METHOD OF SURVEYING BOTTOM CONTOUR OF WATER BODIES AND DEVICE TO THAT END Russian patent published in 2008 - IPC G01S15/06 

FIELD: physics; measurements.

SUBSTANCE: present invention aims at increasing accuracy of surveying a bottom contour. The method of surveying the bottom contour of a water body using a sonic depth finder, mounted at the bottom of a vessel, involves emitting sonar signals in the direction of the bottom of the water body, reception of signals reflected from the bottom surface, measurement of the distance from the tranceiving antenna to the bottom, determination of the coordinates of the vessel using external information sources, measurement of the board keel and heave, true course and speed of the vessel, matching the measurement results on time, calculation of true values of depth with determination of corrections for deviation of the actual speed of sound in water from the calculated value, and mapping the obtained information with determination of geodesic coordinates of the measured depth. When determining true depth values, correction of deviation of the actual sound speed in water from the calculated value is determined from the expression: ΔZ_v=H(C_av/C_o-1), where H is the under-keel clearance (H=ΣC_it_i/2), C_av=V_s4f_scosαΔf_d is the average speed of sound in water, C_o is the speed of sound in water, at which the sonic depth finder is rated, f_s is the frequency of the sonar signal with hydroacoustic Doppler log, Δf_d is the Doppler frequency shift between the emitted and reflected sonar signals of the hydroacoustic log from the bottom of the water body, α is an angle, formed between the direction of transmission of the sonar signal to the bottom surface and the horizontal, V_s is the speed of sound in water when measuring depth using the sonic depth finder, C_i - speed of sound in water when measured with sonic depth finder, t_i is the time interval between transmission of the signal and receiving the echo signal from the bottom. Topographic and navigation bitmaps are coupled when mapping the bottom contour. The device for implementing the method comprises a transceiving antenna, transmission unit, receiving and measuring unit, control unit and a unit for collecting, processing information and mapping the bottom contour of the water body. The device also has a unit for determining average speed of sound in water, in the direction of transmission of the sonar signal.

EFFECT: increased accuracy of surveying the bottom contour.

2 cl, 7 dwg