Water sound velocity estimation device and method based on delay inequality of double transponders

Abstract

The invention discloses a water sound velocity estimation device and method based on delay inequality of double transponders. The device comprises an underwater sound receiving and transmitting transducer module and a double-transponder module, wherein the underwater sound receiving and transmitting transducer module comprises an underwater sound receiving and transmitting transducer and a calculation and control module; the double-transponder module comprises a rigid rod which is vertically arranged, a first transponder and a second transponder which are fixed at two ends of the rigid rod in a rigid connection manner and have no intersection in top view, and a depth meter which is mounted in the middle of the rigid rod; under the control of the calculation and control module, the underwater sound receiving and transmitting transducer transmits underwater sound signals, the first transponder and the second transponder transmit response signals after receiving the underwater sound signals, the underwater sound receiving and transmitting transducer receives the two response signals, and the calculation and control module calculates the underwater sound time delay difference according to the two underwater sound time delay differences and the distance between the two transponders. And obtaining a water sound velocity estimation value. The method is simple and rapid in calculation, and can effectively improve the water sound velocity measurement precision.

Description

Technical Field

[0001] The present invention relates to the technical field of underwater acoustic measurement, and in particular to an underwater acoustic velocity estimation device and method based on dual transponder time delay difference, which is particularly suitable for measuring the acoustic velocity of water bodies in a complex acoustic velocity environment. Background Art

[0002] The speed of sound in water is affected by many factors and is not a constant in complex environments. The importance of accurately measuring it for underwater detection activities is self-evident. How to more accurately estimate the speed of sound in water is an urgent problem to be solved. The existing technology generally calculates the speed of sound by measuring the time it takes for a sound wave pulse to propagate between two points of known distance. The propagation time calculated by this method contains multiple error sources. The error compensation in the existing technology is not universal, and the speed measurement results are greatly affected by environmental factors. A technical solution is urgently needed to solve the problem of poor accuracy of the speed of sound in water caused by large delay errors and failure to eliminate error sources. Summary of the invention

[0003] Purpose of the invention: In view of the problems in the prior art of large time delay error caused by multipath interference of water sound velocity and poor water sound velocity accuracy caused by failure to eliminate error sources, the present invention proposes a water sound velocity estimation device and method based on dual transponder time delay difference, which is particularly suitable for accurate measurement of water sound velocity in shallow waters with complex sound fields such as rivers, lakes and seas.

[0004] Technical solution: A device for estimating underwater acoustic velocity based on dual transponder time delay difference, comprising: an underwater acoustic transceiver module and a dual transponder module, wherein the underwater acoustic transceiver module comprises an underwater acoustic transceiver and a calculation and control module; the dual transponder module comprises a vertically arranged rigid rod, a first transponder and a second transponder fixed at both ends of the rigid rod by a rigid connection and having no intersection in a top view, and a depth meter installed in the middle of the rigid rod;

[0005] Under the control of the calculation and control module, the underwater acoustic transceiver transducer sends an underwater acoustic signal, and the first transponder and the second transponder send a response signal after receiving the underwater acoustic signal. The underwater acoustic transceiver transducer receives the two response signals, and the calculation and control module calculates the delay difference based on the underwater acoustic delay model of the two response signals. The underwater acoustic delay is the time from the underwater acoustic transceiver transducer sending the underwater acoustic signal to the underwater acoustic transceiver transducer receiving the response signal of the corresponding transponder. The estimated value of the water sound speed near the position of the dual transponders is obtained according to the delay difference and the distance between the two transponders, and the depth of this position is determined by measuring with a depth meter.

[0006] Furthermore, a weight is provided at the lower end of the rigid rod so that the rigid rod is vertically downward and the connection line of the dual transponders is perpendicular to the horizontal plane.

[0007] Furthermore, the underwater acoustic delay model of the first responder is as follows:

[0008]

[0009] In the formula, t 1i It is the time from when the hydroacoustic transceiver starts sending out the hydroacoustic signal to when it receives the response signal from the first transponder; The round-trip travel time of the hydroacoustic signal between the hydroacoustic transceiver and the first transponder; is the time delay error of the underwater acoustic signal sent by the underwater acoustic transceiver transducer, and this error is approximately considered to be a constant error; It is the time delay error from the time when the first transponder receives the water acoustic signal sent by the water acoustic transceiver to the time when it starts to send the response signal. When the water acoustic signal remains unchanged, this error is approximately considered to be a constant error; ξ 1i is the first random error term;

[0010] The underwater acoustic delay model of the second transponder is as follows:

[0011]

[0012] In the formula, t 2i It is the time from when the hydroacoustic transceiver starts to send out the hydroacoustic signal to when it receives the response signal from the second transponder; The time it takes for the hydroacoustic signal to travel back and forth between the hydroacoustic transceiver and the second transponder; is the time delay error of the underwater acoustic signal sent by the underwater acoustic transceiver transducer, and this error is approximately considered to be a constant error; It is the time delay error from the time when the second transponder receives the water acoustic signal sent by the water acoustic transceiver to the time when it starts to send the response signal. When the water acoustic signal remains unchanged, this error is approximately considered to be a constant error; ξ 2i is the second random error term;

[0013] The delay difference is:

[0014]

[0015] get where Δξ i =ξ 2i -ξ 1i .

[0016] Furthermore, when the correlation peak is ambiguous when solving the delay difference, it is constrained by the distance between the two transponders, specifically, the ΔT with the smallest Δ among the following values ​​is selected: i :

[0017]

[0018] Where S is the distance between the two transponders, V 理论值is the theoretical value of the underwater acoustic velocity, which is determined by the classical sound speed standard distribution model.

[0019] Furthermore, in order to reduce Δξ i The influence of wild values ​​on delay measurement. Under the control of the calculation and control module, the underwater acoustic transceiver transducer sends underwater acoustic signals multiple times and measures the n-time delay difference ΔT i ,when When the ΔT obtained this time is i Discard, ΔV 阈 is the preset water sound velocity threshold;

[0020] After removing x outliers, the average of the remaining nx delay differences is used as the final delay difference:

[0021]

[0022] Furthermore, the estimated value of water sound speed near the dual transponder position is obtained by the following formula:

[0023] Furthermore, The calculation formula is as follows:

[0024]

[0025] The time taken for the hydroacoustic transceiver to send a hydroacoustic signal to the first transponder to the time when the first transponder receives the hydroacoustic signal; It is the time from when the first transponder receives the underwater acoustic signal sent by the underwater acoustic transceiver transducer and sends back a response signal to when the underwater acoustic transceiver transducer receives the response signal;

[0026] The calculation formula is as follows:

[0027]

[0028] The time taken for the hydroacoustic transceiver to send a hydroacoustic signal to the second transponder to the time when the second transponder receives the hydroacoustic signal; It is the time from the second transponder sending back a response signal after receiving the hydroacoustic signal sent by the hydroacoustic transceiver transducer to the hydroacoustic transceiver transducer receiving the response signal.

[0029] A method for estimating water sound speed based on dual transponder time delay difference comprises the following steps:

[0030] Under the control of the calculation and control module, the underwater acoustic transceiver transducer sends an underwater acoustic signal;

[0031] After receiving the hydroacoustic signal, the first transponder and the second transponder respectively send out a response signal, the first transponder and the second transponder are fixed at two ends of a rigid rod in a rigid connection manner and have no intersection in a top view, and the rigid rod is vertically arranged;

[0032] The hydroacoustic transceiver receives two reply signals;

[0033] The calculation and control module calculates the delay difference based on the water acoustic delay model of the two response signals. The water acoustic delay is the time taken from the water acoustic transceiver transducer sending the water acoustic signal to the water acoustic transceiver transducer receiving the response signal of the corresponding transponder. The water acoustic velocity estimation value near the position of the dual transponder is obtained according to the delay difference and the distance between the two transponders. The depth of the position is measured and determined by the depth gauge installed in the middle of the rigid rod. The water acoustic delay is the time taken from the water acoustic transceiver transducer sending the water acoustic signal to the water acoustic transceiver transducer receiving the response signal of the corresponding transponder. The calculation and control module obtains the water acoustic velocity estimation value near the position of the dual transponder according to the two water acoustic delay differences and the distance between the two transponders. The depth of the position is measured and determined by the depth gauge installed in the middle of the rigid rod.

[0034] The present invention also provides a computing and control module, comprising a processor, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the processor, and when the programs are executed by the processor, the following steps are performed:

[0035] Sending a control instruction to the underwater acoustic transceiver to control it to send an underwater acoustic signal; after the underwater acoustic signal is received by the first transponder and the second transponder, the first transponder and the second transponder respectively send a response signal, the first transponder and the second transponder are fixed to the two ends of the rigid rod in a rigid connection manner and have no intersection in a top view, and the rigid rod is vertically arranged; the two response signals are received by the underwater acoustic transceiver in sequence;

[0036] According to the hydroacoustic time delay model of the two response signals, the time delay difference is calculated. The hydroacoustic time delay is the time from the hydroacoustic transceiver transducer sending the hydroacoustic signal to the hydroacoustic transceiver receiving the response signal of the corresponding transponder. According to the time delay difference and the distance between the two transponders, the estimated value of the hydroacoustic speed near the position of the dual transponders is obtained. The depth of this position is determined by measuring with a depth gauge installed in the middle of the rigid rod.

[0037] The present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the following steps are implemented:

[0038] Sending a control instruction to the underwater acoustic transceiver to control it to send an underwater acoustic signal; after the underwater acoustic signal is received by the first transponder and the second transponder, the first transponder and the second transponder respectively send a response signal, the first transponder and the second transponder are fixed to the two ends of the rigid rod in a rigid connection manner and have no intersection in a top view, and the rigid rod is vertically arranged; the two response signals are received by the underwater acoustic transceiver in sequence;

[0039] According to the hydroacoustic time delay model of the two response signals, the time delay difference is calculated. The hydroacoustic time delay is the time from the hydroacoustic transceiver transducer sending the hydroacoustic signal to the hydroacoustic transceiver receiving the response signal of the corresponding transponder. According to the time delay difference and the distance between the two transponders, the estimated value of the hydroacoustic speed near the position of the dual transponders is obtained. The depth of this position is determined by measuring with a depth gauge installed in the middle of the rigid rod.

[0040] Beneficial effects: The present invention uses a dual transponder fixed connection to receive signals from a transceiver transducer, and immediately sends back a response signal after receiving the hydroacoustic signal from the transducer. Since the two transponders are at different distances from the transceiver transducer, the time at which they receive the hydroacoustic signal is also different, and the time at which the transducer receives the response signal is also different. The present invention uses the time difference of each received signal to estimate the hydroacoustic speed time, approximates some device-related error terms to constants, and cancels them out during the calculation process. The entire calculation method is simple and efficient. The present invention can effectively reduce the influence of important error sources such as sending timing error, transponder response delay, and receiving timing error, and effectively improve the level of hydroacoustic speed measurement. The present invention is suitable for hydroacoustic speed measurement in stationary lakes, and is particularly suitable for hydroacoustic speed measurement in shallow water areas with complex sound field environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a schematic diagram of a water sound velocity measurement device based on double transponder time delay difference of the present invention;

[0042] Figure 2 It is a side view of the dual transponder module of the present invention;

[0043] Figure 3 It is a top view of the dual transponder module in the present invention. DETAILED DESCRIPTION

[0044] The technical solution of the present invention is further described below in conjunction with the accompanying drawings.

[0045] Reference Figure 1 to Figure 3The present invention provides an underwater acoustic velocity estimation device based on dual transponder time delay difference, comprising: an underwater acoustic transceiver module 1 and a dual transponder module 2. The underwater acoustic transceiver module 1 comprises an underwater acoustic transceiver 101 and a calculation and control module 102. The underwater acoustic transceiver 101 is used to send underwater acoustic signals and receive response signals, and the calculation and control module 102 is responsible for all calculation and control operations in this scheme. The dual transponder module 2 comprises two transponders, a first transponder 201 and a second transponder 202. The two transponders are fixed on the same rigid rod 203 by a rigid connection. The distance between the dual transponders depends on the working environment. The dual transponders are fixed at both ends of the rigid rod 203, about 1m to 2m apart, and in order to ensure unobstructed propagation of sound lines, the two are installed in a staggered manner, that is, there is no intersection in the top view during installation, such as Figure 3 As shown, there is an angle α between the support arms of the first transponder 201 and the second transponder 202 in the top view. The rigid rod 203 is arranged vertically, and a weight can be arranged at its lower end. The weight 3 is connected by a cable so that the rigid rod 203 can be vertically downward, and the connection line of the dual transponders is perpendicular to the horizontal plane. A depth meter 204 is installed on the rigid rod 203 to measure the depth of the location of the dual transponder module. The depth value is transmitted to the calculation and control module 102 via a cable. In order to measure the water sound velocity value at a certain depth, the cable can be retracted and released to lift the dual transponder module 2 to a suitable depth, and the depth meter 204 transmits the depth value to the surface receiving device (calculation and control module 102) via a cable.

[0046] Under the control of the calculation and control module 102, the underwater acoustic transceiver 101 sends an underwater acoustic signal. The first transponder 201 and the second transponder 202 are at different distances from the underwater acoustic transceiver 101, and will receive the underwater acoustic signal successively. After receiving the underwater acoustic signal, the transponder will immediately send a response signal, and the underwater acoustic transceiver 101 will receive two response signals, and the receiving time of the two response signals is also different. Based on this, the calculation and control module 102 calculates the delay difference according to the underwater acoustic delay model of the two response signals. The underwater acoustic delay is the time from the underwater acoustic transceiver 101 sending the underwater acoustic signal to the underwater acoustic transceiver 101 receiving the response signal of the corresponding transponder. The calculation and control module 102 obtains the estimated value of the water sound speed near the position of the dual transponders by dividing the distance by the delay difference according to the two underwater acoustic delay differences and the distance between the two transponders.

[0047] The underwater acoustic delay model of the first responder 201 is as follows:

[0048]

[0049] In the formula, t 1iThe time taken for the underwater acoustic transceiver 101 to send out an underwater acoustic signal and receive a response signal from the first responder 201;

[0050] is the round-trip travel time of the underwater acoustic signal between the underwater acoustic transceiver 101 and the first transponder 201, and is calculated as follows:

[0051]

[0052] It is the time taken from the underwater acoustic transceiver 101 sending the underwater acoustic signal to the first transponder 201 to the first transponder 201 receiving the underwater acoustic signal, also called the actual sending time of the underwater acoustic signal, which is obtained through actual measurement; The time taken for the first transponder 201 to send back a response signal after receiving the underwater acoustic signal sent by the underwater acoustic transceiver 101, and for the underwater acoustic transceiver 101 to receive the response signal, is obtained through actual measurement;

[0053] is the time delay error of the underwater acoustic signal sent by the underwater acoustic transceiver 101, which includes level conversion delay failure error, timing error, random error, etc. When the underwater acoustic transceiver remains unchanged, this error is approximately considered to be a constant error;

[0054] It is the time delay error from the time when the first transponder 201 receives the water acoustic signal sent by the water acoustic transceiver 101 to the time when it starts to send the response signal. This error includes the level conversion delay failure error, timing error, the time interval from receiving the water acoustic signal to sending the response signal, other unknown error terms and random errors, etc. When the water acoustic signal remains unchanged and the transponders are of the same model, this error is approximately considered to be a constant error;

[0055] ξ 1i is the random error term of the first responder underwater acoustic delay model, here called the first random error.

[0056] The water acoustic delay model of the second transponder 202 is as follows:

[0057]

[0058] In the formula, t 2i The time taken for the underwater acoustic transceiver 101 to send out an underwater acoustic signal and receive a response signal from the second transponder 202;

[0059] is the round-trip travel time of the water acoustic signal between the water acoustic transceiver transducer 101 and the second transponder 202; The calculation formula is as follows:

[0060]

[0061] The time taken for the underwater acoustic transceiver 101 to send an underwater acoustic signal to the second transponder 202 and for the second transponder 202 to receive the underwater acoustic signal; The time taken for the second transponder 202 to send back a response signal after receiving the underwater acoustic signal sent by the underwater acoustic transceiver 101, and for the underwater acoustic transceiver 101 to receive the response signal;

[0062] is the time delay error of the underwater acoustic signal sent by the underwater acoustic transceiver 101, which includes level conversion delay failure error, timing error, random error, etc. When the underwater acoustic transceiver remains unchanged, this error is approximately considered to be a constant error.

[0063] It is the time delay error from the time when the second transponder 202 receives the water acoustic signal sent by the water acoustic transceiver 101 to the time when it starts to send the response signal. This error includes the level conversion delay failure error, timing error, the time interval from receiving the water acoustic signal to sending the response signal, other unknown error terms and random errors, etc. When the water acoustic signal remains unchanged and the transponders are of the same model, this error is approximately considered to be a constant error. Here

[0064] ξ 2i is the random error term of the hydroacoustic delay model of the second transponder, here called the second random error.

[0065] Then, the delay difference between the two response signals is:

[0066]

[0067] The underwater acoustic transceiver 101 remains unchanged, the first transponder 201 and the second transponder 202 are of the same model, and the constant error term is offset, and the result is where Δξ i =ξ 2i -→ 1i .

[0068] If the correlation peak ambiguity problem occurs when solving the delay difference, since the distance between the two transponders is known, this condition is used as a constraint to solve the correlation peak ambiguity problem (as a result, multiple delay difference values ​​will appear). The specific method of solving the correlation peak ambiguity is to compare multiple delay difference values ​​with the theoretical value to select the smallest ΔT among the following Δ values i :

[0069]

[0070] Where S is the distance between the acoustic centers of the two transponders, obtained by the prior art calibration method, and V 理论值 is the theoretical value of underwater sound velocity, which is determined by the classical sound velocity standard distribution model (such as the Munk sound velocity standard distribution model).

[0071] The delay difference obtained through the above processing may still have abnormal wild values ​​Δξ i Pollution, in order to reduce Δ→ i The influence of wild values ​​on delay measurement. Under the control of the calculation and control module 102, the underwater acoustic transceiver 101 sends the underwater acoustic signal multiple times, and obtains n delay differences ΔT after correlation peak fuzzification. i , and according to the preset hydroacoustic velocity threshold ΔV 阈 (Can be set based on experience) Determine whether the following conditions are met:

[0072]

[0073] If satisfied, then the ΔT obtained this time is i Discard and remove abnormal ΔT i value.

[0074] After removing x outliers, the final delay difference is estimated by the remaining nx delay differences. At this time, the influence of random errors is considered. The random errors fluctuate around the true value. Therefore, the final delay difference estimate can be determined by its mean:

[0075]

[0076] Finally, the estimated value of water sound speed near the dual transponder position is obtained by the following formula:

[0077]

[0078] Based on the water sound velocity estimation device, the present invention provides a water sound velocity estimation method based on dual transponder delay difference, comprising the following steps:

[0079] Step (1), obtaining the acoustic center distance S of the two transponders by a prior art calibration method, and in order to measure the water sound velocity value at a specified depth, retracting and releasing the cable to a suitable depth, and transmitting the depth value to the calculation and control module 102 through a cable by the depth gauge 204 on the dual transponder module 2;

[0080] Step (2), the underwater acoustic transceiver 101 is installed near the cable described in the previous step, and after receiving the sound measurement start instruction issued by the calculation and control module 102, the underwater acoustic transceiver 101 sends an underwater acoustic signal;

[0081] Step (3), after receiving the underwater acoustic signal, the first transponder 201 and the second transponder 202 send out response signals respectively, and the underwater acoustic transceiver 101 receives the two response signals. The calculation and control module 102 calculates the delay difference ΔT according to the underwater acoustic delay model of the two response signals received by the underwater acoustic transceiver 101. i ; Due to the direct calculation of the delay difference, the constant error of the device receiving and sending signals is eliminated;

[0082] Step (4), the calculation and control module 102 uses the distance between the two transponders as a constraint to solve the correlation peak ambiguity problem, controls the underwater acoustic transceiver 101 to send the underwater acoustic signal multiple times to obtain multiple delay differences after the correlation peak ambiguity, removes the random error term related wild values, and obtains the final delay difference by the average value of the remaining delay differences. Combined with the distance between the two transponders, the estimated value of the water sound speed near the position of the two transponders is obtained by dividing the distance by the delay difference.

[0083] Compared with the traditional sound velocity measurement method, the method of the present invention makes up for the defect that a single transponder can only measure the total time of transmission and reception and cannot separate the error source, thereby improving the measurement accuracy. The overall structure of the device is simple and easy to operate. At the same time, compared with the traditional single transponder form, the anti-interference ability is stronger.

[0084] The present invention also provides a computing and control module, comprising a processor, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the processor, and when the programs are executed by the processor, the following steps are performed:

[0085] A control instruction is issued to the underwater acoustic transceiver 101 to control it to send an underwater acoustic signal; after the underwater acoustic signal is received by the first transponder 201 and the second transponder 202, the first transponder 201 and the second transponder 202 respectively send a response signal, the first transponder 201 and the second transponder 202 are fixed at both ends of a rigid rod 203 by a rigid connection and have no intersection in a top view, and the rigid rod 203 is vertically arranged; the two response signals are received by the underwater acoustic transceiver 101 in sequence;

[0086] According to the hydroacoustic time delay model of the two response signals, the delay difference is calculated. The hydroacoustic time delay is the time taken from the hydroacoustic transceiver 101 sending out the hydroacoustic signal to the hydroacoustic transceiver 101 receiving the response signal of the corresponding transponder. According to the delay difference and the distance between the two transponders, the estimated value of the hydroacoustic speed near the position of the dual transponders is obtained. The depth of this position is measured and determined by the depth gauge 204 installed in the middle of the rigid rod 203.

[0087] If the correlation peak is blurred when solving the delay difference, the distance between the two transponders is used as a constraint to solve the correlation peak ambiguity problem, and multiple delay differences are obtained by controlling the underwater acoustic transceiver transducer 101 to send the underwater acoustic signal multiple times through the correlation peak blur. After the random error term related wild values ​​are eliminated, the final delay difference is obtained by the average value of the remaining delay differences. The specific calculation method can refer to the above description of the underwater acoustic speed estimation device and the underwater acoustic speed estimation method, which will not be repeated here.

[0088] The present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the following steps are implemented:

[0089] A control instruction is issued to the underwater acoustic transceiver 101 to control it to send an underwater acoustic signal; after the underwater acoustic signal is received by the first transponder 201 and the second transponder 202, the first transponder 201 and the second transponder 202 respectively send a response signal, the first transponder 201 and the second transponder 202 are fixed at both ends of a rigid rod 203 by a rigid connection and have no intersection in a top view, and the rigid rod 203 is vertically arranged; the two response signals are received by the underwater acoustic transceiver 101 in sequence;

[0090] According to the hydroacoustic time delay model of the two response signals, the delay difference is calculated. The hydroacoustic time delay is the time taken from the hydroacoustic transceiver 101 sending out the hydroacoustic signal to the hydroacoustic transceiver 101 receiving the response signal of the corresponding transponder. According to the delay difference and the distance between the two transponders, the estimated value of the hydroacoustic speed near the position of the dual transponders is obtained. The depth of this position is measured and determined by the depth gauge 204 installed in the middle of the rigid rod 203.

[0091] If the correlation peak is blurred when solving the delay difference, the distance between the two transponders is used as a constraint to solve the correlation peak ambiguity problem, and multiple delay differences are obtained by controlling the underwater acoustic transceiver transducer 101 to send the underwater acoustic signal multiple times through the correlation peak blur. After the random error term related wild values ​​are eliminated, the final delay difference is obtained by the average value of the remaining delay differences. The specific calculation method can refer to the above description of the underwater acoustic speed estimation device and the underwater acoustic speed estimation method, which will not be repeated here.

Claims

1. A device for estimating water sound velocity based on dual transponder time delay difference, characterized in that: include: An underwater acoustic transceiver module (1) and a dual transponder module (2), wherein the underwater acoustic transceiver module (1) comprises an underwater acoustic transceiver transducer (101) and a calculation and control module (102); the dual transponder module (2) comprises a vertically arranged rigid rod (203), a first transponder (201) and a second transponder (202) fixed to both ends of the rigid rod (203) in a rigid connection manner and having no intersection in a top view, and a depth gauge (204) installed in the middle of the rigid rod (203); Under the control of the calculation and control module (102), the underwater acoustic transceiver (101) sends an underwater acoustic signal, and the first transponder (201) and the second transponder (202) send a response signal after receiving the underwater acoustic signal. The underwater acoustic transceiver (101) receives the two response signals, and the calculation and control module (102) calculates the delay difference based on the underwater acoustic delay model of the two response signals. The underwater acoustic delay is the time from the underwater acoustic transceiver (101) sending the underwater acoustic signal to the underwater acoustic transceiver (101) receiving the response signal of the corresponding transponder. The estimated value of the water sound speed near the position of the dual transponders is obtained based on the delay difference and the distance between the two transponders, and the depth of the position is determined by measuring the depth meter (204).

2. The device for estimating water sound velocity based on dual transponder time delay difference according to claim 1, characterized in that: The lower end of the rigid rod (203) is equipped with a weight so that the rigid rod (203) is vertically downward and the connection line of the dual transponders is perpendicular to the horizontal plane.

3. The device for estimating water sound velocity based on dual transponder time delay difference according to claim 1, characterized in that: The water acoustic delay model of the first responder (201) is as follows: Where, t 1i The time taken for the underwater acoustic transceiver (101) to send out an underwater acoustic signal and for the time taken for the underwater acoustic transceiver (101) to receive a response signal from the first responder (201); T 1i is the round-trip travel time of the underwater acoustic signal between the underwater acoustic transceiver transducer (101) and the first transponder (201); is the time delay error of the underwater acoustic signal emitted by the underwater acoustic transceiver (101), and this error is approximately considered to be a constant error; is the time delay error from the time when the first transponder (201) receives the water acoustic signal sent by the water acoustic transceiver (101) to the time when it starts to send the response signal. When the water acoustic signal remains unchanged, this error is approximately considered to be a constant error; ξ 1i is the first random error term; The water acoustic delay model of the second transponder (202) is as follows: Where, t 2i The time taken for the underwater acoustic transceiver (101) to send out an underwater acoustic signal and for the time taken for the underwater acoustic transceiver (101) to receive a response signal from the second responder (202); T 2i is the round-trip travel time of the underwater acoustic signal between the underwater acoustic transceiver transducer (101) and the second transponder (202); is the time delay error of the underwater acoustic signal emitted by the underwater acoustic transceiver (101), and this error is approximately considered to be a constant error; is the time delay error from the time when the second transponder (202) receives the water acoustic signal sent by the water acoustic transceiver (101) to the time when it starts to send the response signal. When the water acoustic signal remains unchanged, this error is approximately considered to be a constant error; ξ 2i is the second random error term; The delay difference is: get where Δξ i =ξ 2i -ξ 1i .

4. The device for estimating water sound velocity based on dual transponder time delay difference according to claim 3 is characterized in that: When the correlation peak is ambiguous when solving the delay difference, it is constrained by the distance between the two transponders. Specifically, the smallest ΔT is selected from the following Δ values: i : Where S is the distance between the two transponders, V 理论值 is the theoretical value of the underwater acoustic velocity, which is determined by the classical sound speed standard distribution model.

5. The device for estimating water sound velocity based on dual transponder time delay difference according to claim 3 is characterized in that: In order to reduce Δξ i In order to determine the influence of wild values ​​on the time delay measurement, under the control of the calculation and control module (102), the underwater acoustic transceiver (101) sends the underwater acoustic signal multiple times, and measures the n-time delay difference ΔT i ,when When the ΔT obtained this time is i Discard, ΔV 阈 is the preset water sound velocity threshold; After removing x outliers, the average of the remaining nx delay differences is used as the final delay difference:

6. The device for estimating water sound velocity based on dual transponder time delay difference according to claim 5, characterized in that: The estimated value of water sound speed near the dual transponder location is obtained by the following formula:

7. The device for estimating water sound velocity based on dual transponder time delay difference according to claim 3 is characterized in that: The calculation formula is as follows: The time taken for the underwater acoustic transceiver (101) to send an underwater acoustic signal to the first transponder (201) to the first transponder (201) to receive the underwater acoustic signal; The time taken for the first transponder (201) to send back a response signal after receiving the underwater acoustic signal sent by the underwater acoustic transceiver (101) to the underwater acoustic transceiver (101) receiving the response signal; The calculation formula is as follows: The time taken for the underwater acoustic transceiver (101) to send an underwater acoustic signal to the second transponder (202) to the second transponder (202) to receive the underwater acoustic signal; It is the time from when the second transponder (202) receives the acoustic signal sent by the acoustic transceiver (101) and then sends back a response signal to when the acoustic transceiver (101) receives the response signal.

8. A method for estimating water sound velocity based on dual transponder time delay difference, characterized in that: The following steps are involved: Under the control of the calculation and control module (102), the underwater acoustic transceiver (101) sends an underwater acoustic signal; After receiving the underwater acoustic signal, the first transponder (201) and the second transponder (202) respectively send out a response signal, the first transponder (201) and the second transponder (202) are fixed to two ends of a rigid rod (203) in a rigid connection manner and have no intersection in a top view, and the rigid rod (203) is arranged vertically; The underwater acoustic transceiver (101) receives two response signals; The calculation and control module (102) calculates the delay difference based on the acoustic delay model of the two response signals, wherein the acoustic delay is the time taken from the acoustic transceiver (101) sending the acoustic signal to the acoustic transceiver (101) receiving the response signal of the corresponding responder, and obtains the estimated value of the acoustic velocity near the position of the dual responders based on the delay difference and the distance between the two responders. The depth of the position is determined by measuring with a depth gauge (204) installed in the middle of the rigid rod (203).

9. A calculation and control module, characterized in that: The invention comprises a processor, a memory and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the processor, and when the programs are executed by the processor, the following steps are performed: A control instruction is sent to the underwater acoustic transceiver (101) to control it to send an underwater acoustic signal; after the underwater acoustic signal is received by the first transponder (201) and the second transponder (202), the first transponder (201) and the second transponder (202) respectively send a response signal, the first transponder (201) and the second transponder (202) are fixed to the two ends of a rigid rod (203) in a rigid connection manner and have no intersection in a top view, and the rigid rod (203) is arranged vertically; the two response signals are received by the underwater acoustic transceiver (101) in sequence; The delay difference is calculated based on the water acoustic delay model of the two response signals. The water acoustic delay is the time taken from the water acoustic transceiver (101) sending out the water acoustic signal to the water acoustic transceiver (101) receiving the response signal of the corresponding transponder. The estimated value of the water acoustic speed near the position of the dual transponders is obtained based on the delay difference and the distance between the two transponders. The depth of the position is determined by measuring with a depth gauge (204) installed in the middle of the rigid rod (203).

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the following steps are implemented: A control instruction is sent to the underwater acoustic transceiver (101) to control it to send an underwater acoustic signal; after the underwater acoustic signal is received by the first transponder (201) and the second transponder (202), the first transponder (201) and the second transponder (202) respectively send a response signal, the first transponder (201) and the second transponder (202) are fixed to the two ends of a rigid rod (203) in a rigid connection manner and have no intersection in a top view, and the rigid rod (203) is arranged vertically; the two response signals are received by the underwater acoustic transceiver (101) in sequence; The delay difference is calculated based on the water acoustic delay model of the two response signals. The water acoustic delay is the time taken from the water acoustic transceiver (101) sending out the water acoustic signal to the water acoustic transceiver (101) receiving the response signal of the corresponding transponder. The estimated value of the water acoustic speed near the position of the dual transponders is obtained based on the delay difference and the distance between the two transponders. The depth of the position is determined by measuring with a depth gauge (204) installed in the middle of the rigid rod (203).

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