MODEL PLANE-DIAGNOSING ENVIRONMENTS BY SURFACE REFLECTION WHILE LANDING AIRCRAFT OF THE HELICOPTER TYPE

The relevance of the study is due to the need to create a radar system for landing a helicopter-type aircraft on an unprepared site with the possibility sensing the underlying surface (landing site), determining the parameters and characteristics of plane-layered media and issuing information to the flight crew about the possibility landing or lack thereof. A variant using the midpoint method related to the bistatic diagnostic method is based on measurements the time delay between the direct wave and the subsurface layer reflected from the base, which is a function its thickness. The data obtained, under certain conditions, allow to restore the geometric and electrophysical parameters of the layered structure. However, there are a number of factors in the diagnosis of plane-layered media by bistatic methods, which make a significant contribution to the total error, especially due to a slight longitudinal heterogeneity, or a weak dispersion even one of the layers of the structure,which cannot be considered in the simulation. Then, in the diagnosis real plane-layered structures based on bistatic data, the error in determining the thickness of the layers and electrophysical parameters increases. The variant using the method surface reflection related to the monostatic method layered media review is less sensitive to horizontal changes in electrophysical and geometric parameters and is the most economical in terms reception, accumulation and processing of data by subsurface sensing radars.

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