Multi-crosslinking pulse laser discrete high-reflection environment echo modeling method

Abstract

The application discloses a kind of pulse laser dynamic intersection discrete high-reflective environment echo modeling methods, belong to pulse laser detection and photoelectric simulation technical field.The method is according to the relative pose of detection system and target to the pulse repetition period is updated periodically, and laser launch source point, emitting direction, receiving field of view and effective receiving window are simultaneously corrected;Combining the spatial distribution of discrete high-reflective scatterer, direction reflection characteristic, propagation loss and echo time delay, the echo contribution in each pulse period is calculated and time series is superimposed, to obtain the pulse echo sequence under dynamic intersection condition.The method can truly represent the distance migration between pulses, echo peak migration and multi-peak structure evolution under high-speed intersection, provide high-fidelity data support for pulse laser detection performance analysis and anti-interference algorithm verification.

Description

Technical Field

[0001] This invention belongs to the field of pulsed laser detection and optoelectronic simulation technology, specifically relating to a method for modeling echoes in dynamic intersection discrete high-reflectivity environments using pulsed lasers. Background Technology

[0002] In the prior art, CN114895288B discloses a "Laser Echo Generation System for 3D Scenes," which extracts graphic information and detection distance information through an image-distance separation module, and then calculates the switching delay of the DMD drive system and the pulse delay of the laser through a synchronization delay module to generate an echo signal for use in lidar testing. This scheme focuses on the synchronous playback and echo generation of dynamic images and distance information, and is more suitable for test scene reproduction; however, it does not adequately consider pulse-by-pulse relative pose updates under dynamic intersection conditions of pulsed lasers, directional reflection of discrete high-reflectivity scatterers, and dynamic correction of receiving criteria.

[0003] In addition, Wang Jiaojiao et al. published "Optimization of LiDAR Echo Scene Generation Based on Similarity Evaluation" in 2021. This work optimizes LiDAR echo scene generation based on 3D scene construction and laser scattering principles. This type of method focuses on scene generation efficiency and similarity evaluation, but lacks integrated modeling mechanistic considerations for the pulsed laser single-pulse "emission-propagation-reception" process, the inter-pulse distance migration under dynamic intersection conditions, and the time delay coupling of multi-peak echoes in discrete high-reflection environments.

[0004] Therefore, while existing technologies can achieve laser echo generation or scene echo simulation to a certain extent, they lack specific descriptions of the differences in echo formation mechanisms under different intersection conditions in pulsed laser detection. Especially in typical intersection scenarios such as head-on encounters, same-direction overtaking, oblique crossings, and lateral passing, significant differences exist in the relative radial velocity between the detection system and the target, line-of-sight angle changes, target attitude exposure relationships, and the effective contribution area of ​​discrete high-reflectivity scatterers. This leads to significant differences in echo delay, peak distribution, and multi-peak structure evolution. Most existing methods employ uniform geometric updates and uniform reception criteria, making it difficult to accurately reflect the impact of different intersection conditions on the pulse echo formation process. Therefore, it is necessary to propose a pulsed laser discrete high-reflectivity environment echo modeling method for different intersection conditions. Summary of the Invention

[0005] This invention proposes a method for modeling echoes in discrete high-reflection environments using multi-crossing pulsed lasers, which addresses the shortcomings of existing echo modeling methods in characterizing variations in inter-pulse distance, line-of-sight angle, effective scattering region, and receiver gating differences under different crossover conditions.

[0006] The technical solution of this invention is: a method for modeling echoes in discrete high-reflectivity environments using multi-crossing pulsed lasers, comprising the following steps:

[0007] Step 1: Establish a spatial model of the detection system, target, and discrete high-reflectivity environment in the global coordinate system. Discretize the target surface into multiple target scattering units and the discrete high-reflectivity environment into multiple environment scattering units. Set the surface normal vector, equivalent reflectivity, and equivalent area of ​​each scattering unit. Proceed to Step 2.

[0008] Step 2: Set the pulsed laser system parameters, including the pulse repetition frequency. Pulse repetition period Pulse width Single pulse energy Maximum effective range Half field of view of the receiving system Reception time window Dielectric attenuation coefficient System comprehensive ratio coefficient Proceed to step 3.

[0009] Step 3: Total simulation time According to the set pulse repetition period Discretize the pulses into multiple pulse emission times, construct a pulse-by-pulse simulation time series, and proceed to step 4.

[0010] Step 4: At each pulse transmission moment, based on the initial state of the detection system and the target, or the position and velocity at the previous pulse transmission moment, update the instantaneous intersection geometry corresponding to the current pulse, obtain the intersection state parameter set, and proceed to step 5.

[0011] Step 5: Based on the above set of intersection state parameters, determine the intersection type corresponding to the current pulse, and proceed to step 6.

[0012] Step 6: Based on the intersection type corresponding to the current pulse, update the positions of the target scattering unit and the environment scattering unit, and calculate the corrected laser emission direction, receiving main axis direction and receiving time window. Merge the updated target scattering unit and environment scattering unit into the effective scattering unit set corresponding to the current pulse, and proceed to step 7.

[0013] Step 7: Calculate the emission path length, return path length, incident angle, exit angle, directional reflection contribution, and round-trip propagation delay for each effective scattering unit, and proceed to step 8.

[0014] Step 8: Based on the intersection type corresponding to the current pulse, screen whether each effective scattering unit belongs to the effective scattering region corresponding to the current intersection type, and establish a receiving effectiveness criterion by combining the maximum effective action distance, receiving field of view, receiving time window and unobstructed conditions, to obtain the receiving effectiveness factor of each effective scattering unit, and proceed to step 9.

[0015] Step 9: Calculate the echo weight of each effective scattering unit based on its directional reflection contribution, effective receiving factor, medium attenuation, and two-way distance attenuation, and proceed to step 10.

[0016] Step 10: Calculate the round-trip propagation delay of the effective scattering unit based on the emission path length, return path length, and speed of light of the effective scattering unit. Then, according to the round-trip propagation delay of the effective scattering unit and combined with the echo weight of the effective scattering unit, superimpose the echo contribution of the effective scattering unit to form the single-pulse echo waveform of the current pulse, and proceed to step 11.

[0017] Step 11: Repeat steps 4 to 10 for all pulses to obtain a complete pulse echo sequence under multiple intersection conditions.

[0018] Compared with the prior art, the significant advantages of this invention are:

[0019] (1) This invention does not use a unified intersection model to process all scenarios. Instead, it constructs an intersection state parameter set to distinguish and model different intersection situations such as head-on intersection, same-direction overtaking, oblique crossing and lateral passing, which can more accurately characterize the differences in echo formation mechanisms under different working conditions.

[0020] (2) Based on the pulse-by-pulse update of relative pose, this invention associates the transmission direction correction, the receiving gating center correction and the effective scattering region screening with the intersection type, which can more realistically reflect the pulse echo peak position migration, peak fluctuation and multi-peak structure evolution characteristics under various intersection conditions.

[0021] (3) This invention realizes the generation of pulse echo sequences under different intersection conditions under a unified modeling framework, which not only maintains the consistency of the model structure, but also enhances the adaptability to complex dynamic scenes. It can be directly used for pulse laser detection performance analysis, anti-interference algorithm design and hardware-in-the-loop simulation verification. Attached Figure Description

[0022] Figure 1 This is a flowchart of the overall process for modeling the echo of a discrete high-reflectivity environment using multi-intersection pulsed lasers according to the present invention.

[0023] Figure 2 This is a three-dimensional simulation model of a discrete high-reflectivity environment.

[0024] Figure 3This diagram illustrates the different intersection scenarios that occur at different times.

[0025] Figure 4 This diagram illustrates the different intersection scenarios caused by different positions.

[0026] Figure 5 This is a schematic diagram of the normalization of the transmitted and simulated echoes. Detailed Implementation

[0027] This invention uses the pulse repetition period as the time advancement benchmark. Based on updating the relative pose of the detection system and the target pulse by pulse, it further constructs a set of intersection state parameters to determine the intersection type of the current pulse. For different intersection types, it corrects the laser emission direction, the receiving main axis direction, the center of the receiving time window, and the set of effective scattering units respectively. On this basis, it calculates the propagation geometry parameters, directional reflection contribution, receiving effectiveness, and echo weight of each effective scattering unit, and forms single-pulse echo and complete pulse echo sequences under the corresponding intersection conditions.

[0028] Combination Figures 1-4 The present invention provides a method for modeling echoes in discrete high-reflectivity environments via dynamic intersection of pulsed lasers, comprising the following steps:

[0029] Step 1: Establish a spatial model of the detection system, target, and discrete high-reflectivity environment in the global coordinate system. Discretize the target surface into multiple target scattering units and the discrete high-reflectivity environment into multiple environment scattering units, and set the surface normal vector, equivalent reflectivity, and equivalent area of ​​each scattering unit.

[0030] A spatial model of the detection system, target, and discrete high-reflectivity environment is established in the global coordinate system O-xyz. Let the... The location of the pulse emission detection system is as follows: The target location is Discretize the target surface into The target scattering unit, the first The initial positions of the target scattering units in the target fixed coordinate system are: Discretize the discrete high-reflectivity environment into The environmental scattering unit, the first The initial position of each environmental scattering unit is Let the first... The surface normal vector of each scattering unit is The equivalent reflectance is The equivalent area is .

[0031] The scattering unit in the discrete high-reflectivity environment includes one or more of the following: foil unit, metal fragment, corner reflector, sheet-like high reflector, or discrete metal component.

[0032] Step 2: Set the pulsed laser system parameters:

[0033] Let the pulse repetition frequency be... The repetition period is The relationship between the two is as follows:

[0034] ,

[0035] Further configure the pulsed laser system parameters as shown in the table below.

[0036]

[0037] Step 3: Total simulation time According to the set pulse repetition period Discretize the pulses into multiple pulse emission times and construct a pulse-by-pulse simulation time series.

[0038] Let the total simulation time be The total number of pulses is ,but:

[0039] ,

[0040] in, This indicates the floor function.

[0041] No. The transmission times of each pulse are:

[0042] .

[0043] Step 4: At each pulse transmission moment, based on the initial state of the detection system and the target, or the position and velocity at the previous pulse transmission moment, update the instantaneous intersection geometry corresponding to the current pulse to obtain the intersection state parameter set.

[0044] In the At each pulse transmission moment, based on the initial state of the detection system and the target, or the position and velocity at the previous pulse moment, the instantaneous intersection geometry corresponding to the current pulse is updated.

[0045] Let the location of the detection system be... The target location is The detection system speed is The target speed is Then the positions of the detection system and the target are updated as follows: and :

[0046] ,

[0047] ,

[0048] Let the relative position vector of the target with respect to the detection system be... The relative distance is Then we have:

[0049] ,

[0050] ,

[0051] Let the unit vector of the line of sight be... The relative velocity vector is The radial relative velocity is The tangential relative velocity is Then we have:

[0052] ,

[0053] ,

[0054] ,

[0055] ,

[0056] Let the distance migration between two adjacent pulses be... The line-of-sight angular velocity is Then we have:

[0057] ,

[0058] ,

[0059] This allows us to construct the intersection state parameter set corresponding to the current pulse. :

[0060] .

[0061] Step 5: Determine the intersection type corresponding to the current pulse based on the above intersection state parameter set.

[0062] Let the unit vector of the velocity direction of the detection system be... The target velocity direction unit vector is The target axial unit vector is The intersection angle is The target exposure angle is Then we have:

[0063] ,

[0064] ,

[0065] ,

[0066] ,

[0067] ,

[0068] in, For the first The target attitude transformation matrix at each pulse transmission moment, where T represents the transpose.

[0069] Based on radial relative velocity Intersection angle and line-of-sight angular velocity Determine the intersection type identifier corresponding to the current pulse. Intersection type The condition is satisfied:

[0070] ,

[0071] in, Indicates a head-on meeting. Indicates overtaking in the same direction. Indicates a diagonal intersection. Indicates a sideways sweep; , and Thresholds are used to define intersection types.

[0072] Step 6: Based on the intersection type corresponding to the current pulse, update the positions of the target scattering unit and the environment scattering unit, and calculate the corrected laser emission direction, receiving main axis direction and receiving time window. Then merge the updated target scattering unit and environment scattering unit into the effective scattering unit set corresponding to the current pulse.

[0073] Calculate the first Position of each target scattering unit in the global coordinate system :

[0074] ,

[0075] in, Indicates the first The initial position vector of each target scattering unit in the target fixed coordinate system This represents the total number of target scattering units; thus, the set of positions of all target scattering units in the global coordinate system is obtained. .

[0076] in, Indicates the first The initial position of each environmental scattering unit. The total number of environmental scattering units. For the first Each pulse emission time.

[0077] By merging all target scattering units with environmental scattering units, we obtain the effective scattering unit location set. :

[0078] ,

[0079] in, Indicates the effective scattering unit number, , This indicates the total number of effective scattering units corresponding to the current pulse. When the environmental scattering unit is stationary, the corresponding velocity vector .

[0080] Let the unit vector of the relative velocity direction be... Then we have:

[0081] ,

[0082] Let the rendezvous type-related launch direction correction factor be: The receiving spindle correction factor is Then the first Unit vector of laser emission direction after pulse correction Corrected receiver main axis direction unit vector and the corrected center delay of the receiving window They are respectively:

[0083] ,

[0084] ,

[0085] Let the first The center delay of the receiving window for each pulse is Then we have:

[0086] ,

[0087] in, The speed of light in a vacuum. This represents the rendezvous type correlation correction coefficient.

[0088] Let the leading edge width and trailing edge width of the receiving window related to the rendezvous type be respectively... and Then the first The receiving time window corresponding to each pulse for:

[0089] ,

[0090] in, This is the lower limit of the receiving time window. This is the upper limit of the receiving time window.

[0091] Step 7: Calculate the emission path length, return path length, incident angle, exit angle, directional reflection contribution, and round-trip propagation delay for each effective scattering element.

[0092] Let the first The effective scattering unit in the first The position of each pulse emission moment is Its launch path length Length of return route Unit vector of launch path direction Return path direction unit vector They are respectively:

[0093] ,

[0094] ,

[0095] ,

[0096] .

[0097] Let the first The incident angle of each effective scattering unit is The angle of departure is ,but:

[0098] ,

[0099] ,

[0100] Let the first The directional reflection function of each effective scattering unit is Then the directional reflection coefficient for:

[0101] .

[0102] No. Round-trip propagation delay of each effective scattering unit for:

[0103] .

[0104] Step 8: Based on the intersection type corresponding to the current pulse, screen whether each effective scattering unit belongs to the effective scattering region corresponding to the current intersection type, and establish a receiving effectiveness criterion by combining the maximum effective action distance, receiving field of view, receiving time window and unobstructed conditions, and obtain the receiving effectiveness factor of each effective scattering unit.

[0105] Let the half-angle of the scattering screening related to the intersection type be... Surface exposure threshold is , used to characterize the The selection factor for whether each effective scattering unit belongs to the effective scattering region corresponding to the current intersection type. satisfy:

[0106] ,

[0107] in, Indicates the first The effective scattering unit in the first The normal vector at the nth pulse moment. Let the nth pulse moment be... The shading indicator factor for each effective scattering unit is When there is no obstruction =1, otherwise =0.

[0108] No. The effective receiving factor of each effective scattering unit is satisfy:

[0109] ,

[0110] in, This indicates the farthest distance at which the receiver can effectively receive the echo from the scattering unit; This means that the distance the scattering unit returns to the receiver cannot exceed the system's maximum effective range. Determine whether the direction of the returned echo falls within the receiver's field of view; Determine whether the arrival time of the echo falls within the time range of the receiving gate opening; Determine whether the path from the transmitter to the scattering unit and then from the scattering unit to the receiver is unobstructed; Used to determine the first Does each effective scattering unit belong to the effective scattering region corresponding to the current intersection type?

[0111] Step 9: Calculate the echo weight of each effective scattering unit based on its directional reflection contribution, effective receiving factor, medium attenuation, and two-way distance attenuation.

[0112] Let the first The effective scattering unit in the first Echo weights at each pulse transmission time satisfy:

[0113] ,

[0114] in, This is the overall proportional coefficient of the system. For single-pulse energy, For the first The equivalent reflectivity of each effective scattering unit. For the first The equivalent area of ​​an effective scattering unit For the first The directional reflection coefficient of each effective scattering unit This is the dielectric attenuation coefficient.

[0115] Step 10: Calculate the round-trip propagation delay of the effective scattering unit based on the emission path length, return path length, and speed of light. Then, based on the round-trip propagation delay of the effective scattering unit and its echo weight, sum the echo contribution of the effective scattering unit to form the single-pulse echo waveform of the current pulse.

[0116] Let the normalized transmitted pulse waveform be Using Gaussian pulses:

[0117] ,

[0118] Let the first The received echo signal corresponding to each pulse is The noise term is ,but:

[0119] ,

[0120] Step 11: Repeat steps 4 to 10 for all pulses to obtain a complete pulse echo sequence under multiple intersection conditions.

[0121] Repeat steps 4 to 10 for all pulses to obtain the complete pulse echo sequence S during the dynamic intersection process:

[0122] ,

[0123] in, This indicates the total number of pulses.

[0124] By changing the detection system velocity, target velocity, target attitude, spatial distribution of discrete high-reflectivity environment, scattering unit orientation, line-of-sight angle, and intersection direction, pulse echo sequences under different intersection conditions are obtained.

[0125] Example 1

[0126] To further illustrate the specific implementation process of the method of the present invention, a simulation scenario of pulsed laser discrete high reflection environment echo under head-on intersection conditions is constructed.

[0127] like Figure 2 As shown, a spatial model of the detection system, target, and discrete high-reflectivity environment is established in the global coordinate system O-xyz. Let the initial position of the detection system be:

[0128] ,

[0129] The initial position of the target is:

[0130] ,

[0131] The detection system speed is:

[0132] ,

[0133] The target speed is:

[0134] ,

[0135] At this moment, the detection system and the target move towards each other along the x-axis, forming a head-on encounter scenario. The target surface is discretized into... Each target scattering unit, the discrete high-reflectivity environment is discretized into An environmental scattering unit. Discrete high-reflectivity scattering units can be deployed in the region near the target. For example, in the global coordinate system O-xyz, the coordinate range along the line of sight of the detection system is x=45~55m, the lateral coordinate range is y=-2~2m, and the height coordinate range is z=-2~2m. These units are used to characterize discrete high-reflectivity scattering units such as chaff, metal fragments, or sheet-like high reflective objects distributed near the target.

[0136] Set the pulse repetition frequency for:

[0137] ,

[0138] Then the pulse repetition period for:

[0139] ,

[0140] Set the pulse width to =10ns, single pulse energy is The maximum effective range is The half-field of view of the receiving system is The dielectric attenuation coefficient is The overall system ratio coefficient is .

[0141] At the moment of the first pulse transmission, the relative position vector between the detection system and the target for:

[0142] ,

[0143] relative distance for:

[0144] ,

[0145] Line of sight unit vector for:

[0146] ,

[0147] Relative velocity vector for:

[0148] ,

[0149] Radial relative velocity for:

[0150] .

[0151] because This indicates that the distance between the detection system and the target is decreasing. If the intersection angle meets the head-on intersection determination condition, then the intersection type of the current pulse is determined to be... This means a head-on encounter.

[0152] Formula for updating based on location:

[0153] ,

[0154] ,

[0155] It can be determined that the change in distance between two adjacent pulses is approximately:

[0156] ,

[0157] That is, after each pulse repetition cycle, the distance between the target and the detection system decreases by approximately 0.03m. This causes a distance migration phenomenon in subsequent pulse echoes, where the echoes move forward pulse by pulse.

[0158] The center delay of the receiving window corresponding to the first pulse It can be approximated as:

[0159] ,

[0160] Therefore, the reception time window can be set around 333ns, for example, it can be set as follows:

[0161] ,

[0162] Used to receive echoes formed by the target and its nearby discrete high-reflectivity scattering units.

[0163] For a given discrete high-reflectivity scattering unit, if its position for:

[0164] ,

[0165] Then its launch path length Approximately:

[0166] ,

[0167] If the send and receive terminals are approximately co-located, then the return path length can be approximated as: .

[0168] Its round-trip propagation delay for:

[0169] ,

[0170] The delay is within the receiving time window [250ns, 450ns], so the scattering unit can participate in the current pulse echo superposition when the field of view, occlusion and intersection effective area screening conditions are met.

[0171] For a scattering element located near the target surface, its echo delay is approximately:

[0172] ,

[0173] For a highly reflective scattering element located behind the target, such as near x=52m, its echo delay is approximately:

[0174] ,

[0175] Therefore, within the same receiving window, target scattering elements and discrete high-reflectivity scattering elements at different locations will contribute echoes at different times. According to the echo weighting calculation formula in this invention:

[0176] ,

[0177] Calculate the echo weight of each effective scattering unit and combine it with the Gaussian emission pulse waveform:

[0178] ,

[0179] The received echo signal of the i-th pulse is obtained:

[0180] ,

[0181] From this, we can obtain Figure 5 The transmitted pulse and the simulated echo are shown as normalized results. Due to the different positions and orientations of the target surface scattering units and the high-reflectivity environment scattering units, their propagation delay, directional reflection contribution, and effective receiving factor are different, and they are ultimately superimposed to form a received echo with peak position differences, peak fluctuations, and a multi-peak structure.

[0182] Repeat the above steps for all pulses to obtain the complete pulse echo sequence:

[0183] ,

[0184] In this embodiment, since the detection system and the target are in a head-on encounter, the distance gradually decreases from the initial 50m with the pulse period, thus the echo center delay shifts forward pulse by pulse. Simultaneously, the different positions, orientations, and effective receiving states of the discrete high-reflectivity scattering units cause changes in the set of effective scattering units and the echo weights in different pulses, leading to dynamic changes in the echo peak value and multi-peak structure during the encounter process. This result demonstrates that the method of this invention can describe the evolution of multi-peak echoes caused by pulse distance migration, receiving window changes, and discrete high-reflectivity environments under short-range dynamic encounter conditions.

Claims

1. A method for modeling high-reflectivity environment echoes from discrete multi-crossing pulsed lasers, characterized in that, Includes the following steps: Step 1: Establish a spatial model of the detection system, target, and discrete high-reflectivity environment in the global coordinate system. Discretize the target surface into multiple target scattering units and the discrete high-reflectivity environment into multiple environment scattering units. Set the surface normal vector, equivalent reflectivity, and equivalent area of ​​each scattering unit. Proceed to Step 2. Step 2: Set the pulsed laser system parameters, including the pulse repetition frequency. Pulse repetition period Pulse width Single pulse energy Maximum effective range Half field of view of the receiving system Reception time window Dielectric attenuation coefficient System comprehensive ratio coefficient Proceed to step 3; Step 3: Total simulation time According to the set pulse repetition period Discretize the pulses into multiple pulse emission times, construct a pulse-by-pulse simulation time series, and proceed to step 4; Step 4: At each pulse transmission moment, based on the initial state of the detection system and the target, or the position and velocity at the previous pulse transmission moment, update the instantaneous intersection geometry corresponding to the current pulse, obtain the intersection state parameter set, and proceed to step 5. Step 5: Based on the above set of intersection state parameters, determine the intersection type corresponding to the current pulse, and proceed to step 6; Step 6: Based on the intersection type corresponding to the current pulse, update the positions of the target scattering unit and the environment scattering unit, and calculate the corrected laser emission direction, receiving main axis direction and receiving time window. Merge the updated target scattering unit and environment scattering unit into the effective scattering unit set corresponding to the current pulse, and proceed to step 7. Step 7: Calculate the emission path length, return path length, incident angle, exit angle, directional reflection contribution, and round-trip propagation delay for each effective scattering element, and proceed to step 8; Step 8: Based on the intersection type corresponding to the current pulse, screen whether each effective scattering unit belongs to the intersection effective scattering area corresponding to the current intersection type, and establish a receiving effectiveness criterion by combining the maximum effective action distance, receiving field of view, receiving time window and unobstructed conditions, and obtain the receiving effectiveness factor of each effective scattering unit, and proceed to step 9. Step 9: Calculate the echo weight of each effective scattering unit based on the directional reflection contribution, effective receiving factor, medium attenuation, and two-way distance attenuation of each effective scattering unit, and proceed to step 10. Step 10: Calculate the round-trip propagation delay of the effective scattering unit based on the emission path length, return path length, and speed of light of the effective scattering unit. According to the round-trip propagation delay of the effective scattering unit, combined with the echo weight of the effective scattering unit, the echo contribution of the effective scattering unit is superimposed to form the single-pulse echo waveform of the current pulse, and then proceed to step 11. Step 11: Repeat steps 4 to 10 for all pulses to obtain a complete pulse echo sequence under multiple intersection conditions.

2. The method according to claim 1, characterized in that: In step 4, let the first... The location of the pulse emission detection system is as follows: The target location is The detection system speed is The target speed is The pulse repetition period is Then the positions of the detection system and the target are updated as follows: and : ， ， Furthermore, the relative position vectors of the detection system and the target are calculated. Relative distance Line of sight unit vector Relative velocity vector Radial relative velocity Tangential relative velocity Distance migration and line-of-sight angular velocity As shown below: ， ， ， ， ， ， ， ， in, Indicates the magnitude of the vector; The above parameters of the detection system and the target are combined to form a rendezvous state parameter set.

3. The method according to claim 2, characterized in that: In step 5, let the unit vector of the velocity direction of the detection system be... The target velocity direction unit vector is The target axial unit vector is The intersection angle is The target exposure angle is Then we have: ， ， ， ， ， in, For the first The target attitude transformation matrix at each pulse transmission moment; T represents the transpose; Furthermore, based on radial relative velocity Intersection angle and line-of-sight angular velocity Determine the intersection type identifier corresponding to the current pulse. Intersection type The condition is satisfied: ， in, Indicates a head-on meeting. Indicates overtaking in the same direction. Indicates a diagonal intersection. Indicates a sideways sweep; , and Thresholds are used to define intersection types.

4. The method according to claim 3, characterized in that: In step 6, calculate the first... Position of each target scattering unit in the global coordinate system : ， in, Indicates the first The initial position vector of each target scattering unit in the target fixed coordinate system This represents the total number of target scattering units; thus, the set of positions of all target scattering units in the global coordinate system is obtained. ; Let the first The velocity vector of each environmental scattering unit is Then the position of the scattering unit in the global coordinate system for: ， in, Indicates the first The initial position of each environmental scattering unit. The total number of environmental scattering units. For the first Each pulse emission time; By merging all target scattering units with environmental scattering units, we obtain the effective scattering unit location set. : ， in, Indicates the effective scattering unit number, , This indicates the total number of effective scattering units corresponding to the current pulse. When the environmental scattering unit is stationary, the corresponding velocity vector .

5. The method according to claim 4, characterized in that: In step 6, let the unit vector of the relative velocity direction be... Then we have: ， Let the rendezvous type-related launch direction correction factor be: The receiving spindle correction factor is Then the first Unit vector of laser emission direction after pulse correction Corrected receiver main axis direction unit vector and the corrected center delay of the receiving window They are respectively: ， ， ， in, The speed of light in a vacuum. This represents the relevance correction coefficient for the intersection type; Let the leading edge width and trailing edge width of the receiving window related to the rendezvous type be respectively... and Then the receiving time window corresponding to the current pulse for: 。 6. The method according to claim 5, characterized in that: In step 7, let the first... The effective scattering unit in the first The position of each pulse emission moment is Its launch path length Length of return route Unit vector of launch path direction Return path direction unit vector Angle of incidence , angle of departure They respectively satisfy: ， ， ， ， ， ， Let the first The directional reflection function of each effective scattering unit is Then the directional reflection coefficient for: ， No. Round-trip propagation delay of each effective scattering unit for: 。 7. The method according to claim 6, characterized in that: In step 8, let the half-angle of the scattering screening related to the intersection type be... Surface exposure threshold is , used to characterize the The selection factor for whether each effective scattering unit belongs to the effective scattering region corresponding to the current intersection type. satisfy: ， in, Indicates the first The effective scattering unit in the first The normal vector at each pulse moment; Let the first The shading indicator factor for each effective scattering unit is When there is no obstruction =1, otherwise =0; No. The effective receiving factor of each effective scattering unit is satisfy: ， in, This indicates the farthest distance at which the receiver can effectively receive the echo from the scattering unit.

8. The method according to claim 7, characterized in that: In step 9, the first The effective scattering unit in the first Echo weights at each pulse transmission time satisfy: ， in, This is the overall proportional coefficient of the system. For single-pulse energy, For the first The equivalent reflectivity of each effective scattering unit. For the first The equivalent area of ​​an effective scattering unit For the first The directional reflection coefficient of each effective scattering unit This is the dielectric attenuation coefficient.

9. The method according to claim 8, characterized in that: In step 10, let the normalized transmitted pulse waveform be... Using Gaussian pulses: ， Then the first The received echo signal corresponding to each pulse is satisfy: ， in, This is the noise term.

10. The method according to claim 9, characterized in that: In step 11, steps 4 to 10 are repeated for all pulses to obtain the complete pulse echo sequence S during the dynamic intersection process: ， in, Indicates the total number of pulses; By changing the detection system velocity, target velocity, target attitude, spatial distribution of discrete high-reflectivity environment, scattering unit orientation, line-of-sight angle, and intersection direction, pulse echo sequences under different intersection conditions are obtained.

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