The use of the monopulse type antenna system in GPR for increasing accuracy of horizontal coordinate measurement

The possibility to increase accuracy of horizontal coordinate measurement of the local near surface object by means of using the monopulse type antenna system is presented. The basic principles of designing such an antenna are discussed. It is shown that if the receiving (or transmitting) unit is placed in the center of the antenna system there is a possibility to form in the symmetry plane an electromagnetic field with zero amplitude or absence of signal reflected from the object located in the symmetry plane owing to symmetry of antenna system and inverse driving of the antenna elements. It is proposed to use this phenomenon to increase accuracy of GPR measurements. Experimental GPR data illustrate high contrast of radar image of the object if these data are acquired by GPR with monopulse type antenna system. Such a design of the antenna system provides high electrodynamic isolation between the transmitting and receiving units of antenna system