Analysis of the features of Earth surface clutter formation in the case of low-flying target detection with the use of a bistatic radar

It has been found that the usage of the bistatic mode makes it possible to reduce the power of clutter due to the decrease of the number and area of elements on the Earth surface that reflect the sounding signal. The power of these reflections to a large extent determines the signal / noise ratio at the input of the air-borne radar receiver and. as a result, the probability of correct detection of targets and accuracy of determining their coordinates. Based on the analysis of the features of the formation of reflecting patches on the Earth surface all possible configurations of these areas and analytical expressions for the calculation of their areas have been obtained. As a result of the study, analytical expressions and graphs of lines of equal distances (izodops) and lines of equal Doppler frequencies (izodals) forming these zones specific for a bistatic radar have been obtained. This has made it possible to develop a universal algorithm for calculating the power of clutter when detecting low-flying targets, which is useful for comparative analysis of the clutter power and detection characteristics for various configurations of the relative position of the receiver, transmitter and targets, as well as for comparing the detection characteristics of a monostatic and a bistatic radars. In accordance with this algorithm calculations have been performed and the graphs of dependency of the clutter power in the Doppler filter bandwidth on the frequency of their adjustment have been obtained as a result of the calculation for monostatic and bistatic radars.