32nd Conference on Broadcast Meteorology/31st Conference on Radar Meteorology/Fifth Conference on Coastal Atmospheric and Oceanic Prediction and Processes

Friday, 8 August 2003
Non-traditional radar method of investigation of cloud environments
Iori F. Kouznetsov, High–Mountain Geophysical Institute, Nalchik, Russia
Poster PDF (76.2 kB)
Radar detection method of characteristics of water cycle in cloud environments

The non-traditional method allowing by the non-coherent radar of any assignment in cm-band to detect the characteristics of water cycle in cloud environments is described in this paper. In the method basis lies the definition principle of spatial modulating waves/ masked in the structure of radar echo. The amplitude and phase of these waves contain the information on the investigated cloud environment. The following characteristics of water cycle, detected with the help of modulating waves, include: •liquid water content averaged on dissipating volume ; •water content of investigated volume; •aggregate state of cloud water in dissipating volume. •characteristic of propagation medium at radiated frequency. • information on energetic potential of the radar. During realization of this method the modulating waves are extracted from radar echo with the help of the detector operating as the radio interferometer. For detection of spatial waves the virtual reference channel is entered into the pattern of the operating radar. The given channel “works” at the same radiated frequency, but already with cloud virtual environment, the characteristics of which are considered as completely known. This way with usage of virtual environment and reference channel is necessary for synthesizing of comparative parameters. Software products created on the basis of radar equation and the fundamental laws of physics support the process of synthesizing of comparative parameters in a reference channel. The main synthesized parameter in a reference channel is the modulating wave, the period and rate of propagation of which in cloud environment depend on mean liquid water content. According to philosophy of method, the reference wave is forced to pass the given spacing interval in investigated and reference environment. If in this case the characteristics of investigated environment will be distinct from characteristics of reference environment, the reference wave will receive the correspondent phase shift. Then using this phase shift the mean length of spatial modulating wave in investigated environment is determined, the period of which is proportional to mean liquid water content. It is possible to explain the philosophy of method and point of view on the nature of spatial modulating waves more argued with the help of phenomenon of diffraction. To do so, bearing on physical analogies, it is necessary to imagine, that the structure of reference and investigated volumes acts as spatial diffraction grid. Then, coming into a point of reception (in a focal plan of the antenna) the secondary wave fronts will be recognized as not continuous but structured, i.e. they will have a different spatial constitution and is received as the fact of spatial modulation. Therefore the physical sense of the subsequent operations at receiving side represents the splitting of averaged intensities of echo into elementary electrical signals proportional to the mean transparency of specific volumes of cloud environment. It is achieved with the help of method of holographic interferometry.

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