Single-Cut Scattered Field Transformation Applicable for Differences in the Radar Ranges of Transmitter and Receiver

This article proposes a new single-cut scattered field transformation method. The method extends the existing radiation reflector model to the case where the measurement distances from a target under test to a transmitter (TX) and a receiver (RX) are different. The method is applied to bistatic measurements using the monostatic to bistatic equivalence theorem (MBET). The new method is based on the Born approximation and has features: 1) a scattered field including not only a far-field (FF) but also a near-field (NF) can be predicted from measured NF samples, where the measurement distances from a target under test to the TX and RX can be different; 2) the scattered field with a zero bistatic angle and the field with the nonzero bistatic angle where the MBET holds can be predicted; 3) the computational time is practical for a large target; and 4) the implementation of the code is easy. The algorithm of the method has simply three steps: inverse Fourier transformation (FT) is implemented with the measured NF samples, the samples with inverse FT are multiplied by a novel weighting factor, and the scattered field is predicted by taking FT of the weighted samples. The proposed method is experimentally and numerically verified.