Cylindrical Scattered Field Transformation Applicable for Differences in the Radar Ranges of Transmitter and Receiver—Far-Field Prediction

This article proposes a new scattered field transformation method for cylindrical scan system based on the Born approximation. The novelty of the method includes: 1) a far-field (FF) can be predicted from measured near-field (NF) samples with an electrically large target for all the spatial dimensions; 2) measurement distances from the origin of the coordinates in the radial direction to a transmitter (TX) and a receiver (RX) can be different; 3) a bistatic FF can be predicted along an elevation angle and 4) the computation time is less than one minute in each azimuth cut-plane of the cylindrical scan for a large target with dimensions about 400 times that of the wavelength. We have already reported the method for a single-cut scan, and this is extended to the two-dimensional cylindrical scan in this article. The advantages of the proposed method over the reported single-cut method are the requirements of 1) and 3) mentioned above. Although the proposed technique can predict the near-field (NF) as well, the procedure to predict the FF is different from that of the NF prediction. Thus, this article focuses on the FF prediction. The proposed method is experimentally and numerically verified.