Prediction of far-field bistatic scattering cross section using spherical, cylindrical and planar scanned near-field data

The far-field radar cross section (RCS) measurement of a large scatterer is generally difficult due to the limitation of available measurement range. One way to avoid this difficulty is to adopt a scale model by compact range measurement. However, there are some problems in this measurement: it is labour intensive and expensive to construct the scale model, and the frequency characteristics of the surface impedance of the scatterer may not be reproduced at shorter wavelength measurements, so real target measurement is necessary to obtain accurate data. There exists a near-field antenna measurement technique, however a direct application of this technique for RCS measurement fails because the RCS depends on the locations of both the source and the observation points. Falconer (1988) has overcome the above difficulty and successfully estimated the far-field RCS by the near-field RCS measurement. We have also proposed a far-field RCS prediction algorithm which uses cylindrical or planar near-field RCS data. However these algorithms are applicable only for the monostatic RCS. We report novel prediction algorithms of the far-field bistatic scattering cross section (SCS) by extending the proposed algorithms. These are presented in cases of spherical, cylindrical and planar scanning. We also show simulation results of the far-field SCS prediction in order to validate our methods.