Propagation Time Estimation by Model Fitness for Microwave Subsurface Radar

Abstract

A time of a microwave propagation from a emitter to a receiver via a reflective object in a soil is estimated based on a model fittness. Since the model fittness is expressed as a function of time and has a single-peaked pattern at the propagation time, the propagation time is determined from the time of the peak of the model fittness. It is proved in this paper that the model fittness can be calculated as an envelope of a cross correlation function between a transmitting wave and a receiving wave. The propagation times are obtained at each measurement point. From sets of the measurement point and the propagation time, a representative position of the object is estimated by a least square method with a non-linear model which is based on geometric relationship among the representative position of the object, measurement positions and an antenna arangement. In this paper, detections of three different size of steel pipes are experimentally demonstrated. As a result, top positions of three steel pipes are precisely identified by proposed methods.