Radar system error rapid calibration method based on precise orbit satellite measurement data

Abstract

The invention discloses a radar system error rapid calibration method based on precise orbit satellite measurement data, and the method comprises the steps: discretizing an azimuth-pitching plane observed by a radar, and dividing the area of the azimuth-pitching plane into grids; the radar system selects a target to track and acquire measurement data according to the forecast value of the fine orbit satellite on the azimuth-pitching plane; the coverage rate and the uniformity index are calculated to serve as density measurement indexes, the density of the measurement data is calculated, and for an area where the coverage rate or the uniformity index does not meet the threshold value requirement, the measurement data are supplemented according to the forecast value of the fine orbit satellite on the azimuth-pitching plane until the threshold value requirement is met; and acquiring a radar measurement error data set according to the acquired radar measurement data and the precise orbit satellite ephemeris, performing fitting by using the radar measurement error data set to acquire a radar system error correction coefficient, and completing radar system error calibration by using the error correction coefficient. According to the invention, the effectiveness and the calibration efficiency of radar system error calibration can be effectively improved.

Description

Technical Field

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

[0002] Regarding the problem of calibrating the system errors of long-range radars, the existing technologies usually use the tracking measurement data of radio stars and artificial satellites with precise orbit data to correct the radar system errors, including the calibration of range zero values and azimuth-elevation axis system errors. The existing technologies usually determine the calibration data set according to the total number of orbits in the tracking arc of the precise orbit satellite, and then perform subsequent fitting and correction. Among them, there may be orbits with repeated transits, which have no increment for the calibration process and ultimately affect the effectiveness of error calibration; in addition, there is no clear guiding standard for the process of tracking and recording data, which may cause waste of radar detection resources and there are obvious deficiencies in calibration efficiency. Summary of the Invention

[0003] The object of the present invention is to provide a method for rapidly calibrating 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 calibration efficiency of radar system error calibration, aiming at the problems existing in the prior art.

[0004] To achieve the above object, one aspect of the present invention provides a method for rapidly calibrating radar system errors based on precise orbit satellite measurement data, including: Step S1, discretize the azimuth-elevation plane of radar observation, divide the azimuth-elevation plane area into grids, where the maximum value of the azimuth range is , the grid step size is ΔA, the maximum value of the elevation range is , the grid step size is ΔE, and the total number of grids is expressed as: ; Step S2, the radar system selects targets for tracking according to the predicted values of the precise orbit satellite on the azimuth-elevation plane and obtains measurement data; Step S3, for each tracking arc, record the grid to which each observation point belongs and mark the grid as covered: , ; Calculate the coverage rate and the uniformity index as density measurement indicators, and calculate the density of the measurement data on the azimuth-elevation plane: , ; Among them , Among them ; Set the thresholds for the coverage rate and the uniformity index. For the areas where the coverage rate or the uniformity index does not meet the threshold requirements, supplement the measurement data in the azimuth-pitch plane according to the predicted values of the precise orbit satellite in the azimuth-pitch plane until both the coverage rate and the uniformity index meet the threshold requirements; Step S4: Obtain a radar measurement error data set based on the acquired radar measurement data and the precise orbit satellite ephemeris, use the radar measurement error data set for fitting to obtain a radar system error correction coefficient, and use the radar system error correction coefficient for radar system error calibration.

[0005] Another aspect of the present invention provides a computer device, including a memory, a processor, and a computer program stored on the memory. The processor executes the computer program to implement the steps of the above method.

[0006] Another aspect of the present invention provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements the steps of the above method.

[0007] Another aspect of the present invention provides a computer program product, including a computer program. When the computer program is executed by a processor, it implements the steps of the above method.

[0008] According to the method for rapid calibration of radar system error based on precise orbit satellite measurement data, computer device, computer-readable storage medium, and computer program product in the above aspects of the present invention, using the arc segment density as the quantitative description standard for the observation arc segment, and by specifically collecting the precise orbit satellite measurement data required for calibration, the effectiveness and calibration efficiency of radar system error calibration can be effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In order to more clearly illustrate the technical solutions of the present invention, the following will briefly introduce the drawings used in the description of the embodiments of the present invention. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings: Figure 1 is a flowchart of a method for rapid calibration of radar system error based on precise orbit satellite measurement data according to an embodiment of the present invention; Figure 2 is a structural diagram of a computer device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0010] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Apparently, the described embodiments are only a part rather than all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0011] An embodiment of the present invention provides a method for quickly calibrating the radar system error based on precise orbit satellite measurement data. Figure 1 It is a flowchart of the method for quickly calibrating the radar system error based on precise orbit satellite measurement data according to an embodiment of the present invention. As Figure 1 shown, the method of the embodiment of the present invention includes steps S1 to S4.

[0012] Step S1: Discretize the azimuth-elevation plane (hereinafter also simply referred to as the AE plane) observed by the radar, and divide the AE plane region with an azimuth range of 0 - and an elevation range of 0 - into grids. , are respectively the maximum value of the azimuth range and the maximum value of the elevation range. Among them, the azimuth range is 0 - 360°, is 360°, and the elevation range can be appropriately adjusted according to the specific performance of the radar device. In this embodiment, the elevation range is set to 3° - 75° for example, is 75°. The grid step size of the azimuth range is ΔA, and the grid step size of the elevation range is ΔE. The grid step sizes ΔA and ΔE are adjustable and are preferably kept within 5°. In this embodiment, for example, ΔA = 5° and ΔE = 2° are set. The total number of grids is expressed as:

[0013] Step S2: The radar system selects corresponding targets for tracking and obtains measurement data according to the predicted values of precise orbit satellites (including low-orbit precise orbit satellites, navigation satellites such as GPS / Beidou, etc.) on the AE plane. Among them, the precise orbit satellites need to track a complete arc segment, and the tracking duration of the navigation satellites is set to about 10 minutes according to experience; Step S3: Calculate the density of the measurement data on the AE plane. For the regions that do not meet the threshold requirements, according to the distribution of the predicted values of the precise orbit satellites on the AE plane, the measurement data of the AE plane is supplemented by the radar system tracking the targets. The specific density calculation method is as follows: For each tracking arc segment, record the grid to which each observation point belongs: ,

[0014] And mark the grid Be covered; define the density metric index as follows: Coverage rate CR: , reflecting the breadth of the plane covered; Uniformity index UI: , where

[0015] After normalization, we get: , where

[0016] Set the threshold of the coverage rate according to experience And the threshold of the uniformity index , in this embodiment, set To be 98%, To be 0.85, when , It is considered to meet the threshold requirements. For the areas where the coverage rate or the uniformity index does not meet the threshold requirements, according to the predicted values of the precise orbit satellite in the azimuth-pitch plane, supplement the measurement data in the azimuth-pitch plane until the coverage rate and the uniformity index meet the threshold requirements.

[0017] Step S4, after the distribution of the measurement data in the AE plane meets the threshold requirements, according to the obtained radar measurement data and the precise orbit satellite ephemeris, obtain the radar measurement error data set. Perform post-processing on the measurement error data set (including outlier rejection, arc segment data rejection beyond the pitch angle range, etc.), and use the radar system error fitting algorithm to obtain the system error correction coefficient to complete the radar system error calibration.

[0018] The precise orbit satellite will regularly publish its precise ephemeris, including the spatial position and velocity information of the satellite at a specific moment. According to the radar station coordinates, the accurate measurement values corresponding to the target can be calculated (usually including the radial distance, azimuth angle, pitch angle, and radial velocity). By subtracting the actual radar measurement value from this accurate value, the radar measurement error data set {ΔR i , ΔA i , ΔE i} can be obtained. The process of radar system error correction is to use the sufficient measurement error data set {ΔR i , ΔA i , ΔE i}, and use the conventional error coefficient fitting method to obtain the error correction coefficient of the radar system, and apply this coefficient to the radar measurement value to complete the measurement system error correction. The specific implementation process of the fitting coefficient is a general method and will not be elaborated here.

[0019] After obtaining the radar system error correction coefficient, let ΔR i = R - Rm , ΔA i = A - A m , ΔE i = E - E m , extract the measurement error information and process it using the following error correction model:

[0020] The meanings of the variables in the above expressions are shown in the following table: Table 1 Meanings of Variables in the Error Correction Model

[0021] Among them, the distance zero value , the azimuth zero value , the pitch zero value , the maximum value of the non - level of the turntable , the non - orthogonal angle between azimuth and pitch , the non - matching angle between azimuth and optoelectronics , the non - orthogonal angle between pitch and optoelectronics , the gravitational deformation of the antenna are correction coefficients obtained by fitting. The direction of the maximum value of the non - level of the turntable is determined by the structure and can be regarded as a known quantity during error correction.

[0022] The method of the embodiment of the present invention is illustrated by an example: Assume that a certain location is used as the station site, and the distribution of radar measurement values and the predicted value distribution of precise orbit satellites in the future for a period of time are obtained. The method of the embodiment of the present invention is based on the distribution density criterion of measurement data in the AE plane (that is, it is judged that there is measurement data coverage in the pitch range of 3 - 75° and the azimuth range of 0 - 360°). For the uncovered part, the predicted values of precise orbit satellites are used to guide the radar operator to collect the corresponding precise orbit satellite measurement data. In this way, for the covered part, there is no need to track the target to collect data again. As long as the uncovered area is filled, the effective calibration of the radar system error can be achieved, thereby improving the resource utilization rate of the radar system and at the same time accelerating the radar system error calibration process.

[0023] In summary, the method for rapidly calibrating the radar system error based on precise orbit satellite measurement data according to the embodiments of the present invention takes the radar azimuth-pitch plane as the reference, discretizes the AE plane, proposes a method for characterizing the density of measurement data distribution, and quantitatively describes the distribution of the precise orbit satellite observation arc segment on the AE plane. The method according to the embodiments of the present invention effectively utilizes precise orbit satellites, navigation satellites such as GPS / Beidou, and according to the distribution of the tracked arc segment and the predicted arc segment of the precise orbit satellite by the radar on the AE plane, taking the arc segment density as the standard, combines the prediction results of the precise orbit satellite, specifically collects the required measurement error data, fits to obtain the correction coefficient of the radar system error, and finally realizes the rapid and effective calibration of the radar system error, greatly improving the calibration efficiency of the radar system error.

[0024] The embodiments of the present invention further provide a computer device, which may be a server, and its internal structure diagram may be as Figure 2 shown. The computer device includes a processor, a memory, and a network interface connected through a system bus. Among them, 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 the computer program in the non-volatile storage medium. The database of the computer device is used to store the operation parameter data of each framework. The network interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, the steps of the method according to the embodiments of the present invention are implemented.

[0025] Those skilled in the art can understand that Figure 2 the structure shown in

[0026] is only a block diagram of some structures 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 those shown in the figure, or combine some components, or have different component arrangements.

[0027] The embodiments of the present invention further provide a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the method according to the embodiments of the present invention are implemented.

[0028] Only some exemplary embodiments of the present invention have been described by way of illustration. Without doubt, for those of ordinary skill in the art, the described embodiments can be modified in various different 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 of the present invention.

Claims

1. A rapid calibration method for radar system error based on precise orbit satellite measurement data, characterized in that Including: Step S1, discretize the azimuth-pitch plane of radar observations, divide the azimuth-pitch plane area into grids, where the maximum value of the azimuth range is , the grid step size is ΔA, the maximum value of the pitch range is , the grid step size is ΔE, and the total number of grids is expressed as:​ ； Step S2: The radar system selects a target for tracking according to the predicted value of the precise orbit satellite in the azimuth-elevation plane and obtains measurement data; Step S3: For each tracking arc segment, record the grid to which each observation point belongs and mark the grid as covered: ， ； Calculate coverage and uniformity index As a density metric, calculate the density of measurement data in the azimuth-elevation plane: ， ； Among them , Among them ; Set the thresholds of the coverage rate and the uniformity index. For the area where the coverage rate or the uniformity index does not meet the threshold requirements, according to the predicted value of the precise orbit satellite in the azimuth-elevation plane, supplement the measurement data of the azimuth-elevation plane until both the coverage rate and the uniformity index meet the threshold requirements; Step S4: According to the obtained radar measurement data and the precise orbit satellite ephemeris, obtain the radar measurement error data set, use the radar measurement error data set for fitting to obtain the radar system error correction coefficient, and use the radar system error correction coefficient to calibrate the radar system error.

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 size ΔA of the azimuth range and the grid step size ΔE of the elevation range are within 5°.

3. The method according to claim 1 or 2, characterized in that, In step S3, the threshold of the coverage rate is set to 98%, and the threshold of the uniformity index is set to 0.

85. When the coverage rate and the uniformity index meet the threshold requirements, otherwise they do not meet the threshold requirements.

4. The method according to claim 1 or 2, characterized in that, In step S4, according to the precise orbit satellite ephemeris and the radar station coordinates, calculate the accurate measurement value corresponding to the target, and use the difference between the accurate measurement value and the actual radar measurement value to obtain the radar measurement error data set.

5. The method according to claim 1 or 2, characterized in that, In step S4, the radar system error calibration is performed as follows: Among them, is the radial distance correction value, is the azimuth angle correction value, is the pitch angle correction value, is the radial distance measurement value, is the azimuth angle measurement value, is the pitch angle measurement value, is the zero distance value, is the zero azimuth value, is the zero pitch value, is the maximum value of the non - level of the large disk, is the non - orthogonality angle of azimuth and pitch, is the non - matching angle of azimuth and optoelectronics, is the non - orthogonality angle of pitch and optoelectronics, is the gravity deformation of the antenna, is the direction of the maximum value of the non - level of the large disk.

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

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

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

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