Method, device and equipment for calculating theoretical extreme cloud penetrating capability of single-photon laser radar

Abstract

The invention relates to the technical field of radars, in particular to a single-photon laser radar theoretical extreme cloud penetrating capability calculation method, device and equipment, and the method comprises the steps: obtaining environment parameters and cloud feature data in a target scene, carrying out the Monte Carlo simulation according to the environment parameters and the cloud feature data, obtaining optical parameters of a corresponding cloud, and obtaining the theoretical extreme cloud penetrating capability of the target scene; constructing a signal and noise model of the spaceborne laser radar based on the environmental parameters, the cloud feature data, the optical parameters and system parameters of the spaceborne laser radar, and calculating theoretical noise and theoretical signals in a target scene by using the signal and noise model; and finally, according to the theoretical noise and the theoretical signal, calculating the theoretical limit cloud penetrating capability of the spaceborne laser radar, if the theoretical limit cloud penetrating capability exceeds a threshold value in the target scene, determining that the spaceborne laser radar can penetrate the cloud with the corresponding optical thickness, otherwise, updating the optical thickness of the corresponding cloud. Therefore, the problem that the applicability of the satellite-borne single-photon laser radar under different atmospheric conditions is not high is solved.

Description

Technical Field

[0001] The present application relates to the field of radar technology, and in particular to a method, device and equipment for calculating the theoretical limit of cloud penetration capability of a single-photon laser radar. Background Art

[0002] Spaceborne single-photon lidar receives information from the atmosphere and surface by emitting laser pulses to the Earth's surface. It has the potential to operate with high resolution, high precision and around the clock, and plays an important role in atmospheric remote sensing, Earth observation, polar glacier detection and marine environment monitoring.

[0003] However, the presence of clouds causes laser signal attenuation and scattering, significantly increasing background noise, thus limiting the effective detection of the ground and other targets beneath the clouds. In thick cloud cover, the detection capability of the lidar may be significantly reduced, or even impossible to penetrate. Summary of the Invention

[0004] The present application provides a method, device and equipment for calculating the theoretical limit of cloud penetration capability of single-photon lidar, so as to solve the problem that spaceborne single-photon lidar is not very applicable under different atmospheric conditions.

[0005] In a first aspect, the present application provides a method for calculating the theoretical limit cloud penetration capability of a single-photon lidar, comprising the following steps: obtaining environmental parameters and cloud characteristic data in a target scene, performing Monte Carlo simulation based on the environmental parameters and cloud characteristic data to obtain optical parameters of the corresponding cloud; constructing a signal and noise model of the satellite-borne lidar based on the environmental parameters, cloud characteristic data, optical parameters and system parameters of the satellite-borne lidar, and using the signal and noise model to calculate the theoretical noise and theoretical signal in the target scene; calculating the theoretical limit cloud penetration capability of the satellite-borne lidar based on the theoretical noise and theoretical signal; if the theoretical limit cloud penetration capability exceeds a threshold value in the target scene, it is determined that the satellite-borne lidar can penetrate clouds of the corresponding optical thickness; otherwise, the optical thickness of the corresponding cloud is updated.

[0006] Optionally, a Monte Carlo simulation is performed based on environmental parameters and cloud characteristic data to obtain optical parameters of the corresponding cloud, including: generating photon packets, initializing the weights and propagation directions of the photon packets; calculating the optical depth of each free transmission when the photon packets collide with particles in the cloud; updating the weights and propagation directions of the photon packets based on the optical depth until the photon packets encounter boundary conditions or termination conditions, and calculating the optical parameters based on the total weight of the photon packets when the simulation of all photon packets is completed.

[0007] Optionally, updating the weight and propagation direction of the photon packet according to the optical depth includes: updating the weight and coordinates of the photon packet according to the optical depth; and updating the propagation direction of the photon packet according to the coordinates of the photon packet.

[0008] Optionally, when the simulation of all photon packets is completed, the optical parameters are calculated based on the total weight of the photon packets, including: when the photon packet passes through the upper boundary, judging whether the propagation direction of the photon packet is received by the receiving field of view, and if so, accumulating the current weight of the photon packet, and when the simulation of all photon packets is completed, calculating the cloud top reflectivity parameter based on the total weight of the photon packets captured by the receiving field of view; when the photon packet passes through the lower boundary, accumulating the current weight of the photon packet, and calculating the cloud diffuse transmittance based on the total weight of the photon packets reaching the lower boundary.

[0009] Optionally, the signal and noise model includes a calculation formula for a theoretical signal and a calculation formula for a theoretical noise, wherein: The calculation formula of the theoretical signal is:

[0010] in, is the laser energy; is the laser emission efficiency; is the receiver optical efficiency; is the detector quantum efficiency; is the laser zenith angle; is the effective optical area of ​​the receiver telescope; is the satellite flight altitude; represents Planck's constant; Indicates the laser frequency; is the correction coefficient of the lidar system; is the surface reflectivity; is the atmospheric direct transmittance; 、 and They are the optical thickness of atmospheric molecules, aerosols and the ozone layer;

[0011] The calculation formula of theoretical noise is:

[0012] in, It is the background noise caused by the backscattering of solar radiation by the atmospheric medium; is the background noise reflected by the Earth's surface from the sun's radiation; is the background noise of the interaction between the atmosphere and the surface; is the dark count noise of the detector.

[0013] Optionally, the theoretical limit cloud penetration capability of the spaceborne lidar is calculated based on the theoretical noise and the theoretical signal, including: estimating the signal echo waveform of the spaceborne lidar; using the harmonic coefficients of the precision rate and the recall rate as parameters of the signal photon extraction algorithm; and calculating the theoretical limit cloud penetration capability corresponding to the theoretical noise and the theoretical signal through the signal echo waveform and the signal photon extraction algorithm.

[0014] Optionally, the calculation formula of the signal echo waveform is:

[0015] in, Represents the convolution operation; is the system impulse response function; is the surface response function; is a Gaussian function.

[0016] Optionally, the calculation formula for the theoretical limit cloud penetration capability is:

[0017] in, and are the starting and ending positions of the signal photon; is the center elevation; is the number of detector channels; is the photon number threshold in the neighborhood; is the theoretical noise; is the surface atmospheric pressure; is the detection probability of each channel; is the elevation range where noise points may exist; is the speed of light; is the RMS pulse width of the signal; For a given and algorithm parameters, based on the Poisson distribution of random variables Exceed Minpts probability; is the repetition frequency of the laser; is the satellite flight speed; is the length of the minor axis of the ellipse; is the ratio of the major and minor axes of the ellipse; For interval and The time interval obtained by discretizing each layer within .

[0018] The second aspect of the present application provides a device for calculating the theoretical limit cloud penetration capability of a single-photon lidar, including: a simulation module for obtaining environmental parameters and cloud characteristic data in a target scene, performing Monte Carlo simulation based on the environmental parameters and cloud characteristic data, and obtaining optical parameters of the corresponding cloud; a construction module for constructing a signal and noise model of the satellite-borne lidar based on the environmental parameters, cloud characteristic data, optical parameters and system parameters of the satellite-borne lidar, and using the signal and noise model to calculate the theoretical noise and theoretical signal in the target scene; a calculation module for calculating the theoretical limit cloud penetration capability of the satellite-borne lidar based on the theoretical noise and theoretical signal. If the theoretical limit cloud penetration capability exceeds the threshold value in the target scene, it is determined that the satellite-borne lidar can penetrate clouds of the corresponding optical thickness; otherwise, the optical thickness of the corresponding cloud is updated.

[0019] The third aspect of the present application provides an electronic device, comprising: a memory, a processor, and a computer program stored in the memory and runnable on the processor, wherein the processor executes the program to implement the method for calculating the theoretical limit cloud penetration capability of the single-photon lidar of the first aspect.

[0020] Therefore, this application has the following beneficial effects: The embodiment of the present application obtains the environmental parameters and cloud characteristic data in the target scene, performs Monte Carlo simulation based on the two, obtains the optical parameters of the corresponding cloud, and then constructs a signal and noise model of the satellite-borne laser radar based on the environmental parameters, cloud characteristic data, optical parameters and system parameters of the satellite-borne laser radar. The signal and noise model is used to calculate the theoretical noise and theoretical signal in the target scene. Finally, the theoretical limit cloud penetration capability of the satellite-borne laser radar is calculated based on the theoretical noise and theoretical signal. If the theoretical limit cloud penetration capability exceeds the threshold value in the target scene, it is determined that the satellite-borne laser radar can penetrate the cloud of the corresponding optical thickness. Otherwise, the optical thickness of the corresponding cloud is updated. The theoretical limit cloud penetration capability of the satellite-borne single-photon laser radar can be calculated, and the applicability of the satellite-borne laser radar under different atmospheric conditions can be evaluated. In this way, the problem of low applicability of the satellite-borne single-photon laser radar under different atmospheric conditions is solved.

[0021] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which: Figure 1 A schematic flow chart of a method for calculating the theoretical limit of cloud penetration capability of a single-photon lidar provided in accordance with an embodiment of the present application; Figure 2This is a flow chart of an embodiment of a method for calculating the theoretical limit cloud penetration capability of a spaceborne single-photon lidar provided according to one embodiment of the present application; Figure 3 A schematic diagram of the point cloud distribution of single-track sample data provided according to one embodiment of the present application and the theoretical limit cloud penetration capability using the calculation method of the present invention; Figure 4 Schematic diagram of the structure of a device for calculating the theoretical limit of cloud penetration capability of a single-photon laser radar according to an embodiment of the present application; Figure 5 A schematic diagram of the structure of an electronic device provided according to an embodiment of the present application. DETAILED DESCRIPTION

[0023] The following describes in detail embodiments of the present application. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0024] The following describes the method, device and equipment for calculating the theoretical limit cloud penetration capability of a single-photon laser radar according to an embodiment of the present application with reference to the accompanying drawings. In response to the problem of low applicability of satellite-borne single-photon laser radars under different atmospheric conditions mentioned in the above background technology, the present application provides a method for calculating the theoretical limit cloud penetration capability of a single-photon laser radar. In this method, by obtaining environmental parameters and cloud feature data under the target scene, a Monte Carlo simulation is performed based on the two to obtain the optical parameters of the corresponding cloud. Then, a signal and noise model of the satellite-borne laser radar is constructed based on the environmental parameters, cloud feature data, optical parameters and system parameters of the satellite-borne laser radar. The theoretical noise and theoretical signal under the target scene are calculated using the signal and noise model. Finally, the theoretical limit cloud penetration capability of the satellite-borne laser radar is calculated based on the theoretical noise and theoretical signal. If the theoretical limit cloud penetration capability exceeds the threshold under the target scene, it is determined that the satellite-borne laser radar can penetrate the cloud of the corresponding optical thickness. Otherwise, the optical thickness of the corresponding cloud is updated. The theoretical limit cloud penetration capability of the satellite-borne single-photon laser radar can be calculated to evaluate the applicability of the satellite-borne laser radar under different atmospheric conditions. Thus, the problem of low applicability of satellite-borne single-photon laser radar under different atmospheric conditions is solved.

[0025] Specifically, Figure 1 A flowchart of a method for calculating the theoretical limit of cloud penetration capability of a single-photon lidar provided in an embodiment of the present application.

[0026] like Figure 1 As shown, the method for calculating the theoretical limit of cloud penetration capability of the single-photon laser radar includes the following steps: In step S101, environmental parameters and cloud characteristic data of a target scene are obtained, and Monte Carlo simulation is performed based on the environmental parameters and cloud characteristic data to obtain optical parameters of the corresponding cloud.

[0027] Among them, environmental parameters include the solar zenith angle and solar azimuth angle; cloud characteristic data include cloud type and cloud optical thickness; cloud optical parameters include cloud top reflectivity and cloud diffuse transmittance; Monte Carlo simulation is a computational algorithm based on repeated random sampling, which is used to simulate the transmission process of photons in the cloud layer to obtain cloud optical parameters.

[0028] It is understandable that the embodiments of the present application can calculate the optical parameters of the cloud layer by simulating the transmission of photons in the cloud layer based on the environmental parameters of the target scene and cloud characteristic data using the Monte Carlo simulation method.

[0029] In an embodiment of the present application, a Monte Carlo simulation is performed based on environmental parameters and cloud characteristic data to obtain the optical parameters of the corresponding cloud, including: generating photon packets and initializing the weights and propagation directions of the photon packets; when the photon packets collide with particles in the cloud, calculating the optical depth of each free transmission; updating the weights and propagation directions of the photon packets according to the optical depth until the photon packets encounter boundary conditions or termination conditions. When the simulation of all photon packets is completed, the optical parameters are calculated based on the total weight of the photon packets.

[0030] The boundary condition or termination condition refers to the stopping condition set during the simulation process. It can be set to stop the simulation when the geometric position of the photon packet leaves the cloud layer of the set optical thickness, or when the energy (weight) of the photon packet is less than 0. The specific setting is based on the actual situation and is not specifically limited here.

[0031] It can be understood that the embodiment of the present application uses the Monte Carlo simulation method to generate and track the transmission process of multiple photon packets in the cloud layer based on environmental parameters and cloud characteristic data. First, the weight and propagation direction of the photon packet are initialized, and the optical depth when the photon packet collides with the particles in the cloud layer is calculated. The optical depth is used to update the weight and direction of the photon packet until the photon packet meets the boundary condition or termination condition. Finally, at the end of the simulation of all photon packets, the optical parameters of the cloud layer are calculated based on the total weight of all photon packets.

[0032] In an embodiment of the present application, updating the weight and propagation direction of the photon packet according to the optical depth includes: updating the weight and coordinates of the photon packet according to the optical depth; and updating the propagation direction of the photon packet according to the coordinates of the photon packet.

[0033] It can be understood that the embodiment of the present application is divided into two steps to update the weight and propagation direction of the photon packet according to the optical depth. First, the weight of the photon packet is updated by the calculated optical depth, and the coordinates of the photon packet are updated to represent its new position. Then, the propagation direction of the photon packet is updated based on the new coordinate position.

[0034] In an embodiment of the present application, when the simulation of all photon packets is completed, the optical parameters are calculated based on the total weight of the photon packets, including: when the photon packet passes through the upper boundary, determining whether the propagation direction of the photon packet is received by the receiving field of view, and if so, accumulating the current weight of the photon packet, and when the simulation of all photon packets is completed, calculating the cloud top reflectivity parameter based on the total weight of the photon packets captured by the receiving field of view; when the photon packet passes through the lower boundary, accumulating the current weight of the photon packet, and calculating the cloud diffuse transmittance based on the total weight of the photon packets reaching the lower boundary.

[0035] Among them, the total weight of the photon packet captured by the receiving field of view is , the cloud top reflectivity can be calculated as: ; Let the total weight of the photon packet reaching the lower boundary be , the cloud diffuse transmittance can be calculated as: , in the above two formulas is the total number of photon packets; is the half field of view angle of the lidar receiving aperture.

[0036] It can be understood that after all photon packets are simulated, the embodiment of the present application calculates the optical parameters based on the total weight of the photon packets, accumulates the weights of these photon packets by judging whether the photon packets that pass through the upper boundary of the cloud layer fall into the receiving field of view, and calculates the cloud top reflectivity parameters according to the total weight of the photon packets captured by the receiving field of view angle using the above formula; at the same time, the weights of the photon packets that pass through the lower boundary of the cloud layer and reach the ground are accumulated, and the cloud diffuse transmittance is calculated according to the total weight of the photon packets that reach the lower boundary using the above formula.

[0037] In step S102, a signal and noise model of the spaceborne lidar is constructed based on environmental parameters, cloud feature data, optical parameters and system parameters of the spaceborne lidar, and the theoretical noise and theoretical signal in the target scene are calculated using the signal and noise model.

[0038] It can be understood that the embodiments of the present application can utilize environmental parameters, cloud feature data and optical parameters obtained through Monte Carlo simulation, combined with the system parameters of the satellite-borne lidar system, to construct a signal and noise model to calculate the theoretical noise and theoretical signal that the lidar is expected to receive in the target scene.

[0039] In the embodiment of the present application, the signal and noise model includes a calculation formula for a theoretical signal and a calculation formula for a theoretical noise, wherein: The calculation formula of the theoretical signal is:

[0040] in, is the laser energy; is the laser emission efficiency; is the receiver optical efficiency; is the detector quantum efficiency; is the laser zenith angle; is the effective optical area of ​​the receiver telescope; is the satellite flight altitude; represents Planck's constant; Indicates the laser frequency; is the correction coefficient of the lidar system; is the surface reflectivity; is the atmospheric direct transmittance; 、 and They are the optical thickness of atmospheric molecules, aerosols and the ozone layer;

[0041] The calculation formula of theoretical noise is:

[0042] in, It is the background noise caused by the backscattering of solar radiation by the atmospheric medium; is the background noise reflected by the Earth's surface from the sun's radiation; is the background noise of the interaction between the atmosphere and the surface; is the dark count noise of the detector.

[0043] In step S103, the theoretical limit cloud penetration capability of the spaceborne lidar is calculated based on the theoretical noise and theoretical signal. If the theoretical limit cloud penetration capability exceeds the threshold value under the target scene, it is determined that the spaceborne lidar can penetrate clouds of the corresponding optical thickness; otherwise, the optical thickness of the corresponding cloud is updated.

[0044] The threshold is set according to actual needs and is not specifically limited here. Generally, it can be set to 0.8.

[0045] It can be understood that the embodiments of the present application can evaluate the theoretical limit cloud penetration capability of the satellite-borne lidar in the target scene based on the calculated theoretical noise and theoretical signal, and determine whether the theoretical limit cloud penetration capability exceeds the preset threshold. If it exceeds, it is confirmed that the lidar can penetrate the cloud layer of this optical thickness; otherwise, the optical thickness of the corresponding cloud needs to be updated.

[0046] In an embodiment of the present application, the theoretical limit cloud penetration capability of the spaceborne lidar is calculated based on the theoretical noise and the theoretical signal, including: estimating the signal echo waveform of the spaceborne lidar; using the harmonic coefficients of the precision rate and the recall rate as parameters of the signal photon extraction algorithm; and calculating the theoretical limit cloud penetration capability corresponding to the theoretical noise and the theoretical signal through the signal echo waveform and the signal photon extraction algorithm.

[0047] The signal echo waveform depends on the surface scattering characteristics, surface shape, and the impulse response function of the system. The calculation method will be described in detail below and will not be repeated here. The precision rate refers to the proportion of samples predicted as positive by the classifier that are actually positive. The recall rate refers to the proportion of samples that are actually positive that are correctly predicted as positive. The harmonic coefficient of the precision rate and the recall rate is the weighted harmonic mean of the precision rate and the recall rate.

[0048] It can be understood that the embodiments of the present application can first estimate the signal echo waveform of the spaceborne lidar based on the theoretical noise and theoretical signal, and then use the harmonic coefficient calculated by the precision rate and the recall rate as the parameter of the signal photon extraction algorithm. Through the signal echo waveform and the signal photon extraction algorithm, the theoretical limit cloud penetration capability of the spaceborne lidar corresponding to the current theoretical noise and signal levels is calculated.

[0049] In the embodiment of the present application, the calculation formula of the signal echo waveform is:

[0050] in, Represents the convolution operation; is the system impulse response function; is the surface response function; is a Gaussian function.

[0051] In the embodiment of the present application, the calculation formula for the theoretical limit cloud penetration capability is:

[0052] in, and are the starting and ending positions of the signal photon; is the center elevation; is the number of detector channels; is the photon number threshold in the neighborhood; is the theoretical noise; is the surface atmospheric pressure; is the detection probability of each channel; is the elevation range where noise points may exist; is the speed of light; is the RMS pulse width of the signal; For a given and algorithm parameters, based on the Poisson distribution of random variables Exceed Minpts probability; is the repetition frequency of the laser; is the satellite flight speed; is the length of the minor axis of the ellipse; is the ratio of the major and minor axes of the ellipse; For interval and The time interval obtained by discretizing each layer within .

[0053] According to the method for calculating the theoretical limit cloud penetration capability of a single-photon lidar proposed in an embodiment of the present application, by obtaining environmental parameters and cloud characteristic data in the target scene, Monte Carlo simulation is performed based on the two to obtain the optical parameters of the corresponding cloud, and then a signal and noise model of the satellite-borne lidar is constructed based on the environmental parameters, cloud characteristic data, optical parameters and system parameters of the satellite-borne lidar. The theoretical noise and theoretical signal in the target scene are calculated using the signal and noise model. Finally, the theoretical limit cloud penetration capability of the satellite-borne lidar is calculated based on the theoretical noise and theoretical signal. If the theoretical limit cloud penetration capability exceeds the threshold in the target scene, it is determined that the satellite-borne lidar can penetrate clouds of the corresponding optical thickness. Otherwise, the optical thickness of the corresponding cloud is updated. The theoretical limit cloud penetration capability of the satellite-borne single-photon lidar can be calculated, and the applicability of the satellite-borne lidar under different atmospheric conditions can be evaluated.

[0054] The following is a further description of the calculation method of the theoretical limit of cloud penetration capability of single-photon laser radar through a specific embodiment. Figure 2 This is a flow chart of an embodiment of a method for calculating the theoretical limit of cloud penetration capability of the satellite-borne single-photon lidar in this embodiment. In this embodiment, the lidar adopts the new generation photon counting lidar ICESat-2, and the target area is a certain province area selected in this embodiment. ICESat-2 is equipped with a photon counting lidar ATLAS, which can measure and record at the level of single photons. ATLAS emits 532nm laser pulses at a repetition frequency of 10Khz and acquires photons at intervals of 0.7m along the track. The laser pulse energy emitted by the laser is divided into three groups, each group contains a strong beam and a weak beam, and the strong and weak beams in the same group are spaced 90m apart in the vertical track direction.

[0055] In this example, the trajectory data of the ICESat-2 LiDAR is selected. The ICESat-2 ATL03 dataset provides LiDAR point cloud data detected along the satellite's flight trajectory, including specific transit time, longitude and latitude, elevation information, solar azimuth, and solar zenith angle. The ATL09 dataset provides environmental data of the target sea area, including aerosol optical depth. τ a , sea surface atmospheric pressureP In addition, the environmental parameters of this embodiment are selected from the MODIS surface reflectance data of the corresponding study area.

[0056] The specific steps of the method for calculating the theoretical limit of cloud penetration capability of single-photon lidar are as follows: Step S1: Perform Monte Carlo simulation based on environmental parameters and cloud characteristics to obtain cloud optical parameters corresponding to cloud optical thickness and environmental parameters.

[0057] Specifically, environmental parameter data includes the solar zenith angle and solar azimuth angle, and cloud characteristic data includes cloud type and cloud optical thickness. The specific steps are as follows: Step S1.1: Update the transmission of photon packets in the cloud layer through Monte Carlo simulation.

[0058] First, generate a photon packet and initialize the photon packet weight to , initial direction ( ) by the solar zenith angle and azimuth Decide:

[0059] in is the solar zenith angle, is the solar azimuth.

[0060] When a photon packet collides with a particle in the cloud, it may be absorbed by the particle in the cloud or scattered in a new direction. The optical depth of each free transmission can be expressed as

[0061] in is a random number that obeys a uniform distribution of 0-1. Then the weight of the photon packet is updated to

[0062] in It is the single scattering ratio, which can be set to 1 in the 532nm band, indicating that the photons have The probability of not being absorbed and being scattered in a new direction can be set to 1. At the same time, the coordinates of the photon packet are updated to

[0063] At the same time, when the photon collides with the particle and scatters, the direction will change, and the updated direction can be expressed as

[0064] in is the phase angle of scattering, obeying Uniform distribution, scattering angle This can be determined by looking up the cloud scattering phase function for the cloud type (ice cloud / water cloud). Through the above process, as the photon packet transmits through the cloud layer, its position, weight, and direction are continuously updated until the photon packet encounters a boundary condition or a termination condition.

[0065] Step S1.2: Calculation of cloud optical parameters.

[0066] When the photon packet passes through the upper boundary, it is determined whether the propagation direction of the photon packet can be received by the receiving field of view. If so, the current weight of the photon packet is accumulated. :

[0067] When all photon packet simulations are completed, the total weight of the photon packets that can be captured by the receiving field of view is w r , then the cloud top reflectivity can be calculated as:

[0068] When the photon packet passes through the lower boundary, that is, passes through the cloud and reaches the surface, the current weight of the photon packet is accumulated :

[0069] When all photon packet simulations are completed, the total weight of the photon packets that can finally reach the surface is , then the cloud diffuse transmittance can be calculated as:

[0070] Step S2: Based on the environmental parameters, system parameters, and cloud characteristics input in step S1 and the cloud optical parameters obtained by simulation, a signal and noise model of the spaceborne lidar is constructed, and the theoretical noise and theoretical signal under the corresponding scenario are calculated.

[0071] Specifically, the environmental parameter data include solar zenith angle, aerosol optical depth, surface atmospheric pressure and surface reflectivity, cloud characteristic data is cloud optical depth, and the simulated cloud optical parameters include cloud top reflectivity parameter and cloud diffuse transmittance. LiDAR system parameter data include LiDAR laser energy , LiDAR detector quantum efficiency , LiDAR flight altitude , LiDAR radiation correction coefficient , LiDAR receiver optical efficiency , laser frequency , LiDAR filter bandwidth , the half field of view angle of the laser radar receiving aperture and the effective area of ​​the telescope .

[0072] For ICESat-2 LiDAR, , , , = 0.15, = 0.4, , =1.9, =0.41m 2 , , .

[0073] The specific steps include: Step S2.1: Calculate the theoretical signal of the spaceborne lidar in the corresponding scene.

[0074] In the Earth observation scenario, the number of photons in the echo signal of the spaceborne single-photon lidar can be expressed as:

[0075] in is the laser energy, is the laser emission efficiency, is the receiver optical efficiency, is the detector quantum efficiency, is the laser zenith angle, is the effective optical area of ​​the receiver telescope, is the satellite flight altitude, represents Planck's constant, represents the laser frequency, is the correction coefficient of the lidar system, is the surface reflectivity. is the atmospheric direct transmittance, 、 and They are the optical thickness of atmospheric molecules, aerosols and the ozone layer. The optical thickness of the ozone layer can be approximated to be a constant of 0.02 in the 532nm band. The optical thickness of atmospheric molecules is affected by the surface atmospheric pressure. P The impact can be calculated as = , The standard atmospheric pressure is 1013.25hPa, and the aerosol optical depth is directly provided by the ICESat-2 ATL09 product.

[0076] S2.2 Calculate the theoretical noise of the spaceborne lidar in the corresponding scenario.

[0077] In the Earth observation scenario, the background noise level of the satellite-borne single-photon lidar receiver can be expressed by the noise rate. The total background noise includes the atmosphere, surface noise, and detector dark count noise, which can be expressed as:

[0078] in is the background noise caused by the backscattering of solar radiation by the atmospheric medium, is the background noise of solar radiation reflected from the Earth’s surface, is the background noise of the interaction between the atmosphere and the land, is the dark count noise of the detector.

[0079] The background noise caused by the backscattering of solar radiation by the atmospheric medium can be expressed as:

[0080] in β is the ratio of air molecules under the cloud, which can be set to 0.6. is the diffuse transmittance of atmospheric molecules, calculated as . Background noise caused by atmospheric Rayleigh scattering , background noise from aerosol backscattering and background noise from cloud backscatter It can be calculated using the single scattering approximation as:

[0081]

[0082]

[0083] in is the filter bandwidth, is the half field of view of the receiving aperture, is the solar irradiance at the average distance between the sun and the earth, for a wavelength of 532nm, , is the aerosol single scattering albedo and can be set to 0.95. is the Rayleigh scattering phase function, is the aerosol scattering phase function, which is specifically expressed as:

[0084]

[0085] The background noise of solar radiation reflected from the Earth's surface can be calculated as:

[0086] in is the overall diffuse transmittance of the atmosphere, which can be calculated as = , is the diffuse transmittance of the cloud layer, which can be calculated from step 1. is the ozone layer diffuse transmittance, is the aerosol diffuse transmittance, which is calculated as follows:

[0087] in is the forward scattering rate, which can be calculated as:

[0088] During the transmission of solar background radiation, some photons are scattered by the atmosphere and then reflected by the ground surface to enter the receiving field of view. Alternatively, photons that are reflected by the ground surface but do not enter the receiving field of view are scattered by the atmosphere and then re-enter the receiving field of view. The specific calculation is:

[0089] in, is the atmospheric equivalent reflectivity, which is calculated as follows:

[0090] in The cloud top reflectivity can be obtained in step 1.

[0091] Step S3: Estimate the signal echo waveform and calculate the theoretical maximum F-score under corresponding signal and noise levels by changing different algorithm parameters.

[0092] The detailed steps include: Step S3.1: Estimating signal echo waveform The echo waveform measured by the laser altimeter depends on the surface scattering characteristics, surface shape and the impulse response function of the system, which can be expressed as:

[0093] Where ⊗ represents the convolution operation, is the system impulse response function, is the surface response function, is a Gaussian function used to represent the combined effect of echo broadening caused by surface roughness and surface slope. For land areas, it is usually and Combined and represented by a Gaussian function, its RMS pulse width can be calculated as:

[0094] in is the variance of surface roughness, is the slope along the track, is the speed of light, is half of the laser divergence angle.

[0095] Step S3.2: Calculate the theoretical maximum F-score Using precision and recall The harmonic coefficient F-score is used as a quantitative indicator of the signal photon extraction algorithm capability, specifically expressed as:

[0096] in Indicates the number of signal points correctly identified by the algorithm; Indicates the number of signal photons that are mistakenly identified as noise; Indicates the number of noise photons that are mistakenly identified as signals. For density-based signal photon extraction algorithms, the neighborhood is mostly elliptical, mainly including the length of the minor axis of the ellipse. , the ratio of the major axis to the minor axis and the photon number threshold in the neighborhood Three algorithm parameters. For different signal and noise levels, the goal is to calculate the theoretical maximum F-score by changing the different signal photon extraction algorithm parameters.

[0097] Specifically, Types of photons can be divided into those far away from the signal region and close to signal areas Considering that the number of noise photons satisfies the Poisson distribution, It can be expressed as:

[0098] in represents the repetition frequency of the laser, is the satellite flight speed, is the speed of light, is the total background noise rate, is the possible elevation range of the noise point, is the cumulative range along the track, is the RMS pulse width of the signal, Indicates that at a given noise rate and algorithm parameters, based on the Poisson distribution of random variables Exceed probability.

[0099] For those close to the signal area The modeling of the quantity is more complicated. The signal echo function of the received signal at the elevation is , the starting and ending positions of the signal photon are and . Close to the signal area Point distribution and Range. To model the theoretical number of points within the elliptical neighborhood, the interval [ , + r ]and[ Each layer within ] is discretized into a size In this study, It is set to 3cm or 0.2ns because it is equal to the temporal resolution of ICESat-2. We discretize each elliptical neighborhood in the elevation direction by layer, and the horizontal length at different vertical positions is It varies and can be calculated using the following formula:

[0100] The number of laser pulses contained in the corresponding time interval is:

[0101] The expected number of signal photons in all channels in each time interval is However, due to the dead time effect of the photon counting detector, some of the subsequent photons may not be recorded. Assume that the dead time effect lasts for , then the corresponding vertical range is According to the additivity of Poisson distribution, the expected number of photons in each channel during the dead time is

[0102] Taking into account the dead zone effect, the expected number of photons recorded by a single channel in each time interval can be corrected to:

[0103] in is the number of detector channels, | represents the expected number of laser pulses that successfully record photons, | It is a statistical problem that can be used to obtain corresponding results for different input parameters based on Monte Carlo simulation and lookup table methods.

[0104] The entire ellipse neighborhood (with the center elevation l The total number of photons recorded in all time intervals (centered on ), that is, the discrete convolution of the number of photons recorded in all time intervals, can be expressed as:

[0105] The distribution of photon numbers still obeys the Poisson distribution, that is, ) | , By placing and The results of all layers within the range are accumulated to represent the area close to the signal Number of points.

[0106]

[0107] Therefore, the total The number of photons can be expressed as: Similarly, for TP and FN Modeling the number of photons of a certain type follows a similar process. TP and FN Photons are distributed in the interval Since the expected number of photons in the signal region is greater than the expected number of photons in the noise region, the dead time effect needs to be considered. In the case of multiple detectors, the detection probability of each channel can be expressed as:

[0108] in t d is the dead zone duration, The number of time intervals within the dead zone duration. The results of all layers within TP and FN The number of points can be expressed as

[0109] Therefore, the F-score can be calculated as:

[0110] Step S4: Determine whether the maximum F-score exceeds a threshold. If so, the system can penetrate clouds of corresponding optical thickness under the current environmental parameters. Otherwise, update the cloud optical thickness and repeat steps S1-S4.

[0111] When the critical point where the F-score is lower than the threshold is found, the corresponding cloud optical thickness is the limit of cloud optical thickness that can be penetrated, that is, the limit of cloud optical thickness that can be penetrated by the spaceborne single-photon lidar is

[0112] According to the above steps, in the embodiment, the system hardware parameters of the laser radar carried by the ICESat-2 satellite and the corresponding environmental parameters are used to calculate the maximum F-score along the track of the experimental area. Figure 3 (a) is the point cloud distribution of the single-track sample data of a certain province (2023 / 09 / 25, RDT#0095) selected in this embodiment. Figure 3 (b) is the theoretical optimal F-score (light line) extracted from the sample data using the method of this embodiment, and the light-colored dots are the F-score results actually calculated for the sample data. The theoretical F-score is consistent with the actual F-score. Generally speaking, F-score>0.8 is considered to have good performance. The gray area is the along-track area where the theoretical F-score<0.8, that is, the area that cannot penetrate the cloud layer, and the remaining white areas correspond to the area that can penetrate the cloud layer. The cloud optical thickness inverted at the boundary is the maximum cloud layer that the system can penetrate in this scenario, such as Figure 3 The black dashed line in (b) indicates the

[0113] Next, a device for calculating the theoretical limit cloud penetration capability of radar proposed in an embodiment of the present application will be described with reference to the accompanying drawings.

[0114] Figure 4 It is a block diagram of a device for calculating the theoretical limit of cloud penetration capability of a single-photon laser radar according to an embodiment of the present application.

[0115] like Figure 4 As shown, the single-photon laser radar theoretical limit cloud penetration capability calculation device 10 includes: a simulation module 201, a construction module 202 and a calculation module 203.

[0116] Among them, the simulation module 201 is used to obtain the environmental parameters and cloud characteristic data under the target scene, and perform Monte Carlo simulation based on the environmental parameters and cloud characteristic data to obtain the optical parameters of the corresponding cloud; the construction module 202 is used to construct a signal and noise model of the spaceborne lidar based on the environmental parameters, cloud characteristic data, optical parameters and system parameters of the spaceborne lidar, and use the signal and noise model to calculate the theoretical noise and theoretical signal under the target scene; the calculation module 203 is used to calculate the theoretical limit cloud penetration capability of the spaceborne lidar based on the theoretical noise and theoretical signal. If the theoretical limit cloud penetration capability exceeds the threshold under the target scene, it is determined that the spaceborne lidar can penetrate the cloud of the corresponding optical thickness; otherwise, the optical thickness of the corresponding cloud is updated.

[0117] In an embodiment of the present application, the simulation module 201 is further used to: perform Monte Carlo simulation based on environmental parameters and cloud characteristic data to obtain optical parameters of the corresponding cloud, generate photon packets, and initialize the weight and propagation direction of the photon packets; when the photon packet collides with particles in the cloud layer, calculate the optical depth of each free transmission; update the weight and propagation direction of the photon packet according to the optical depth until the photon packet encounters a boundary condition or termination condition, and when the simulation of all photon packets is completed, calculate the optical parameters based on the total weight of the photon packet.

[0118] In an embodiment of the present application, the simulation module 201 is further used to: update the weight and propagation direction of the photon packet according to the optical depth, update the weight and coordinates of the photon packet according to the optical depth; and update the propagation direction of the photon packet according to the coordinates of the photon packet.

[0119] In an embodiment of the present application, the simulation module 201 is further used to: when the simulation of all photon packets is completed, calculate the optical parameters based on the total weight of the photon packets; when the photon packet passes through the upper boundary, determine whether the propagation direction of the photon packet is received by the receiving field of view; if so, accumulate the current weight of the photon packet; when the simulation of all photon packets is completed, calculate the cloud top reflectivity parameter based on the total weight of the photon packets captured by the receiving field of view; when the photon packet passes through the lower boundary, accumulate the current weight of the photon packet, and calculate the cloud diffuse transmittance based on the total weight of the photon packets reaching the lower boundary.

[0120] In the embodiment of the present application, the calculation formula of the theoretical signal is:

[0121] in, is the laser energy; is the laser emission efficiency; is the receiver optical efficiency; is the detector quantum efficiency; is the laser zenith angle; is the effective optical area of ​​the receiver telescope; is the satellite flight altitude; represents Planck's constant; Indicates the laser frequency; is the correction coefficient of the lidar system; is the surface reflectivity; is the atmospheric direct transmittance; 、 and They are the optical thickness of atmospheric molecules, aerosols and the ozone layer;

[0122] The calculation formula of theoretical noise is:

[0123] in, It is the background noise caused by the backscattering of solar radiation by the atmospheric medium; is the background noise reflected by the Earth's surface from the sun's radiation; is the background noise of the interaction between the atmosphere and the surface; is the dark count noise of the detector.

[0124] In an embodiment of the present application, the calculation module 203 is further used to: calculate the theoretical limit cloud penetration capability of the spaceborne lidar based on the theoretical noise and the theoretical signal, and estimate the signal echo waveform of the spaceborne lidar; use the harmonic coefficient of the precision rate and the recall rate as parameters of the signal photon extraction algorithm; and calculate the theoretical limit cloud penetration capability corresponding to the theoretical noise and the theoretical signal through the signal echo waveform and the signal photon extraction algorithm.

[0125] In the embodiment of the present application, the calculation formula of the signal echo waveform is:

[0126] in, Represents the convolution operation; is the system impulse response function; is the surface response function; is a Gaussian function.

[0127] In the embodiment of the present application, the calculation formula for the theoretical limit cloud penetration capability is:

[0128] in, and are the starting and ending positions of the signal photon; is the center elevation; is the number of detector channels; is the photon number threshold in the neighborhood; is the theoretical noise; is the surface atmospheric pressure; is the detection probability of each channel; is the elevation range where noise points may exist; is the speed of light; is the RMS pulse width of the signal; For a given and algorithm parameters, based on the Poisson distribution of random variables Exceed Minpts probability; is the repetition frequency of the laser; is the satellite flight speed; is the length of the minor axis of the ellipse; is the ratio of the major and minor axes of the ellipse; For interval and The time interval obtained by discretizing each layer within .

[0129] It should be noted that the above explanation of the embodiment of the method for calculating the theoretical limit of cloud penetration capability of a single-photon laser radar is also applicable to the device for calculating the theoretical limit of cloud penetration capability of a single-photon laser radar in this embodiment, and will not be repeated here.

[0130] According to the device for calculating the theoretical limit cloud penetration capability of a single-photon lidar proposed in an embodiment of the present application, by obtaining environmental parameters and cloud characteristic data in a target scene, Monte Carlo simulation is performed based on the two to obtain the optical parameters of the corresponding cloud. Then, a signal and noise model of the satellite-borne lidar is constructed based on the environmental parameters, cloud characteristic data, optical parameters and system parameters of the satellite-borne lidar. The theoretical noise and theoretical signal in the target scene are calculated using the signal and noise model. Finally, the theoretical limit cloud penetration capability of the satellite-borne lidar is calculated based on the theoretical noise and theoretical signal. If the theoretical limit cloud penetration capability exceeds the threshold in the target scene, it is determined that the satellite-borne lidar can penetrate clouds of the corresponding optical thickness. Otherwise, the optical thickness of the corresponding cloud is updated. The theoretical limit cloud penetration capability of the satellite-borne single-photon lidar can be calculated, and the applicability of the satellite-borne lidar under different atmospheric conditions can be evaluated.

[0131] Figure 5 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. The electronic device may include: Memory 301 , processor 302 , and computer programs stored in the memory 301 and executable on the processor 302 .

[0132] When the processor 302 executes the program, the method for calculating the theoretical limit cloud penetration capability of the single-photon laser radar provided in the above embodiment is implemented.

[0133] Furthermore, the electronic device further includes: The communication interface 303 is used for communication between the memory 301 and the processor 302 .

[0134] The memory 301 is used to store computer programs that can be run on the processor 302 .

[0135] The memory 301 may include a high-speed RAM (Random Access Memory) memory, and may also include a non-volatile memory, such as at least one disk memory.

[0136] If the memory 301, processor 302, and communication interface 303 are implemented independently, the communication interface 303, memory 301, and processor 302 can be connected to each other via a bus and communicate with each other. The bus can be an ISA (Industry Standard Architecture) bus, a PCI (Peripheral Component Interconnect) bus, or an EISA (Extended Industry Standard Architecture) bus. Buses can be divided into address buses, data buses, control buses, etc. For ease of representation, Figure 5 Only one thick line is used in the diagram, but this does not mean that there is only one bus or one type of bus.

[0137] Optionally, in a specific implementation, if the memory 301, the processor 302 and the communication interface 303 are integrated on a chip, the memory 301, the processor 302 and the communication interface 303 can communicate with each other through an internal interface.

[0138] The processor 302 may be a CPU (Central Processing Unit), or an ASIC (Application Specific Integrated Circuit), or one or more integrated circuits configured to implement the embodiments of the present application.

[0139] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0140] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of this application, "N" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0141] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or N executable instructions for implementing a custom logical function or process step, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may be performed in a different order than shown or discussed, including performing functions in a substantially simultaneous manner or in a reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present application pertain.

[0142] It should be understood that various parts of the present application can be implemented using hardware, software, firmware, or a combination thereof. In the above-described embodiments, the steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used to implement the method: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application-specific integrated circuit having a suitable combination of logic gate circuits, a programmable gate array, a field programmable gate array, etc.

[0143] A person skilled in the art may understand that all or part of the steps carried out in the method for implementing the above-mentioned embodiment may be completed by instructing the relevant hardware through a program, and the above-mentioned program may be stored in a computer-readable storage medium, which, when executed, includes one of the steps of the method embodiment or a combination thereof.

[0144] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A method for calculating the theoretical limit of cloud penetration capability of a single-photon laser radar, characterized in that: The following steps are involved: Acquiring environmental parameters and cloud characteristic data in a target scene, performing Monte Carlo simulation based on the environmental parameters and the cloud characteristic data, and obtaining optical parameters of the corresponding cloud; constructing a signal and noise model of the spaceborne lidar based on the environmental parameters, the cloud characteristic data, the optical parameters, and system parameters of the spaceborne lidar, and calculating theoretical noise and theoretical signal in the target scene using the signal and noise model; The theoretical limit cloud penetration capability of the spaceborne lidar is calculated based on the theoretical noise and the theoretical signal. If the theoretical limit cloud penetration capability exceeds a threshold value in the target scene, it is determined that the spaceborne lidar can penetrate clouds of the corresponding optical thickness; otherwise, the optical thickness of the corresponding cloud is updated.

2. The method for calculating the theoretical limit of cloud penetration capability of single-photon laser radar according to claim 1 is characterized in that: The performing of Monte Carlo simulation according to the environmental parameters and the cloud characteristic data to obtain optical parameters of the corresponding cloud includes: Generate photon packets and initialize the weight and propagation direction of the photon packets; When a photon packet collides with a particle in the cloud, the optical depth of each free transmission is calculated; The weight and propagation direction of the photon packet are updated according to the optical depth until the photon packet encounters a boundary condition or a termination condition. When the simulation of all photon packets is completed, the optical parameters are calculated according to the total weight of the photon packet.

3. The method for calculating the theoretical limit of cloud penetration capability of single-photon laser radar according to claim 2, characterized in that: The updating of the weight and propagation direction of the photon packet according to the optical depth includes: updating the weight and coordinates of the photon packet according to the optical depth; The propagation direction of the photon packet is updated according to the coordinates of the photon packet.

4. The method for calculating the theoretical limit of cloud penetration capability of a single-photon laser radar according to claim 2, characterized in that: When all photon packet simulations are completed, optical parameters are calculated based on the total weight of the photon packets, including: When the photon packet passes through the upper boundary, it is determined whether the propagation direction of the photon packet is received by the receiving field of view. If so, the current weight of the photon packet is accumulated. When the simulation of all photon packets is completed, the cloud top reflectivity parameter is calculated based on the total weight of the photon packets captured by the receiving field of view. When a photon packet passes through the lower boundary, the current weight of the photon packet is accumulated, and the cloud diffuse transmittance is calculated based on the total weight of the photon packets reaching the lower boundary.

5. The method for calculating the theoretical limit of cloud penetration capability of single-photon laser radar according to claim 1 is characterized in that: The signal and noise model includes a calculation formula for theoretical signals and a calculation formula for theoretical noise, wherein: The calculation formula of the theoretical signal is: in, is the laser energy; is the laser emission efficiency; is the receiver optical efficiency; is the detector quantum efficiency; is the laser zenith angle; is the effective optical area of ​​the receiver telescope; is the satellite flight altitude; represents Planck's constant; Indicates the laser frequency; is the correction coefficient of the lidar system; is the surface reflectivity; is the atmospheric direct transmittance; 、 and They are the optical thickness of atmospheric molecules, aerosols and the ozone layer; for ; for and sum; The calculation formula of the theoretical noise is: in, It is the background noise caused by the backscattering of solar radiation by the atmospheric medium; is the background noise reflected by the Earth's surface from the sun's radiation; is the background noise of the interaction between the atmosphere and the surface; is the dark count noise of the detector.

6. The method for calculating the theoretical limit of cloud penetration capability of single-photon laser radar according to claim 1, characterized in that: The calculating the theoretical limit cloud penetration capability of the spaceborne laser radar according to the theoretical noise and the theoretical signal includes: estimating a signal echo waveform of the spaceborne laser radar; The harmonic coefficient of precision and recall is used as the parameter of the signal photon extraction algorithm; The theoretical limit cloud penetration capability corresponding to the theoretical noise and the theoretical signal is calculated using the signal echo waveform and the signal photon extraction algorithm.

7. The method for calculating the theoretical limit of cloud penetration capability of a single-photon laser radar according to claim 6, characterized in that: The calculation formula of the signal echo waveform is: in, Represents the convolution operation; is the system impulse response function; is the surface response function; is a Gaussian function.

8. The method for calculating the theoretical limit of cloud penetration capability of a single-photon laser radar according to claim 6, characterized in that: The calculation formula of the theoretical limit cloud penetration capability is: in, and are the starting and ending positions of the signal photon; is the center elevation; is the number of detector channels; is the photon number threshold in the neighborhood; is the theoretical noise; is the surface atmospheric pressure; is the detection probability of each channel; is the elevation range where noise points may exist; is the speed of light; is the RMS pulse width of the signal; For a given and algorithm parameters, based on the Poisson distribution of random variables Exceed Minpts probability; is the repetition frequency of the laser; is the satellite flight speed; is the length of the minor axis of the ellipse; is the ratio of the major and minor axes of the ellipse; For interval and The time interval obtained by discretizing each layer within .

9. A device for calculating the theoretical limit of cloud penetration capability of a single-photon laser radar, characterized in that: include: A simulation module is used to obtain environmental parameters and cloud characteristic data in a target scene, and perform Monte Carlo simulation based on the environmental parameters and cloud characteristic data to obtain optical parameters of the corresponding cloud; A construction module is used to construct a signal and noise model of the spaceborne lidar based on the environmental parameters, the cloud characteristic data, the optical parameters, and the system parameters of the spaceborne lidar, and calculate the theoretical noise and theoretical signal in the target scene using the signal and noise model; A calculation module is used to calculate the theoretical limit cloud penetration capability of the spaceborne laser radar based on the theoretical noise and the theoretical signal. If the theoretical limit cloud penetration capability exceeds a threshold value in the target scene, it is determined that the spaceborne laser radar can penetrate clouds of corresponding optical thickness; otherwise, the optical thickness of the corresponding cloud is updated.

10. An electronic device, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the method for calculating the theoretical limit cloud penetration capability of a single-photon laser radar as described in any one of claims 1 to 8.

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