CROSS-SECTION COMPUTATION OF TRIHEDRAL CORNER REFLECTORS WITH THE GEOMETRICAL-OPTICS APPROXIMATION

A Monte Carlo type numerical method based upon the geometrical optics (GO) approximation to compute the monostatic radar cross section of trihedral corner reflectors is introduced. Advantages of the method are its simplicity and the possibility to use it for the most complex reflector shapes. Disadvantage is its slow convergence as a function of the number N of rays involved, and hence the amount of computer time needed. Comparison of numerical with experimental and GO analytical results for the often used triangular and square-based reflectors confirm the validity of the numerical method. The analytical results presented are valid for a wider angular range than those given in the most commonly used literature. The method was utilized in the problem of finding a reflector shape exhibiting a relatively flat angular RCS pattern. The pattern of the resulting optimal reflector varies less than approximately 1 dBm2 within a region of about +/- 25-degrees - 30-degrees around boresight. For the most commonly used triangular reflector this region is only about +/- 10-degrees - 15-degrees wide.