Signal simulation device and method of Doppler laser wind finding radar

Abstract

The invention relates to the technical field of laser wind-finding radar systems, and discloses a signal simulation device and method of a Doppler laser wind-finding radar. The coupling module is arranged at the laser output end of the laser radar and is used for receiving emergent laser of the laser radar; the coupling module comprises a polarization modulation unit, a coupling lens, an optical fiber patch cord and a displacement adjustment unit, the polarization modulation unit is arranged close to the laser radar, and the displacement adjustment unit and the end face of the optical fiber patch cord are placed at the image space focal plane of the coupling lens; the delay module is arranged at one end, away from the laser radar, of the coupling module and is in optical fiber connection with the coupling module; and the frequency shift module is arranged at one end, far away from the coupling module, of the delay module and is in optical fiber connection with the delay module. According to the invention, the problems of low optical coupling efficiency, complex test system, insufficient bandwidth of the frequency shift module and the like in the prior art can be effectively solved, and the overall performance of the radar system is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of laser wind measuring radar systems, and in particular to a signal simulation device and method for a Doppler laser wind measuring radar. Background Art

[0002] Doppler wind radar is a device that uses laser as carrier and the Doppler effect to measure atmospheric wind speed. It is widely used in meteorological observation, aviation safety, wind energy assessment and other fields. Compared with traditional wind measuring instruments such as ultrasonic anemometers and mechanical anemometers, Doppler wind radar has significant advantages in terms of strong remote sensing capability, high measurement accuracy, wide speed measurement range and good real-time performance. Doppler wind radar emits a laser beam into the atmosphere, and the laser interacts with aerosols and cloud particles in the atmosphere. The returned scattered light signal will produce a frequency shift due to the Doppler effect. By receiving and analyzing this frequency shift, wind speed information can be obtained. Laser wind radar emits a laser beam into the atmosphere and collects the backscattered light signal of aerosols and other particles in the atmosphere after it is transmitted in the atmosphere, and calculates the Doppler frequency shift using the interferometric measurement method. The collected signal has attenuation, delay and Doppler frequency shift compared with the transmitted laser, which is caused by propagation and scattering of several kilometers in the atmosphere. Therefore, it is difficult to create a standard physical quantity environment in real space to test the performance of wind measurement radar.

[0003] At present, the performance test of Doppler wind radar is mainly carried out through wind tunnel experiments, field experiments, vehicle-mounted experiments and airborne experiments. Wind tunnel experiments can provide a controllable wind field environment. The size and performance of the wind tunnel limit the test range of the radar. Generally, only large and medium-sized wind tunnels with high construction and operation costs can meet the test needs. Field experiments rely on natural wind fields, which have good authenticity, but are greatly affected by environmental conditions, and the stability and repeatability of the test results are poor. Vehicle-mounted experiments carry the wind radar to be tested and the comparative experimental equipment on the vehicle platform to test the wind radar. Similar to field experiments, they are extremely dependent on natural wind field conditions and cannot perform accurate and standardized tests. Airborne experiments can effectively verify the performance of aviation laser wind radar under actual flight conditions by carrying radar equipment for flight tests, but the test cost is high and the test conditions are difficult to control. In the current production process, the performance test of Doppler laser wind radar is mainly carried out by building a corresponding test environment. There are many related patents that detail the method of Doppler laser wind radar performance test. Performance testing has the following disadvantages: low spatial optical coupling efficiency; complex test system design; need to design a complex frequency shift module; frequency shift module frequency shift bandwidth is not large enough.

[0004] Therefore, it is necessary to provide a signal simulation device and method for a Doppler laser wind radar to solve the problems existing in the prior art. Summary of the invention

[0005] In view of this, the present invention proposes a signal simulation device and method for a Doppler laser wind radar, aiming to solve the problems of low spatial optical coupling efficiency, complex test system design, the need to design a complex frequency shift module, and insufficient frequency shift bandwidth of the frequency shift module.

[0006] On the one hand, the present invention provides a signal simulation device for a Doppler laser wind radar, comprising:

[0007] LiDAR;

[0008] A coupling module is arranged at the laser output end of the laser radar and is used to receive the output laser of the laser radar; the coupling module includes a polarization modulation unit, a coupling lens, an optical fiber jumper and a displacement adjustment unit, the polarization modulation unit is arranged close to the laser radar, and the end face of the displacement adjustment unit and the optical fiber jumper are placed at the image side focal plane of the coupling lens;

[0009] A delay module is arranged at an end of the coupling module away from the laser radar, and the delay module is connected to the coupling module by an optical fiber;

[0010] The frequency shift module is arranged at an end of the delay module away from the coupling module, and the frequency shift module is connected to the delay module by an optical fiber.

[0011] Further, including:

[0012] The polarization modulation unit is used to couple the incident laser into the polarization-maintaining optical fiber along the direction of the fast axis or the slow axis, so as to keep the laser always maintaining the linear polarization property during the entire optical transmission process;

[0013] The fiber optic patch cord is based on polarization maintaining device characteristics.

[0014] Furthermore, the polarization modulation unit includes an adjustable polarization adjustment device, and the adjustable polarization adjustment device is used to adjust the polarization state of the laser emitted by the laser radar.

[0015] Furthermore, the displacement adjustment unit includes an electrically controlled displacement stage, and the electrically controlled displacement stage is used to adjust the spatial position and pitch angle of the optical fiber end face.

[0016] Furthermore, the signal simulation device of the Doppler laser wind radar also includes:

[0017] A power detection module is arranged at an end of the coupling module away from the laser radar. The power detection module includes a splitter and a power meter. The power meter is connected to one of the output optical fibers of the splitter to detect the optical power.

[0018] Furthermore, the splitter comprises:

[0019] One input end and two output ends, the splitter divides the laser power of the input end into two paths at a ratio of 90:10 and outputs through the output ends, wherein 10% enters the power meter and 90% enters the delay module.

[0020] Further, the power meter comprises:

[0021] A power meter probe and a power meter head, wherein the power meter is connected to one of the output ends of the splitter to detect the laser power and to feed back the power information to the host computer in real time, and is matched with the coupling module to feed back the coupling power of the coupling module in real time.

[0022] Furthermore, the frequency shift module includes:

[0023] Optical switch, used to modulate the laser to produce the corresponding frequency shift value;

[0024] The acousto-optic frequency shifter includes a plurality of adjustable frequency shift units, so that the adjustable frequency shift modules form different frequency shift ranges, so that the laser frequency shift changes continuously;

[0025] A plurality of fiber optic reflectors are provided, wherein the fiber optic reflectors are connected to the acousto-optic frequency shifter through optical fibers, and the fiber optic reflectors are provided on a side of the acousto-optic frequency shifter away from the optical switch. The fiber optic reflectors are used to return the laser to its original path, passing through the acousto-optic frequency shifter twice, thereby doubling the frequency shift amount.

[0026] Furthermore, the optical switch includes an input port, a control port and a plurality of output ports, wherein the output port is connected to each acousto-optic frequency shifter via an optical fiber, and the control port is connected to a host computer, and a path is autonomously selected through a control program so that the selected path meets the requirements of the set frequency shift value.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention simulates the laser frequency shift caused by the modulation of the laser by atmospheric particles and the time delay between the measuring laser and the reference laser when the laser of the wind measuring radar measures the wind speed at a long distance in the atmosphere through the modulation of the laser by each module, realizes the simulation of the Doppler wind measuring signal, returns the modulated laser to the laser radar, compares the measured value of the laser radar with the set value of the signal simulation, and thus achieves the purpose of testing the performance of the Doppler wind measuring radar; the device provided by the present invention significantly improves the spatial optical coupling efficiency, reduces the optical loss, and solves the problem of low optical coupling efficiency in the traditional system by optimizing the design of the coupling module. At the same time, the modular design simplifies the structure of the test system, reduces the complexity of design and debugging, and improves the maintainability and scalability of the system. In addition, the optimized design of the frequency shift module not only simplifies the frequency shift implementation process, but also improves its frequency shift amount and bandwidth, ensures that the requirements of the Doppler laser wind measuring radar are met, and enhances the adaptability and accuracy of the system. Therefore, the present invention can effectively solve the problems of low optical coupling efficiency, complex test system, and insufficient bandwidth of the frequency shift module in the prior art, and improves the overall performance of the radar system.

[0028] On the other hand, the present application also provides a signal simulation method for a Doppler laser wind radar, comprising:

[0029] The coupling module is aimed at the outgoing laser of the laser radar, and the laser is focused on the end face of the optical fiber through the coupling lens;

[0030] The coupled optical fiber is divided into two outputs through a splitter, one of which is connected to a power meter. The upper computer software monitors and feedbacks the power of the laser coupled into the optical fiber through the power meter, and controls the polarization modulation unit and the displacement adjustment unit to adjust the physical position of the optical fiber end face to maximize the coupled power; the other output of the splitter is connected to the delay module;

[0031] The delay module is connected to the optical switch, and the host computer control software inputs the required frequency shift amount. The program controls the optical switch to select the path within the range according to the frequency shift size.

[0032] The laser passes through the delay module and enters the frequency shift module. After being emitted from the frequency shift module, it returns to the original path and passes through the delay module again, and then is emitted through the coupling module.

[0033] It can be understood that the signal simulation device and method of a Doppler laser wind radar provided in the present application have the same beneficial effects, which will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0035] Figure 1 A structural diagram of a signal simulation device for a Doppler laser wind radar provided in an embodiment of the present invention;

[0036] Figure 2 A structural diagram of a coupling module provided in an embodiment of the present invention;

[0037] Figure 3 A structural diagram of a power detection module provided in an embodiment of the present invention;

[0038] Figure 4 A structural diagram of a frequency shift module provided in an embodiment of the present invention;

[0039] Figure 5 The present invention provides a flow chart of a signal simulation method for a Doppler laser wind radar. DETAILED DESCRIPTION

[0040] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features described in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0041] In some embodiments of the present application, see Figure 1 As shown, this embodiment provides a signal simulation device for a Doppler laser wind radar, comprising:

[0042] LiDAR;

[0043] A coupling module is arranged at the laser output end of the laser radar and is used to receive the output laser of the laser radar; the coupling module includes a polarization modulation unit, a coupling lens, an optical fiber jumper and a displacement adjustment unit, the polarization modulation unit is arranged close to the laser radar, and the end face of the displacement adjustment unit and the optical fiber jumper is placed at the image focal plane of the coupling lens;

[0044] A delay module is arranged at an end of the coupling module away from the laser radar, and the delay module is connected to the coupling module by an optical fiber;

[0045] The frequency shift module is arranged at an end of the delay module away from the coupling module, and the frequency shift module is connected to the delay module by optical fiber.

[0046] It can be understood that the present invention simulates the laser frequency shift caused by the modulation of the laser by atmospheric particles and the time delay between the measuring laser and the reference laser when the laser of the wind measuring radar measures the wind speed at a long distance in the atmosphere through the modulation of the laser by each module, thereby simulating the Doppler wind measurement signal, returning the modulated laser to the laser radar, and comparing the measured value of the laser radar with the set value of the signal simulation, so as to achieve the purpose of testing the performance of the Doppler wind measuring radar; the device provided by the present invention significantly improves the spatial optical coupling efficiency and reduces the optical loss by optimizing the design of the coupling module, thereby solving the problem of low optical coupling efficiency in the traditional system. At the same time, the modular design simplifies the structure of the test system, reduces the complexity of design and debugging, and improves the maintainability and scalability of the system. In addition, the optimized design of the frequency shift module not only simplifies the frequency shift implementation process, but also improves its frequency shift amount and bandwidth, ensuring that it meets the needs of the Doppler laser wind measuring radar and enhancing the adaptability and accuracy of the system. Therefore, the present invention can effectively solve the problems of low optical coupling efficiency, complex test system and insufficient bandwidth of the frequency shift module in the prior art, and improve the overall performance of the radar system. Specifically, Figure 2 This is the structural diagram of the coupling module.

[0047] In some embodiments of the present application, including:

[0048] The polarization modulation unit is used to couple the incident laser into the polarization-maintaining fiber along the fast axis or slow axis to keep the laser linearly polarized throughout the entire optical transmission process;

[0049] Fiber optic patch cables are based on polarization maintaining device characteristics.

[0050] In some embodiments of the present application, the polarization modulation unit includes an adjustable polarization adjustment device, and the adjustable polarization adjustment device is used to adjust the polarization state of the laser emitted by the laser radar.

[0051] In some embodiments of the present application, the displacement adjustment unit includes an electrically controlled displacement stage, and the electrically controlled displacement stage is used to adjust the spatial position and pitch angle of the optical fiber end face.

[0052] See also Figure 3 In some embodiments of the present application, the signal simulation device of the Doppler laser wind radar further includes:

[0053] The power detection module is arranged at the end of the coupling module away from the laser radar. The power detection module includes a splitter and a power meter. The power meter is connected to one of the output optical fibers of the splitter to detect the optical power.

[0054] In some embodiments of the present application, the splitter includes:

[0055] One input end and two output ends, the splitter divides the laser power at the input end into two paths at a ratio of 90:10 and outputs through the output ends, wherein 10% enters the power meter and 90% enters the delay module.

[0056] In some embodiments of the present application, the power meter includes:

[0057] The power meter probe and the power meter head are connected to one of the output ends of the splitter to detect the laser power and provide real-time feedback of the power information to the host computer. Together with the coupling module, the coupling power of the coupling module is provided in real time.

[0058] See also Figure 4 In some embodiments of the present application, the frequency shift module includes:

[0059] Optical switch, used to modulate the laser to produce the corresponding frequency shift value;

[0060] The acousto-optic frequency shifter includes a plurality of adjustable frequency shift units, so that the adjustable frequency shift modules form different frequency shift ranges, so that the laser frequency shift changes continuously;

[0061] A plurality of fiber optic reflectors are provided, and the fiber optic reflectors are connected to the acousto-optic frequency shifter through optical fibers, and the fiber optic reflectors are arranged on the side of the acousto-optic frequency shifter away from the optical switch. The fiber optic reflectors are used to return the laser to its original path, passing through the acousto-optic frequency shifter twice, so as to double the frequency shift amount.

[0062] In some embodiments of the present application, the optical switch includes an input port, a control port, and a plurality of output ports. The output port is connected to each acousto-optic frequency shifter through an optical fiber, and the control port is connected to a host computer. The path is selected autonomously through a control program so that the selected path meets the requirements of the set frequency shift value.

[0063] On the other hand, see Figure 5 As shown, the present application also provides a signal simulation method of a Doppler laser wind measuring radar, which is applied to the signal simulation device of the Doppler laser wind measuring radar, and comprises the following steps:

[0064] S100, the coupling module is aligned with the output laser of the laser radar, and the laser is focused on the end face of the optical fiber through the coupling lens;

[0065] S200, the coupled optical fiber is divided into two outputs through a splitter, one of which is connected to a power meter. The upper computer software monitors and feedbacks the power of the laser coupled into the optical fiber through the power meter, and controls the polarization modulation unit and the displacement adjustment unit to adjust the physical position of the optical fiber end face to maximize the coupling power; the other output of the splitter is connected to the delay module;

[0066] S300, the delay module is connected to the optical switch, the host computer control software inputs the required frequency shift amount, and the program controls the optical switch to select the path within the range according to the frequency shift amount;

[0067] S400, the laser passes through the delay module and enters the frequency shift module, and then returns to the original path after being emitted from the frequency shift module, passes through the delay module again, and then is emitted through the coupling module.

[0068] It can be understood that the present invention regulates the polarization, delay and frequency shift of the laser through various modulation modules, and then transmits it to the Doppler wind measuring radar, that is, the laser radar, through the coupling module to realize the signal simulation of the Doppler wind measuring radar, which is used to detect and calibrate the performance of the Doppler laser radar.

[0069] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0070] The present application is described with reference to flowcharts and / or block diagrams of methods, devices (systems) and computer program products according to embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0071] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0072] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A signal simulation device for a Doppler laser wind radar, characterized in that: include: LiDAR; A coupling module is arranged at the laser output end of the laser radar and is used to receive the output laser of the laser radar; the coupling module includes a polarization modulation unit, a coupling lens, an optical fiber jumper and a displacement adjustment unit, the polarization modulation unit is arranged close to the laser radar, and the end face of the displacement adjustment unit and the optical fiber jumper are placed at the image side focal plane of the coupling lens; A delay module is arranged at an end of the coupling module away from the laser radar, and the delay module is connected to the coupling module by an optical fiber; The frequency shift module is arranged at an end of the delay module away from the coupling module, and the frequency shift module is connected to the delay module by an optical fiber.

2. The signal simulation device of the Doppler laser wind radar according to claim 1, characterized in that: include: The polarization modulation unit is used to couple the incident laser into the polarization-maintaining optical fiber along the direction of the fast axis or the slow axis, so as to keep the laser always maintaining the linear polarization property during the entire optical transmission process; The fiber optic patch cord is based on polarization maintaining device characteristics.

3. The signal simulation device of the Doppler laser wind radar according to claim 1, characterized in that: The polarization modulation unit includes an adjustable polarization adjustment device, and the adjustable polarization adjustment device is used to adjust the polarization state of the laser emitted by the laser radar.

4. The signal simulation device of the Doppler laser wind radar according to claim 1, characterized in that: The displacement adjustment unit comprises an electrically controlled displacement stage, and the electrically controlled displacement stage is used to adjust the spatial position and the pitch angle of the optical fiber end face.

5. The signal simulation device of Doppler laser wind radar according to claim 1, characterized in that: The signal simulation device of the Doppler laser wind measuring radar also includes: A power detection module is arranged at an end of the coupling module away from the laser radar. The power detection module includes a splitter and a power meter. The power meter is connected to one of the output optical fibers of the splitter to detect the optical power.

6. The signal simulation device for Doppler laser wind radar according to claim 5, characterized in that: The splitter comprises: One input end and two output ends, the splitter divides the laser power of the input end into two paths at a ratio of 90:10 and outputs through the output ends, wherein 10% enters the power meter and 90% enters the delay module.

7. The signal simulation device for Doppler laser wind radar according to claim 5, characterized in that: The power meter comprises: A power meter probe and a power meter head, wherein the power meter is connected to one of the output ends of the splitter to detect the laser power and to feed back the power information to the host computer in real time, and is matched with the coupling module to feed back the coupling power of the coupling module in real time.

8. The signal simulation device for Doppler laser wind radar according to claim 1, characterized in that: The frequency shift module comprises: Optical switch, used to modulate the laser to produce the corresponding frequency shift value; The acousto-optic frequency shifter includes a plurality of adjustable frequency shift units, so that the adjustable frequency shift modules form different frequency shift ranges, so that the laser frequency shift changes continuously; A plurality of fiber optic reflectors are provided, wherein the fiber optic reflectors are connected to the acousto-optic frequency shifter through optical fibers, and the fiber optic reflectors are provided on a side of the acousto-optic frequency shifter away from the optical switch. The fiber optic reflectors are used to return the laser to its original path, passing through the acousto-optic frequency shifter twice, thereby doubling the frequency shift amount.

9. The signal simulation device for Doppler laser wind radar according to claim 8, characterized in that: The optical switch comprises an input port, a control port and a plurality of output ports. The output port is connected to each acousto-optic frequency shifter through an optical fiber. The control port is connected to a host computer and a path is selected autonomously through a control program so that the selected path meets the requirements of the set frequency shift value.

10. A signal simulation method for a Doppler laser wind radar, applied to the signal simulation device for a Doppler laser wind radar as claimed in any one of claims 1 to 9, characterized in that: include: The coupling module is aimed at the outgoing laser of the laser radar, and the laser is focused on the end face of the optical fiber through the coupling lens; The coupled optical fiber is divided into two outputs through a splitter, one of which is connected to a power meter. The upper computer software monitors and feedbacks the power of the laser coupled into the optical fiber through the power meter, and controls the polarization modulation unit and the displacement adjustment unit to adjust the physical position of the optical fiber end face to maximize the coupled power; the other output of the splitter is connected to the delay module; The delay module is connected to the optical switch, and the host computer control software inputs the required frequency shift amount. The program controls the optical switch to select the path within the range according to the frequency shift size. The laser passes through the delay module and enters the frequency shift module. After being emitted from the frequency shift module, it returns to the original path and passes through the delay module again, and then is emitted through the coupling module.

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