Determination algorithm of underlying surfaces border position by pulse altimeter signals

The determination algorithm of underlying surfaces by pulse altimeter signals is described. The algorithm basis is the principle of comparison of reference standard distributions with a current posteriori distribution of a reflected signal´s echo amplitude. As the result of comparison of statistical distributions a posteriori evaluation of correct discrimination is formed. The maximum of a posteriori probability has its own minimum in case of detected crossing of underlying surfaces border. It allows forming the evaluation of underlying surfaces border position.