Patent RU-2602993-C1 (RU)
Title: System of acoustic tomography of hydrophysical and geophysical fields in marine environment
Inventor: MIRONENKO MIKHAIL VLADIMIROVICH
IPC: G01V1/00
Filed: 2015-09-11
Granted: 2016-11-20
Abstract: FIELD: electronics. 
     SUBSTANCE: proposed technical solution is development of structure and system operation principles of characteristics long-range (rear-illuminated tracing) acoustic tomography of hydrophysical and geophysical fields and sea bottom, as well as control of their space-time dynamics. Information fields are measured and recorded in a wide range of frequencies, composing hundreds-tens-units of kilohertz, hundreds-tens-units-fraction of Herz, including a range of VLF-oscillations of moving objects as a whole. Acoustic tomography system of hydrophysical and geophysical fields of the marine environment includes radiating and receiving acoustic transducers arranged on opposite boundaries of the controlled section of the medium, working zone of nonlinear interaction and parametric conversion of pervious medium pumping waves with measured data formed between them, radiating and receiving channels of the monitoring system connected with transducers, at that, the radiating channel of the system includes series-connected stabilized frequency audio signal generator, power amplifier of generated signals and a matching unit of its output with an underwater cable and then to the radiating transducer, and receiving channel of the system includes series-connected broadband amplifier of nonlinearly converted pervious pumping signals, narrow-band spectrum analyzer and a recorder of recovered information signals by the analyzer functionally connected with it. According to invention, the receiving transducer of the measuring system is formed as a linear discrete antenna, containing n elements (hydrophones) horizontally located in the direction of the radiating system unit, herewith, each element of the antenna is connected with appropriate input of n-channel preamplifier, outputs of which are connected to inputs of n-channel unit of frequency-time conversion of signals in high-frequency domain through a multicore underwater cable, while its outputs are connected to inputs of switching of receiving channels and forming a continuous signal, output of which is connected to the input of the broadband amplifier. Besides, the n-number of receiving transducers (hydrophones) in a linear receiving antenna is installed in an amount of 10 elements, and the distance between them is a half of rear-illuminated acoustic wave length. Besides, the frequency-time conversion scope of received pervious signals is set in compliance with the n-number of receiving channels. Therewith, a spectrum narrow-band analysis unit is functionally connected to a switching unit of receiving channels and formation of continuous signal. Besides, the controlled medium is sounded by rear-illuminated acoustic signals of stable frequency in the frequency range of tens-hundreds Hertz. 
     EFFECT: technical effect of the proposed invention consists in solving the problem of characteristics rear-illuminated acoustic tomography of hydrophysical and geophysical fields and sea bottom, as well as observing their space-time dynamics on water areas of the length of tens-hundreds of kilometers, in the frequency range of tens-units of kilohertz, hundreds-tens-units-fraction hertz. 
     5 cl, 10 dwg