Abstract:

An extrapolation technique by correction dealing with near-distance RCS measurement of aircraft targets is set up.In general,the far-field condition is hard to meet in RCS measurement.According to shape of aircraft targets,an illuminating spherical wave can be equivalent to cylindrical wave.An arithmetic utilizing conductive board as a reference deduces the phase-correction coefficient g(x) between cylindrical and plane wave,then far-field RCS of target can be gained.By simulation for a simple target,the RCS extrapolated can be obtained correctly.Experimental results of complex aircraft target at different distances show that the RCS after extrapolating makes an agreement precisely,moreover,it permits the measurement distance reduced the minimum distance of far-field.Also,there is no serious limitation of measurement for target in dimension of aperture and depth.

Key words: spherical wave,;aircraft,;radar cross section (RCS);correction coefficient;extrapolation