RU96121682A

RU96121682A - METHOD FOR DETERMINING SOUND SPEED DISTRIBUTION IN LIQUID MEDIA

Info

Publication number: RU96121682A
Application number: RU96121682/28A
Authority: RU
Inventors: Н.Н. Касьяненко; Г.Н. Серавин
Original assignee: Н.Н. Касьяненко; Г.Н. Серавин
Filing date: 1996-11-06
Publication date: 1999-01-20

Claims

1. The method of determining the distribution of sound velocity in a liquid medium, which consists in sensing acoustic reflectors located in the liquid medium from the point of emission with acoustic signals, receiving acoustic signals reflected from them at the first, second and third reception points, the first receiving point being combined with an acoustic source, and the second and third reception points are removed from it at fixed distances, measuring the propagation times of acoustic signals from the radiation point to the reflection points and further to the reception points, finding according to their values, taking into account the known distances from the acoustic source to the reception points of the desired parameter, characterized in that they additionally receive reflected acoustic signals at least at the fourth reception point, which is located on the same line with the first, second and third reception points, according to the propagation times of the acoustic signals from the reflection points to the receiving points, the angles of arrival of the acoustic signals to the receiving points are found by the known distance between the receiving points of the acoustic signals and taking them into account, the values of the speed of sound in the liquid at the acoustic reflectors and their vertical coordinates are determined.

2. The method according to p. 1, characterized in that the points of reception of acoustic signals are located on one side of the acoustic source.

3. The method according to p. 2, characterized in that the angles of arrival of the received acoustic signals at the receiving points are found by the formulas

Here φ _1i , φ _2i and φ _3i - the angle of arrival of the acoustic signal from the i-th reflector to the first, second and third points of reception, starting from the farthest from the radiation point;

τ ₁₂ = t _1i - t _2i ;
τ ₂₃ = t _2i - t _3i ;
τ ₁₃ = t _1i - t _3i ;
t _1i , t _2i and t _3i - propagation time of the acoustic signal from the i-th reflector to the first, second and third points of reception, respectively, starting from the farthest from the radiation point;
t ₀₁ , t ₀₂ and t ₀₃ - propagation time of the acoustic signal between the first and second, second and third, first and third points of reception, respectively.

4. The method according to p. 2, characterized in that the value of the speed of sound with _i at the horizons z _{i of} acoustic reflectors in a liquid medium with constant gradients of the speed of sound is found by the formulas

z _i = D ₃ tgφ _3i ;
d _ik = D _i - D _k ;

with _i (z _i ) is the value of the soundness of the sound of the i-th reflector located on the horizon z _i ;
i, k are the numbers of reception points for i = 1, k = 2, 3; i = 2, k = 3;
d _ik is the distance between the corresponding points of reception;
D _i , D _k - the distance between the radiation point and the receiving points.