CN101566691B - Method and system for tracking and positioning underwater target - Google Patents

Abstract

The present invention is an underwater target tracking and positioning method, comprising the steps of: a central processing unit sends an opening instruction and the required positioning data rate information to a blue-green laser emitting and receiving integrated rotatable device; scans an underwater transponder, and sends The laser signal of the rate information; the underwater transponder reflects the laser signal according to the original path, and the transducer is turned on; after receiving the reflected laser signal, it sends a synchronous timing signal to the central processing unit, and the central processing unit starts timing; the underwater transponder according to the data The rate information transmits a periodic frequency-hopping pulse signal of the corresponding data rate to the hydrophone; the hydrophone sends the direct signal to the central processor; the central processor calculates the distance information, performs coordinate correction, and calculates the coordinates of the underwater transponder. The invention also relates to an underwater target tracking and positioning system. The invention adopts blue-green laser synchronous time synchronization and underwater acoustic frequency hopping mechanism to respectively solve the problems of synchronization error and multipath interference existing in the existing short-baseline underwater acoustic positioning system.

Description

A method and system for underwater target tracking and positioning

technical field

The present invention relates to the communication field, and more specifically, relates to an underwater target tracking and positioning method and system.

Background technique

The underwater acoustic positioning system mainly refers to the tracking and positioning of objects in local areas or the navigation system of ships. According to the distance between primitives (receivers or interrogators), hydroacoustic positioning systems can be divided into long baseline systems, short baseline systems and ultra-short baseline systems.

The Chinese invention patent application with the publication number CN101246215A and the publication date of August 20, 2008 is based on a long baseline positioning system, which consists of a differential GPS reference station, an underwater transceiver, a GPS buoy, and a ship-based control center. The time difference between the signal of the transceiver and each GPS buoy (at least 4) is used to calculate the distance to each point, thereby obtaining the specific position of the underwater target. The disadvantage of this technology is that due to the large distance between the primitives (generally required to be hundreds to thousands of meters), the update rate of the position data is low, reaching the level of minutes; the deployment, calibration and recovery of the primitives take a long time, and These operations are more complicated. It is generally suitable for positioning and navigation in fixed underwater areas, such as underwater construction, submarine cable laying, etc. For non-fixed areas, such as frogman underwater positioning, this technology is generally not applicable due to the difficulty in the layout of primitives and the low update rate of position data.

The synchronous time synchronization of the traditional short-baseline synchronous positioning system is completed by underwater acoustic inquiry and response. The basic unit of short baseline is generally installed on the mother ship or on a portable pedestal. The basic unit sends an inquiry signal to the underwater transponder, and the underwater transponder sends back a response signal at another frequency after receiving the interrogation signal. The transponder starts timing after receiving the interrogation signal, and the clock of the water primitive subtracts one-half of the "inquiry-response" time from the moment when the interrogation signal arrives. The mother ship primitive detects the response signal of the underwater transponder, calculates the distance from the underwater transponder to each primitive, and thus obtains the coordinates of the underwater transponder relative to the mother ship. Because the distance between primitives is relatively short, the method of synchronous beacon is generally adopted; and since the synchronous clock for sending and receiving is determined by the transmission between underwater acoustic signals, the transmission speed of underwater acoustic signals is slow. There may be relative movement between the devices, so there is a certain error in the selection of the synchronization time, that is, the synchronization error. Synchronization error is an important factor affecting the accuracy of the positioning system.

The transponder in the hydroacoustic positioning system periodically sends pulses to each primitive, and one problem that must be solved is the range ambiguity problem. In a synchronous beacon system, the beacon emits acoustic pulses at a period T with an unambiguous distance cT. When the distance between the beacon and the receiver is R≤cT, the target distance can be calculated. But when R>cT, the transmitted signal of the first frame falls into the second frame after being propagated, causing the observer to not know the true propagation time. As a result, the distance may be miscalculated, which is distance ambiguity. Increasing the signal transmission period of the beacon can expand the unambiguous distance. For example, if the signal transmission period T of the beacon is increased by n times, the unambiguous distance will also be increased by n times accordingly. But this will reduce the data rate, and this method is obviously not suitable for high-speed moving targets.

In the deep sea environment, the effect of multipath is not obvious, so there is no need to consider too much when tracking and positioning. In shallow seas, the multi-channel feature of underwater sound is most obvious. For example, in a uniform shallow sea with a depth of 100m, the transmitter and receiver are placed at a depth of 50m with a distance of 10km. The amplitude of the reflected sound is -0.98, and the delay is 1.379ms. The amplitude of the second reflected sound is 0.92, and the delay is 5.517ms. The amplitude of the third reflected sound is -0.893, the time delay is 12.44ms..., at least 9 paths are important, and the total time delay is 67.59ms. It can be seen that in shallow seas, since the amplitude of the reflected sound pulse is not much different from the amplitude of the direct sound, it is more difficult to distinguish directly from the amplitude. The current commonly used method is the time window method - to estimate the arrival time of the direct signal. During this time period, the receiver is turned on to receive the signal, and in the time period, the receiver is turned off to avoid other signals. This method is effective for positioning systems with slow movement speed and low data rate. For high-speed moving objects, the positioning data rate is high, the direct signal will overlap with the reflected signal of the previous signal, and there may be more than one signal received within the time window. If the time window is too small, effective direct signal cannot be guaranteed to be received.

In previous positioning systems, transponders often sent a single hydroacoustic frequency signal. Neither the ambiguous distance problem nor the multipath transmission problem can be overcome. Especially in the case of serious shallow sea reflection and many noise sources, it is easy to cause positioning errors. For high-speed moving objects, the transmission path changes rapidly, and a high data rate must be adopted to describe the motion trajectory. The high data rate shortens the unambiguous distance, and when the moving object exceeds the range of the unambiguous distance, multiple solutions will appear in the tracking and positioning of the system. For this reason, in order to locate and track high-speed moving objects in shallow seas, effective anti-multipath methods must be adopted.

For high-speed moving objects, in order to describe their trajectory more comprehensively, it is necessary to adopt the method of synchronous beacons, and at the same time increase the update rate of positioning data sent by synchronous beacons. When the data update rate increases, when the distance of the transceiver device is greater than the distance transmitted by a periodic pulse, the previous pulse signal will fall into the next clock cycle for detection, resulting in multiple values in the measurement distance. Therefore, there is a contradiction between avoiding multiple values in the measurement distance and improving the update rate of positioning data.

Compared with the deep sea area, the underwater acoustic signal transmission in the shallow sea area has serious multipath problems. The power difference between the direct signal and the reflected signal is not large, and it is difficult to distinguish from the power. It can be seen that it is difficult for the traditional positioning system to send a single pulse to solve the multipath problem in the shallow sea area.

Contents of the invention

Aiming at the defects and deficiencies in the existing short-baseline underwater acoustic positioning system, the primary purpose of the present invention is to provide an underwater target tracking and positioning method, which solves the existing problems by adopting blue-green laser synchronous time synchronization and underwater acoustic frequency hopping mechanism respectively. There are synchronization errors and multipath interference problems that exist in short-baseline hydroacoustic positioning systems.

Another object of the present invention is to provide an underwater target tracking and positioning system.

The present invention adopts the following technical solutions to achieve the above-mentioned primary purpose: a method for tracking and locating an underwater target, comprising the following steps: Step 1, the central processing unit sends an opening command and the required positioning to the blue-green laser emitting and receiving integrated rotatable device Data rate information; step 2, the blue-green laser emitting and receiving integrated rotatable device scans the underwater transponder, and sends a laser signal containing data rate information to the transponder; step 3, the underwater transponder sends the blue-green laser The integrated rotatable device for emission and reception reflects the laser signal, and the transducer is turned on; step 4, after receiving the reflected laser signal, the rotatable device for green laser emission and reception sends a synchronous timing signal to the central processor, and the central processor starts the synchronous clock , start timing; step 5, the underwater transponder transmits a periodic frequency-hopping pulse signal of the corresponding data rate to the hydrophone according to the data rate information contained in the laser signal; step 6, the hydrophone sends the periodic frequency-hopping pulse signal The direct signal is sent to the central processing unit; step 7, the central processing unit calculates the distance information according to the direct signal; performs coordinate correction according to the signal of the angle measuring instrument; and calculates the coordinate of the underwater transponder according to the data of the depth sensor.

The present invention adopts the following technical solution to achieve the above another object: an underwater target tracking and positioning system, including a signal-connected underwater acoustic array and an underwater transponder, characterized in that: the underwater acoustic array includes a polyhedral base frame, A central processing unit, a display device, a depth sensor arranged on the bottom surface of the polyhedron pedestal, at least one angle measuring instrument, at least one hydrophone, and a blue-green laser emitting and receiving integrated rotatable device arranged under the hydrophone, the central The processor is respectively connected with the depth sensor, the angle measuring instrument, the hydrophone, and the blue-green laser emitting and receiving integrated rotatable device; the underwater transponder includes the blue-green laser receiving and reflecting device, the control center, the jump frequency converter and underwater acoustic transducer; the laser signal reflected by the blue-green laser receiving and reflecting device is the laser signal emitted by the blue-green laser transmitting and receiving integrated rotatable device; the underwater acoustic frequency-hopping pulse signal generated by the frequency hopper is obtained by The underwater acoustic transducer sends to the hydrophone, and the pulse period T is controlled by the laser signal.

The polyhedron pedestal is a regular tetrahedron pedestal, and a hydrophone is respectively placed at three corners of the bottom surface of the pedestal, and the three hydrophones form a hydrophone matrix connected to the central processing unit; The underwater acoustic frequency hopping pulse signal is sent from the underwater acoustic transducer to the hydrophone array.

The underwater acoustic array also includes a signal-connected preamplifier and a hydrophone array processing unit, wherein the preamplifier is connected to the hydrophone array, and the hydrophone array processing unit is connected to the central processing unit.

The integrated rotatable device for transmitting and receiving blue-green laser includes a blue-green laser transmitter and a blue-green laser receiver, wherein the blue-green laser receiver includes a laser receiving antenna, a photosensitive device connected between the laser receiving antenna and the central processing unit ; The blue-green laser receiving and reflecting device includes a laser receiving antenna, a photosensitive device, a laser amplifier, and a laser reflector connected in sequence, wherein the photosensitive device is connected to the control center.

The pulse rule of the underwater acoustic frequency hopping pulse signal is: send the underwater acoustic frequency hopping pulse signal with period T, and take n periods T as a frame; in one frame, the frequency of each period signal floats at f ₀ In an area at the center, the frequency intervals of two adjacent frequency-hopping pulse signals transmitted differ by at least 2Δf.

The action principle of the present invention is:

1. Synchronous time synchronization with blue and green lasers, precise tracking and positioning. The blue-green laser transmitter of the underwater acoustic array adopts an omnidirectional scanning method, and the blue-green laser receiving reflection device is installed on the underwater transponder. When the laser signal scans the surface of the underwater transponder, the underwater transponder receives the laser signal and starts the clock. At the same time, a part of the laser signal is returned to the blue-green laser receiver on the water surface according to the original path. The blue-green laser receiver of the underwater acoustic array also starts timing after receiving the reflected signal.

Because the transmission speed of light under water is about 225,000 kilometers per second, and the transmission speed of underwater sound in air is about 1.5 kilometers per second. The difference between the two is 10 ⁵ orders of magnitude. So in short distances, the time for light to travel is negligible relative to the time for sound to travel. For example, to transmit a distance of 450m, it takes 0.3 seconds for sound, but only 2 microseconds for light. The synchronous clock error of the two is extremely small, and the measurement accuracy will be greatly improved. At the same time, the blue-green laser receiver of the underwater acoustic array can detect the angle of the reflected light, and can judge the approximate orientation of the underwater transponder in time.

If it is used to determine the position of a stationary object, the specific position can be accurately obtained by adopting a dual-mode method of a single laser and a single hydrophone. For moving objects, especially high-speed moving objects, such as torpedoes, underwater divers, and underwater robots, since the moving area may exceed the reach of the blue-green laser, a multi-element approach (such as multiple hydrophones) ) can also accurately track and locate.

2. Based on the blue-green laser data rate control and underwater acoustic frequency hopping mechanism, it solves the problem of multipath interference. The invention proposes a way of transmitting periodic frequency-hopping pulse signals. After the blue-green laser confirms the synchronous opening signal, the underwater transponder sends a periodic frequency-hopping pulse signal to the hydrophone base array according to a certain rule, which makes the positioning signal interval of the same frequency longer, which is beneficial to the hydrophone base array pairing. Discrimination of direct and non-direct signals. After the hydrophone array receives and saves the frequency-hopping pulse signal, it selects the direct signal, rejects the subsequent reflected signal, and transmits the direct signal to the central processor, which calculates the distance information based on the direct signal. At the same time, the underwater acoustic frequency hopping mechanism also enables the system to expand the unambiguous distance without reducing the data rate.

For underwater moving objects, when the moving speed is fast, in order to accurately detect its trajectory, a large positioning data rate is required; and when the moving speed is slow, the positioning data rate does not need to be too high. In order to adjust the data rate according to the needs, blue-green laser signals of different frequencies are emitted to represent different data rate requirements. After receiving the blue-green laser signals of this frequency, the transponder sends the corresponding data rate positioning frequency-hopping pulse signal according to its requirements. This enables efficient use of system resources.

It can be seen from the above technical scheme and working principle that, compared with the prior art, the present invention has the following advantages:

1. Accurate synchronous time synchronization improves the positioning accuracy of the short baseline system. The system adopts laser time synchronization, which overcomes the inaccurate problem of underwater acoustic time synchronization in the traditional short baseline positioning system, and improves the accuracy of system positioning and tracking.

2. The blue-green laser transponder system realizes the control of the data rate of the underwater transponder. The laser "inquiry-response" mechanism can send instructions to the underwater transponder to adjust the positioning data rate according to the speed of the object's movement. For low-speed moving objects, the laser signal commands the underwater transponder to adopt a low positioning data rate; for high-speed moving objects, the laser signal commands the system to adopt a high positioning data rate.

3. The transponder sends a frequency-hopping positioning signal, which solves the problem of ambiguity in position and the problem of multiple positioning solutions in the prior art, and can be used for trajectory tracking of underwater high-speed moving objects.

4. The frequency hopping positioning system also overcomes the serious problem of underwater acoustic multipath interference in shallow sea areas, can quickly distinguish direct signals and reflected signals, and is suitable for scenes with relatively complex underwater acoustic channels such as shallow seas.

Description of drawings

Fig. 1 is a schematic diagram of the overall structure of portable underwater acoustic positioning equipment and underwater transponder equipment;

Fig. 2 is a block diagram of the internal structure of the underwater acoustic matrix;

Fig. 3 is a block diagram of the internal structure of the underwater transponder;

Fig. 4 is a sequence diagram of tracking and positioning in an embodiment of the present invention;

Fig. 5 is the working flow diagram of the central processing unit of underwater acoustic array among the present invention;

Fig. 6 is the work flowchart of the control center of underwater transponder among the present invention;

Fig. 7a is a schematic diagram of the frequency hopping rule of the underwater transponder on the time axis;

Fig. 7b is a schematic diagram of the frequency distribution of the frequency hopping pulse signal.

Detailed ways

The present invention will be further described in detail below in conjunction with the embodiments and the accompanying drawings, but the embodiments of the present invention are not limited thereto.

As shown in Figure 1, the system of the present invention is mainly composed of an underwater acoustic matrix and an underwater transponder. Fig. 2 shows the internal structural module diagram of the underwater acoustic array. As can be seen from Fig. 2, the underwater acoustic array includes a base frame 11, a hydrophone array 12, a blue-green laser emitting and receiving integrated rotatable device 13, a water pressure A sensor 14, a posture detection device 15, a central processing unit 16, and a display device 17. The hydrophone array 12 is connected to the hydrophone array processing unit 18 through the preamplifier 19, and the central processing unit 16 is respectively connected to the hydrophone array processing unit 18, the water pressure sensor 14, the posture detection device 15, and the display device 17. , Blue-green laser emitting and receiving integrated rotatable device 13 is connected. The blue-green laser emitting and receiving integrated rotatable device 13 is arranged under the hydrophone matrix, as shown in Figure 2, it is mainly composed of a blue-green laser transmitter 130, a laser receiver and a rotating device, wherein the laser receiver includes a laser Receiving antenna 131 and photosensitive device 132; can rotate and scan 360° to capture underwater transponders. The base frame 11 is a regular tetrahedron made of stainless steel pipes, and a hydrophone is respectively placed at three corners of the bottom surface of the regular tetrahedron, and the three hydrophones form a hydrophone matrix 12 . Each module in Figure 2 is described below:

Blue-green laser emitter 130: There is a light-transmitting window similar to that in the atmosphere in the ocean, that is, the attenuation of blue-green light in the wavelength band of 0.47-0.58 μm by sea water is much smaller than that of other light bands, and can be used for Measurement and communication of underwater targets. YAG frequency doubled blue-green laser is currently the most mature and practical device, due to its high peak power, narrow pulse width, long life, high conversion efficiency, small size, light weight, good stability, not afraid of shock and vibration, etc. , to meet the requirements in the present invention. According to the requirements of different data rates sent by the central processor, the laser transmitter also sends laser signals of different frequencies to the underwater transponder. After receiving the frequency, the underwater transponder will send corresponding underwater acoustic signals according to the data rate requirements. Frequency hopping pulse signal.

Blue-green laser receiver: composed of a laser receiving antenna 131 and a photosensitive device 132 . A convex lens is arranged at the front end of the laser receiving antenna 131, and a photosensitive device 132 is arranged at the focal point of the convex lens. After the incident light is focused by the convex lens, it enters the photosensitive device 132, which can improve the sensitivity of the laser receiver.

Attitude detection device 15: On the sea, due to reasons such as waves, the mother ship itself may sway, causing the underwater array to sway. And the base array itself may also be affected by the current and deviate from the horizontal plane under water. In order to center the underwater transponder relative to the receiving pedestal, a position correction must be made. Two attitude detection devices 15 installed on the bottom surface of the base frame 11 are used as angle measuring instruments to measure the real-time tilt angle of the base frame in water. In this embodiment, the posture detection device adopts a posture sensor. The data of the two posture detection devices 15 are sent to the central processing unit 16 for coordinate correction.

Water pressure sensor 14: As a depth sensor, it is installed on the bottom surface of base frame 11 to detect the depth of the underwater array and send the data to the central processing unit 16. The purpose of doing this is to make the underwater transponder relatively hydrophone The coordinates of the device matrix 12 are converted into the coordinates of the ship.

Hydrophone matrix processing unit 18: connected between the preamplifier 19 and the central processing unit 16; used to detect whether the pulse signal received by each hydrophone is a direct signal or an indirect signal, and send the time of the direct signal to to the CPU 16. After the underwater transponder receives the signal from the laser transmitter, the clock starts timing and reflects the signal back according to the original path. After the laser receiver receives the reflected signal, it also starts timing. Because the transmission speed of the speed of light in water is extremely fast, it can be ignored in a short distance (for example, light only needs 2 microseconds to transmit a distance of 450m). The synchronization clock error of the two is extremely small. The accuracy of measurement will also be greatly improved.

Central processing unit 16: In the opening stage, according to the requirements of the external controller, signal requests of different frequencies will be sent to the blue-green laser emitting and receiving integrated rotatable device 13, and the blue-green laser transmitter 130 will send different laser signals according to different requests. Pulse to underwater transponder. In the signal processing stage, the distance between the object and each hydrophone can be obtained by comparing the direct signal time sent by the hydrophone array processing unit 18 with its own time. According to the inclination angle sent by the array posture detection device 15, the coordinates of the array are corrected in real time to obtain the coordinates of the transponder. Then according to the water depth data obtained by the water pressure sensor 14, the coordinates of the transponder relative to the bottom of the ship can be obtained. By drawing the coordinates of each time, the trajectory of the object can be obtained.

Fig. 3 is a block diagram of the internal structure of the underwater transponder. As shown in FIGS. 1 and 3 , the underwater transponder includes a blue-green laser receiving and reflecting device 21 , a control center 22 , a frequency hopper 24 and an underwater acoustic transducer 23 . Wherein the blue-green laser receiving and reflecting device 21 comprises a laser receiver, a laser reflector 213, and the laser reflector 213 is preceded by a laser amplifier 211; after the weak signal detected by the laser receiver is amplified by the laser amplifier 211, it is reflected back by the original path In FIG. 2 , the blue-green laser emitting and receiving integrated rotatable device 13 is on the laser receiver. The laser receiver in FIG. 3 is the same as the laser receiver shown in FIG. 2 , and is also composed of a laser receiving antenna 210 and a photosensitive device 212 . After the laser receiver receives the laser signal, it sends the data rate information contained in the laser signal to the control center 22; 24 generated underwater acoustic frequency-hopping pulse signals corresponding to the data rate. The pulse pattern generated by the frequency hopper 24 is shown in FIG. 7 , wherein the period T is controlled by the laser signal. After the laser receiver receives the signal sent by the blue-green laser transmitter 130 again, the control center 22 judges the information of the signal, if it is the information to change the data rate, then make a corresponding change, if it is a shutdown command, then the command The frequency hopper 24 and the underwater acoustic transducer 23 enter a dormant state, waiting for the next opening signal.

In order to meet the needs of tracking high-speed moving objects, the underwater transponder sends underwater acoustic frequency-hopping pulse signals. After receiving the laser start signal, the underwater acoustic frequency hopping pulse signal is sent in a period T, and n periods T are taken as a frame. In one frame, the frequency of each periodic signal floats in an area centered on f ₀ , the size of the area can be adjusted according to the needs of anti-multipath, and the frequency interval between two adjacent frequency-hopping pulse signals sent The difference is at least 2Δf; the frequency hopping law is specifically shown in Figure 7a. In one frame, the frequency of the first cycle is f ₀ , the frequency of the second cycle is f ₀ +2Δf, and the frequency of the third cycle is f ₀ -Δf, the frequency of the fourth period is f ₀ +Δf..., the number n of periods contained in one frame is determined according to the need to overcome multipath. The hydrophone can receive a certain frequency signal for the first time, and when it is a direct signal, all the frequency signals that arrive within a time less than nT are discarded. If the frequency signal reached after the nT time is a reflected signal, the signal will become quite weak due to multiple reflections, and the control center 22 can clearly distinguish it.

Fig. 4 shows the sequence diagram of the system at the beginning of tracking and positioning, and Fig. 5 and Fig. 6 respectively show the processing flow chart of the central processor of the underwater acoustic array and the processing flow chart of the control center of the underwater transponder. The present invention implements the main steps of underwater target positioning as follows:

Start tracking: as shown in Figures 4 and 5, the central processing unit sends an opening instruction to the blue-green laser emitting and receiving integrated rotatable device, and the opening instruction contains the required data rate information. The blue-green laser emitting and receiving integrated rotatable device starts to rotate and scan the underwater transponder, and sends a laser signal containing data rate information. When the underwater transponder is scanned, the underwater transponder will reflect the laser signal according to the original path, and at the same time, the underwater transducer will be turned on. After the blue-green laser emitting and receiving integrated rotatable device receives the reflected laser signal, it sends a synchronous timing signal to the central processing unit, and the central processing unit starts the synchronous clock, starts timing, and waits for the underwater acoustic frequency-hopping pulse emitted by the underwater transponder Signal. According to the data rate information contained in the laser signal, the underwater transponder transmits a periodic frequency-hopping pulse signal of the corresponding data rate to the hydrophone array as required. The frequency-hopping law is shown in Figure 7a, and the frequency distribution of the frequency-hopping pulse signal is as follows: Figure 7b shows. The hydrophone base array starts to receive the periodic frequency hopping pulse signal, and distinguishes the direct signal and the reflected signal, selects the direct signal and sends it to the central processing unit. The central processor calculates the distance information according to the direct signal; receives the signal from the attitude detection device to obtain the tilt of the base frame, and corrects its coordinates algorithmically during the calculation; then calculates the underwater transponder according to the data of the water pressure sensor. The coordinates relative to the bottom of the ship are displayed on the display.

Change the data rate: According to actual needs, when the object moves fast, in order to achieve accurate position tracking, a higher positioning data rate is adopted; when the object moves slowly, in order to save the battery consumption of the underwater acoustic transponder, At the same time, in order to reduce the load of the central processing unit, the positioning data rate can be reduced. At this time, as shown in Figure 5, the blue-green laser emitter of the underwater acoustic array scans again and emits a laser signal to the underwater transponder. As shown in Figure 6, after the laser receiving antenna of the underwater transponder receives the laser signal, it reflects the laser signal according to the original path again. After the blue-green laser transmitting and receiving integrated rotatable device receives the reflected laser signal, the synchronization of the central The clock restarts. The underwater acoustic transducer of the underwater transponder sends a periodic frequency-hopping pulse signal of the corresponding data rate to the hydrophone array according to the requirements of the laser signal. The frequency-hopping rule is shown in Figure 7a.

Closing stage: The blue-green laser emitting and receiving integrated rotatable device sends a closing command to the underwater transponder, the underwater transponder is closed, and the underwater acoustic transducer enters a dormant state, waiting for the next opening command.

The above-mentioned embodiment is a preferred embodiment of the present invention, but the embodiment of the present invention is not limited by the above-mentioned embodiment, and any other changes, modifications, substitutions, combinations, Simplifications should be equivalent replacement methods, and all are included in the protection scope of the present invention.

Claims (8)

1. submarine target method for tracking and positioning is characterized in that may further comprise the steps:

Step 1 receives integrated rotatable device by central processing unit to the bluish-green laser emission and sends open command and needed locator data rate information;

Step 2, the bluish-green laser emission receives integrated rotatable device and scans transponder under water, and sends the laser signal that comprises data rate information to transponder;

Step 3, transponder is pressed original route and is received integrated rotatable device reflector laser signal to the bluish-green laser emission under water, and transducer is opened;

After step 4, green Laser emission receive integrated rotatable device and receive the reflector laser signal, send the time synchronisation signal to central processing unit, central processing unit starts synchronous clock, picks up counting;

Step 5, transponder is according to the data rate information that laser signal comprised, to the cycle frequency hopping pulse signal of nautical receiving set emission corresponding data rate under water;

Step 6, nautical receiving set is issued central processing unit with the direct signal in the cycle frequency hopping pulse signal;

Step 7, central processing unit be according to direct signal, computed range information; According to the signal of angel measuring instrument, carry out coordinates correction; According to the data of depth transducer, calculate the coordinate of transponder under water again.

2. submarine target method for tracking and positioning according to claim 1 is characterized in that: the pulse rule of the said frequency hopping pulse signal of step 5 is: send underwater sound frequency hopping pulse signal with cycle T, with n cycle T as a frame; In a frame, the frequency of each periodic signal is floated with f ₀In the zone for the center, the frequency interval of adjacent two the frequency hopping pulse signals that sent differs 2 Δ f at least.

3. submarine target tracing-positioning system according to the said method of claim 1; Comprise underwater sound basic matrix that signal connects and transponder under water; It is characterized in that: said underwater sound basic matrix comprises polyhedron pedestal, central processing unit, display device and is arranged on depth transducer, at least one angel measuring instrument, at least one nautical receiving set on the polyhedron pedestal bottom surface; And the integrated rotatable device of bluish-green laser emission reception that is arranged on the nautical receiving set below, central processing unit receives integrated rotatable device signal with depth transducer, angel measuring instrument, nautical receiving set, bluish-green laser emission respectively and is connected; Said transponder under water comprises that the bluish-green laser of signal connection receives reflection unit, control center, frequency hopper and underwater acoustic transducer successively; It is the integrated rotatable device of bluish-green laser emission reception institute emitted laser signal that bluish-green laser receives reflection unit institute laser light reflected signal; The underwater sound frequency hopping pulse signal that frequency hopper produced is sent to nautical receiving set by underwater acoustic transducer, and recurrence interval T Stimulated Light signal controlling.

4. submarine target tracing-positioning system according to claim 3; It is characterized in that: said polyhedron pedestal is the positive tetrahedron pedestal; A nautical receiving set is being placed at three angles, pedestal bottom surface respectively, and three nautical receiving sets are formed the hydrophone array that is connected with central processing unit; The underwater sound frequency hopping pulse signal that frequency hopper produced is sent to hydrophone array by underwater acoustic transducer.

5. submarine target tracing-positioning system according to claim 4; It is characterized in that: said underwater sound basic matrix also comprises prime amplifier, the hydrophone array processing unit that signal connects; Wherein prime amplifier is connected with hydrophone array, and the hydrophone array processing unit is connected with central processing unit.

6. submarine target tracing-positioning system according to claim 4; It is characterized in that: said bluish-green laser emission receives integrated rotatable device and comprises bluish-green laser transmitter and bluish-green laser receiver, and wherein the bluish-green laser receiver comprises the laser pick-off antenna, is connected the photosensitive device between laser pick-off antenna and the central processing unit; Said bluish-green laser receives reflection unit and comprises laser pick-off antenna, photosensitive device, laser amplifier, the laser reflector that connects successively, and wherein photosensitive device is connected with control center.

7. submarine target tracing-positioning system according to claim 4 is characterized in that: the pulse rule of said underwater sound frequency hopping pulse signal is: send underwater sound frequency hopping pulse signal with cycle T, with n cycle T as a frame; In a frame, the frequency of each periodic signal is floated with f ₀In the zone for the center, the frequency interval of adjacent two the frequency hopping pulse signals that sent differs 2 Δ f at least.

8. submarine target tracing-positioning system according to claim 4 is characterized in that: said angel measuring instrument is an Attitute detecting device; Said depth transducer is a hydraulic pressure sensor.

Images