RU1829019C - Method for determination of depth of water area by phase sonar of side scanning pattern and phase sonar of side scanning pattern direction for implementation of said method - Google Patents

Abstract

The invention relates to hydrography, in particular to methods and technical means for determining water depths by a side-scan phase sonar, and can be used to take a survey of the bottom relief of the water area. The purpose of the invention is to simplify the process of determining depths of a water area with a side-scan phase sonar. A method for determining water depths by a side-scan sonar, including emitting a hydroacoustic signal to the bottom and receiving reflected signals at two points vertically at a given distance, measuring the delay time of the arrival of common-mode signals, the delay time of the arrival of the reflected hydroacoustic signal vertically, the pitch angle antenna carrier, determination by calculation of the delay time of the arrival of common-mode signals in case of reflection from a flat bottom surface for each race the even direction and determination by the received data of the direction of arrival of in-phase signals and the desired depths of the water area by calculation. The side-view phase sonar for determining the depths of the water area contains functionally connected first 2 and second 3 antennas, one of which is a receiving-transmitting unit 4, the first 5 and second 6 receiving-measuring units, a control unit 7, a unit 8 for determining the arrival delay time reflected from the flat the bottom surface of common-mode signals in each calculated direction, calculator 9 and recorder 10. 2 pp f-ly, 2 ill. Ё 00 hO Oh Oh Che

Description

Oig. I

The invention relates to the field of hydrography, in particular, to methods and technical means for determining water depths by a side-scan phase sonar, and can be used to take pictures of the bottom relief of the water area.

A known method for determining the depths of the water with a side-scan phase sonar, including emitting a hydroacoustic signal to the bottom and receiving reflected signals at two points located at a vertical distance d, measuring the delay time ts of the reflected signals and their phase shift p at these points, determining the direction (a) receiving reflected signals according to the formula

&

(1)

where f is the frequency of the sonar signal;

C is the speed of sound propagation in water.

The device measures the angle {fy of the side rolling of the antenna carrier and calculates the depths (Z) of the water area according to the formula

Z $ sin y

(2)

where a + / 3,

However, this method has insufficient accuracy.

This is explained by the fact that when using it, there is a significant error (s) in determining the direction (y) of arrival of the reflected signals from the measured values of their phase shift p at the receiving points.

The value of m, starting from formula (1), can be calculated by the formula

1

- (

1p)

t

(3)

where t is the measurement error p.

Since a reliable determination of the direction of y (without ambiguity resolution) is possible only in the case of a small separation of d antennas not exceeding two wavelengths (A), the possible range of the phase shift of y for d A will be 0-2 p.

The error m j-, as can be seen from formula (3), varies nonlinearly and when t, and when p 2n reaches a maximum and can be 2 gig.

This circumstance causes a significant error (mz) in determining the depth of the water area /. Using the known method.

The value of mz, starting from formula (2). can be calculated by the formula

10

C -t.3 mz -i- cos 9 m i

(4)

5

0

5

5

0

5

0

5

0

where a + p.

For example, when m / s, 7 s yK30 ° cos, 87 m 2 -0.0017 (that of modern phase side-scan sonars does not exceed 1 °). Then mz will be 13 m or about 4% of the value.

Acceptable error in determining the depth of the water area in accordance with regulatory documents for surveying the topography of the bottom is 1% of the depth Z.

There is also a known method for determining the depths of the water with a side-scan phase sonar, selected as a prototype, which includes simultaneously emitting the main and auxiliary sonar signals, differing in frequency by a small amount, and receiving the reflected main and auxiliary signals at two points located along vertical at a given distance d, measuring the time tc of the arrival delay of the common-mode main and auxiliary signals using two multi-channel two-frequency receiving eritelnyh blocks, the measurement device the angle of roll carrier antennas, determining from the data arrival directions of the main-phase signals and the desired depth of the water area by calculation.

A known side-view phase sonar is selected as a prototype of the device, which contains the first and second two-frequency antennas located vertically at a given distance (d), the transmitting unit, the first and second two-frequency multi-channel receiving and measuring units, a control unit, a calculator, and a recorder while the outputs of the first and second two-frequency antennas are connected respectively to the inputs of the first and second two-frequency multi-channel receiving and measuring units, the output of the transmitting unit is connected to zluchayuschey anti tennoy, outputs of first and second two-frequency multichannel priemoizmeritelnyh blocks are connected to the output of the calculator, the latter output is connected to the logger.

A disadvantage of the method and apparatus (phase side-scan sonar) is that they are difficult to use.

This is explained by the fact that in order to increase the accuracy of determining the depths of the water area in these technical solutions, the reflected hydroacoustic signals are received at two points located vertically at a large distance (I) of several wavelengths compared to the analogue, and measured the delay time of the signals, that is, signals in which the phase shift is absent or a multiple of an integer of 2 p.

The fulfillment of this action ensures high accuracy in determining the depths of the water area, since during the phase shift, as can be seen from formula (3), the error will be minimal and equal to t.

However, in this case, there is a need to solve a complex problem - the elimination of ambiguity in determining the directions of arrival of common-mode signals. To solve this problem when using the first known known method, it is necessary, in addition to the main ones, to perform the following additional complex actions:

- to accept, at a third point, vertically on an auxiliary base at a given distance from the common point, the reflected sonar signals;

-measure at the third and main points the delay time of the arrival of common-mode signals.

In order to carry out these actions, it is necessary to provide a side-view phase sonar with a receiving antenna and a receiver-measuring unit, i.e., significantly complicate the structural diagram and increase the weight and size characteristics of the side-view phase sonar.

When using the prototype method to solve the same problem, it is necessary to perform, in addition to the main ones, the following additional steps:

- emit an auxiliary sonar signal at a predetermined frequency different from the fundamental;

-receive reflected auxiliary signals (common mode) in the same cases where the main common mode signal is received;

-measure the arrival delay time of auxiliary common-mode signals.

In order to carry out these actions, it is necessary to use an auxiliary side-scan phase sonar. That is, to implement this

of the method, it is necessary to use almost two phase side-scan sonars operating at different frequencies, which leads to significant difficulty in using the prototype method and

prototype devices.

The aim of the invention is to simplify

the process of determining the depth of the water

side-scan phase sonar.

The goal is achieved in that

in a method for determining water depths by a side-scan phase sonar, including emitting a sonar signal to the bottom and receiving reflected signals at two points located

vertically at a given distance, measuring the delay time of the arrival of common-mode signals, the pitch angle of the carrier antenna and determining from the received data directions $ p of arrival of common-mode signals and the desired depths of the water area by calculation, measuring the time ts of the delay of arrival of the reflected hydroacoustic signal vertically, separate time delays (tp) of arrival

common-mode signals in the case of their reflection from a flat bottom surface for each calculated ((9p) direction according to the formula

TPn 7T

tb

ZHTEG + G

cos ($ pn + j3) sin with sin (0pn -F / TJsin (9pn -}

(5)

where n- 1.2, 3 .... N;

N cl / A the number of estimated directions BP;

E, is the general angle of inclination of the bottom in the sounding band,

Then, the convergence of the calculated Tr and measured tc values is determined by the criterion (cg) calculated by the formula

M-1

 2, Ktpn + 1-tpn) - m 1

- (tcm-f-i-tcm)} 2,

(6)

where M is the number of measured tc values for each number M of design directions 9p.

In this case, the initial value of n is successively changed from 1 to K N - M, and after

the desired directions of arrival of the common-mode signals take M calculated directions Op characterized by a minimum value of c.

This goal is also achieved by the fact that the side-scan phase sonar, containing the first and second antennas located vertically at a given distance, the transmitting unit, the first and second receiving-measuring units, the control unit, the calculator and the recorder, while the outputs of the first and second antennas are connected respectively, to the inputs of the first and second receiving-measuring devices, the output of the transmitting unit is connected to the receiving-radiating antenna, the output of the first and second receiving-measuring units are connected to the input of the computational Itel, the output of the latter is connected to the registrar, and the control unit is connected to the first and second receiving and measuring units, the transmitting unit, the calculator, and the registrar, and is equipped with a unit for determining the time delays of the arrival of common-mode signals reflected from the flat bottom of the bottom in each calculated direction, the input of which is connected to the control unit , and the output is connected to the input of the calculator.

It is the supply of the well-known phase side-scan sonar with a unit for determining the time delays of arrival of common-mode signals reflected from the flat bottom surface in each calculation direction, in accordance with the method, achieving the objective of the inventions.

The derivation of formula (5) can be done as follows. In the absence of a general angle of inclination of the bottom Ј, the delay time tpn of the arrival of the in-phase signal of the outflow channel C can be calculated by the formula

tpn

tb

sin (tfpn + Ј)

In the presence of a general bottom angle, the value will change by the delay time tpn of the arrival of the in-phase signal from point D to point C,

In ABCD, the angle at 180 ° is (9Pn + / 3); angle p 180 ° - Ј - 180 ° + (Orp + p) VRP + / 3 - Ј From D BCD, by the sine theorem, we can write that

ttb COS (0pn + fi) Sing

tpn IgG + p) (Vpn + p-Z) (ti)

Putting together the right sides of formulas (7) and (8),

get the formula (5). Value general 5 10 15 20 25

30 35

40 45

fifty

55

bottom angle угла can be determined in advance from a small-scale bathymetric map and used as a constant value in the calculations. The value of Ј can be calculated from the values of the measured time delays of the arrival of common-mode signals from the port side and starboard sides using the well-known formula. In all calculations, the angle / Winter sign + when the carrier rolls to the starboard side and the sign when rolls to the left side. Angle Ј has a + sign as the depth increases from starboard to port and the sign - in the opposite direction.

Based on the theory of probability, the criterion calculated by formula (6) is the most acceptable for characterizing the convergence of tB and tc. This is substantiated as follows. In the differences Pn + 1 tpn and tcm + 1-tcm, there are practically no errors from refraction and from sound propagation in water, i.e. these differences can be determined with the required accuracy.

At cr min M the values of tc and the corresponding M values of tp differ by a small amount, and at cr 0 the data tc and tp are equal. This allows us to conclude that both the M directions of vn, by which tc and M directions of VRP are measured, by which tp are determined, also differ by a small amount at cr min, and at o2 0 they are equal to each other. This circumstance makes it possible to reliably determine the directions according to the known calculated directions BP „according to the claimed method.

In FIG. 1 schematically depicts a method for determining water depths by a side-scan phase sonar. In FIG. 2 is a block diagram of a side-view phase sonar for implementing the method.

The side-view phase sonar for implementing the inventive method (see Fig. 1) contains (see Fig. 2) mounted on a carrier 1, for example, a ship, the first 2 and second 3 antennas, one of which, for example 3, is emitting, located vertically at a given distance, transmitting unit 4, first 5 and second 6 receiving and measuring units, control unit 7, unit 8 for determining the time delays of arrival of common-mode signals reflected from the flat bottom surface in each calculation direction, calculator 9 and recorder 10. In this case, the outputs : he first 2 and second antenna 3 are respectively connected to the inputs of the first 5 and second 6 priemoizmeritelnyh blocks yield

the transmitting unit 4 is connected to the receiving-antenna 3, the outputs of the first 5 and second 6 receiving-measuring units, the unit 8 for determining the time delays of arrival of common-mode signals reflected from the flat bottom surface are connected to the input of the calculator 9 for each calculated direction, the output of the last is connected to the recorder 10, and the control unit 7 is connected to the first 5 and second 6 receiving and measuring units, the transmitting unit 4, the unit 8 for determining the arrival delay time of the common-mode signals reflected from the flat bottom surface at each CB calculated direction calculator 9 and 10 registrar.

The control unit 7 and the calculator 9 can be made in the form of a computer of type SM-4.

The first version of the unit 8 for determining the time delays of arrival of common-mode signals reflected from the flat bottom of the bottom in each calculation direction can be made in the form of series-connected first 5 or second 6 receiving and measuring units, a carrier roll angle sensor and a microprocessor that implements the formula

tb

+

(Orp + p)

tb cos (grp + / 3) sin Ј

+

sin (6kn + / S) sin (6fen + yS-Ј)

where IB is the directional delay time measured by the receiver unit, i.e. in a direction that differs from the vertical by a minimum amount.

It is also possible to use a narrow-beam echo sounder or any standard modern echo sounder of a carrier vessel 1 as this unit 8.

This phase side-scan sonar during the implementation of the claimed method works as follows.

According to the command pulses generated by the control unit 7 in accordance with the control program, an acoustic pulse is generated in the transmitting unit 4 and emitted by its receiving-emitting antenna 3 towards the bottom, as well as receiving and converting the reflected signals of the first 2 and second 3 into an electrical signal antennas. Then, these signals, at command pulses generated by the control unit 7, are received from the first 2 and second 3 antennas, respectively, at the input of the first 5 and second 6 receiving and measuring units. In the first 5 and second 6 receiving and measuring blocks, electrical signals are generated proportional to the time delays tc of arrival of the reflected common-mode signals, and in block 8, electric signals are generated that are proportional to the time delays tc of the arrival of common-mode signals reflected from each flat bottom surface for each

the calculated direction of the GRP, which are calculated by the formula

fifteen

RP arcsin -ft

where n is the sequence number of the calculated direction (0, 1, 2 .... N),

Then, according to command pulses generated by the control unit 7, electric signals proportional to the values of tp and tc are fed to the input of the calculator. In the calculator 9, according to the program, the arrival directions of the reflected common-mode signals and the desired

5 depths Z of the water area according to the formula (2).

Then, according to the command signals generated by the control unit 7, electrical signals proportional to Z are fed to the recorder 10.

Claims (1)

1. The method of determining the depths of the water phase sonar side view, including the radiation of the sonar signal to the bottom and 5 receiving the reflected signals at two points vertically located at a given distance, measuring the delay time tc of the common-mode signals, the angle угла of the side rolling of the antenna carrier and determining The calculated data for the directions of arrival of the common-mode signals and the desired depths of the water area is also distinguished by the fact that, in order to simplify the process of determining the depths of the water area with a 5-phase side-scan sonar, the delay time of the arrival of the reflected sonar signal vertically is measured, the delay time tB of the arrival of the same common-mode signals in the case of reflection from a flat bottom surface in each calculated direction 9Р according to the formula tpn - tb sin (0pn + + + tb cos (VRP + fi) sin Ј sin (0pn +) sin (0pn + / S-) where n is 1, 2, 3 .... N; N is the number of calculated directions BP: Ј - the general angle of inclination of the bottom in the banding, then, the convergence of the calculated tp and measured tc values is determined by criteriono2 calculated by the formula ,,  L L (tpn + 1 tpn) - (tcm + 1 - tcm) r, m - 1 where M is the number of measured values of tc, for each number M of design directions BP. in this case, the initial value n from 1 to is successively measured, and M design directions bp, characterized by a minimum value, are taken as the desired directions of arrival of the common-mode signals. 2, Phase side-scan sonar for determining the depths of the water area, containing the first and second antennas, one of which is receiving-emitting, located vertically at a given distance, the transmitting unit, the first and second receiving and measuring blocks, a control unit, a calculator and a recorder, while the outputs of the first and second antennas are connected respectively to the inputs of the first and second receiving and measuring blocks, output the transmitting unit is connected to the receiving antenna, the outputs of the first and second receiving and measuring units are connected to the inputs of the calculator, the output of the latter is connected to the recorder, and the control unit is connected to the first and second receiving and measuring units, a transmitting unit, a calculator and a registrar, characterized in that it is equipped with a unit for determining a delay time of arrival of common-mode signals reflected from the flat bottom surface in each calculation direction, the input of which is connected to the output of the control unit, and the output connected to input calculator. AND & / I if1 Skyline Lm Profile relief bottom