Unambiguous identification of the uneven boundary of a half-space probed by acoustic or electromagnetic waves

It is shown that the use of 1. e physical optics approximation (POA) to simulate the response (i.e., predictor), on a line above the open cylindrical boundary in its cross-section plane, to two probe plane waves of different frequencies, e intersecting canonical boundary approximation (ICBA) of the wave-boundary interaction for a trial boundary (i.e., estimator), and analysis of the comparison equation and/or cost function, employing the ICBA as estimator and either the ICBA or POA as predictor es a nonambiguous identification of the scattering boundary.