A method for field calibration of two-stage installation errors of space target precision tracking camera and two-dimensional turntable

Abstract

The present invention discloses an outfield calibration method for two-stage installation errors of a space target precision tracking camera and a two-dimensional turntable, and belongs to the field of error calibration technology. The method comprises: extracting shooting information of each angle in an inertial coordinate system according to starry sky images of multiple different shooting angles; calculating the true value of the horizon sight vector in the northeast sky coordinate system according to the true value of the inertial sight vector of the equatorial coordinate in the inertial coordinate system, combined with the transfer matrix from the northeast sky coordinate system to the inertial coordinate system; calculating the measured value of the horizon sight vector at the corresponding angle according to the turntable rotation angle and the equipment installation matrix at each angle; inputting the error of the true value and the measured value of the horizon sight vector at all shooting angles into the least squares iterative algorithm for optimization calibration, and outputting the optimal turntable installation matrix and camera installation matrix. The present invention can realize the calibration of the precision tracking camera of the two-dimensional turntable in ground tests, and improve the pointing accuracy of the precision tracking camera.

Description

Technical Field

[0001] The present invention relates to the technical field of error calibration, and in particular to an outfield calibration method for two-stage installation errors of a space target precision tracking camera and a two-dimensional turntable. Background Art

[0002] The space target precision tracking camera is mainly used to accurately track and observe various space targets in the universe. It can provide high real-time and high-precision data support for space target detection and other tasks. In related technologies, the on-orbit two-dimensional turntable drives the precision tracking camera to point to the space target with pointing accuracy requirements, and the pointing accuracy of the precision tracking camera needs to be verified through calibration and ground tests.

[0003] The current existing methods only calibrate the installation matrix of the turntable, and are unable to calibrate the two-dimensional turntable and the precision tracking camera installed on it at the same time, which makes it difficult for the actual observation results to meet the high-precision requirements.

[0004] Based on this, there is an urgent need for an outdoor calibration method for the two-level installation errors of the space target precision tracking camera and the two-dimensional turntable to solve the above technical problems. Summary of the invention

[0005] The present invention provides a method for field calibration of two-stage installation errors of a space target precision tracking camera and a two-dimensional turntable, which can solve the problem that the related technology cannot calibrate the two-dimensional turntable and the precision tracking camera at the same time. The technical solution is as follows:

[0006] On the one hand, a method for field calibration of two-stage installation errors of a space target precision tracking camera and a two-dimensional turntable is provided, the method comprising:

[0007] Extracting shooting information of each angle in an inertial coordinate system from starry sky images at multiple different shooting angles; wherein the shooting information includes the shooting time, the turntable angle and the equatorial coordinates of the starry sky target corresponding to each angle;

[0008] According to the true value of the inertial sight line vector of the equatorial coordinate in the inertial coordinate system, in combination with the transfer matrix from the northeast celestial coordinate system to the inertial coordinate system, the true value of the horizon sight line vector in the northeast celestial coordinate system is calculated; wherein the transfer matrix is ​​calculated based on the geographical longitude and latitude information of the shooting location;

[0009] According to the turntable rotation angle and equipment installation matrix of each angle, calculate the horizon sight vector measurement value of the corresponding angle;

[0010] The error between the true value and the measured value of the horizon sight vector at all shooting angles is input into the least squares iterative algorithm for optimization calibration, and the optimal turntable installation matrix and camera installation matrix are output.

[0011] On the other hand, a device for calibrating the two-stage installation errors of a space target precision tracking camera and a two-dimensional turntable is provided, the device comprising:

[0012] An extraction module is used to extract the shooting information of each angle in the inertial coordinate system according to the starry sky images of multiple different shooting angles; wherein the shooting information includes the shooting star time corresponding to each angle, the turntable angle and the equatorial coordinates of the starry sky target;

[0013] A first calculation module is used to calculate the true value of the horizon sight line vector in the northeast sky coordinate system according to the true value of the inertial sight line vector of the equatorial coordinate in the inertial coordinate system and in combination with a transfer matrix from the northeast sky coordinate system to the inertial coordinate system; wherein the transfer matrix is ​​calculated according to the geographical longitude and latitude information of the shooting location;

[0014] The second calculation module is used to calculate the horizon sight vector measurement value of the corresponding angle according to the turntable rotation angle and the equipment installation matrix at each angle;

[0015] The optimization module inputs the error between the true value and the measured value of the horizon sight vector under all shooting angles into the least squares iterative algorithm for optimization calibration, and outputs the optimal turntable installation matrix and camera installation matrix.

[0016] On the other hand, a computer device is provided, which includes a memory and a processor, the memory is used to store computer programs, and the processor is used to execute the computer programs stored in the memory to implement the steps of the above-mentioned method for field calibration of two-stage installation errors of space target precision tracking camera and two-dimensional turntable.

[0017] On the other hand, a computer-readable storage medium is provided, in which a computer program is stored. When the computer program is executed by a processor, the steps of the above-mentioned method for field calibration of two-level installation errors of a space target precision tracking camera and a two-dimensional turntable are implemented.

[0018] On the other hand, a computer program product is provided, including a computer program, which, when executed by a processor, implements the steps of the above-mentioned method for field calibration of two-stage installation errors of a space target precision tracking camera and a two-dimensional turntable.

[0019] The technical solution provided by the present invention can at least bring the following beneficial effects: first, by taking multiple starry sky images at different angles, determine the true equatorial coordinates, rotation angle information and shooting star time in the inertial coordinate system of the shooting location; then, combine the geographic longitude and latitude data of the shooting location to calculate the coordinate system transfer matrix at the shooting time; calculate the true value of the horizon sight vector in the northeast sky coordinate system according to the true equatorial coordinates and the transfer matrix; calculate the measured value of the horizon sight vector according to the rotation angle information and the installation matrix; finally, use the least squares iteration to calibrate the true value and measured value of the sight vector to obtain the optimal turntable installation matrix and camera installation matrix. This method effectively solves the problem that the pointing accuracy of the two-dimensional turntable and the precision tracking camera in the ground test is affected by the non-verticality of the two-dimensional turntable installation and the precision tracking camera installation, and improves the pointing accuracy of the precision tracking camera. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 It is a flow chart of a method for field calibration of two-stage installation errors of a space target precision tracking camera and a two-dimensional turntable provided by an embodiment of the present invention;

[0022] Figure 2 It is a structural diagram of an outfield calibration device for two-stage installation errors of a space target precision tracking camera and a two-dimensional turntable provided by an embodiment of the present invention;

[0023] Figure 3 It is a hardware architecture diagram of a computer device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0025] As mentioned above, the existing methods only calibrate the installation matrix of the turntable and cannot provide high-precision camera pointing. There is no high-precision calibration method for both the two-dimensional turntable installation matrix and the precision camera non-perpendicularity error matrix.

[0026] Based on this, the concept of the present invention is to establish a relationship between the sight line vector and the installation information of the turntable and the camera, and to achieve error calibration of the turntable and the camera at the same time based on the real sight line vector extracted from the starry sky image.

[0027] The specific implementation of the above concept is described below.

[0028] Please refer to Figure 1 , an embodiment of the present invention provides a method for field calibration of two-stage installation errors of a space target precision tracking camera and a two-dimensional turntable, the method comprising:

[0029] Step 100, extracting shooting information of each angle in an inertial coordinate system based on the starry sky images at multiple different shooting angles; wherein the shooting information includes the shooting star time corresponding to each angle, the turntable angle, and the equatorial coordinates of the starry sky target;

[0030] Step 102, calculating the true value of the horizon sight line vector in the northeast sky coordinate system according to the true value of the inertial sight line vector of the equatorial coordinate in the inertial coordinate system and combining the transfer matrix from the northeast sky coordinate system to the inertial coordinate system; wherein the transfer matrix is ​​calculated according to the geographical longitude and latitude information of the shooting location;

[0031] Step 104, calculating the horizon sight vector measurement value of the corresponding angle according to the turntable rotation angle and the equipment installation matrix at each angle;

[0032] Step 106, the error between the true value and the measured value of the horizon sight vector at all shooting angles is input into a least squares iterative algorithm for optimization calibration, and the optimal turntable installation matrix and camera installation matrix are output.

[0033] In the embodiment of the present invention, firstly, the true equatorial coordinates, rotation angle information and shooting star time in the inertial coordinate system of the shooting location are determined by shooting multiple starry sky images at different angles; then, the coordinate system transfer matrix at the shooting time is calculated in combination with the geographic longitude and latitude data of the shooting location; the true value of the horizon sight vector in the northeast sky coordinate system is calculated according to the true equatorial coordinates and the transfer matrix; the measured value of the horizon sight vector is calculated according to the rotation angle information and the installation matrix; finally, the true value and measured value of the sight vector are calibrated by the least squares iteration to obtain the optimal turntable installation matrix and camera installation matrix. This method effectively solves the problem that the pointing accuracy of the two-dimensional turntable and the precision tracking camera in the ground test is affected by the non-verticality of the two-dimensional turntable installation and the precision tracking camera installation, and improves the pointing accuracy of the precision tracking camera.

[0034] Described below Figure 1 How the various steps are performed.

[0035] First, with respect to step 100, shooting information of each angle in the inertial coordinate system is extracted based on a plurality of starry sky images at different shooting angles.

[0036] In the embodiment of the present invention, in order to ensure the pointing accuracy of the turntable in the entire sky area, it is necessary to rotate the turntable at least 6 different angles and take starry sky images, for example, 150 degrees in azimuth and 60 degrees in pitch, and then the camera takes the starry sky image at this angle. At the same time, the 6 angles are required to cover the pointing of the entire sky area as evenly spaced as possible to ensure that the calibration result can achieve high-precision pointing of the camera in the entire sky area. If the calibration is concentrated in a certain direction, only the pointing accuracy in that direction can be guaranteed.

[0037] Furthermore, stars or other targets are extracted from the captured starry sky image to obtain the right ascension lan and declination lon, i.e., the equatorial coordinates, of the corresponding target at the shooting angle, as well as the shooting star time when the image was taken; at the same time, the turntable angle information corresponding to the shooting angle is recorded.

[0038] Then, for step 102, the true value of the inertial sight line vector in the northeast celestial coordinate system is calculated based on the true value of the inertial sight line vector of the equatorial coordinate in the inertial coordinate system and the transfer matrix from the northeast celestial coordinate system to the inertial coordinate system.

[0039] In the embodiment of the present invention, the true value of the inertial sight line vector It is directly calculated based on the extracted target equatorial coordinates. The sight vector is used to indicate the direction of the turntable camera. The true value of the inertial sight vector is the sight vector of the inertial coordinate system, which is well known to those skilled in the art and will not be elaborated here.

[0040] Furthermore, the transfer matrix from the northeastern celestial coordinate system to the inertial coordinate system corresponding to the shooting star time t is calculated by the following process:

[0041] First, calculate the time under the J2000.0 standard corresponding to the shooting star time t at the current angle :

[0042]

[0043] in, It is the time interval of GPS time zero UTC relative to the standard J2000.0 (i.e. 12:0:00 on January 1, 2000), ignoring leap seconds; The time difference between GPS timing zero UTC and TDT (=leap second + 32.184);

[0044] According to the geographical latitude and geographic longitude Calculate the transfer matrix of the Northeast Celestial Coordinate System relative to the 84 Geocentric System :

[0045]

[0046] Calculate the transfer matrix of the 84 geocentric system relative to the instantaneous J2000 coordinate system :

[0047]

[0048] in, is Greenwich Mean Time, ;

[0049] The transfer matrix from the northeastern sky coordinate system to the inertial coordinate system is calculated by the following formula: :

[0050]

[0051] in, is the precession-nutation matrix.

[0052] In getting the transfer matrix Then, the true value of the horizon sight vector corresponding to the equatorial coordinates in the northeast sky coordinate system at time t is calculated by the following formula: :

[0053] .

[0054] With respect to step 104, the horizon sight line vector measurement value of the corresponding angle is calculated according to the turntable rotation angle and the equipment installation matrix at each angle.

[0055] In the embodiment of the present invention, the horizon sight vector measurement value Calculated by the following formula:

[0056]

[0057] In the formula, Install the matrix for the turntable to be calibrated, Install the matrix for the camera to be calibrated, and are the azimuth and elevation angles of the turntable, is the camera projection matrix, and They are the rotation matrices around the y-axis and z-axis of the coordinate system respectively.

[0058] It is worth noting that the initial value of the installation matrix to be calibrated is the unit matrix and cannot be directly measured; the actual error terms include the installation error of the two-dimensional turntable, the non-perpendicularity error of the precision tracking camera, and the non-perpendicularity error of the turntable azimuth and pitch angle. That is, the above formula should actually be:

[0059]

[0060] Due to the non-verticality error of the turntable's azimuth and elevation It is not observable, so it cannot be solved by calibration optimization. This error is composed of the installation error of the 2D turntable and the compensation of the non-perpendicularity error of the precision tracking camera.

[0061] For step 106, the error between the true value and the measured value of the horizon sight vector at all shooting angles is input into the least squares iterative algorithm for optimization calibration, and the optimal turntable installation matrix and camera installation matrix are output.

[0062] In the embodiment of the present invention, the error between the true value and the measured value is .

[0063] The least squares method is a commonly used mathematical optimization technique for finding the best linear fit for data. It finds the best fitting line or curve by minimizing the sum of squares of the errors. In practical applications, when the problem is large or the model is complex, it may become infeasible to directly solve the least squares problem. In this case, it is necessary to use an iterative method to gradually approach the optimal solution.

[0064] Iterative optimization algorithms start with an initial guess and then gradually adjust this guess to reduce the value of the objective function (in this case, the sum of squared errors). This process is repeated until a stopping condition is reached, such as reaching a predetermined maximum number of iterations, or the change in the objective function is less than a certain threshold.

[0065] Taking 6 different shooting angles as an example, the objective function to be iteratively solved is set as follows in this embodiment of the present invention:

[0066]

[0067] The errors calculated from the six sets of data are used as samples to input into the least squares iterative algorithm for 100 iterations, and the optimal turntable installation matrix and camera installation matrix are solved by the gradient descent method through the objective function. In other words, through the least squares iterative optimization, the error between the real sight vector and the measured sight vector gradually approaches the optimal solution.

[0068] It is worth noting that the above solution process is well known to those skilled in the art and will not be described in detail here.

[0069] The feasibility of the above method is demonstrated by an embodiment below:

[0070] The turntable drives the precision tracking camera to take a star map. At this time, the star time t is 54390523 relative to the UTC time on January 1, 2023. The turntable azimuth 0°, pitch angle is 60°, the line of sight vector extracted from the star map has a right ascension lan=311.315° and a declination lon=10.9279°; the right ascension and declination are converted to inertial pointing .

[0071] Experiment with local geographic latitude and longitude , They are 40°4'33.98'' and 116°16'44.61'' respectively;

[0072] Calculate the transfer matrix from the northeastern celestial coordinate system to the inertial system at star time 54390523 , and convert the right ascension and declination into inertial pointing Switch to the northeast celestial coordinate system and get ;

[0073] Calculate the camera sight vector at 54390523 seconds in the northeastern sky coordinate system

[0074] ;

[0075] For each star hour, Perform least squares iterative optimization to obtain the optimal turntable installation matrix and the camera mounting matrix .

[0076] In summary, the calibration of the two-dimensional turntable precision tracking camera in ground tests is realized through the above method, which improves the pointing accuracy of the precision tracking camera.

[0077] Please refer to Figure 2 The embodiment of the present invention provides a device for calibrating the two-stage installation error of a space target precision tracking camera and a two-dimensional turntable in an out-of-field manner, the device comprising:

[0078] The extraction module 200 is used to extract the shooting information of each angle in the inertial coordinate system according to the starry sky images of multiple different shooting angles; wherein the shooting information includes the shooting star time corresponding to each angle, the turntable rotation angle and the equatorial coordinates of the starry sky target;

[0079] The first calculation module 202 is used to calculate the true value of the horizon sight line vector in the northeast sky coordinate system according to the true value of the inertial sight line vector of the equatorial coordinate in the inertial coordinate system and in combination with the transfer matrix from the northeast sky coordinate system to the inertial coordinate system; wherein the transfer matrix is ​​calculated according to the geographical longitude and latitude information of the shooting location;

[0080] The second calculation module 204 is used to calculate the horizon sight vector measurement value of the corresponding angle according to the turntable rotation angle and the equipment installation matrix at each angle;

[0081] The optimization module 206 inputs the error between the true value and the measured value of the horizon sight vector at all shooting angles into the least squares iterative algorithm for optimization calibration, and outputs the optimal turntable installation matrix and camera installation matrix.

[0082] In the embodiment of the present invention, the shooting angles include at least 6, each shooting angle value is equal, and the sum of all shooting angles covers the directions of the entire sky area.

[0083] In the embodiment of the present invention, when calculating the transfer matrix, the first calculation module 202 is specifically used to perform the following operations: calculate the time corresponding to the shooting star time t at the current angle under the J2000.0 standard :

[0084]

[0085] in, It is the time interval of GPS time zero UTC relative to the J2000.0 standard; The time difference between GPS timing zero point UTC and TDT;

[0086] According to the geographical latitude and geographic longitude Calculate the transfer matrix of the Northeast Celestial Coordinate System relative to the 84 Geocentric System :

[0087]

[0088] Calculate the transfer matrix of the 84 geocentric system relative to the instantaneous J2000 coordinate system :

[0089]

[0090] in, is Greenwich Mean Time, ;

[0091] The transfer matrix from the northeastern sky coordinate system to the inertial coordinate system is calculated by the following formula: :

[0092]

[0093] Among them, Precession-nutation matrix.

[0094] In the embodiment of the present invention, the first calculation module 202 calculates the true value of the horizon sight vector When , it is used to perform the following operations:

[0095]

[0096] In the formula, is the true value of the inertial sight line vector corresponding to the equatorial coordinate in the inertial coordinate system; is the transfer matrix from the northeast celestial coordinate system to the inertial system.

[0097] In the embodiment of the present invention, the second calculation module 204 calculates the horizon sight vector measurement value When , it is used to perform the following operations:

[0098]

[0099] In the formula, Install the matrix for the turntable to be calibrated, Install the matrix for the camera to be calibrated, and are the azimuth and elevation angles of the turntable, is the camera projection matrix, and They are the rotation matrices around the y-axis and z-axis of the coordinate system respectively.

[0100] In the embodiment of the present invention, when the optimization module 206 inputs the error between the true value and the measured value of the horizon sight vector at all shooting angles into the least squares iterative algorithm for optimization calibration and outputs the optimal turntable installation matrix and camera installation matrix, it is specifically used to perform the following operations:

[0101] The least squares algorithm is used to iteratively optimize the error of the sight vector until the change of the preset objective function is less than the preset threshold or the number of iterations reaches the maximum value, and the optimal turntable installation matrix and camera installation matrix are obtained.

[0102] It should be noted that the device for field calibration of the two-stage installation error of the space target precision tracking camera and the two-dimensional turntable provided in the above embodiment is only illustrated by the division of the above-mentioned functional modules. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. In addition, the device for field calibration of the two-stage installation error of the space target precision tracking camera and the two-dimensional turntable provided in the above embodiment belongs to the same concept as the method embodiment of field calibration of the two-stage installation error of the space target precision tracking camera and the two-dimensional turntable. The specific implementation process is detailed in the method embodiment, which will not be repeated here.

[0103] The embodiment of the present application also provides a computer device, please refer to Figure 3The computer device includes a processor and a memory, wherein the memory stores at least one instruction, at least one program, a code set or an instruction set, and the at least one instruction, at least one program, a code set or an instruction set is loaded and executed by the processor to implement the field calibration method for the two-level installation error of the space target precision tracking camera and the two-dimensional turntable provided in the above-mentioned method embodiments.

[0104] An embodiment of the present application also provides a computer-readable storage medium, on which is stored at least one instruction, at least one program, code set or instruction set, and the at least one instruction, at least one program, code set or instruction set is loaded and executed by a processor to implement the field calibration method for the two-level installation error of the space target precision tracking camera and the two-dimensional turntable provided in the above-mentioned method embodiments.

[0105] An embodiment of the present application also provides a computer program product, which includes a computer program. A processor of a computer device reads the computer program from a computer-readable storage medium, and the processor executes the computer program, so that the computer device executes the field calibration method for the two-stage installation error of the space target precision tracking camera and the two-dimensional turntable as described in any of the above embodiments.

[0106] For the convenience of description, the above system or device is described by dividing it into various modules or units according to its functions. Of course, when implementing the present application, the functions of each unit can be implemented in the same or multiple software and / or hardware.

[0107] It can be known from the description of the above implementation methods that those skilled in the art can clearly understand that the present application can be implemented by means of software plus a necessary general hardware platform. Based on such an understanding, the technical solution of the present application can be essentially or partly contributed to the prior art in the form of a software product, which can be stored in a storage medium such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in the various embodiments of the present application or certain parts of the embodiments.

[0108] Finally, it should be noted that, in this article, relational terms such as first, second, third and fourth are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0109] The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A method for field calibration of two-stage installation errors of a space target precision tracking camera and a two-dimensional turntable, characterized in that: The method comprises: Extracting shooting information of each angle in an inertial coordinate system from starry sky images at multiple different shooting angles; wherein the shooting information includes the shooting time, the turntable angle and the equatorial coordinates of the starry sky target corresponding to each angle; According to the true value of the inertial sight line vector of the equatorial coordinate in the inertial coordinate system, in combination with the transfer matrix from the northeast celestial coordinate system to the inertial coordinate system, the true value of the horizon sight line vector in the northeast celestial coordinate system is calculated; wherein the transfer matrix is ​​calculated based on the geographical longitude and latitude information of the shooting location; According to the turntable rotation angle and equipment installation matrix of each angle, calculate the horizon sight vector measurement value of the corresponding angle; The error between the true value and the measured value of the horizon sight vector at all shooting angles is input into the least squares iterative algorithm for optimization calibration, and the optimal turntable installation matrix and camera installation matrix are output.

2. The method according to claim 1, characterized in that The shooting angles include at least 6, each shooting angle value is equal, and the sum of all shooting angles covers the directions of the entire sky area.

3. The method according to claim 1, characterized in that The transfer matrix is ​​calculated by the following formula: Calculate the time under the J2000.0 standard corresponding to the shooting star time t at the current angle : in, It is the time interval of GPS time zero UTC relative to the J2000.0 standard; The time difference between GPS timing zero point UTC and TDT; According to the geographical latitude and geographic longitude Calculate the transfer matrix of the Northeast Celestial Coordinate System relative to the 84 Geocentric System : Calculate the transfer matrix of the 84 geocentric system relative to the instantaneous J2000 coordinate system : in, is Greenwich Mean Time, ; The transfer matrix from the northeastern sky coordinate system to the inertial coordinate system is calculated by the following formula: : in, is the precession-nutation matrix.

4. The method according to claim 3, characterized in that The true value of the horizon sight vector Calculated by the following formula: In the formula, is the true value of the inertial sight line vector corresponding to the equatorial coordinate in the inertial coordinate system; is the transfer matrix from the northeast celestial coordinate system to the inertial system.

5. The method according to claim 4, characterized in that The measured value of the horizon sight vector Calculated by the following formula: In the formula, Install the matrix for the turntable to be calibrated, Install the matrix for the camera to be calibrated, and are the azimuth and elevation angles of the turntable, is the camera projection matrix, and They are the rotation matrices around the y-axis and z-axis of the coordinate system respectively.

6. The method according to claim 1, characterized in that The error between the true value and the measured value of the horizon sight vector at all shooting angles is input into the least squares iterative algorithm for optimization calibration, and the optimal turntable installation matrix and camera installation matrix are output, including: The least squares algorithm is used to iteratively optimize the error of the sight vector until the change of the preset objective function is less than the preset threshold or the number of iterations reaches the maximum value, and the optimal turntable installation matrix and camera installation matrix are obtained.

7. A device for calibrating the two-stage installation error of a space target precision tracking camera and a two-dimensional turntable, characterized in that: The device comprises: An extraction module is used to extract the shooting information of each angle in the inertial coordinate system according to the starry sky images of multiple different shooting angles; wherein the shooting information includes the shooting star time corresponding to each angle, the turntable angle and the equatorial coordinates of the starry sky target; A first calculation module is used to calculate the true value of the horizon sight line vector in the northeast sky coordinate system according to the true value of the inertial sight line vector of the equatorial coordinate in the inertial coordinate system and in combination with a transfer matrix from the northeast sky coordinate system to the inertial coordinate system; wherein the transfer matrix is ​​calculated according to the geographical longitude and latitude information of the shooting location; The second calculation module is used to calculate the horizon sight vector measurement value of the corresponding angle according to the turntable rotation angle and the equipment installation matrix at each angle; The optimization module inputs the error between the true value and the measured value of the horizon sight vector under all shooting angles into the least squares iterative algorithm for optimization calibration, and outputs the optimal turntable installation matrix and camera installation matrix.

8. A computer device, characterized in that: The computer device includes a memory and a processor, the memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory to implement the steps of any one of the methods described in claims 1-6.

9. A computer-readable storage medium, characterized in that: The storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method described in any one of claims 1 to 6 are implemented.

10. A computer program product, characterized in that The method comprises a computer program, wherein when the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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