Ultra-long baseline transmission-type visibility monitoring method and related device

Abstract

The invention provides an ultra-long baseline transmission-type visibility monitoring method and a related device, and belongs to the technical field of visibility monitoring. The method comprises the following steps of: acquiring a second pulse signal by a transmitting end, and performing spectrum spreading on the obtained second pulse signal to obtain a second pulse signal after spectrum spreading; inputting the second pulse signal after spectrum spreading into an optical modulator to obtain a modulated second pulse signal; inputting the modulated second pulse signal into an optical amplifier to obtain a radiated optical signal; the receiving end obtains the signal output by the optical detector and despreads the obtained signal output by the optical detector to obtain the despread signal output by the optical detector; and monitoring the ultra-long baseline transmission-type visibility based on the signal output by the despread light detector to obtain an ultra-long baseline transmission-type visibility monitoring result. According to the invention, the problem that the full-path visibility monitoring above the kilometer level cannot be realized because estimation can only be carried out through a model extrapolation mode according to the measurement result of a relatively small observation area is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of visibility monitoring, and in particular relates to an ultra-long baseline transmission-type visibility monitoring method and related devices. Background Art

[0002] The baseline refers to the straight-line distance between the transmitting end (light source) and the receiving end (detector) of the photoelectric instrument. The baseline is one of the core parameters of the transmission optical measurement device and will directly affect the visibility measurement accuracy and measurement range.

[0003] Visibility monitoring is a core technology in modern meteorological and environmental observation, crucial for ensuring human safety and understanding atmospheric physical processes. By quantifying atmospheric transparency, visibility monitoring has direct applications in aviation safety (e.g., airport runway visibility warning), intelligent traffic management (speed control in foggy areas on highways), and environmental pollution assessment (analyzing the correlation between haze and visibility). It serves as a key basis for preventing low-visibility accidents and formulating emission reduction policies.

[0004] The baseline length of currently available transmission-type visibility monitoring devices is usually between 5 and 150 meters. It can only be estimated through model extrapolation based on the measurement results of a smaller observation area. Therefore, it is impossible to achieve full-path visibility monitoring above the kilometer level.

[0005] The existing transmission-type visibility monitoring devices have the following two drawbacks:

[0006] 1. When measuring “points leading to lines”, if there is an obvious non-uniform distribution phenomenon in the atmospheric environment (such as fog), the measurement results will have a large deviation.

[0007] 2. The measurement results under high visibility have low confidence due to short baseline and insufficient signal-to-noise ratio.

[0008] Furthermore, existing transmissive visibility monitoring devices cannot simply significantly extend the baseline length. While increasing the power and receiving aperture can marginally extend the measurement baseline, this would require not only larger sites and increased energy consumption, but also significantly increase site construction and maintenance costs. Summary of the Invention

[0009] The purpose of the present invention is to provide an ultra-long baseline transmission-type visibility monitoring method and related devices, which are used to solve the problem that the existing technology can only make estimates based on the measurement results of a smaller observation area through model extrapolation, and cannot achieve full-path visibility monitoring above the kilometer level.

[0010] In order to achieve the above object, the present invention adopts the following technical solutions:

[0011] In a first aspect, the present invention provides an ultra-long baseline transmission-type visibility monitoring method, comprising the following steps:

[0012] The transmitting end obtains the pulse-second signal and performs spectrum spreading on the obtained pulse-second signal to obtain a spectrum-spread pulse-second signal;

[0013] Inputting the spread spectrum pulse-second signal into the optical modulator to obtain a modulated pulse-second signal;

[0014] The modulated pulse-per-second signal is input into an optical amplifier to obtain a radiated optical signal;

[0015] The receiving end obtains the signal output by the optical detector and despreads the signal output by the optical detector to obtain the despread signal output by the optical detector;

[0016] The ultra-long baseline transmission type visibility is monitored based on the signal output by the despread optical detector to obtain the ultra-long baseline transmission type visibility monitoring result.

[0017] A further improvement of the present invention is that the calculation formula of the second pulse signal after spectrum spread is:

[0018] d(t)=a(t)·c(t)

[0019] Wherein, d(t) is the pulse-per-second signal after spectrum spreading, a(t) is the pulse-per-second signal, and c(t) is the spreading code.

[0020] A further improvement of the present invention is that the calculation formula of the modulated second pulse signal is:

[0021] s(t)=A2·a(t)·c(t)

[0022] Where s(t) is the modulated pulse-second signal, A2 is the gain of the optical modulator, a(t) is the pulse-second signal, and c(t) is the spread spectrum code.

[0023] A further improvement of the present invention is that the calculation formula of the radiated light signal is:

[0024] T(t)=A1·s(t)

[0025] Wherein, T(t) is the radiated optical signal, A1 is the gain of the optical amplifier, and s(t) is the modulated pulse-per-second signal.

[0026] A further improvement of the present invention is that the calculation formula of the signal output by the light detector is:

[0027] r1(t)=A3·R(t)+n(t)

[0028] Where r1(t) is the signal output by the light detector, A3 is the receiving gain, R(t) is the optical signal received by the receiver, and n(t) is the noise at the receiver.

[0029] The calculation formula of the optical signal R(t) received by the receiving end is:

[0030] R(t)=T(t)·q(t)

[0031] Where T(t) is the radiated light signal, and q(t) is the atmospheric optical information at both the transmitting and receiving ends.

[0032] A further improvement of the present invention is that the calculation formula of the signal output by the despread optical detector is:

[0033] r1(t)·c(t)=A3·T(t)·q(t)·c(t)+n(t)·c(t)

[0034] Where r1(t)·c(t) is the despread signal output by the optical detector, A3 is the receiving gain, T(t) is the radiated optical signal, q(t) is the atmospheric optical information at both the transmitter and receiver, c(t) is the spreading code, and n(t) is the noise at the receiver.

[0035] A further improvement of the present invention is that the calculation formula of the ultra-long baseline transmission visibility is:

[0036]

[0037] Among them, V is the ultra-long baseline transmission visibility, d is the distance of light propagation between the transmitter and the receiver, p is an empirical parameter, λ is the wavelength of the laser, and A r is the signal amplitude value output by the optical detector after despreading, EDFA o is the output power value read by EDFA (Erbium-Doped Fiber Amplifier), and K is the coefficient of the visibility monitoring system;

[0038] The calculation formula of the visibility monitoring system coefficient K is:

[0039]

[0040] Among them, η r is the efficiency of the receiving optical system, I ∞ is the total light intensity in the entire plane when the light propagates for a distance of d, R is the responsivity of the light detector, G is the amplification gain of the detector, G p is the processing gain, η t is the efficiency of the transmitting optical system, I r(d) is the total light intensity within the receiving aperture with a radius of r when the light propagates a distance d;

[0041] Processing gain G p The calculation formula is:

[0042]

[0043] Among them, G p is the processing gain, R c is the chip rate of the spreading code, B m is the baseband signal bandwidth.

[0044] In a second aspect, the present invention provides an ultra-long baseline transmission-type visibility monitoring system, comprising a spectrum spreading module, a modulation module, an amplification module, a despreading module, and a monitoring module;

[0045] The spectrum spreading module is used to obtain a second pulse signal at the transmitting end, and perform spectrum spreading on the obtained second pulse signal to obtain a second pulse signal after spectrum spreading;

[0046] The modulation module is used to input the second pulse signal after spectrum spread into the optical modulator to obtain a modulated second pulse signal;

[0047] The amplification module is used to input the modulated pulse-per-second signal into the optical amplifier to obtain a radiated optical signal;

[0048] The despreading module is used for obtaining the signal output by the optical detector at the receiving end, and despreading the signal output by the optical detector to obtain the despread signal output by the optical detector;

[0049] The monitoring module is used to monitor the ultra-long baseline transmission type visibility based on the signal output by the despread light detector to obtain the ultra-long baseline transmission type visibility monitoring result.

[0050] In a third aspect, the present invention provides an electronic device comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the ultra-long baseline transmission-type visibility monitoring method introduced above when executing the computer program.

[0051] In a fourth aspect, the present invention provides a storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the ultra-long baseline transmission-type visibility monitoring method introduced above.

[0052] Compared with the prior art, the present invention has the following beneficial effects:

[0053] The ultra-long baseline transmission-type visibility monitoring method proposed in the present invention, on the one hand, first performs spectrum spreading on the pulse-second signal at the transmitting end of the present invention to obtain the spread pulse-second signal, and then inputs the spread pulse-second signal into an optical modulator for processing. This operation can enhance the anti-interference capability of the pulse-second signal, thereby ensuring the stable transmission of the pulse-second signal. On the other hand, the signal output by the optical detector at the receiving end of the present invention is first despread to obtain the despread signal output by the optical detector, and then monitors the ultra-long baseline transmission-type visibility based on the despread signal output by the optical detector. This operation can improve the signal-to-noise ratio and thus increase the range of subsequent visibility monitoring, thereby effectively solving the problem in the prior art that it can only make estimates based on the measurement results of a smaller observation area through model extrapolation, and cannot achieve full-path visibility monitoring above the kilometer level. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 Flowchart of the ultra-long baseline transmission-type visibility monitoring method of the present invention;

[0055] Figure 2 Schematic diagram of the ultra-long baseline transmission-type visibility monitoring system of the present invention;

[0056] Figure 3 Schematic diagram of the ultra-long baseline transmission-type visibility monitoring method in Example 3 of the present invention;

[0057] Figure 4 Schematic diagram of the structure of the electronic device of the present invention. DETAILED DESCRIPTION

[0058] In order to further understand the content of the present invention, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the embodiments are only for explaining the present invention and are not intended to limit it.

[0059] The ultra-long baseline transmission-type visibility monitoring method proposed in the present invention comprises the following steps: a transmitter acquires a pulse-second signal and performs spectrum spreading on the acquired pulse-second signal to obtain a spread pulse-second signal; the spread pulse-second signal is input into an optical modulator to obtain a modulated pulse-second signal; the modulated pulse-second signal is input into an optical amplifier to obtain a radiated optical signal; a receiver acquires the signal output by a light detector and despreads the signal to obtain a despread light detector output signal; and ultra-long baseline transmission-type visibility is monitored based on the despread light detector output signal to obtain ultra-long baseline transmission-type visibility monitoring results. Compared with the prior art, the present invention effectively solves the problem that prior art methods can only estimate visibility over a small observation area through model extrapolation, thus failing to achieve full-path visibility monitoring at the kilometer level or above.

[0060] Example 1:

[0061] The flow chart of the ultra-long baseline transmission visibility monitoring method of the present invention is as follows: Figure 1 As shown, the ultra-long baseline transmission-type visibility monitoring method of the present invention comprises the following steps:

[0062] S1. The transmitter obtains a pulse-second signal and performs spectrum spreading on the obtained pulse-second signal to obtain a spread-spectrum pulse-second signal;

[0063] S2. The spread spectrum pulse-second signal is input into the optical modulator to obtain a modulated pulse-second signal;

[0064] S3. The modulated pulse-second signal is input into the optical amplifier to obtain a radiated optical signal;

[0065] S4. The receiving end obtains the signal output by the optical detector and despreads the signal output by the optical detector to obtain the despread signal output by the optical detector;

[0066] S5. Monitor the ultra-long baseline transmission visibility based on the signal output by the despread optical detector to obtain an ultra-long baseline transmission visibility monitoring result.

[0067] Example 2:

[0068] The schematic diagram of the ultra-long baseline transmission type visibility monitoring system of the present invention is as follows Figure 2 As shown, the ultra-long baseline transmission-type visibility monitoring system of the present invention includes a spectrum spreading module, a modulation module, an amplification module, a despreading module and a monitoring module.

[0069] The spectrum spreading module is used to obtain the pulse-per-second signal at the transmitting end, and perform spectrum spreading on the obtained pulse-per-second signal to obtain the spread-spectrum pulse-per-second signal.

[0070] The modulation module is used to input the second pulse signal after spectrum spread into the optical modulator to obtain a modulated second pulse signal.

[0071] The amplification module is used to input the modulated second pulse signal into the optical amplifier to obtain a radiated optical signal.

[0072] The despreading module is used at the receiving end to obtain the signal output by the optical detector, and despread the obtained signal output by the optical detector to obtain the despread signal output by the optical detector.

[0073] The monitoring module is used to monitor the ultra-long baseline transmission type visibility based on the signal output by the despread optical detector to obtain the ultra-long baseline transmission type visibility monitoring result.

[0074] Example 3:

[0075] The principle diagram of the ultra-long baseline transmission type visibility monitoring method of the present invention is as follows: Figure 3 As shown, the ultra-long baseline transmission-type visibility monitoring method of the present invention comprises the following steps:

[0076] In this embodiment, a baseline longer than 500 meters is determined to be an ultra-long baseline.

[0077] S1. The transmitter obtains a pulse-per-second signal and performs spectrum spreading on the obtained pulse-per-second signal to obtain a spread-spectrum pulse-per-second signal.

[0078] First, the transmitter obtains a second pulse signal (also called second pulse) a(t), and performs spectrum spreading on the obtained second pulse signal to obtain a second pulse signal d(t) after spectrum spreading.

[0079] The calculation formula of the second pulse signal after spectrum spread is:

[0080] d(t)=a(t)·c(t)

[0081] Wherein, d(t) is the pulse-per-second signal after spectrum spreading, a(t) is the pulse-per-second signal, and c(t) is the spreading code.

[0082] S2. Input the spread-spectrum pulse-second signal into the optical modulator to obtain a modulated pulse-second signal.

[0083] Specifically, the spread spectrum pulse-per-second signal d(t) is input into an optical modulator and modulated on an optical signal with a center frequency f0 to obtain a modulated pulse-per-second signal.

[0084] The calculation formula of the modulated second pulse signal is:

[0085] s(t)=A2·a(t)·c(t)

[0086] Where s(t) is the modulated pulse-second signal, A2 is the gain of the optical modulator, a(t) is the pulse-second signal, and c(t) is the spread spectrum code.

[0087] S3. Input the modulated second pulse signal into the optical amplifier to obtain a radiated optical signal.

[0088] The calculation formula of the radiated light signal is:

[0089] T(t)=A1·s(t)

[0090] Wherein, T(t) is the radiated optical signal, A1 is the gain of the optical amplifier, and s(t) is the modulated pulse-per-second signal.

[0091] S4. The receiving end obtains the signal output by the optical detector and despreads the signal output by the optical detector to obtain the despread signal output by the optical detector.

[0092] The receiving end obtains the signal r1(t) output by the optical detector, and despreads the obtained signal output by the optical detector to obtain the despread signal r2(t) output by the optical detector.

[0093] The calculation formula of the signal output by the light detector is:

[0094] r1(t)=A3·R(t)+n(t)

[0095] Where r1(t) is the signal output by the optical detector, A3 is the receiving gain, R(t) is the optical signal received by the receiver, and n(t) is the noise at the receiver.

[0096] The calculation formula of the optical signal R(t) received by the receiving end is:

[0097] R(t)=T(t)·q(t)

[0098] Where T(t) is the radiated light signal, and q(t) is the atmospheric optical information at both the transmitting and receiving ends.

[0099] The calculation formula of the signal output by the despread optical detector is:

[0100] r1(t)·c(t)=A3·T(t)·q(t)·c(t)+n(t)·c(t)

[0101] Where r1(t)·c(t) is the despread signal output by the optical detector, A3 is the receiving gain, T(t) is the radiated optical signal, q(t) is the atmospheric optical information at both the transmitter and receiver, c(t) is the spreading code, and n(t) is the noise at the receiver.

[0102] Express r1(t)·c(t) as r2(t), and substitute the calculation formulas of r1(t) and T(t) into r1(t)·c(t). The final calculation formula of r2(t) is:

[0103]

[0104] Among them, r2(t) is the signal output by the despread optical detector, A is the integrated gain, a(t) is the pulse-per-second signal, q(t) is the atmospheric optical information at both the transmitter and receiver, n(t) is the noise at the receiver, and B m is the baseband signal bandwidth, R c is the chip rate of the spreading code.

[0105] The calculation formula of comprehensive gain A is:

[0106] A=A1·A2·A3

[0107] Among them, A1 is the gain of the optical amplifier, A2 is the gain of the optical modulator, and A3 is the receiving gain.

[0108] S5. Monitor the ultra-long baseline transmission visibility based on the signal output by the despread optical detector to obtain an ultra-long baseline transmission visibility monitoring result.

[0109] The calculation formula of ultra-long baseline transmission visibility is:

[0110]

[0111] Where V is the ultra-long baseline transmission visibility, d is the distance of light propagation between the transmitter and the receiver (i.e., the measurement baseline length), p is an empirical parameter, λ is the wavelength of the laser, and A r is the signal amplitude value output by the optical detector after despreading, EDFA o is the output power value read by EDFA, and K is the coefficient of the visibility monitoring system.

[0112] The calculation formula of the visibility monitoring system coefficient K is:

[0113]

[0114] Among them, η r is the efficiency of the receiving optical system, I ∞ is the total light intensity in the entire plane when the light propagates for a distance of d, R is the responsivity of the light detector, G is the amplification gain of the detector, G p is the processing gain, η t is the efficiency of the transmitting optical system, I r (d) is the total light intensity within the receiving aperture with a radius of r when the light propagates a distance d.

[0115] Processing gain G p The calculation formula is:

[0116]

[0117] Among them, G p is the processing gain, R c is the chip rate of the spreading code, B m is the baseband signal bandwidth.

[0118] The total light intensity I within the receiving aperture with a radius of r when the light propagates for a distance of d r (d) and the total light intensity I in the entire plane when the distance of light propagation is d ∞ Specifically, I(r,z) is the sum of r in [0,r r ] and the integral over [0,+∞), the calculation formula of I(r,z) is:

[0119]

[0120] Where I0 is the peak irradiance at the center of the beam, r is the radial distance from the axis, and w(z) is the radius of the laser beam, i.e., the irradiance is 1 / e of I0. 2 The radius of the circle surrounding the fortress, w0 is the beam waist radius, and z is the distance the wavefront propagates from the plane when it is flat.

[0121] The calculation formula of the beam waist radius w0 is:

[0122]

[0123] Among them, θ is the divergence angle at both ends of the beam waist, and λ is the wavelength of the laser.

[0124] Example 4:

[0125] See also Figure 4 As shown, the present invention also provides an electronic device 100 for an ultra-long baseline transmission visibility monitoring method; the electronic device 100 includes a memory 101, at least one processor 102, a computer program 103 stored in the memory 101 and executable on the at least one processor 102, and at least one communication bus 104.

[0126] The memory 101 can be used to store the computer program 103. The processor 102 implements the steps of the ultra-long baseline transmissive visibility monitoring method described in Example 1 by running or executing the computer program stored in the memory 101 and calling the data stored in the memory 101. The memory 101 can mainly include a program storage area and a data storage area. The program storage area can store an operating system and at least one application required for a function (such as a sound playback function, an image playback function, etc.); the data storage area can store data (such as audio data) generated based on the use of the electronic device 100. In addition, the memory 101 can include non-volatile memory, such as a hard disk, internal memory, a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device.

[0127] The at least one processor 102 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The processor 102 may be a microprocessor or any conventional processor, etc. The processor 102 is the control center of the electronic device 100 and connects various parts of the entire electronic device 100 using various interfaces and lines.

[0128] The memory 101 in the electronic device 100 stores a plurality of instructions to implement the ultra-long baseline transmission-type visibility monitoring method, and the processor 102 can execute the plurality of instructions to implement:

[0129] The transmitting end obtains the pulse-second signal and performs spectrum spreading on the obtained pulse-second signal to obtain a spectrum-spread pulse-second signal;

[0130] Inputting the spread spectrum pulse-second signal into the optical modulator to obtain a modulated pulse-second signal;

[0131] The modulated pulse-per-second signal is input into an optical amplifier to obtain a radiated optical signal;

[0132] The receiving end obtains the signal output by the optical detector and despreads the signal output by the optical detector to obtain the despread signal output by the optical detector;

[0133] The ultra-long baseline transmission type visibility is monitored based on the signal output by the despread optical detector to obtain the ultra-long baseline transmission type visibility monitoring result.

[0134] Example 5:

[0135] If the module / unit integrated in the electronic device 100 is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the process in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form, etc. The computer-readable medium may include: any entity or device that can carry the computer program code, recording medium, U disk, mobile hard disk, magnetic disk, optical disk, computer memory and read-only memory (ROM, Read-Only Memory).

[0136] It will be understood by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0137] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, 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 produce 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 flowcharts and / or block diagrams. 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.

[0138] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work 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 The function specified in one or more boxes.

[0139] 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 the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0140] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the 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 by the scope of protection of the claims of the present invention.

Claims

1. An ultra-long baseline transmission visibility monitoring method, characterized in that: The following steps are involved: The transmitting end obtains the pulse-second signal and performs spectrum spreading on the obtained pulse-second signal to obtain a spectrum-spread pulse-second signal; Inputting the spread spectrum pulse-second signal into the optical modulator to obtain a modulated pulse-second signal; The modulated pulse-per-second signal is input into an optical amplifier to obtain a radiated optical signal; The receiving end obtains the signal output by the optical detector and despreads the signal output by the optical detector to obtain the despread signal output by the optical detector; The ultra-long baseline transmission type visibility is monitored based on the signal output by the despread optical detector to obtain the ultra-long baseline transmission type visibility monitoring result.

2. The ultra-long baseline transmission-type visibility monitoring method according to claim 1, characterized in that: The calculation formula of the second pulse signal after spectrum spread is: d(t)=a(t)·c(t) Wherein, d(t) is the pulse-per-second signal after spectrum spreading, a(t) is the pulse-per-second signal, and c(t) is the spreading code.

3. The ultra-long baseline transmission-type visibility monitoring method according to claim 1, characterized in that: The calculation formula of the modulated second pulse signal is: s(t)=A2·a(t)·c(t) Where s(t) is the modulated pulse-second signal, A2 is the gain of the optical modulator, a(t) is the pulse-second signal, and c(t) is the spread spectrum code.

4. The ultra-long baseline transmission-type visibility monitoring method according to claim 1, characterized in that: The calculation formula of the radiated light signal is: T(t)=A1·s(t) Wherein, T(t) is the radiated optical signal, A1 is the gain of the optical amplifier, and s(t) is the modulated pulse-per-second signal.

5. The ultra-long baseline transmission-type visibility monitoring method according to claim 1, characterized in that: The calculation formula of the signal output by the light detector is: r1(t)=A3·R(t)+n(t) Where r1(t) is the signal output by the light detector, A3 is the receiving gain, R(t) is the optical signal received by the receiver, and n(t) is the noise at the receiver. The calculation formula of the optical signal R(t) received by the receiving end is: R(t)=T(t)·q(t) Where T(t) is the radiated light signal, and q(t) is the atmospheric optical information at both the transmitting and receiving ends.

6. The ultra-long baseline transmission-type visibility monitoring method according to claim 1, characterized in that: The calculation formula of the signal output by the despread optical detector is: r1(t)·c(t)=A3·T(t)·q(t)·c(t)+n(t)·c(t) Where r1(t)·c(t) is the despread signal output by the optical detector, A3 is the receiving gain, T(t) is the radiated optical signal, q(t) is the atmospheric optical information at both the transmitter and receiver, c(t) is the spreading code, and n(t) is the noise at the receiver.

7. The ultra-long baseline transmission-type visibility monitoring method according to claim 1, characterized in that: The calculation formula of ultra-long baseline transmission visibility is: Among them, V is the ultra-long baseline transmission visibility, d is the distance of light propagation between the transmitter and the receiver, p is an empirical parameter, λ is the wavelength of the laser, and A r is the signal amplitude value output by the optical detector after despreading, EDFA o is the output power value read by EDFA, K is the coefficient of visibility monitoring system; The calculation formula of the visibility monitoring system coefficient K is: Among them, η r is the efficiency of the receiving optical system, I ∞ is the total light intensity in the entire plane when the light propagates for a distance of d, R is the responsivity of the light detector, G is the amplification gain of the detector, G p is the processing gain, η t is the efficiency of the transmitting optical system, I r (d) is the total light intensity within the receiving aperture with a radius of r when the light propagates a distance d; Processing gain G p The calculation formula is: Among them, G p is the processing gain, R c is the chip rate of the spreading code, B m is the baseband signal bandwidth.

8. An ultra-long baseline transmission-type visibility monitoring system, characterized in that: It includes a spectrum spreading module, a modulation module, an amplification module, a despreading module and a monitoring module; The spectrum spreading module is used to obtain a second pulse signal at the transmitting end, and perform spectrum spreading on the obtained second pulse signal to obtain a second pulse signal after spectrum spreading; The modulation module is used to input the second pulse signal after spectrum spread into the optical modulator to obtain a modulated second pulse signal; The amplification module is used to input the modulated pulse-per-second signal into the optical amplifier to obtain a radiated optical signal; The despreading module is used for obtaining the signal output by the optical detector at the receiving end, and despreading the signal output by the optical detector to obtain the despread signal output by the optical detector; The monitoring module is used to monitor the ultra-long baseline transmission type visibility based on the signal output by the despread light detector to obtain the ultra-long baseline transmission type visibility monitoring result.

9. An electronic device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the ultra-long baseline transmission-type visibility monitoring method described in any one of claims 1 to 7 are implemented.

10. A storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the ultra-long baseline transmission-type visibility monitoring method according to any one of claims 1 to 7 are implemented.

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