Near field RCS test facility and testing method

摘要

A method for determining the far field radar signature of relatively large and complex objects, like a fighter aircraft, and the facility to provide the data for the method. The method includes reflecting different frequencies of near field radar energy off of an object while translating the object in a radial direction with respect to the radar so the resulting radar return includes a moving signal representative of the radar return of the object and a stationary return representative of environmental clutter. The environmental clutter and R 4 amplitude variations caused by signal strength variations due to the different overall reflection distances during translation are removed from the radar signal. Multipath reflections may also be removed. The resultant signal is transformed from a spherical wave to a cylindrical wave so that for objects having a major dimension that is presented to the radar with respect to a much smaller minor dimension at right angles thereto, the radar signature as determined by the method is almost identical to that obtainable at a far field radar range. In addition, the facility includes an electromagnetically shielded building, object translating devices with position feedback, object rotators, and a computer to perform the transformations.