Method for calculating transmitting power of marine laser

Abstract

The invention provides a maritime laser transmitting power calculation method. The maritime laser transmitting power calculation method comprises the steps that S1, the relation between the laser transmission distance and the area from laser to a target light spot is obtained according to the input atmospheric environment; s2, unmanned aerial vehicle damage conditions are obtained according to the input unmanned aerial vehicle material type; and S3, according to the input knock-down distance, the flight speed of the unmanned aerial vehicle, the relationship between the laser transmission distance and the area of the laser to the target light spot, and the damage condition of the unmanned aerial vehicle, determining the transmitting power of the laser. According to the method, the required laser transmitting power can be obtained according to actual use requirements, and a basis is provided for laser type selection and laser system design.

Description

Technical Field

[0001] The present invention relates to the technical field of lasers, and particularly relates to a method for calculating the emission power of a marine laser. Background Art

[0002] The technology of lasers has been developing increasingly mature and has become an important means for countering drones at sea. However, its research and development cost is high and its installability is low. Moreover, there is currently no method for calculating the theoretical emission power of a laser based on specific technical indicators. Therefore, it is of guiding significance for the design work to form a method for calculating and analyzing the laser emission power under different atmospheric conditions and different performance indicators for laser selection. Summary of the Invention

[0003] The purpose of the present invention is to provide a method for calculating the emission power of a marine laser, so as to realize the calculation of the emission power of the laser required under different conditions.

[0004] To solve the above technical problems, the present invention provides a method for calculating the emission power of a marine laser, including: S1. Obtain the relationship between the laser transmission distance and the laser spot area on the target according to the input atmospheric environment; S2. Obtain the damage conditions of the drone according to the input type of drone material; S3. Determine the emission power of the laser according to the input shooting-down distance, the flight speed of the drone, the relationship between the laser transmission distance and the laser spot area on the target, and the damage conditions of the drone.

[0005] According to the above solution, the types of the input atmospheric environment include the marine environment and the land environment.

[0006] According to the above solution, the step S1 includes: S101. Determine the spot expansion caused by vacuum diffraction according to the laser transmission distance, the laser emission aperture, and the laser emission wavelength; S102. Determine the spot expansion caused by tracking according to the laser transmission distance and the variance of the optical axis jitter caused by tracking; S103. Determine the maximum distance at which the phase between two points on the beam cross-section remains coherent according to the plane wave parameters, the laser emission wavelength, the refractive index structure constant, and the laser transmission distance; S104. Determine the beam quality factor generated by atmospheric turbulence according to the maximum distance at which the phase between two points on the beam cross-section remains coherent and the laser emission aperture; S105. Determine the laser beam quality factor after being affected by atmospheric turbulence according to the initial emitted beam quality factor and the beam quality factor generated by atmospheric turbulence; S106. Determine the laser spot area on the target based on the laser beam quality factor affected by atmospheric turbulence, the spot expansion caused by vacuum diffraction, and the spot expansion caused by tracking and aiming.

[0007] According to the above solution, the types of UAV materials include fiberglass, carbon fiber, thin aluminum plate, model aircraft light wood / foam, and fiberglass reinforced plastic.

[0008] According to the above solution, when the laser power density on the target is greater than the corresponding power density threshold of a certain UAV material, and the laser energy density on the target is greater than the energy density threshold of this UAV material, it is considered that the damage condition of this UAV material is reached; when at least the damage condition of one of the UAV materials on the UAV is satisfied, it is considered that the UAV damage condition is reached.

[0009] According to the above solution, step S3 includes: S301. Determine the laser power density on the target and the laser energy density on the target required to shoot down the UAV according to the UAV damage condition; S302. Determine the irradiation time of the laser on the UAV according to the laser power density on the target and the laser energy density on the target; S303. Determine the minimum starting damage distance of the laser to the UAV according to the irradiation time of the laser on the UAV, the UAV flight speed, and the shooting-down distance; S304. Determine the laser transmitter power according to the laser spot area on the target corresponding to the minimum starting damage distance.

[0010] According to the above solution, this method is realized by using MATLAB software for modeling and simulation.

[0011] The present invention also provides a computer device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, the steps of the above-mentioned method for calculating the laser transmitter power at sea are realized.

[0012] The present invention also provides a computer storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the above-mentioned method for calculating the laser transmitter power at sea are realized.

[0013] Beneficial effects By establishing a correlation model between atmospheric environment parameters and laser transmission characteristics, and combining the damage thresholds of target materials and dynamic parameters (such as flight speed and action distance), this method realizes the accurate quantitative calculation of laser transmitter power. This calculation model provides a scientific basis for the effectiveness evaluation and parameter optimization of high-energy laser application systems, and can significantly improve the rationality of system design and environmental adaptability.

[0014] Furthermore, by differentiating the marine / land environmental parameter library, a differential laser transmission attenuation calculation model is established. This technical feature effectively solves the problem of additional attenuation of laser transmission caused by the high humidity and salt spray environment in the ocean, making the calculation results more in line with the requirements of actual engineering applications and enhancing the regional adaptability of system deployment.

[0015] Furthermore, in the calculation of the laser-to-target spot area, by calculating independent influencing factors such as vacuum diffraction expansion, tracking and pointing error expansion, and atmospheric turbulence expansion step by step, and adopting a beam quality factor correction algorithm, the theoretical deviation rate of spot area calculation is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a flowchart of the method for calculating the emission power of a marine laser in the first embodiment of the present invention; Figure 2 is the analysis result of the laser emission power under different atmospheric environment conditions in the first embodiment of the present invention; Figure 3 is the analysis result of the laser emission power under different target material conditions in the first embodiment of the present invention (the atmospheric environment and the target flight speed remain unchanged); Figure 4 is the analysis result of the laser emission power under different target flight speed conditions in the first embodiment of the present invention (the atmospheric environment and the target material remain unchanged). DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present disclosure clearer, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present disclosure. Apparently, the described embodiments are some, but not all, of the embodiments of the present disclosure. All other embodiments obtained by those of ordinary skill in the art based on the described embodiments of the present disclosure without creative efforts shall fall within the scope of protection of the present disclosure.

[0018] Embodiment 1: This embodiment provides a method for calculating the emission power of a marine laser, including: S1. Obtain the relationship between the laser transmission distance and the laser-to-target spot area according to the input atmospheric environment; S2. Obtain the drone damage conditions according to the input type of drone material; S3. Determine the laser emission power according to the input shooting-down distance, drone flight speed, the relationship between the laser transmission distance and the laser-to-target spot area, and the drone damage conditions.

[0019] Furthermore, the types of the input atmospheric environment include marine environment and land environment.

[0020] Further, the step S1 includes: S101. Determine the spot expansion caused by vacuum diffraction according to the laser transmission distance, laser emission aperture, and laser emission wavelength. The spot expansion caused by vacuum diffraction is expressed as , then:

[0021] where is the laser transmission distance, is the laser emission aperture (300 mm is taken in this embodiment), is the laser emission wavelength (1.075 μm is taken in this embodiment); S102. Determine the spot expansion caused by tracking and aiming according to the laser transmission distance and the variance of the optical axis jitter caused by tracking. The spot expansion caused by tracking and aiming is expressed as , then:

[0022] where is the variance of the optical axis jitter caused by tracking; in this embodiment, the tracking accuracy is 15 urad; S103. Determine the maximum distance at which the phase between two points on the beam cross-section remains coherent according to the plane wave parameter, laser emission wavelength, refractive index structure constant, and laser transmission distance. The maximum distance at which the phase between two points on the beam cross-section remains coherent is expressed as , then:

[0023] where is the plane wave parameter (the value taken in this embodiment is 0.815), is the refractive index structure constant (in this embodiment, the modified hufnagel-valley turbulence model is cited, and at a height of 0 m, then ) S104. Determine the beam quality factor generated by atmospheric turbulence according to the maximum distance at which the phase between two points on the beam cross-section remains coherent and the laser emission aperture. The beam quality factor generated by atmospheric turbulence is expressed as , then:

[0024] S105. Determine the laser beam quality factor after being affected by atmospheric turbulence according to the initial emitted beam quality factor and the beam quality factor generated by atmospheric turbulence. The laser beam quality factor after being affected by atmospheric turbulence is expressed as , then there is:

[0025] Among them, is the beam quality factor of the initially emitted beam; S106. Determine the laser-to-target spot area according to the laser beam quality factor after being affected by atmospheric turbulence, the spot expansion caused by vacuum diffraction, and the spot expansion caused by tracking and pointing. The radius of the laser-to-target spot is expressed as , then there is:

[0026] Then obtain the laser-to-target spot area according to the radius of the laser-to-target spot.

[0027] It should be understood that when the laser is transmitted through the atmosphere, the total radius of the laser spot reaching the target surface is the superposition of the spot expansions caused by vacuum diffraction, atmospheric turbulence, optical axis jitter, and atmospheric thermal blooming. The action distance of the marine laser is relatively short. Therefore, the spot expansion caused by atmospheric thermal blooming is ignored, and only the spot expansions caused by vacuum diffraction, atmospheric turbulence, and optical axis jitter are analyzed. Furthermore, the types of UAV materials include fiberglass, carbon fiber, thin aluminum plate, model aircraft balsa / foam, and fiberglass reinforced plastic; it should be understood that in this embodiment, the irradiation target of the laser is a UAV. At sea, the UAV has the characteristics of small volume, low infrared radiation intensity, and small radar cross-section. Consumer-grade quadcopter UAVs and small fixed-wing UAVs are typical targets. The body materials of different targets have different ignition points and melting point characteristics, which have a certain impact on the laser damage efficiency. The damage conditions of different UAV materials referred to in this embodiment are shown in the following table: Table 1 Damage Conditions of UAV Materials

[0028] Furthermore, when the laser-on-target power density is greater than the corresponding power density threshold of a certain UAV material, and the laser-on-target energy density is greater than the energy density threshold of this UAV material, it is considered that the damage condition of this UAV material is reached; when at least one of the damage conditions of the UAV materials on the UAV is satisfied, it is considered that the UAV damage condition is reached; The damage conditions of UAV materials are expressed as follows:

[0029]

[0030] Among them, is the laser-on-target power density, is the laser-on-target energy density, , is the corresponding power density threshold of a certain drone material, is the energy density threshold of a certain drone material.

[0031] Furthermore, step S3 includes: S301, determining the laser target power density and laser target energy density required to shoot down the drone based on the drone damage condition; S302, determining the laser irradiation time for the UAV based on the laser on-target power density and the laser on-target energy density; S303, determining the minimum starting damage distance of the laser to the UAV based on the laser irradiation time of the UAV, the flight speed of the UAV, and the shooting distance; S304, determining the laser emission power according to the laser-to-target spot area corresponding to the minimum starting damage distance; The laser emission power is expressed as , then:

[0032] in, is the transmittance of the laser emission system, which is 0.93 in this embodiment; is the average reflection coefficient of the target UAV shell to the laser, which is 0.3 in this embodiment; is the laser energy concentration ratio, which is 0.838 in this embodiment; is the coupling angle between the laser and the target UAV. In this implementation, 30° oblique illumination is used (for example, 1 km high and 1.7 km away); is the atmospheric transmission coefficient. In this embodiment, the atmospheric transmission coefficient of the near-infrared band at 1.3 km under the condition of 10 km visibility is 0.78.

[0033] Furthermore, the method is implemented by modeling and simulation using MATLAB software.

[0034] For ease of understanding, this embodiment is given as follows: Determine the shooting distance and target type based on user needs. Using foam and fiberglass as the damage materials, and a maximum UAV flight speed of 85m / s, if the target needs to be shot down at 1km, the laser needs to be able to damage the target at a distance of 1.85km. Taking into account the slant distance at a flight altitude of 1000m, the actual minimum starting damage distance is 2103m (not considering the distance caused by free fall after the target is shot down). Similarly, the relationship between different shooting distances and laser emission power is simulated through MATLAB. See Figures 2 to 4 .

[0035] Example Two: The embodiment of the present invention provides a computer device, such as a smart phone capable of executing programs, a tablet computer, a notebook computer, a desktop computer, a rack server, a blade server, a tower server or a cabinet server (including an independent server or a server cluster composed of multiple servers), etc. The computer device in this embodiment at least includes, but is not limited to, a memory and a processor that can communicate with each other through a system bus.

[0036] In this embodiment, the memory (i.e., the readable storage medium) includes flash memory, a hard disk, a multimedia card, a card-type memory (e.g., SD or DX memory, etc.), a random access memory (RAM), a static random access memory (SRAM), a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), a programmable read-only memory (PROM). The memory can also be an external storage device of the computer device, such as a plug-in hard disk equipped on the computer device, a SmartMedia Card (SMC), a Secure Digital (SD) card, a Flash Card, etc. Of course, the memory can also include both the internal storage unit of the computer device and its external storage device. In this embodiment, the memory is generally used to store the operating system installed on the computer device and various application software, such as the program code of the method for calculating the emission power of the marine laser in Example One. In addition, the memory can also be used to temporarily store various data that have been output or will be output.

[0037] In some embodiments, the processor can be a central processing unit (CPU), a controller, a microcontroller, a microprocessor, or other data processing chips. The processor is generally used to control the overall operation of the computer device. In this embodiment, the processor is used to run the program code stored in the memory or process data to implement the method for calculating the emission power of the marine laser in Example One.

[0038] Example Three: The present application also provides a computer-readable storage medium, such as a flash memory, a hard disk, a multimedia card, a card-type memory (e.g., SD or DX memory, etc.), a random access memory (RAM), a static random access memory (SRAM), a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), a programmable read-only memory (PROM), a magnetic memory, a magnetic disk, an optical disk, a server, an App application store, etc., on which a computer program is stored, and when the program is executed by a processor, corresponding functions are implemented. The computer-readable storage medium of this embodiment is used to store the program code of the method for calculating the emission power of a marine laser, and when executed by a processor, it implements the method for calculating the emission power of a marine laser in Embodiment 1.

[0039] It should be noted that according to the needs of implementation, the various steps / components described in the present application can be split into more steps / components, or two or more steps / components or partial operations of steps / components can be combined into new steps / components to achieve the purpose of the present invention.

[0040] Those skilled in the art can easily understand that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for calculating the emission power of a marine laser, characterized in that, Including: S1. Obtain the relationship between the laser transmission distance and the laser-to-target spot area according to the input atmospheric environment; S2. Obtain the damage conditions of the UAV according to the input UAV material type; S3. Determine the laser transmitter power according to the input shooting-down distance, UAV flight speed, the relationship between the laser transmission distance and the laser-to-target spot area, and the UAV damage conditions.

2. The method for calculating the emission power of a marine laser according to claim 1, wherein The types of the input atmospheric environment include marine environment and land environment.

3. The method for calculating the emission power of a marine laser according to claim 1, wherein The step S1 includes: S101. Determine the spot expansion caused by vacuum diffraction according to the laser transmission distance, laser emission aperture, and laser emission wavelength; S102. Determine the spot expansion caused by tracking according to the laser transmission distance and the variance of the optical axis jitter caused by tracking; S103. Determine the maximum distance for the phase to remain coherent between two points on the beam cross-section according to the plane wave parameters, laser emission wavelength, refractive index structure constant, and laser transmission distance; S104. Determine the beam quality factor generated by atmospheric turbulence according to the maximum distance for the phase to remain coherent between two points on the beam cross-section and the laser emission aperture; S105. Determine the laser beam quality factor after being affected by atmospheric turbulence according to the initial emitted beam quality factor and the beam quality factor generated by atmospheric turbulence; S106. Determine the laser-to-target spot area according to the laser beam quality factor after being affected by atmospheric turbulence, the spot expansion caused by vacuum diffraction, and the spot expansion caused by tracking.

4. The method for calculating the emission power of a marine laser according to claim 1, characterized in that, The UAV material types include fiberglass, carbon fiber, thin aluminum plate, model aircraft balsa wood / foam, and fiberglass reinforced plastic.

5. The method for calculating the emission power of a marine laser according to claim 1, characterized in that, When the laser power density on the target is greater than the corresponding power density threshold of a certain UAV material, and the laser energy density on the target is greater than the energy density threshold of this UAV material, it is considered that the damage condition of this UAV material is reached; when at least the damage condition of one of the UAV materials on the UAV is satisfied, it is considered that the UAV damage condition is reached.

6. The method for calculating the emission power of a marine laser according to claim 6, characterized in that, The step S3 includes: S301. Determine the laser power density on the target and the laser energy density on the target required to shoot down the UAV according to the UAV damage conditions; S302. Determine the irradiation time of the laser on the UAV according to the laser power density on the target and the laser energy density on the target; S303. Determine the minimum starting damage distance of the laser to the UAV according to the irradiation time of the laser on the UAV, the UAV flight speed, and the shooting-down distance; S304. Determine the laser transmitter power according to the laser-to-target spot area corresponding to the minimum starting damage distance.

7. The method for calculating the emission power of a marine laser according to claim 1, characterized in that, This method is realized by building a model and simulating using MATLAB software.

8. A computer device, comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, When the processor executes the computer program, it realizes the steps of the method for calculating the laser transmitter power of the marine laser according to any one of claims 1 to 7.

9. A computer storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it realizes the steps of the method for calculating the laser transmitter power of the marine laser according to any one of claims 1 to 7.

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