CN-122001467-A - Tracking precision measuring method, system, medium and product of laser communication terminal

CN122001467ACN 122001467 ACN122001467 ACN 122001467ACN-122001467-A

Abstract

A tracking precision measuring method, a system, a medium and a product of a laser communication terminal relate to the field of photoelectric tracking measurement. In the method, a tracking laser beam of a laser communication terminal is controlled to execute scanning with a preset scanning track, a space coordinate point on the preset scanning track and corresponding laser echo intensity are recorded, and a reflection characteristic mapping chart is generated. Tracking a preset tracking point and collecting a time sequence of the measured echo intensity. Based on each intensity sampling value in the actually measured echo intensity time sequence, reversely searching on the local reflection characteristic mapping diagram, determining a plurality of target space coordinate points, determining a trajectory line of an equal-intensity space position, determining a trajectory line time sequence, processing the trajectory line time sequence by adopting a path optimizing algorithm, solving the most probable real motion trajectory of the laser spot center, and calculating the comprehensive tracking precision index. By implementing the technical scheme provided by the application, the accuracy of tracking precision measurement is improved.

Inventors

MA ZHENGWEI
SHEN XIANGLI
CHU ZHUQIN

Assignees

蓝星光域(上海)航天科技有限公司
光驭(北京)科技有限公司

Dates

Publication Date: 20260508
Application Date: 20251230

Claims (10)

1. A tracking accuracy measurement method of a laser communication terminal, the method comprising: controlling a tracking laser beam of the laser communication terminal to scan a target area on a non-cooperative target with a preset scanning track by taking a preset tracking point as a center; Recording a space coordinate point on the preset scanning track and laser echo intensities corresponding to the space coordinate points in the scanning process, and generating a reflection characteristic map; Controlling the laser communication terminal to track the preset tracking point, and collecting laser echo intensity in the tracking process within a preset time period to obtain a real-time measured echo intensity time sequence; According to each intensity sampling value in the actually measured echo intensity time sequence, reversely searching on the local reflection characteristic mapping diagram, determining a plurality of target space coordinate points, determining an equal-intensity space position track line based on the plurality of target space coordinate points, and ensuring that the difference value between the target laser echo intensity corresponding to the target space coordinate points and the intensity sampling value is in a preset difference value range; determining a trajectory time sequence based on equal-intensity spatial position trajectories corresponding to all intensity sampling values in the measured echo intensity time sequence; processing the trajectory time sequence by adopting a path optimizing algorithm, and solving the most probable real motion trajectory of the laser spot center on the target area; and comparing the most probable real motion track with the reference coordinate sequence of the preset tracking point by point, and calculating to obtain the comprehensive tracking precision index of the laser communication terminal.
2. The method according to claim 1, wherein the processing the trajectory time sequence by using a path optimizing algorithm, to solve a most probable real motion trajectory of a laser spot center on the target area, specifically includes: discretizing each equal-intensity spatial position track line in the track line time sequence to generate a candidate position point set formed by a plurality of candidate position points; Constructing a time sequence state diagram based on the candidate position point set, wherein each moment in the time sequence state diagram corresponds to a state level, and the state level is composed of the candidate position point set at the corresponding moment; A state transition path is constructed between any candidate position point at a first moment and any candidate position point at a second moment, wherein the first moment and the second moment are any two adjacent moments in the preset time period, and the second moment is the next moment of the first moment; applying a dynamic programming algorithm to determine an optimal path from a state level at an initial moment to a state level at an end moment, wherein the accumulation sum of transition costs of all state transition paths passed by the optimal path is minimum; And determining the candidate position point sequence through which the optimal path sequentially passes as the most probable real motion track of the laser spot center.
3. The method according to claim 2, wherein said constructing a time-series state diagram based on said candidate set of location points, in particular comprises: sequentially numbering all the moments in the preset time period to form a state level sequence of the time sequence state diagram; based on the state hierarchy sequences, in each state hierarchy, arranging candidate position points at corresponding moments according to a two-dimensional spatial position relationship to form a state node matrix; And connecting the state transition paths one by one between the state node matrixes of two adjacent state levels to obtain the time sequence state diagram.
4. The method according to claim 1, wherein the scanning the target area on the non-cooperative target with the preset scanning track specifically comprises: Performing sparse raster scanning on the target area with a first preset spatial resolution based on the preset scanning track to obtain laser echo intensities of grid points, and obtaining sparse echo intensity data; based on the sparse echo intensity data, calculating echo intensity gradients between adjacent grid points, and identifying a high-contrast area with the echo intensity gradients larger than a preset gradient threshold; And carrying out local encryption scanning on the high-contrast area at a second preset spatial resolution higher than the first preset spatial resolution.
5. The method according to claim 1, wherein the step of acquiring the laser echo intensity during the tracking process within the preset time period to obtain the time sequence of the measured echo intensity specifically comprises: Controlling a tracking laser beam of the laser communication terminal to track the non-cooperative target in a region with the preset tracking point as the center and the diameter of a preset tracking window; controlling a detection laser beam of the laser communication terminal to scan and detect the non-cooperative target along the motion track of the preset tracking point in the target area, wherein the detection laser beam is coaxial with the tracking laser beam; And acquiring echo intensity signals of the detection laser beam, and carrying out normalization processing to obtain the actually-measured echo intensity time sequence, wherein the actually-measured echo intensity time sequence is synchronous with the scanning process of the detection laser beam.
6. The method according to claim 1, wherein the point-by-point comparison is performed on the most probable real motion trajectory and the reference coordinate sequence of the preset tracking point, so as to calculate an integrated tracking precision index of the laser communication terminal, and specifically includes: Time alignment is carried out on the most probable real motion track and the reference coordinate sequence of the preset tracking point, and an instantaneous tracking error vector at each moment is calculated; Decomposing the instantaneous tracking error vector according to the horizontal direction and the vertical direction to obtain a horizontal tracking error sequence and a vertical tracking error sequence; Respectively carrying out statistical processing on the horizontal tracking error sequence and the vertical tracking error sequence, and calculating a mean value and a standard deviation to obtain a horizontal tracking precision index and a vertical tracking precision index; and calculating the comprehensive tracking precision index according to the horizontal tracking precision index and the vertical tracking precision index.
7. The method according to claim 1, wherein before the controlling the tracking laser beam of the laser communication terminal to scan the target area on the non-cooperative target with the preset scanning trajectory centering on the preset tracking point, the method further comprises: Acquiring type, size and spatial attitude information of the non-cooperative targets; Determining a characteristic region on the non-cooperative target according to the type and the size of the non-cooperative target; And selecting a target area from the characteristic areas according to the spatial pose of the non-cooperative target and the position distribution of the characteristic areas on the non-cooperative target.
8. A tracking accuracy measurement system of a laser communication terminal, characterized in that the tracking accuracy measurement system of a laser communication terminal comprises one or more processors and a memory, the memory being coupled to the one or more processors, the memory being for storing computer program code comprising computer instructions, the one or more processors invoking the computer instructions to cause the tracking accuracy measurement system of a laser communication terminal to perform the method of any of claims 1-7.
9. A computer readable storage medium comprising instructions which, when run on a tracking accuracy measurement system of a laser communication terminal, cause the tracking accuracy measurement system of the laser communication terminal to perform the method of any of claims 1-7.
10. A computer program product, characterized in that the computer program product, when run on a tracking accuracy measurement system of a laser communication terminal, causes the tracking accuracy measurement system of the laser communication terminal to perform the method according to any of claims 1-7.

Description

Tracking precision measuring method, system, medium and product of laser communication terminal Technical Field The application relates to the field of photoelectric tracking measurement, in particular to a tracking precision measurement method, a tracking precision measurement system, a tracking precision measurement medium and a tracking precision measurement product of a laser communication terminal. Background Along with the rapid development of space technology and information technology, laser communication has great potential in the fields of satellite communication, unmanned aerial vehicle networking, deep space exploration and the like due to the advantages of high speed, good directivity, strong anti-interference capability, high confidentiality and the like. In a laser communication system, in order to establish and maintain a stable communication link, a transmitting end and a receiving end must implement high-precision pointing, capturing and tracking. Particularly, when communication is performed between dynamic platforms (such as satellites and unmanned aerial vehicles), the tracking system needs to have extremely high dynamic performance under the influence of platform vibration, attitude change and relative motion. How to accurately measure the dynamic tracking accuracy of the laser communication terminal in real time becomes a key for evaluating and optimizing the performance of the communication system. However, in the traditional laboratory tracking precision testing method based on static or preset track targets, disturbance characteristics in a complex dynamic environment are difficult to truly restore, so that the deviation between a measurement result and actual application performance is large, and reliable basis cannot be provided for on-orbit or off-site application of the system. The prior art proposes a measurement method based on a cooperative target, which is to install a high-precision position sensitive detector on a tracked target to calculate the offset of the center of a laser spot relative to the center of the detector in real time as an instantaneous tracking error. The tracking accuracy can be obtained by statistically analyzing the error data. The method can truly reflect the pointing deviation in the dynamic target tracking process because the measuring reference is arranged at the target end, and the reliability of dynamic tracking precision measurement is remarkably improved. However, in some scenarios, such as unmanned reconnaissance to ground or automatic driving environment awareness, the laser terminal needs to continuously track non-cooperative targets (e.g., vehicles or building feature points) to complete lidar scanning imaging or target attention. At this time, since the target cannot install the dedicated measurement device, the tracking accuracy needs to be reversely deduced by analyzing the diffuse reflection echo signal of the target surface. Because the echo signals are simultaneously affected by the terminal tracking jitter, the target surface reflectivity, the three-dimensional morphology and the attitude change, the two effects are difficult to effectively separate in the prior art, and the real tracking error caused by the terminal cannot be accurately estimated. Disclosure of Invention The application provides a tracking precision measuring method, a system, a medium and a product of a laser communication terminal, which improve the accuracy of tracking precision measurement. The first aspect of the application provides a tracking precision measurement method of a laser communication terminal, which comprises the steps of controlling a tracking laser beam of the laser communication terminal to take a preset tracking point as a center, scanning a target area on a non-cooperative target with a preset scanning track, recording a space coordinate point on the preset scanning track and laser echo intensities corresponding to the space coordinate points in the scanning process, generating a reflection characteristic mapping graph, controlling the laser communication terminal to track the preset tracking point, collecting the laser echo intensities in the tracking process in a preset time period to obtain a measured echo intensity time sequence, reversely searching on the local reflection characteristic mapping graph according to each intensity sampling value in the measured echo intensity time sequence, determining a plurality of target space coordinate points, determining equal-intensity space position track points based on the plurality of target space coordinate points, determining equal-intensity space position track points corresponding to the target laser echo intensities and the intensity sampling values in the preset scanning track, determining equal-intensity space position track points corresponding to all the intensity sampling values in the measured echo intensity time sequence based on the preset scanning process, comparing the measured ech