The methods of signal processing consist of preliminary processing and autocorrelation processing. The preliminary processing includes deduction of direct transmission signal between receiving and transmitting antennas and considering of effect of surface unevenness on direct transmission signal. At present the program for automatic data interpretation is being developed which would include the following methods for identification of mine classes: detecting of complex resonant frequencies of object, method of neural networks. The possibility exists to record reflected signals above various mines and to enter those signals into database. This database will be later used for neural network training and mine class identification.
Operating Mirador georadar proceeds as follows. The antenna unit mounted on telescopic bar moves at small height (between 3-5 and 10 cm ) above ground surface along a line of nearby 1 m in length. The lesser is this height, the higher is radar sensitivity. Once the movement of the antenna unit is completed, the monitor displays the vertical ground section along scanning line. As this takes place signals usually undergo preliminary processing.
Fig. 1 shows results of this sounding. The antenna unit was moving at height of 5 cm . The reflected signal contains two basic oscillation half-cycles. As per the sign of the first oscillation the dielectric type of object can be identified which is of lesser dielectric permeability as compared to ground or a metallic one. A very evident object image is on display to be used by operator for preliminary processing. A special procedure using signal recordings along several scanning lines allows to receive three-dimensional image of objects (Fig. 3). Automatic interpretation program will be applied either during scanning along lines or in combination with autocorrelation processing upon sounding along several lines.
When identifying the object the program displays its photo chosen from database with assessment of reliability level of identification and it labels the object on horizontal volume section