Based on experimental works devoted to study of a lowfrequency (central frequency is 33 Hz) emitter and shorebased laser strainmeter for investigation of the Earth's crust structure and definition of the main elastic properties of rocks on emitter-receiver paths, it has been shown that application of these instruments with an increase in the power of receivers and a tunable central frequency of radiation is a promising feature due to the broad operational frequency range and high sensitivity of the laser strainmeters. As is known (1-3), in the low frequency region, seismoacoustic surface waves become the dominating mechanism of acoustic energy transport in the shelf zone, and this feature can be used during experiments on study of the crustal structure within shelf zones of different seas. Since the frequencies of signals emitted by lowfrequency hydroacoustic emitters are about 20-35 Hz (i.e., wavelengths in water are about 75- 40 m, and about 150-100 m in the solid medium at an elastic wave velocity of about 3000 m/s), the depth of the signal penetration into the Earth's crust is signifi� cant. All soundings of sediments or water medium are implemented using the technique of signal investiga� tion at the chosen frequencies and their reception by various, preferably broadband, receivers. Broadband receiver systems are used in order to avoid probable distortion of the received information. The time inter� vals between emission and reception time must be measured very accurately in order to obtain the appro� priate thicknesses of studied layers, but this cannot be done if harmonic or pulsed signals are used. In the studies of this kind, complex, phaseshift signals (M� sequences) are preferred; their application in hydroa� coustic and seismoacoustic tomography and inversion studies allows specialists to define the arrival times with a high accuracy. Additionally, signal attenuation does not affect the processing result significantly, because the main processing stage is not related to spectraltemporal investigation of the signal behavior, but to convolution of the received and emitted signals. This peculiarity makes this technique feasible even with significant noise, whose amplitude can exceed that of the received hydroacoustic or seismoacoustic signals.