A nondestructive noncontact method of the sea-bottom structure investigation
The paper describes a nondestructive noncontact method of the sea-bottom structure investigation using hydroacoustic and laser radiation types. A practical implementation of this method is also presented. The research complex incorporates a state-of-the-art low-frequency hydroacoustic radiating system and a system of coastal laser strainmeters arranged in the sea-waters and the coastal-grounds of the special selection. The hydroacoustic radiators are put to generate a seismic signal. Seismic superficial waves are recorded by the coastal laser strainmeters. Optical parts of the strainmeters are constructed as the unequal-path Michelson interferometer where the frequency-stable helium-neon lasers serve as the emission sources. A preliminary model of the sea-bottom testing ground has been developed by application of geologic-geophysical procedures. The model-based analysis of the timing data of the recorded seismic waves was carried out. The prospectivity of the used method was proved.