Patent ID: 9158026
Filing Date: 2015-10-13
Classification: G01S,G01V

Abstract:
1. A method for detection of underground anomalies comprising: placing an electromagnetic wave transmitter connected to an antenna in a first borehole in a ground; placing an electromagnetic wave receiver connected to an antenna in a second borehole, both antennas for the transmitter and the receiver comprising leaky transmission lines; selecting dielectric and magnetic constants of said leaky transmission lines to be smaller than those of the ground so that a speed of electromagnetic wave propagation through said leaky transmission lines is faster than a speed of propagation through the ground; injecting an electromagnetic pulse into one of the antennas, wherein the pulse gradually leaks out as a shock wave which is received as a received signal at another of the antennas, and wherein an underground anomaly diffracts the shock wave, resulting in a detectable disturbance in the received signal; and locating said anomaly as a function of a time delay of the disturbance relative to the transmitted signal.