Optimal polarizations for partially polarized backscatter

Optimal polarizations are those which produce nulls in the co-polarized (CO-POL) and cross-polarized (X-POL) components of backscattered radiation. The discussion of optimal polarizations is here extended to the partially polarized case where nulls are replaced by minima. The width of the minima is related to the degree of polarization of the received radiation and, experimentally, to the correlation of orthogonal components. Formulas are presented for the location and width of these minima.