Satellite earth imaging control method and device and electronic equipment

Abstract

The invention provides a satellite earth imaging control method and device and electronic equipment. The control method comprises the following steps: performing basic control on a satellite based on a satellite platform and a satellite turntable; according to the coordinates of the satellite, the pointing direction of the camera and the camera angular velocity measured by the camera, the corrected single-stage integral time is calculated; the corrected single-stage integration time is sent to camera electronics, the camera electronics controls a camera shutter according to the corrected single-stage integration time, and the single-stage integration time is the exposure time in the earth imaging process. According to the invention, the defects of low stability and the like of a rotary table system to-earth optical high-resolution imaging satellite are overcome, and the stability of satellite to-earth imaging is improved.

Description

Technical Field

[0001] The present invention mainly relates to the field of satellite control technology, and in particular to a control method, device and electronic equipment for satellite earth imaging. Background Art

[0002] Satellite imaging control is a complex technology involving many aspects. Its core lies in how to accurately image the earth or other celestial bodies through the observation instruments on the satellite and ensure that the quality of these images meets specific application requirements.

[0003] The orbit design of the satellite is the basis of imaging control. Geosynchronous orbit and polar orbit are two common types of satellite orbits. Geosynchronous orbit satellites can continuously observe a certain area of ​​the earth, while polar orbit satellites can provide global coverage observation capabilities. In the process of satellite imaging of the earth, precise control of orbit altitude and inclination is essential to ensure the continuity and coverage of imaging. In addition, satellite attitude control refers to adjusting the pointing and attitude of the satellite so that its observation instruments can accurately point to the target area. This includes the roll, pitch and yaw control of the satellite to ensure stability and accuracy during imaging.

[0004] In the prior art, at high rotation speeds, the turntable's own stability is relatively low, only about 0.006° / s around the Y axis and only 0.02° / s around the Z axis, which seriously affects the quality of satellite imaging of the earth. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a control method, device and electronic equipment for satellite earth imaging, so as to solve the shortcomings of low stability of turntable system earth optical high-resolution imaging satellite and improve the stability of satellite earth imaging.

[0006] To solve the above technical problems, in a first aspect, the present invention provides a control method for satellite earth imaging, comprising: performing basic control of the satellite based on a satellite platform and a satellite turntable; calculating a corrected single-stage integration time according to the coordinates of the satellite, the camera pointing, and the camera angular velocity measured by the camera; sending the corrected single-stage integration time to camera electronics, and the camera electronics controlling a camera shutter according to the corrected single-stage integration time, wherein the single-stage integration time is the exposure time during earth imaging.

[0007] Optionally, calculating the corrected single-stage integration time according to the coordinates of the satellite, the camera pointing, and the camera angular velocity measured by the camera includes:

[0008] The satellite coordinates at time t0 are The satellite line of sight vector measured according to the current attitude of the satellite is The coordinates of the intersection of the satellite line of sight and the ground at the current moment are for:

[0009]

[0010] in, is the ground height at the intersection of the satellite line of sight and the ground;

[0011] The satellite coordinates at the next moment t1 are Satellite boresight vector Then the coordinates of the intersection of the satellite line of sight and the ground at the next moment are

[0012] Actual sweep speed at time t0 for:

[0013] Actual forward / backward swing angle of the satellite at time t0 Obtained from the vector angle formula: Then the single-stage integration time of the camera at time t0 is The calculation formula is: in It is the ground resolution of the camera in the push-scan direction at time t0.

[0014] Optionally, calculating the corrected single-stage integration time according to the coordinates of the satellite, the camera pointing, and the camera angular velocity measured by the camera also includes: calculating the corrected single-stage integration time according to the coordinates of the satellite, the camera pointing, and the camera angular velocity measured by the camera in a ground-fixed system.

[0015] Optionally, it also includes: calculating the satellite pointing point based on the coordinates of the satellite, the camera pointing, and the satellite rotation angle γ around the Z axis; sending the satellite pointing point to the turntable motor, driving the turntable motor to point to the satellite pointing point, wherein the satellite pointing point is the intersection of the satellite visual axis and the ground.

[0016] Optionally, it also includes: performing push-scanning according to the satellite pointing point to form a Markov strip, including: determining the starting point of the Markov strip; during the push-scanning process, controlling the ground strip to adapt to the satellite attitude; and the satellite is always aligned with the TDI direction when it shakes around the Z axis.

[0017] Optionally, according to the coordinates of the satellite, the camera pointing, and the satellite rotation angle γ around the Z axis, calculating the satellite pointing point further includes:

[0018] The satellite coordinates at time t0 in the ground-fixed system are The satellite line of sight vector measured according to the current attitude of the satellite is Calculate the coordinates of the intersection of the satellite line of sight and the ground at the current moment Satellite coordinates at time t1 Satellite actual flight velocity vector N 2p :

[0019] N 2p Transformation from earth-solid system to native system Then the virtual flight speed vector corrected around the Z axis is in is the rotation angle of the satellite around the Z axis at time t1;

[0020] Will Converted to the ground-fixed coordinate N2, then without the deviation angle Always point to the point

[0021] The next point of reference corrected by the earth's curvature without the deviation angle

[0022]

[0023] The pointing vector is the ground height at the intersection of the satellite line of sight and the ground;

[0024] The Cartesian coordinate system Convert to spherical coordinates (a, e, r), and then correct a for the rotation of the earth to get a′:

[0025] Convert (a′, e, r) to Cartesian coordinate system to get the point at time t1 after correction for the rotation of the earth.

[0026] In a second aspect, the present invention provides a control axis for satellite earth imaging, comprising: a basic control module for performing basic control of the satellite based on a satellite platform and a satellite turntable; a first calculation module for calculating a corrected single-stage integration time according to the coordinates of the satellite, the camera pointing, and the camera angular velocity measured by the camera; a first control module for sending the corrected single-stage integration time to camera electronics, and the camera electronics controlling the camera shutter according to the corrected single-stage integration time, wherein the single-stage integration time is the exposure time during earth imaging.

[0027] Optionally, a second calculation module is also included, which is used to calculate the satellite pointing point based on the coordinates of the satellite, the camera pointing, and the satellite rotation angle γ around the Z axis; send the satellite pointing point to the turntable motor, drive the turntable motor to point to the satellite pointing point, wherein the satellite pointing point is the intersection of the satellite visual axis and the ground.

[0028] Optionally, a second control module is also included, which is used to perform push-scanning according to the satellite pointing point to form a Markov strip, including: determining the starting point of the Markov strip; during the push-scanning process, controlling the ground strip to adapt to the satellite attitude; and the satellite is always aligned with the TDI direction when it shakes around the Z axis.

[0029] In a third aspect, the present invention provides an electronic device comprising: a processor and a memory, wherein the memory stores programs or instructions that can be run on the processor, and when the program or instructions are executed by the processor, the steps of the control method for satellite earth imaging as described in the first aspect are implemented.

[0030] In a fourth aspect, the present invention provides a readable storage medium storing a program or instruction, which, when executed by a processor, implements the steps of the control method for satellite earth imaging as described in the first aspect.

[0031] Compared with the prior art, the present invention has the following advantages: first, basic control of the satellite is performed based on the satellite platform and the satellite turntable; then, the corrected single-stage integration time is calculated according to the satellite's coordinates, the camera pointing, and the camera angular velocity measured by the camera; finally, the corrected single-stage integration time is sent to the camera electronics, and the camera electronics controls the camera shutter according to the corrected single-stage integration time, wherein the single-stage integration time is the exposure time in the process of ground imaging, thereby solving the shortcomings of low stability of turntable-based ground optical high-resolution imaging satellites, improving the stability of satellite ground imaging, and being suitable for tasks such as multi-strip splicing, multi-target observation, and along-track observation of ground high-resolution imaging satellites to obtain information on key targets. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings are included to provide a further understanding of the present application. They are included and constitute a part of the present application. The accompanying drawings illustrate embodiments of the present application and together with the present specification serve to explain the principles of the present application. In the accompanying drawings:

[0033] Figure 1 This is a typical schematic diagram of the process of basic satellite control based on the satellite platform and satellite turntable;

[0034] Figure 2 It is a schematic flow chart of a control method for satellite earth imaging according to an embodiment of the present invention;

[0035] Figure 3 is a schematic diagram of calculating a single-stage integration time in one embodiment of the present invention;

[0036] Figure 4 is a schematic diagram of a satellite line of sight during calculation of a single-stage integration time in one embodiment of the present invention;

[0037] Figure 5 It is a schematic diagram of the traditional Markov strip formation;

[0038] Figure 6 is a schematic diagram of calculating a satellite pointing point in one embodiment of the present invention;

[0039] Figure 7 is a schematic diagram of a satellite axis in the process of calculating a satellite pointing point in one embodiment of the present invention;

[0040] Figure 8 is a schematic diagram of Markov band formation in one embodiment of the present invention;

[0041] Fig. 9 It is a schematic diagram of ground strip splicing imaging in the present invention;

[0042] Fig.10 It is a schematic diagram of the earth imaging process in the present invention;

[0043] Fig.11 2 is a schematic diagram of the structure of a control device for satellite earth imaging according to an embodiment of the present invention;

[0044] Fig.12 FIG. 4 is a schematic diagram of an electronic device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0045] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for the description of the embodiments. Obviously, the drawings described below are only some examples or embodiments of the present application. For ordinary technicians in this field, the present application can also be applied to other similar scenarios based on these drawings without creative work. Unless it is obvious from the language environment or otherwise explained, the same reference numerals in the figures represent the same structure or operation.

[0046] As shown in this application and claims, unless the context clearly indicates an exception, the words "a", "an", "an" and / or "the" do not refer to the singular and may also include the plural. Generally speaking, the terms "include" and "comprise" only indicate the inclusion of the steps and elements that have been clearly identified, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0047] In addition, it should be noted that the use of words such as "first" and "second" to define components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above words have no special meaning and cannot be understood as limiting the scope of protection of this application. In addition, although the terms used in this application are selected from well-known and commonly used terms, some terms mentioned in the specification of this application may be selected by the applicant at his or her discretion, and their detailed meanings are explained in the relevant parts of the description of this article. In addition, it is required to understand this application not only by the actual terms used, but also by the meaning implied by each term.

[0048] Flowcharts are used in the present application to illustrate the operations performed by the system according to the embodiments of the present application. It should be understood that the preceding or following operations are not necessarily performed accurately in order. On the contrary, various steps may be processed in reverse order or simultaneously. At the same time, other operations may be added to these processes, or one or more operations may be removed from these processes.

[0049] Figure 1 This is a typical schematic diagram of the basic control process of the satellite based on the satellite platform and satellite turntable. Figure 1 As shown in the figure, in the platform-turntable closed-loop stability control system, the platform control system only performs primary coarse control to ensure coarse pointing and coarse stability. The turntable control system performs secondary control to improve pointing accuracy and stability and reduce the stabilization time of strip switching. The low-frequency vibration of the platform mainly comes from the change of satellite motion attitude and the resonance or thermal transient effect of the solar array. The frequency of this type of disturbance is at the Hz level. The turntable control frequency is usually above 200Hz, which can offset the platform disturbance. Therefore, the main purpose of the turntable stability control system is to offset the low-frequency vibration of the platform.

[0050] The platform-turntable closed-loop stability control adopts a stabilization and tracking separation design, that is, a stabilization loop based on gyro feedback is added to the tracking loop. Since the signal output frequency of the gyro sensor can reach KHz or even megahertz, the gyro sampling frequency will not limit the design and implementation of the closed-loop bandwidth. Secondly, the gyro measures the physical quantity of the camera's speed relative to the inertial space, which can be used to achieve inertial stabilization of the camera and suppress carrier vibration. The high-bandwidth stabilization loop can also provide a good object characteristic for the design of the tracking controller, which is conducive to improving the tracking accuracy of the final system. It can be seen that the separation of stabilization and tracking is a necessary means for the control of the optoelectronic tracking system of the motion platform.

[0051] The sampling frequency of the gyro installed on the camera is 100Hz, while the frequency of high-amplitude vibrations on the satellite platform is often less than 10Hz, so the bandwidth requirements for the velocity loop are not very high. The difference between the star sensor and the guidance data is used to obtain the miss distance as the position input. Since the sampling frequency of the star sensor is only 10Hz, the star sensor must be corrected by gyro integration to increase its frequency. The platform-turntable closed-loop stability control achieves stability around the X-axis: 0.003° / s, stability around the Y-axis: 0.006° / s, and stability around the Z-axis: 0.02° / s. Even so, the stability of basic satellite control based on the satellite platform and satellite turntable is still difficult to meet the increasingly high demand for satellite imaging of the earth.

[0052] An embodiment of the present invention adds a guidance law control system on the basis of the existing platform-turntable control system to form a three-level stabilization system of platform-turntable-guidance law. When the platform and turntable are unstable, the guidance law is used to ensure the stability of the camera's visual axis.

[0053] Figure 2 FIG. 1 is a flow chart of a control method for satellite imaging of the earth according to an embodiment of the present invention, with reference to FIG. Figure 2 As shown, method 200 includes: S210, basic control of the satellite based on the satellite platform and the satellite turntable; S220, calculating the corrected single-stage integration time according to the coordinates of the satellite, the camera pointing, and the camera angular velocity measured by the camera; S230, sending the corrected single-stage integration time to the camera electronics, and the camera electronics controlling the camera shutter according to the corrected single-stage integration time, wherein the single-stage integration time is the exposure time during the ground imaging process.

[0054] During the along-track push-scanning process, the image velocity mismatch can be decomposed into the along-track direction and the through-track direction. The image velocity mismatch in the along-track direction is manifested as inaccurate exposure time, that is, the exposure time is inconsistent with the time it takes for the linear array to scan one pixel. The image velocity mismatch in the through-track direction is manifested as a "serial" of TDI (Time Delay Integration), that is, the same object is not accumulated in the same column of TDI. The image velocity mismatch in the direction of rotation around the optical axis can also be decomposed into the along-track direction and the through-track direction. The method of this embodiment can measure the true pitch angular velocity of the camera through a high-frequency gyroscope, and then correct the camera exposure time to ensure that the camera line frequency is correct, thereby solving the problem of pitch image velocity mismatch.

[0055] refer to Figure 3 As shown, in this embodiment, the satellite computer sends the satellite coordinates and camera pointing, the camera high-frequency gyroscope measures the actual camera angular velocity, and the turntable control box calculates the corrected single-stage integration time after receiving the above data and sends it to the camera electronics. The camera electronics controls the camera shutter according to the corrected single-stage integration time.

[0056] In this embodiment, the precise correction of exposure time mainly corrects the stability of the camera along the track. The low-frequency vibration of the camera along the track is manifested as inaccurate line frequency calculation, and the exposure time is inconsistent with the time it takes for the linear array to scan one pixel, that is, the speed-to-height ratio is inaccurate. The method of this embodiment measures the true pitch angular velocity of the camera through a high-frequency gyroscope with a frequency of 100Hz, and then corrects the camera exposure time every 10ms to ensure that the camera line frequency within 10ms after the exposure time is corrected, thereby solving the pitch image speed mismatch problem.

[0057] In one example, based on the satellite coordinates, camera pointing, and camera angular velocity measured by the camera, the corrected single-stage integration time is calculated as follows:

[0058] refer to Figure 4 As shown, the satellite coordinates at time t0 are The satellite line of sight vector measured according to the current attitude of the satellite is The coordinates of the intersection of the satellite line of sight and the ground at the current moment are for:

[0059]

[0060] in, is the ground height at the intersection of the satellite line of sight and the ground;

[0061] The satellite coordinates at the next moment t1 are Satellite boresight vector Then the coordinates of the intersection of the satellite line of sight and the ground at the next moment are

[0062] Actual sweep speed at time t0 for:

[0063] Actual forward / backward swing angle of the satellite at time t0 Obtained from the vector angle formula: Then the single-stage integration time of the camera at time t0 is The calculation formula is: in It is the ground resolution of the camera in the push-scan direction at time t0. The calculation formula is:

[0064] In this embodiment, the camera electronics controls the camera shutter according to the modified single-stage integration time, so that the stability around the Y-axis during satellite imaging of the earth can be improved from 0.006° / s to 0.001° / s.

[0065] In one example, calculating the corrected single-stage integration time according to the coordinates of the satellite, the camera pointing, and the camera angular velocity measured by the camera also includes: calculating the corrected single-stage integration time according to the coordinates of the satellite, the camera pointing, and the camera angular velocity measured by the camera in an earth-fixed system.

[0066] In one example, the control method for satellite imaging of the earth may also include calculating the satellite pointing point based on the satellite's coordinates, camera pointing, and the satellite's rotation angle γ around the Z axis; sending the satellite pointing point to the turntable motor, and driving the turntable motor to point to the satellite pointing point, wherein the satellite pointing point is the intersection of the satellite's visual axis and the ground.

[0067] Traditional turntables only have two degrees of freedom: pitch and azimuth, and lack the degree of freedom around the Z axis. Figure 5 As shown, it includes: ① draw a strip on the earth's surface (using a large arc or other method) and the strip's centerline; ② point the optical axis to the starting point of the strip's centerline and keep it pointing to the centerline during the push-scan process; ③ control the satellite to rotate around the optical axis to ensure that the TDI direction always coincides with the strip's centerline; ④ continuously push forward and rotate around the optical axis to ensure alignment. In this process, the Z-axis pointing accuracy is very high, and the Z-axis pointing accuracy directly affects the image quality.

[0068] In this embodiment, the control method for satellite imaging of the earth includes a stability control method around the Z axis, which is a ground parameter strip guidance law control, and can achieve high stability around the Z axis using only a two-dimensional turntable.

[0069] refer to Figure 6 As shown, the satellite computer sends the satellite coordinates P, the camera pointing D, and the satellite rotation angle γ around the Z axis. After receiving the above data, the turntable control box calculates the pointing point S and sends it to the turntable motor to drive the motor to point to a specific position.

[0070] In one example, according to the coordinates of the satellite, the camera pointing, and the satellite rotation angle γ around the Z axis, calculating the satellite pointing point further includes:

[0071] refer to Figure 7 As shown, the satellite coordinates at time t0 in the ground-fixed system are The satellite line of sight vector measured according to the current attitude of the satellite is Calculate the coordinates of the intersection of the satellite line of sight and the ground at the current moment Satellite coordinates at time t1 Satellite actual flight velocity vector N 2p :

[0072] N 2p Transformation from earth-solid system to native system Then the virtual flight speed vector corrected around the Z axis is in is the rotation angle of the satellite around the Z axis at time t1;

[0073] Will Converted to the ground-fixed coordinate N2, then without the deviation angle Always point to the point

[0074] The next point of reference corrected by the earth's curvature without the deviation angle

[0075]

[0076] The pointing vector is the ground height at the intersection of the satellite line of sight and the ground;

[0077] The Cartesian coordinate system Convert to spherical coordinates (a, e, r), and then correct a for the rotation of the earth to get a′:

[0078] Convert (a′, e, r) to Cartesian coordinate system to get the point at time t1 after correction for the rotation of the earth.

[0079] In one example, the control method of satellite imaging of the earth in this embodiment further includes performing push-scanning according to the satellite pointing point to form a Markov strip. Specifically, the steps are: determining the starting point of the Markov strip; during the push-scanning process, controlling the ground strip to adapt to the satellite attitude; and the satellite is always aligned with the TDI direction when shaking around the Z axis.

[0080] Exemplary, reference Figure 8 As shown, the formation of Markov strips is specifically as follows: ① Only the starting point of the strip is determined instead of the entire strip, because the shape of the strip changes continuously with the satellite attitude; ② During push-scanning, the satellite attitude is not controlled to adapt to the strip, but the ground strip adapts to the satellite attitude. When the satellite shakes around the Z axis, the direction of the strip is constantly changed to always align with the TDI direction; ③ The satellite does not need to change its attitude when switching strips, and there will be a maximum angle of 1.7° between adjacent strips. The main advantage of the Markov strip is that during the strip push-scanning process, the Z-axis pointing accuracy requirement is very low, because the strip changes with the satellite's attitude around the Z axis. Through the above control method, the equivalent stability of the satellite around the Z axis in this embodiment is increased from 0.02° / s to 0.0004° / s.

[0081] refer to Fig. 9 and Fig.10As shown, the method of this embodiment is adopted to stitch and image ground strips, use linear array imaging, and use a turntable to quickly and maneuverably stitch 5 strips, so as to achieve coverage of a large area of ​​75km×100km.

[0082] For example, the push sweep time of a single strip is 10 seconds, the strip switching time is 16 seconds, the total time is 114 seconds, and the maximum forward / backward swing is ±36.2°. The time allocation is shown in Table 1.

[0083] Table 1 Time allocation of the strip sweep process

[0084]

[0085] The control method of satellite earth imaging in this embodiment first performs basic control of the satellite based on the satellite platform and the satellite turntable, then calculates the corrected single-stage integration time according to the satellite's coordinates, camera pointing, and camera angular velocity measured by the camera, and finally sends the corrected single-stage integration time to the camera electronics. The camera electronics controls the camera shutter according to the corrected single-stage integration time, wherein the single-stage integration time is the exposure time during the earth imaging process, thereby solving the shortcomings of low stability of turntable-based high-resolution earth optical imaging satellites, improving the stability of satellite earth imaging, and being suitable for tasks such as multi-strip stitching, multi-target observation, and along-track observation of high-resolution earth imaging satellites to obtain information on key targets.

[0086] Another embodiment of the present invention provides a control device 1100 for satellite earth imaging, which mainly includes: a basic control module 1101, used to perform basic control of the satellite based on a satellite platform and a satellite turntable; a first calculation module 1102, used to calculate a corrected single-stage integration time according to the coordinates of the satellite, the camera pointing, and the camera angular velocity measured by the camera; a first control module 1103, used to send the corrected single-stage integration time to the camera electronics, and the camera electronics controls the camera shutter according to the corrected single-stage integration time, wherein the single-stage integration time is the exposure time during the earth imaging process.

[0087] In one example, according to the coordinates of the satellite, the camera pointing, and the camera angular velocity measured by the camera, calculating the corrected single-stage integration time includes:

[0088] The satellite coordinates at time t0 are The satellite line of sight vector measured according to the current attitude of the satellite is The coordinates of the intersection of the satellite line of sight and the ground at the current moment are for:

[0089]

[0090] in, is the ground height at the intersection of the satellite line of sight and the ground;

[0091] The satellite coordinates at the next moment t1 are Satellite boresight vector Then the coordinates of the intersection of the satellite line of sight and the ground at the next moment are

[0092] Actual sweep speed at time t0 for:

[0093] Actual forward / backward swing angle of the satellite at time t0 Obtained from the vector angle formula: Then the single-stage integration time of the camera at time t0 is The calculation formula is: in It is the ground resolution of the camera in the push-scan direction at time t0.

[0094] In one example, calculating the corrected single-stage integration time according to the coordinates of the satellite, the camera pointing, and the camera angular velocity measured by the camera may include calculating the corrected single-stage integration time according to the coordinates of the satellite, the camera pointing, and the camera angular velocity measured by the camera in an earth-fixed system.

[0095] In one example, the device 1100 may also include a second calculation module, which is used to calculate the satellite pointing point based on the coordinates of the satellite, the camera pointing, and the satellite rotation angle γ around the Z axis; send the satellite pointing point to the turntable motor, and drive the turntable motor to point to the satellite pointing point, where the satellite pointing point is the intersection of the satellite visual axis and the ground.

[0096] In one example, the device 1100 may further include a second control module, which is used to perform push-scanning according to the satellite pointing point to form a Markov strip, specifically including determining the starting point of the Markov strip; during the push-scanning process, controlling the ground strip to adapt to the satellite attitude, and the satellite is always aligned with the TDI direction when shaking around the Z axis.

[0097] In one example, according to the coordinates of the satellite, the camera pointing, and the satellite rotation angle γ around the Z axis, calculating the satellite pointing point includes:

[0098] The satellite coordinates at time t0 in the ground-fixed system are The satellite line of sight vector measured according to the current attitude of the satellite is Calculate the coordinates of the intersection of the satellite line of sight and the ground at the current moment Satellite coordinates at time t1 Satellite actual flight velocity vector N 2p :

[0099] N 2pTransformation from earth-solid system to native system Then the virtual flight speed vector corrected around the Z axis is in is the rotation angle of the satellite around the Z axis at time t1;

[0100] Will Converted to the ground-fixed coordinate N2, then without the deviation angle Always point to the point

[0101] The next point of reference corrected by the earth's curvature without the deviation angle

[0102]

[0103] The pointing vector is the ground height at the intersection of the satellite line of sight and the ground;

[0104] The Cartesian coordinate system Convert to spherical coordinates (a, e, r), and then correct a for the rotation of the earth to get a′:

[0105] Convert (a′, e, r) to Cartesian coordinate system to get the point at time t1 after correction for the rotation of the earth.

[0106] The details of other operations performed by each module in this embodiment can be referred to the aforementioned embodiments and will not be elaborated here.

[0107] The control device for satellite earth imaging in this embodiment first performs basic control of the satellite based on the satellite platform and the satellite turntable, and then calculates the corrected single-stage integration time according to the satellite's coordinates, camera pointing, and camera angular velocity measured by the camera. Finally, the corrected single-stage integration time is sent to the camera electronics, and the camera electronics controls the camera shutter according to the corrected single-stage integration time, wherein the single-stage integration time is the exposure time during the earth imaging process, thereby solving the shortcomings of low stability of turntable-based high-resolution optical earth imaging satellites, improving the stability of satellite earth imaging, and being suitable for tasks such as multi-strip stitching, multi-target observation, and along-track observation of high-resolution earth imaging satellites to obtain information on key targets.

[0108] A control device for satellite-to-earth imaging in the embodiment of the present application may be a device, or a component, integrated circuit, or chip in a terminal. A control device for satellite-to-earth imaging in the embodiment of the present application may be a device having an operating system. The operating system may be an Android operating system, an iOS operating system, or other possible operating systems, which are not specifically limited in the embodiment of the present application.

[0109] The present application also provides an electronic device, comprising: a memory for storing programs or instructions executable by a processor; and a processor for executing the above-mentioned programs or instructions to implement the various processes of the above-mentioned satellite earth imaging control method embodiment, and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0110] Fig.12 1 is a schematic diagram of an electronic device according to an embodiment of the present invention. The electronic device 1200 may include an internal communication bus 1201, a processor 1202, a read-only memory (ROM) 1203, a random access memory (RAM) 1204, and a communication port 1205. When applied to a personal computer, the electronic device 1200 may also include a hard disk 1206. The internal communication bus 1201 can realize data communication between components of the electronic device 1200. The processor 1202 can make judgments and issue prompts. In some embodiments, the processor 1202 can be composed of one or more processors. The communication port 1205 can realize data communication between the electronic device 1200 and the outside. In some embodiments, the electronic device 1200 can send and receive information and data from the network through the communication port 1205. The electronic device 1200 may also include different forms of program storage units and data storage units, such as a hard disk 1206, a read-only memory (ROM) 1203 and a random access memory (RAM) 1204, which can store various data files used for computer processing and / or communication, as well as possible programs or instructions executed by the processor 1202. The results processed by the processor 1202 are transmitted to the user device through the communication port 1205 and displayed on the user interface.

[0111] The above-mentioned satellite earth imaging control method can be implemented as a computer program, stored in the hard disk 1206, and can be recorded in the processor 1202 for execution to implement any satellite earth imaging control method in the present application.

[0112] An embodiment of the present application also provides a readable storage medium, on which a program or instruction is stored. When the program or instruction is executed by a processor, each process of the above-mentioned satellite earth imaging control method embodiment is implemented, and the same technical effect can be achieved. To avoid repetition, it will not be repeated here.

[0113] The processor is the processor in the electronic device in the above embodiment. The readable storage medium includes a computer readable storage medium, such as a computer read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0114] For those skilled in the art, the above invention disclosure is only used as an example and does not constitute a limitation of the present application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements and amendments to the present application. Such modifications, improvements and amendments are suggested in the present application, so such modifications, improvements and amendments still belong to the spirit and scope of the exemplary embodiments of the present application.

[0115] Although the present application has been described with reference to the current specific embodiments, ordinary technicians in this technical field should recognize that the above embodiments are only used to illustrate the present application, and various equivalent changes or substitutions may be made without departing from the spirit of the present application. Therefore, as long as the changes and modifications to the above embodiments are within the essential spirit of the present application, they will fall within the scope of the claims of the present application.

Claims

1. A control method for satellite imaging of the earth, characterized in that: include: Performing basic control of the satellite based on the satellite platform and the satellite turntable; Calculating a corrected single-stage integration time according to the coordinates of the satellite, the camera pointing, and the camera angular velocity measured by the camera; The corrected single-stage integration time is sent to the camera electronics, which controls the camera shutter according to the corrected single-stage integration time, wherein the single-stage integration time is the exposure time during the ground imaging process.

2. The control method for satellite earth imaging according to claim 1, characterized in that: According to the coordinates of the satellite, the camera pointing, and the camera angular velocity measured by the camera, the corrected single-stage integration time is calculated including: The satellite coordinates at time t0 are The satellite line of sight vector measured according to the current attitude of the satellite is The coordinates of the intersection of the satellite line of sight and the ground at the current moment are for: in, is the ground height at the intersection of the satellite line of sight and the ground; The satellite coordinates at the next moment t1 are Satellite boresight vector Then the coordinates of the intersection of the satellite line of sight and the ground at the next moment are Actual sweep speed at time t0 for: Actual forward / backward swing angle of the satellite at time t0 Obtained from the vector angle formula: Then the single-stage integration time of the camera at time t0 is The calculation formula is: in It is the ground resolution of the camera in the push-scan direction at time t0.

3. The control method for satellite earth imaging according to claim 2, characterized in that: According to the coordinates of the satellite, the camera pointing, and the camera angular velocity measured by the camera, calculating the corrected single-stage integration time also includes: In the ground-fixed system, the corrected single-stage integration time is calculated according to the coordinates of the satellite, the camera pointing, and the camera angular velocity measured by the camera.

4. The control method for satellite imaging of the earth as claimed in claim 1, characterized in that: Also includes: Calculate the satellite pointing point according to the coordinates of the satellite, the camera pointing, and the satellite rotation angle γ around the Z axis; The satellite pointing point is sent to a turntable motor, and the turntable motor is driven to point to the satellite pointing point, wherein the satellite pointing point is the intersection of the satellite visual axis and the ground.

5. The control method for satellite imaging of the earth as claimed in claim 4, characterized in that: Also includes: Push-scanning is performed according to the satellite pointing point to form a Markov strip, including: Determining the starting point of the Markov band; During push-scanning, the ground strip is controlled to adapt to the satellite attitude; the satellite is always aligned with the TDI direction when it oscillates around the Z axis.

6. The control method for satellite earth imaging according to claim 4, characterized in that: According to the coordinates of the satellite, the camera pointing, and the satellite rotation angle γ around the Z axis, calculating the satellite pointing point also includes: The satellite coordinates at time t0 in the ground-fixed system are The satellite line of sight vector measured according to the current attitude of the satellite is Calculate the coordinates of the intersection of the satellite line of sight and the ground at the current moment Satellite coordinates at time t1 Satellite actual flight velocity vector N 2p Transformation from earth-solid system to native system Then the virtual flight speed vector corrected around the Z axis is in is the rotation angle of the satellite around the Z axis at time t1; Will Converted to the ground-fixed coordinate N2, then without the deviation angle Always point to the point The next point of reference corrected by the earth's curvature without the deviation angle The pointing vector is the ground height at the intersection of the satellite line of sight and the ground; The Cartesian coordinate system Convert to spherical coordinates (a, e, r), and then correct a for the rotation of the earth to get a′: Convert (a′, e, r) to Cartesian coordinate system to get the point at time t1 after correction for the rotation of the earth.

7. A control axis for satellite imaging of the earth, characterized in that: include: A basic control module, used for performing basic control of the satellite based on a satellite platform and a satellite turntable; A first calculation module is used to calculate a corrected single-stage integration time according to the coordinates of the satellite, the camera pointing, and the camera angular velocity measured by the camera; The first control module is used to send the corrected single-stage integration time to the camera electronics, and the camera electronics controls the camera shutter according to the corrected single-stage integration time, wherein the single-stage integration time is the exposure time during the ground imaging process.

8. The control device for satellite imaging of the earth as claimed in claim 7, characterized in that: It also includes a second calculation module, which is used to calculate the satellite pointing point based on the coordinates of the satellite, the camera pointing, and the satellite rotation angle γ around the Z axis; send the satellite pointing point to the turntable motor, drive the turntable motor to point to the satellite pointing point, wherein the satellite pointing point is the intersection of the satellite visual axis and the ground.

9. The control device for satellite imaging of the earth as claimed in claim 7, characterized in that: It also includes a second control module, which is used to perform push-scanning according to the satellite pointing point to form a Markov strip, including: determining the starting point of the Markov strip; during the push-scanning process, controlling the ground strip to adapt to the satellite attitude; and the satellite is always aligned with the TDI direction when it shakes around the Z axis.

10. An electronic device, characterized in that: include: A processor and a memory, wherein the memory stores a program or instruction that can be run on the processor, and when the program or instruction is executed by the processor, the steps of the satellite earth imaging control method as described in any one of claims 1 to 6 are implemented.

11. A readable storage medium, characterized in that: The readable storage medium stores a program or instruction, and when the program or instruction is executed by the processor, the steps of the satellite earth imaging control method as described in any one of claims 1-6 are implemented.

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