track the diffraction pattern and higher order moments ofturbulence parameters by evaluating the rate of pattern changes with a higher temporalresolution than the traditional techniques. They also argue that there would be an advantageto use overlapping receiving antennas, which gains signal-to-noise ratio and thus accuracy.Characteristics of the scattering medium can be obtained with other assumptions than theearly standard techniques. It is assumed that this new structure-function based techniquecan properly complement the commonly used ones.Basing on the earlier work using existing commercial FM-radio transmitters to do passiveradar observations of ionospheric irregularities, John Sahr presented a paper with ideas howto implement this technique for neutral atmosphere studies, which could be a superbalternative to high-power MST radars. Such a system would include a network ofdistributed receivers separated by some hundred kilometer. Since the cross section ofscatterers in the neutral atmosphere is much smaller than of those in the ionosphere, largerreceiving antennas have to be used, and higher synchronization accuracy is needed becausethe scattering is more coherent than that from the ionosphere. There is a requirement toseparate ground clutter from the desired forward scatter. The receiving systems,32