Small field of view camera fast star aiming and tracking device, method and detection device

Abstract

The present invention relates to a star aiming and tracking device and method, and specifically to a fast star aiming and tracking device, method and detection device for a small field of view camera. The problem of difficulty and slow speed in manually adjusting the aiming and pointing of a small field of view camera to a star to be observed is solved. The device includes a mounting base plate, a two-dimensional turntable, a star sensor and an electric control box; the star sensor and the two-dimensional turntable are fixedly mounted on the same reference plane, and the target vector of the star sensor measurement coordinate system relative to the J2000.0 inertial coordinate system can be directly converted into the target vector under the two-dimensional turntable coordinate system through the mounting matrix, regardless of whether the measurement reference is leveled or pointed to the initial zero position, and the aiming and pointing process is simple. The detection device with the star aiming and tracking device can be portable and moved arbitrarily, and can be repeatedly extended and retracted at any time. Switching between different observed stars is simple and easy, and the direction can be switched by simply finding the right ascension and declination information of the measured target in the star library and inputting it.

Description

Technical Field

[0001] The invention relates to a star aiming and tracking device and method, and in particular to a fast star aiming and tracking device, method and detection device for a small-field-of-view camera. Background Art

[0002] The star magnitude detection capability is one of the main performance indicators of space optical cameras. In addition to the indoor calibration test in the design and production stage, outdoor testing and verification of the actual detection capability of the camera by photographing stars in the sky is usually indispensable. Especially for optical cameras with special spectral bands or narrow bands, the data simulation analysis error is extremely large. The indoor detection capability test is limited by the spectrum of the light source and is difficult to accurately simulate. The spectra of different stars have significant and stable characteristics. Selecting stars of the corresponding spectrum bands outdoors to calibrate optical cameras with special spectral bands or narrow bands has become an important means. To calibrate the camera detection capability using stars distributed in the celestial sphere outdoors, aiming the camera at the stars is the first step. Only by aiming and stably pointing at the stars can the camera parameters be adjusted and optimized to calibrate the detection capability. However, for cameras with a field of view of 5mrad or even smaller, it is very difficult to quickly point to the stars to be observed within the 2πrad celestial sphere. The equipment installation base needs to be strictly adjusted to the level and the zero reference north calibrated. In theory, a 5mrad camera field of view requires 3.5×10^5 seamless stitching times to scan half of the celestial sphere. It is very likely that faint star targets will pass through the field of view or be missed during the process of manually pointing the camera blindly to find stars. Even if a star happens to enter the camera's field of view at a certain moment, due to the rotation of the earth, for a 5mrad camera field of view, stars other than the North Star only stay in the field of view for about 19.1 seconds. This short time makes it difficult to calibrate and verify the camera's star detection capability. Summary of the invention

[0003] The object of the present invention is to provide a device and method for fast star aiming and tracking of a small-field-of-view camera, so as to solve the problem of difficulty and slow speed in manually adjusting the aiming direction of a small-field-of-view camera to a star to be observed.

[0004] The technical solution of the present invention is to provide a milliradian-level small-field camera fast star aiming and tracking device, which is special in that it includes a mounting base plate, a two-dimensional turntable, a star sensor and an electric control box;

[0005] The two-dimensional turntable and the star sensor are fixedly mounted on the mounting base plate;

[0006] The two-dimensional turntable is composed of a vertical azimuth axis system, a horizontal pitch axis system and a pitch stage; the pitch stage is used to fix and install a small field of view camera, and the small field of view camera can realize pitch azimuth adjustment based on the two-dimensional turntable;

[0007] The two-dimensional turntable, star sensor and small field camera meet the following installation relationship:

[0008] The two-dimensional turntable coordinate system XzYzZz: The Xz axis points to the camera visual axis direction when the turntable azimuth angle and pitch angle are both 0°; the Zz axis is defined as the normal direction of the mounting surface of the mounting base plate, and the Yz axis, Xz axis and Zz axis satisfy the right-hand relationship; the angle of rotation around the Zz axis is defined as the azimuth angle; when the pitch stage is horizontal, that is, when the small field of view camera is horizontal, the pitch angle of the two-dimensional turntable is 0°;

[0009] The star sensor measurement coordinate system is XsYsZs: the Zs axis is defined as the direction of the star sensor's visual axis, the Xs axis and the Ys axis are perpendicular to the Zs axis, and the Xs axis and the Ys axis are parallel to the row and column directions of the star sensor's photoelectric detector;

[0010] The electric control box includes a memory and a processor. The memory stores a computer program. When the computer program is executed by the processor, the following process is implemented:

[0011] Step 1, calculating the pointing vector from the surface test site to the star to be observed;

[0012] The observation vector r of the star to be observed relative to the center of the earth is calculated according to the right ascension α and declination δ of the star to be observed in the J2000.0 inertial coordinate system; the observation vector r of the star to be observed relative to the center of the earth is equivalent to the pointing vector of the surface test site pointing to the star to be observed;

[0013] Step 2: The star sensor is matched with the star map in its field of view, and the attitude change of its measurement coordinate system relative to the J2000.0 inertial coordinate system is output and represented by the attitude matrix A;

[0014] Step 3: Obtain the observation vector in the measurement coordinate system of the corresponding star sensor based on the attitude matrix A;

[0015] Step 4: convert the observation vector of the star sensor measurement coordinate system into the observation vector of the two-dimensional turntable coordinate system through the installation matrix M of the star sensor measurement coordinate system and the two-dimensional turntable coordinate system;

[0016] Step 5, calculating the azimuth and elevation angles of the small field of view camera pointed at the star to be observed;

[0017] According to the definition of the azimuth and pitch angles of the two-dimensional turntable and their positive and negative signs, calculate the azimuth angle Az corresponding to the observation vector in the two-dimensional turntable coordinate system t and pitch angle El t , drive the two-dimensional turntable axis system to rotate so that the visual axis of the small-field camera points to the star to be observed in the predetermined airspace.

[0018] Furthermore, the observation vector r of the star to be observed relative to the center of the Earth in step 1 is J2000.0 It is expressed by the following formula:

[0019]

[0020] Furthermore, the posture matrix A in step 2 is expressed as follows:

[0021]

[0022] Among them, q0, q1, q2, and q3 are attitude quaternions.

[0023] Furthermore, in step 3, the observation vector r corresponding to the star sensor measurement coordinate system is obtained based on the attitude matrix A. s (t) are as follows:

[0024]

[0025] Where t is time, x s is the X component of the observation vector in the star sensor measurement coordinate system, y s is the Y component of the observation vector in the star sensor measurement coordinate system, z s is the Z component of the observation vector in the star sensor measurement coordinate system.

[0026] Furthermore, in step 4, the observation vector r in the two-dimensional turntable coordinate system cl (t) is as follows:

[0027]

[0028] x cl is the X component of the observation vector in the two-dimensional turntable coordinate system, y cl is the Y component of the observation vector in the two-dimensional turntable coordinate system, z cl is the Z component of the observation vector in the two-dimensional turntable coordinate system.

[0029] Furthermore, in step 5, the sign of the azimuth and pitch angles of the two-dimensional turntable is defined as follows:

[0030] Definition of the sign of the azimuth angle of a two-dimensional turntable:

[0031] Looking against the Zz axis, clockwise rotation angles are positive, and counterclockwise rotation angles are negative;

[0032] Definition of the positive and negative signs of the pitch angle of a two-dimensional turntable:

[0033] Looking against the Yz axis, clockwise rotation angles are positive and counterclockwise rotation angles are negative.

[0034] Furthermore, the azimuth angle Az corresponding to the observation vector in the two-dimensional turntable coordinate system in step 5 is t and pitch angle El t as follows:

[0035]

[0036] The present invention also provides a method for fast star tracking using a small field of view camera based on the above device, which is special in that it comprises the following steps:

[0037] Step 1, calculating the pointing vector from the surface test site to the star to be observed;

[0038] The observation vector r of the star to be observed relative to the center of the earth is calculated according to the right ascension α and declination δ of the star to be observed in the J2000.0 inertial coordinate system; the observation vector r of the star to be observed relative to the center of the earth is equivalent to the pointing vector of the surface test site pointing to the star to be observed;

[0039] Step 2: The star sensor matches the star map in its field of view and outputs the attitude change of its measurement coordinate system relative to the J2000.0 inertial coordinate system to the electronic control box, which is represented by the attitude matrix A.

[0040] Step 3: The electronic control box obtains the observation vector in the measurement coordinate system of the corresponding star sensor based on the attitude matrix A;

[0041] Step 4: The electric control box converts the observation vector of the star sensor measurement coordinate system into the observation vector of the two-dimensional turntable coordinate system through the installation matrix M of the star sensor measurement coordinate system and the two-dimensional turntable coordinate system;

[0042] Step 5, calculating the azimuth and elevation angles of the small field of view camera pointed at the star to be observed;

[0043] According to the definition of the azimuth and pitch angles of the two-dimensional turntable and their positive and negative signs, calculate the azimuth angle Az corresponding to the observation vector in the two-dimensional turntable coordinate system t and pitch angle El t The electric control box drives the axis system of the two-dimensional turntable to rotate so that the visual axis of the small-field camera points to the star to be observed in the predetermined airspace.

[0044] Furthermore, the observation vector r of the star to be observed relative to the center of the earth in step 1 above is J2000.0 It is expressed by the following formula:

[0045]

[0046] Furthermore, the posture matrix A in the above step 2 is expressed by the following formula:

[0047]

[0048] Among them, q0, q1, q2, and q3 are attitude quaternions.

[0049] Furthermore, in the above step 3, the observation vector r corresponding to the star sensor measurement coordinate system is obtained based on the attitude matrix A. s (t) are as follows:

[0050]

[0051] Where t is time, x s is the X component of the observation vector in the star sensor measurement coordinate system, y s is the Y component of the observation vector in the star sensor measurement coordinate system, z s is the Z component of the observation vector in the star sensor measurement coordinate system.

[0052] Furthermore, in the above step 4, the observation vector r in the two-dimensional turntable coordinate system cl (t) is as follows:

[0053]

[0054] x cl is the X component of the observation vector in the two-dimensional turntable coordinate system, y cl is the Y component of the observation vector in the two-dimensional turntable coordinate system, z cl is the Z component of the observation vector in the two-dimensional turntable coordinate system.

[0055] Furthermore, in the above step 5, the positive and negative signs of the azimuth and pitch angles of the two-dimensional turntable are defined as follows:

[0056] Definition of the sign of the azimuth angle of a two-dimensional turntable:

[0057] Looking against the Zz axis, clockwise rotation angles are positive, and counterclockwise rotation angles are negative;

[0058] Definition of the positive and negative signs of the pitch angle of a two-dimensional turntable:

[0059] Looking against the Yz axis, clockwise rotation angles are positive and counterclockwise rotation angles are negative.

[0060] Furthermore, the azimuth angle Az corresponding to the observation vector in the two-dimensional turntable coordinate system in step 5 above is t and pitch angle El t as follows:

[0061]

[0062] The present invention also provides an outdoor detection device with a small field of view camera, which is special in that it includes the above-mentioned small field of view camera fast star aiming and tracking device and a small field of view camera, the small field of view camera is fixedly mounted on the pitch stage of the two-dimensional turntable in the small field of view camera fast star aiming and tracking device, and the pitch azimuth adjustment can be achieved based on the two-dimensional turntable.

[0063] The beneficial effects of the present invention are:

[0064] 1. When existing small-field-of-view cameras are pointed at stars in the field, the measurement base is usually required to have high leveling accuracy, which is less than 1 / 2 of the field of view. This results in a long time for repeated leveling in the early preparation after each deployment of the equipment, and re-leveling is required after movement. The present invention fixes the star sensor and the two-dimensional turntable on the same reference plane. The target vector of the star sensor measurement coordinate system relative to the J2000.0 inertial coordinate system can be directly converted into the target vector in the two-dimensional turntable coordinate system through the installation matrix M, regardless of whether the measurement reference is leveled or pointed to the initial zero position, and the aiming and pointing process is simple.

[0065] 2. The device of the present invention points to and tracks stars without the need for accurately measuring the position of the ground station. It is directly calculated based on the right ascension and declination of the stars in the J2000.0 inertial coordinate system and the measurement reference attitude in the J2000.0 inertial system, avoiding the association of geodetic coordinates and the precession of the earth's rotation polar motion. Usually, the elevation angle of the ground station pointing to the star is defined relative to the local level, and the local level is closely related to the local latitude, altitude and other geographical information. The smaller the camera field of view, the higher the latitude and longitude of the measuring station, the higher the measurement accuracy.

[0066] 3. The small field of view camera outdoor detection device based on the device of the present invention can be portable and moved arbitrarily during testing, and can be repeatedly expanded and retracted at any time. It is also simple and easy to switch between different observed stars. You only need to find the right ascension and declination information of the target in the star library and input it to switch the direction. The right ascension and declination information does not change with time and can be injected in advance. The angle directly used to point to the star during conventional field testing requires strict time unification due to the rotation of the earth, so high-precision pointing to the star target requires strict time unification. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Figure 1 This is a schematic diagram of the structure of a fast star aiming and tracking device for a small field of view camera in an embodiment;

[0068] The reference numerals in the figure are: 1, mounting base plate; 2, two-dimensional turntable; 3, star sensor; 4, electric control box; 5, small field camera; 21, pitch stage;

[0069] Figure 2 Schematic diagram of the rotation relationship between the star sensor measurement coordinate system XsYsZs and the two-dimensional turntable measurement coordinate system XclYclZcl in the embodiment; in the figure, a, b, c refer to the rotation angle between the two coordinate systems.

[0070] Figure 3 It is a flowchart of a method for fast star aiming and tracking with a small field of view camera in an embodiment;

[0071] Figure 4 This is the actual pointing effect of the small field of view camera in the embodiment. DETAILED DESCRIPTION

[0072] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0073] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0074] This embodiment is suitable for fast star tracking of a small-field-of-view camera. Here, a small-field-of-view camera generally refers to a camera with a field of view of the order of milliradians. It is very difficult for such a camera to quickly point to and aim at a star to be observed within a 2πrad celestial sphere.

[0075] like Figure 1 As shown, the device includes a mounting base plate 1, a two-dimensional turntable 2, a star sensor 3 and an electric control box 4. Among them, the two-dimensional turntable 2 is composed of a vertical azimuth axis system, a horizontal pitch axis system and a pitch stage 21 that can carry the test piece. The star sensor 3 and the two-dimensional turntable 2 are fixedly mounted on the mounting base plate 1, and the pitch stage 21 of the two-dimensional turntable 2 is used to fix the small field of view camera 5 to be tested. According to actual needs, the entire device is placed in the use environment by moving the mounting base plate 1.

[0076] The installation relationship between the two-dimensional turntable 2, the star sensor 3 and the small field camera 5 to be measured is as follows:

[0077] The coordinate system of the two-dimensional turntable 2 is XzYzZz: When the pitch stage 21 is horizontal, it is defined as the pitch 0° of the two-dimensional turntable 2. The Xz axis points to the direction of the camera's visual axis when the turntable's azimuth angle and pitch angle are both 0°. The Zz axis is defined as the normal direction of the mounting surface of the mounting base plate 1, and the Yz axis satisfies the right-hand relationship with the Xz axis and the Zz axis. The angle of rotation around the vertical axis Zz axis is defined as the azimuth angle. Definition of the positive and negative signs of the azimuth angle of the two-dimensional turntable 2: Looking against the Zz axis, the clockwise rotation angle is positive, and the counterclockwise rotation angle is negative; definition of the positive and negative signs of the pitch angle of the two-dimensional turntable 2: Looking against the Yz axis, the clockwise rotation angle is positive, and the counterclockwise rotation angle is negative.

[0078] The measurement coordinate system of star sensor 3 is XsYsZs: the visual axis direction of star sensor 3 is defined as Zs axis, Xs axis and Ys axis are perpendicular to Zs axis, and Xs axis and Ys axis are parallel to the row and column directions of star sensor 3 photoelectric detector.

[0079] The electric control box 4 is electrically connected to the two-dimensional turntable 2 and the star sensor 3. Rapid star aiming and tracking can be achieved through the following process:

[0080] Calculate the pointing vector of the surface test site pointing to the star to be observed. Calculate the observation vector r relative to the center of the earth according to the right ascension and declination αδ of the star to be observed.

[0081]

[0082] Since stars are very far away, at least several light years away, and the radius of the earth is only about 6378km, which is much smaller than the distance between the star to be observed and the center of the earth, the geocentric observation vector can be equated to the vector pointing from the surface test site to the star to be observed.

[0083] The star sensor 3 outputs the attitude change of its measurement coordinate system relative to the inertia of J2000.0 according to the star map matching in its field of view. The attitude is usually represented by the attitude matrix A represented by the attitude quaternions q0, q1, q2, q3.

[0084]

[0085] The observation vector corresponding to the star sensor 3 measurement coordinate system is described as:

[0086]

[0087] Due to the rotation of the Earth, this attitude changes with time t.

[0088] The installation matrix of the measurement coordinate system of the star sensor 3 and the coordinate system of the two-dimensional turntable 2 is M, which is a function of the three angles a, b, and c, that is:

[0089]

[0090] The observation vector of the measurement coordinate system of the star sensor 3 is converted into the observation vector of the coordinate system of the two-dimensional turntable 2 through the M matrix.

[0091]

[0092] When the measurement coordinate system of the star sensor 3 is installed in parallel with the measurement coordinate system of the two-dimensional turntable 2, the M matrix is ​​the unit matrix. At this time, the posture is also the posture of the two-dimensional turntable 2 coordinate system relative to the J2000.0 coordinate system.

[0093] Calculate the azimuth pitch angle of the small field camera 5 pointed at the star. According to the definition of the azimuth pitch angle and its sign of the two-dimensional turntable 2, calculate the azimuth angle Az corresponding to the vector t and pitch angle El t The control box drives the 2-axis system of the two-dimensional turntable to rotate so that the camera's visual axis points to the target star in the predetermined airspace.

[0094]

[0095]

[0096] The attitude matrix of the two-dimensional turntable 2 measurement coordinate system relative to the J2000.0 inertial system and the azimuth angle and pitch angle of the two-dimensional turntable 2 are updated with time t, keeping the camera's visual axis pointing to track the observed star, so that the observed target star is always in the center of the field of view of the small field of view camera 5.

[0097] The above calculation process can be performed in a control box, which includes a memory and a processor. The memory stores a computer program, and when the computer program is executed by the processor, the above calculation process is realized.

[0098] At the same time, this embodiment can also provide an outdoor detection device with a small field of view camera 5 including the above-mentioned small field of view camera 5 fast star aiming and tracking device. The small field of view camera 55 is fixedly mounted on the pitch stage 21 of the two-dimensional turntable 22 in the small field of view camera 5 fast star aiming and tracking device, and the pitch azimuth adjustment can be realized based on the two-dimensional turntable 22.

Claims

1. A fast star tracking device for a small field of view camera, characterized in that: It comprises a mounting base plate (1), a two-dimensional turntable (2), a star sensor (3) and an electric control box (4); The two-dimensional turntable (2) and the star sensor (3) are both fixedly mounted on the mounting base plate (1); The electric control box (4) is electrically connected to the two-dimensional turntable (2) and the star sensor (3); The two-dimensional turntable (2) is composed of a vertical azimuth axis system, a horizontal pitch axis system and a pitch stage (21); the pitch stage (21) is used to fix and install a small-field-of-view camera (5), and the small-field-of-view camera (5) can achieve pitch azimuth adjustment based on the two-dimensional turntable (2); The two-dimensional turntable (2), the star sensor (3) and the small field camera (5) satisfy the following installation relationship: The coordinate system of the two-dimensional turntable (2) is XzYzZz: the Xz axis points to the camera visual axis direction when the azimuth angle and pitch angle of the turntable are both 0°; the Zz axis is defined as the normal direction of the mounting surface of the mounting base plate (1); the Yz axis satisfies the right-hand relationship with the Xz axis and the Zz axis; the angle of rotation around the Zz axis is defined as the azimuth angle, and the angle of rotation around the Yz axis is defined as the pitch angle; The star sensor (3) measurement coordinate system is XsYsZs: the Zs axis is defined as the visual axis direction of the star sensor (3), the Xs axis and the Ys axis are perpendicular to the Zs axis, and the Xs axis and the Ys axis are parallel to the row and column directions of the photoelectric detector of the star sensor (3); The electric control box (4) comprises a memory and a processor. The memory stores a computer program. When the computer program is executed by the processor, the following process is implemented: Step 1, calculating the pointing vector from the surface test site to the star to be observed; The observation vector r of the star to be observed relative to the center of the earth is calculated according to the right ascension α and declination δ of the star to be observed in the J2000.0 inertial coordinate system; the observation vector r of the star to be observed relative to the center of the earth is equivalent to the pointing vector of the surface test site pointing to the star to be observed; Step 2: The star sensor (3) matches the star map in its field of view and outputs the attitude change of its measurement coordinate system relative to the J2000.0 inertial coordinate system, which is represented by the attitude matrix A. Step 3: Obtain the observation vector in the measurement coordinate system of the corresponding star sensor (3) based on the attitude matrix A; Step 4: convert the observation vector of the measurement coordinate system of the star sensor (3) into the observation vector of the coordinate system of the two-dimensional turntable (2) through the installation matrix M of the coordinate system of the star sensor (3) and the coordinate system of the two-dimensional turntable (2); Step 5, calculating the azimuth and elevation angles of the small field of view camera (5) pointed at the star to be observed; According to the definition of the azimuth and elevation angles of the two-dimensional turntable (2) and their positive and negative signs, calculate the azimuth angle Az corresponding to the observation vector in the coordinate system of the two-dimensional turntable (2): t and pitch angle El t , driving the axis system of the two-dimensional turntable (2) to rotate so that the visual axis of the small-field-of-view camera (5) points to the star to be observed in the predetermined airspace.

2. The fast star tracking device for a small field of view camera according to claim 1, characterized in that: The observation vector r of the star to be observed relative to the center of the Earth in step 1 J2000.0 It is expressed by the following formula:

3. The fast star tracking device for a small field of view camera according to claim 2, characterized in that: The posture matrix A in step 2 is expressed as follows: Among them, q0, q1, q2, and q3 are attitude quaternions.

4. The fast star tracking device for a small field of view camera according to claim 3, characterized in that: In step 3, based on the attitude matrix A, the observation vector r corresponding to the star sensor (3) in the measurement coordinate system is obtained. s (t) are as follows: Where t is time, x s is the X component of the observation vector in the measurement coordinate system of the star sensor (3), y s is the Y component of the observation vector in the measurement coordinate system of the star sensor (3), z s is the Z component of the observation vector in the coordinate system measured by the star sensor (3).

5. The fast star tracking device for a small field of view camera according to claim 4, characterized in that: In step 4, the observation vector r in the coordinate system of the two-dimensional turntable (2) cl (t) is as follows: x cl is the X component of the observation vector in the two-dimensional turntable (2) coordinate system, y cl is the Y component of the observation vector in the two-dimensional turntable (2) coordinate system, z cl is the Z component of the observation vector in the two-dimensional turntable (2) coordinate system.

6. The fast star tracking device for a small field of view camera according to claim 5, characterized in that: In step 5, the sign of the azimuth and elevation angles of the two-dimensional turntable (2) is defined as follows: Definition of the sign of the azimuth angle of a two-dimensional turntable (2): Looking against the Zz axis, clockwise rotation angles are positive, and counterclockwise rotation angles are negative; Definition of the positive and negative signs of the pitch angles of a two-dimensional turntable (2): Looking against the Yz axis, clockwise rotation angles are positive and counterclockwise rotation angles are negative.

7. The fast star tracking device for a small field of view camera according to claim 6, characterized in that: The azimuth angle Az corresponding to the observation vector in the two-dimensional turntable (2) coordinate system in step 5 t and pitch angle El t as follows:

8. A method for fast star tracking with a small field of view camera based on the fast star tracking device for a small field of view camera according to claim 1, characterized in that: The following steps are involved: Step 1, calculating the pointing vector from the surface test site to the star to be observed; The observation vector r of the star to be observed relative to the center of the earth is calculated according to the right ascension α and declination δ of the star to be observed in the J2000.0 inertial coordinate system; the observation vector r of the star to be observed relative to the center of the earth is equivalent to the pointing vector of the surface test site pointing to the star to be observed; Step 2, the star sensor (3) outputs the attitude change of its measurement coordinate system relative to the J2000.0 inertial coordinate system to the electronic control box (4) according to the star map matching in its field of view, which is represented by the attitude matrix A; Step 3, the electric control box (4) obtains the observation vector corresponding to the star sensor (3) in the measurement coordinate system based on the attitude matrix A; Step 4, the electric control box (4) converts the observation vector of the measurement coordinate system of the star sensor (3) into the observation vector of the coordinate system of the two-dimensional turntable (2) through the installation matrix M of the coordinate system of the star sensor (3) and the coordinate system of the two-dimensional turntable (2); Step 5, calculating the azimuth and elevation angles of the small field of view camera (5) pointed at the star to be observed; According to the definition of the azimuth and elevation angles of the two-dimensional turntable (2) and their positive and negative signs, the electric control box (4) calculates the azimuth angle Az corresponding to the observation vector in the coordinate system of the two-dimensional turntable (2) t and pitch angle El t The electric control box (4) drives the axis system of the two-dimensional turntable (2) to rotate so that the visual axis of the small-field camera (5) points to the star to be observed in the predetermined airspace.

9. The fast star tracking method for a small field of view camera according to claim 8, characterized in that: The observation vector r of the star to be observed relative to the center of the Earth in step 1 J2000.0 It is expressed by the following formula:

10. The fast star tracking method for a small field of view camera according to claim 9, characterized in that: The posture matrix A in step 2 is expressed as follows: Among them, q0, q1, q2, and q3 are attitude quaternions.

11. The fast star tracking method for a small field of view camera according to claim 10, characterized in that: In step 3, based on the attitude matrix A, the observation vector r corresponding to the star sensor (3) in the measurement coordinate system is obtained. s (t) are as follows: Where t is time, x s is the X component of the observation vector in the measurement coordinate system of the star sensor (3), y s is the Y component of the observation vector in the measurement coordinate system of the star sensor (3), z s is the Z component of the observation vector in the measurement coordinate system of the star sensor (3).

12. The fast star tracking method for a small field of view camera according to claim 11, characterized in that: In step 4, the observation vector r in the coordinate system of the two-dimensional turntable (2) cl (t) is as follows: x cl is the X component of the observation vector in the two-dimensional turntable (2) coordinate system, y cl is the Y component of the observation vector in the two-dimensional turntable (2) coordinate system, z cl is the Z component of the observation vector in the two-dimensional turntable (2) coordinate system.

13. The fast star tracking method for a small field of view camera according to claim 12, characterized in that: In step 5, the sign of the azimuth and elevation angles of the two-dimensional turntable (2) is defined as follows: Definition of the sign of the azimuth angle of a two-dimensional turntable (2): Looking against the Zz axis, clockwise rotation angles are positive, and counterclockwise rotation angles are negative; Definition of the positive and negative signs of the pitch angles of a two-dimensional turntable (2): Looking against the Yz axis, clockwise rotation angles are positive and counterclockwise rotation angles are negative.

14. The fast star tracking method for a small field of view camera according to claim 13, characterized in that: The azimuth angle Az corresponding to the observation vector in the two-dimensional turntable (2) coordinate system in step 5 t and pitch angle El t as follows:

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