Seismoacoustic survey of artificial inhomogeneities in the ground

The results of processing the field test data obtained for the seismoacoust ic system designed at the Institute of Applied Physics of the Russian Acade my of Sciences for the visualization of underground engineering structures are presented. The described experiment is the first demonstration of the u se of a high-power, high-stability transmitting-receiving system for produc ing a coherent insonification with a frequency of 195 Hz. The receiving ele ment of the system is a synthetic aperture array. With the use of focusing as a method of the final signal processing, an image of a tunnel lying at a depth of 30 m is obtained in three spatial cross-sections, which demonstra tes the possibility of a three-dimensional, coherent, high-frequency seismi c survey of engineering structures. (C) 2001 MAX "Nauka/Interperiodica".