A rapid calibration method for radar system errors based on precise orbit satellite measurement data

Abstract

The present invention discloses a rapid calibration method for radar system errors based on precision-track satellite measurement data, comprising the following steps: discretizing the azimuth-pitch plane observed by the radar and dividing the azimuth-pitch plane area into a grid; the radar system selecting a target for tracking and acquiring measurement data based on the predicted value of the precision-track satellite in the azimuth-pitch plane; calculating coverage and uniformity index as density metrics to calculate the density of the measurement data; for areas where the coverage or uniformity index does not meet a threshold requirement, padding the measurement data based on the predicted value of the precision-track satellite in the azimuth-pitch plane until the threshold requirement is met; acquiring a radar measurement error dataset based on the acquired radar measurement data and the precision-track satellite ephemeris; fitting the radar measurement error dataset to obtain a radar system error correction coefficient; and completing radar system error calibration using the error correction coefficient. The present invention can effectively improve the effectiveness and efficiency of radar system error calibration.

Description

Technical Field

[0001] The present invention belongs to the field of radar system error calibration, and in particular relates to a radar system error rapid calibration method based on precise orbit satellite measurement data, a computer device, a computer-readable storage medium, and a computer program product. Background Art

[0002] To address the problem of calibrating the system errors of long-range radars, existing technologies typically utilize tracking measurement data from radio satellites and artificial satellites with precise orbit data to correct radar system errors, including calibration of range zero and azimuth-pitch axis errors. Existing technologies typically determine the calibration data set based on the total number of orbits in the tracking arc of the precise orbit satellite, and then perform subsequent fitting corrections. This may include repeated orbits, which do not increase the calibration process and ultimately affect the effectiveness of the error calibration. Furthermore, the lack of clear guidance standards for the tracking data collection process can lead to a waste of radar detection resources and significant shortcomings in calibration efficiency. Summary of the Invention

[0003] The purpose of the present invention is to address the problems existing in the prior art and provide a method for rapid calibration of radar system errors based on precise orbit satellite measurement data, a computer device, a computer-readable storage medium and a computer program product, which can effectively improve the effectiveness and efficiency of radar system error calibration.

[0004] To achieve the above objectives, one aspect of the present invention provides a method for rapid calibration of radar system errors based on precise orbit satellite measurement data, comprising:

[0005] Step S1, discretize the azimuth-elevation plane observed by the radar, and divide the azimuth-elevation plane area into grids, where the maximum value of the azimuth range is , the grid step is ΔA, and the maximum value of the pitch range is , the grid step is ΔE, the total number of grids Expressed as:

[0006] ;

[0007] Step S2: The radar system selects a target to track and obtains measurement data based on the predicted value of the precise orbit satellite in the azimuth-pitch plane;

[0008] Step S3: record each observation point for each tracking arc segment Belonging grid and mark the grid Covered by:

[0009] , ;

[0010] Calculating coverage and uniformity index As a density measure, the density of the measurement data in the azimuth-elevation plane is calculated:

[0011] , ;

[0012] in , ,in ;

[0013] Set thresholds for coverage and uniformity. For areas where coverage or uniformity does not meet the thresholds, use the azimuth-elevation plane measurement data predicted by precise orbit satellites until both coverage and uniformity meet the thresholds.

[0014] Step S4: obtaining a radar measurement error data set based on the acquired radar measurement data and the fine orbit satellite ephemeris, fitting the radar measurement error data set to obtain a radar system error correction coefficient, and calibrating the radar system error using the radar system error correction coefficient.

[0015] Another aspect of the present invention provides a computer device, comprising a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the above method.

[0016] Another aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, which implements the steps of the above method when executed by a processor.

[0017] Yet another aspect of the present invention provides a computer program product, comprising a computer program, which implements the steps of the above method when executed by a processor.

[0018] According to the above aspects of the present invention, the rapid calibration method for radar system errors based on fine-track satellite measurement data, computer equipment, computer-readable storage medium, and computer program product use arc density as a quantitative characterization standard for observed arcs. By targetedly collecting the fine-track satellite measurement data required for calibration, the effectiveness and efficiency of radar system error calibration can be effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the present invention, the following briefly introduces the drawings used in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive efforts.

[0020] Figure 1 This is a flow chart of a method for rapid calibration of radar system errors based on precise orbit satellite measurement data according to an embodiment of the present invention;

[0021] Figure 2 It is a structural diagram of a computer device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0022] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0023] An embodiment of the present invention provides a method for rapid calibration of radar system errors based on precise orbit satellite measurement data. Figure 1 FIG. 1 is a flow chart of a method for rapid calibration of radar system errors based on precise orbit satellite measurement data according to an embodiment of the present invention. Figure 1 As shown, the method of the embodiment of the present invention includes steps S1 to S4.

[0024] Step S1: discretize the azimuth-elevation plane (hereinafter referred to as AE plane) observed by the radar, and divide the azimuth range 0- 、Pitch range 0- The AE plane area is divided into a grid, 、 The azimuth range is 0-360°, The pitch range is 360°, and the pitch range can be appropriately adjusted according to the specific performance of the radar equipment. In this embodiment, the pitch range is set to 3°-75°, for example. The grid step size in the azimuth range is ΔA, and the grid step size in the elevation range is ΔE. The grid step sizes ΔA and ΔE are adjustable and should be kept within 5°. In this embodiment, for example, ΔA = 5° and ΔE = 2° are set. The total number of grids is expressed as:

[0025]

[0026] In step S2, the radar system selects the corresponding target for tracking and obtains measurement data based on the predicted values ​​of precise orbit satellites (including low-orbit precise orbit satellites and GPS / Beidou navigation satellites) on the AE plane. Precise orbit satellites need to track the entire arc segment, and the tracking time of navigation satellites is set to about 10 minutes based on experience.

[0027] Step S3: Calculate the density of the measurement data on the AE plane. For areas that do not meet the threshold requirements, the radar system tracks the target and supplements the measurement data on the AE plane based on the distribution of the predicted values ​​of the precise orbit satellite on the AE plane. The specific density calculation method is as follows:

[0028] For each tracking arc, record each observation point Belongs to the grid:

[0029] ,

[0030] and mark the grid Covered; the density metrics are defined as follows:

[0031] Coverage CR: , reflecting the breadth of the plane covered;

[0032] Uniformity Index UI: ,in

[0033] After normalization, we get: ,in

[0034] Set coverage thresholds based on experience and the threshold value of the uniformity index In this embodiment, set is 98%, is 0.85, when 、 For areas where coverage or uniformity index do not meet the threshold requirements, the azimuth-pitch plane measurement data is supplemented based on the predicted values ​​of the precise orbit satellites on the azimuth-pitch plane until the coverage and uniformity index meet the threshold requirements.

[0035] In step S4, after the distribution of the measured data on the AE plane meets the threshold requirement, a radar measurement error dataset is obtained based on the acquired radar measurement data and the refined satellite ephemeris. This measurement error dataset is post-processed (including removing outliers and arc segments outside the pitch angle range). A radar system error fitting algorithm is used to obtain the system error correction coefficient, completing the radar system error calibration.

[0036] The precise orbit satellite will regularly release its precise ephemeris, which contains the satellite's spatial position and velocity information at a specific moment. According to the radar station coordinates, the accurate measurement value corresponding to the target (usually including radial distance, azimuth, pitch angle and radial velocity) can be calculated. The radar measurement error data set {ΔR i ,ΔAi ,ΔE i The process of radar system error correction is to use a full set of measurement error data {ΔR i ,ΔA i ,ΔE i}, using conventional error coefficient fitting methods to obtain the radar system error correction coefficient, and then applying this coefficient to the radar measurement value to complete the measurement system error correction. The specific implementation process of fitting the coefficient is a general method and will not be repeated here.

[0037] After obtaining the radar system error correction coefficient, let ΔR i =RR m ,ΔA i =AA m ,ΔE i =EE m , extract the measurement error information and use the following error correction model for processing:

[0038]

[0039] The meaning of each variable in the above expression is shown in the following table:

[0040] Table 1 Meaning of variables in the error correction model

[0041]

[0042] Among them, the distance from zero , azimuth zero value , pitch zero value 、The maximum value of the market is not level 、Azimuth and elevation non-orthogonality angle 、Azimuth photoelectric mismatch angle , Pitch optoelectronic non-orthogonal angle , Antenna gravity deformation It is the correction coefficient obtained by fitting, and the market is not in the direction of the maximum value Through structural determination, it can be regarded as a known quantity when correcting for errors.

[0043] The method of the embodiment of the present invention is illustrated by an example: assuming that a certain location is used as the station site, the distribution of radar measurement values ​​and the distribution of predicted values ​​of fine-track satellites for a period of time in the future are obtained. The method of the embodiment of the present invention is based on the distribution density criterion of the measurement data on the AE plane (that is, it is determined that there is measurement data coverage in the 3-75° pitch and 0-360° azimuth planes). For the uncovered areas, the radar operator is guided to collect the corresponding fine-track satellite measurement data in a targeted manner based on the predicted values ​​of the fine-track satellites. In this way, the covered areas do not need to track the target to collect data. Only the uncovered areas need to be filled to achieve effective calibration of the radar system error, thereby improving the resource utilization of the radar system and accelerating the radar system error calibration process.

[0044] In summary, the rapid calibration method for radar system errors based on precise orbit satellite measurement data in the embodiment of the present invention takes the radar azimuth-elevation plane as a reference, and by discretizing the AE plane, proposes a method for characterizing the density of the distribution of measurement data, quantitatively describing the distribution of the arc segments observed by the precise orbit satellite on the AE plane. The method of the embodiment of the present invention effectively utilizes precise orbit satellites, GPS / Beidou and other navigation satellites, and based on the distribution of the tracked and predicted arc segments of the precise orbit satellites on the AE plane by the radar, takes the arc segment density as a standard, and combines the prediction results of the precise orbit satellite to specifically collect the required measurement error data, and fits the correction coefficient of the radar system error, ultimately achieving rapid and effective calibration of the radar system error, greatly improving the calibration efficiency of the radar system error.

[0045] The embodiment of the present invention further provides a computer device, which may be a server, and its internal structure diagram may be as shown in FIG. Figure 2 As shown. The computer device includes a processor, a memory and a network interface connected via a system bus. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and computer program in the non-volatile storage medium. The database of the computer device is used to store operating parameter data of each framework. The network interface of the computer device is used to communicate with an external terminal via a network connection. When the computer program is executed by the processor, the steps of the method of the embodiment of the present invention are implemented.

[0046] Those skilled in the art will understand that Figure 2 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than shown in the figure, or combine certain components, or have a different component arrangement.

[0047] An embodiment of the present invention further provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the steps of the method of the embodiment of the present invention are implemented.

[0048] An embodiment of the present invention further provides a computer program product, including a computer program, which implements the steps of the method of the embodiment of the present invention when executed by a processor.

[0049] The above description is merely illustrative of certain exemplary embodiments of the present invention. It goes without saying that those skilled in the art will be able to modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and description are illustrative in nature and should not be construed as limiting the scope of protection of the claims.

Claims

1. A method for rapid calibration of radar system errors based on precise orbit satellite measurement data, characterized in that: include: Step S1, discretize the azimuth-elevation plane observed by the radar, and divide the azimuth-elevation plane area into grids, where the maximum value of the azimuth range is , the grid step is ΔA, and the maximum value of the pitch range is , the grid step is ΔE, the total number of grids Expressed as: ； Step S2: The radar system selects a target to track and obtains measurement data based on the predicted value of the precise orbit satellite in the azimuth-pitch plane; Step S3: record each observation point for each tracking arc segment Belonging grid and mark the grid Covered by: ， ； Calculating coverage and uniformity index As a density measure, the density of the measurement data in the azimuth-elevation plane is calculated: ， ； in , ,in ; Set thresholds for coverage and uniformity. For areas where coverage or uniformity does not meet the thresholds, use the azimuth-elevation plane measurement data predicted by precise orbit satellites until both coverage and uniformity meet the thresholds. Step S4: obtaining a radar measurement error data set based on the acquired radar measurement data and the fine orbit satellite ephemeris, fitting the radar measurement error data set to obtain a radar system error correction coefficient, and calibrating the radar system error using the radar system error correction coefficient.

2. The method according to claim 1, wherein In step S1 , the azimuth range is 0-360°, the elevation range is 3-75°, and the grid step ΔA of the azimuth range and the grid step ΔE of the elevation range are within 5°.

3. The method according to claim 1 or 2, wherein: In step S3, the coverage threshold Set to 98%, the threshold of the uniformity index Set to 0.85, when the coverage And uniformity index The threshold requirement is met when the value is greater than 1, otherwise the threshold requirement is not met.

4. The method according to claim 1 or 2, wherein: In step S4, the accurate measurement value corresponding to the target is calculated based on the precise orbit satellite ephemeris and the radar station coordinates, and the radar measurement error data set is obtained by subtracting the accurate measurement value from the actual radar measurement value.

5. The method according to claim 1 or 2, wherein: In step S4, radar system error calibration is performed as follows: in, is the radial distance correction value, is the azimuth correction value, is the pitch angle correction value, is the radial distance measurement, is the azimuth measurement value, is the measured value of the pitch angle, is the distance from zero, is the orientation zero value, is the pitch zero value, It is the maximum value of the market level. is the azimuth-pitch non-orthogonality angle, is the azimuth photoelectric mismatch angle, is the non-orthogonal angle of the pitch photoelectricity, is the antenna gravity deformation, The maximum direction of the market is not horizontal.

6. A computer device comprising a memory, a processor, and a computer program stored in the memory, wherein: The processor executes the computer program to implement the steps of the method according to any one of claims 1 to 5.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 5 are implemented.

8. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 5 are implemented.

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