A detector apparatus, detection system, and method are provided for determining optimum operational angles based on the statistical correlation of wavelength-specific electromagnetic propagation and surface interaction. These techniques can be used within the radar community in both military and commercial radar applications for airborne radar system users to determine optimum operational depression angles based on the purpose of the effort, the operational frequency, and the terrain-type to be encountered. The method requires the user to interface with a standard computer equipped with the commercially available MATLAB® software package where the operation is presented as a graphic user interface (GUI) that once invoked allows the user to set specific parameters corresponding to the desired terrain type. Upon doing so, the algorithms are exercised and the results are displayed in a series of figures identifying the optimum operational angles.