Method and system for calculating and analyzing spatial synchronization rate of formation sar satellite

Abstract

This invention provides a method and system for calculating and analyzing the spatial synchronization rate of formation SAR satellites, including: calculating the attitude guidance angles of the two satellites based on their respective orbital parameters at the analysis time; calculating the imaging regions of the two satellites based on their positions, attitude information, and beam information; and analyzing the spatial synchronization rate of the two satellites based on their imaging regions, taking into account the influence of various engineering errors. This invention addresses the need for on-orbit image distortion correction by considering the real-time on-orbit attitude guidance of the satellites during analysis, closely approximating the actual on-orbit state. Considering practical engineering, this invention can guide the design of spatial synchronization and the control of various errors in actual development, effectively supporting the demonstration and analysis of indicators such as the spatial synchronization rate of formation SAR satellites. This invention has wide applicability, suitable for the indicator analysis and demonstration stage, the development and testing stage, and the long-term on-orbit operation stage.

Description

Technical Field

[0001] This invention relates to the field of ground-based calculation, analysis, and demonstration of formation satellite indicators, specifically to a method and system for calculating and analyzing the spatial synchronization rate of formation SAR satellites. Background Technology

[0002] Satellites in orbit are affected by the Earth's rotation and elliptical orbits, leading to issues such as image position shifts and distortions during imaging. This is particularly true for SAR satellites, where the Doppler center shifts due to the Earth's curvature and rotation; typical shift values ​​exceed the system pulse repetition frequency, impacting image quality. Therefore, SAR satellites typically operate according to a designed two-dimensional attitude guidance system to improve imaging quality and simplify post-processing.

[0003] Interferometric Synthetic Aperture Radar (InSAR) systems utilize echo data from multiple receiving antennas of arrayed SAR satellites for interferometric processing. This allows for estimation of ground elevation, measurement of ocean current height and velocity, and detection and location of moving ground targets. In the one-transmit-many-receive mode of this system, any satellite in the array transmits a signal, and two satellites simultaneously receive the signal, resulting in near-zero temporal interference. However, spatial synchronization must be addressed, requiring formation configuration design and, if necessary, attitude adjustments to auxiliary satellites to ensure maximum overlap between the observation areas of the two satellites. Zero temporal interference indicates that the InSAR system's one-transmit-two-receive system is synchronous, eliminating the possibility of image decoherence due to long time intervals. The ground performance evaluation phase requires analysis and calculation of the spatial synchronization rate of the arrayed satellites to verify the effectiveness of the implemented measures and assess whether they meet the requirements.

[0004] Patent document CN112327262A discloses an on-orbit calibration method and system for SAR beam pointing consistency of distributed InSAR satellites. It is applicable to the calibration and maintenance of SAR beam pointing consistency in distributed InSAR satellites under dual-satellite (one transmitter, two receivers) or multi-satellite (one transmitter, multiple receivers) systems. It solves problems such as inconsistent SAR beam pointing between two satellites during on-orbit operation, inconsistent SAR temperature environments caused by inconsistent transmit and receive states during imaging, leading to beam pointing offset, reduced receiving energy of the auxiliary satellite, decreased coherence between the two satellites, and reduced mapping accuracy. However, patent document CN112327262A does not involve a method for evaluating and calculating the synchronization rate.

[0005] Patent document CN102967851A discloses a spatial synchronization method for bistatic SAR, which introduces a method for generating airborne bistatic SAR antenna pointing control parameters through coordinate transformation based on GPS spatial coordinate information and attitude information of the carrier platform. However, patent document CN102967851A only involves a method to achieve synchronization by adjusting the antenna beam pointing, which is ineffective for antennas without beam scanning capabilities and is not applicable to large phased array antennas that cannot be directly driven in orbit. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the purpose of this invention is to provide a method and system for calculating and analyzing the spatial synchronization rate of formation SAR satellites.

[0007] A method for calculating and analyzing the spatial synchronization rate of SAR satellite formations according to the present invention includes:

[0008] Step S1: Obtain the satellite attitude guidance angles of the two satellites;

[0009] Step S2: Calculate the imaging areas of the two satellites respectively based on the satellite attitude guidance angle;

[0010] Step S3: Calculate the overlap rate of the imaging areas of the two stars based on their respective imaging regions, and complete the analysis and calculation of the spatial synchronization rate.

[0011] Preferably, step S1, which calculates the satellite attitude guidance angles of the two satellites based on their respective orbital parameters at the analysis time in the source data, includes:

[0012] Step S1.1: Calculate the yaw guidance angle ψ:

[0013]

[0014]

[0015] Where: i is the orbital inclination, u is the latitudinal argument, and ω s ω represents the satellite's real-time angular velocity in orbit. e This is the Earth's rotational angular velocity;

[0016] Step S1.2: Calculate the pitch guidance angle θ:

[0017]

[0018] Where: e is the orbital eccentricity, and f is the true anomaly angle;

[0019] Step S1.3: Obtain the satellite attitude guidance angle based on the yaw guidance angle ψ and the pitch guidance angle θ. in Indicates the rolling direction guide angle.

[0020] Preferably, step S2, which calculates the imaging regions of the two satellites based on the satellite attitude guidance angle and the range beamwidth and azimuth beamwidth in the source data, includes:

[0021] Step S2.1: Select the wave position to be analyzed and determine the beam pointing angle α and range beamwidth β of that wave position. W azimuth beamwidth β L Among them, the wave positions to be analyzed cover the proximal wave position, the central wave position, and the distal wave position;

[0022] Step S2.2: Based on the beam pointing angle α and range beamwidth β of the stated wave position... W azimuth beamwidth β L Determine the range of the conical field of view:

[0023]

[0024]

[0025]

[0026]

[0027] Where A1, A2, A3, and A4 represent the angle matrix between the four edges of the SAR conical field of view and the center line, respectively;

[0028] Step S2.3: Calculate the ground imaging area based on the satellite attitude guidance angle and the range of the conical field of view angle, that is, determine the intersection points of the four edges of the conical field of view with the Earth in sequence.

[0029] Preferably, step S2.3 includes:

[0030] Step S2.3.1: Based on the attitude guidance angle and edge field of view angles A1, A2, A3, and A4, obtain the edge vector direction in the orbital coordinate system according to the specified transformation sequence;

[0031] Where A1 corresponds to the edge vector L1 O We obtain it from the following formula:

[0032]

[0033] Where rotx, roty, and rotz represent the transformation matrices corresponding to rotations around the x, y, and z axes, respectively.

[0034] A1(2) represents the second element of the included angle matrix A1; A1(1) represents the first element of the included angle matrix A1;

[0035] Where A2 corresponds to the edge vector L2 O We obtain it from the following formula:

[0036]

[0037] A2(2) represents the second element of the included angle matrix A2; A2(1) represents the first element of the included angle matrix A2;

[0038] Where A3 corresponds to the edge vector L3 O We obtain it from the following formula:

[0039]

[0040] A3(2) represents the second element of the included angle matrix A3; A3(1) represents the first element of the included angle matrix A3;

[0041] Where A4 corresponds to the edge vector L4 O We obtain it from the following formula:

[0042]

[0043] A4(2) represents the second element of the included angle matrix A4; A4(1) represents the first element of the included angle matrix A4;

[0044] Step S2.3.2: Based on the satellite position, velocity, and time information, convert the edge vector direction to a description in the Earth-fixed coordinate system;

[0045] Step S2.3.3: Equivalently represent the Earth as an ellipsoid and describe the ellipsoid equation in the Earth-fixed coordinate system; determine the spatial straight line based on the satellite position coordinates and the direction of the edge vector; transform the problem of solving the field of view range into solving the problem of finding the intersection point of the spatial straight line and the ellipsoid;

[0046] Step S2.3.4: After obtaining the coordinates of the ellipsoidal intersection point of the spatial line and the ellipsoid, convert the position coordinates into latitude and longitude descriptions to obtain the imaging areas of the two star formations described by latitude and longitude.

[0047] Preferably, it further includes:

[0048] Step S4: Analyze the overlap rate of the imaging region after adding engineering errors.

[0049] A system for calculating and analyzing the spatial synchronization rate of SAR satellite formations according to the present invention includes:

[0050] Module M1: Obtains the satellite attitude guidance angles of the two satellites;

[0051] Module M2: Calculates the imaging areas of the two satellites respectively based on the satellite attitude guidance angle;

[0052] Module M3: Calculates the overlap rate of the imaging areas of the two stars based on their respective imaging regions, and completes the analysis and calculation of the spatial synchronization rate.

[0053] Preferably, module M1 calculates the satellite attitude guidance angles of the two satellites based on their respective orbital parameters at the analysis time in the source data, including:

[0054] Module M1.1: Calculate the yaw guidance angle ψ:

[0055]

[0056]

[0057] Where: i is the orbital inclination, u is the latitudinal argument, and ω s ω represents the satellite's real-time angular velocity in orbit. e This is the Earth's rotational angular velocity;

[0058] Module M1.2: Calculate the pitch guidance angle θ:

[0059]

[0060] Where: e is the orbital eccentricity, and f is the true anomaly angle;

[0061] Module M1.3: Based on the yaw guidance angle ψ and pitch guidance angle θ, obtain the satellite attitude guidance angle. in Indicates the rolling direction guide angle.

[0062] Preferably, module M2 calculates the imaging regions of the two satellites based on the satellite attitude guidance angle and the range beamwidth and azimuth beamwidth in the source data, including:

[0063] Module M2.1: Select the waveform to be analyzed and determine the beam pointing angle α and range beamwidth β of that waveform. W azimuth beamwidth β L Among them, the wave positions to be analyzed cover the proximal wave position, the central wave position, and the distal wave position;

[0064] Module M2.2: Based on the beam pointing angle α and range beamwidth β of the stated wave position W azimuth beamwidth β L Determine the range of the conical field of view:

[0065]

[0066]

[0067]

[0068]

[0069] Where A1, A2, A3, and A4 represent the angle matrix between the four edges of the SAR conical field of view and the center line, respectively;

[0070] Module M2.3: Calculate the ground imaging area based on the satellite attitude guidance angle and the range of the conical field of view angle, that is, determine the intersection points of the four edges of the conical field of view with the Earth in sequence.

[0071] Preferably, module M2.3 includes:

[0072] Module M2.3.1: Based on the attitude guidance angle and edge field of view angles A1, A2, A3, A4, obtain the edge vector direction in the orbital coordinate system according to the specified transformation sequence;

[0073] Where A1 corresponds to the edge vector L1 O We obtain it from the following formula:

[0074]

[0075] Where rotx, roty, and rotz represent the transformation matrices corresponding to rotations around the x, y, and z axes, respectively.

[0076] A1(2) represents the second element of the included angle matrix A1; A1(1) represents the first element of the included angle matrix A1;

[0077] Where A2 corresponds to the edge vector L2 O We obtain it from the following formula:

[0078]

[0079] A2(2) represents the second element of the included angle matrix A2; A2(1) represents the first element of the included angle matrix A2;

[0080] Where A3 corresponds to the edge vector L3 O We obtain it from the following formula:

[0081]

[0082] A3(2) represents the second element of the included angle matrix A3; A3(1) represents the first element of the included angle matrix A3;

[0083] Where A4 corresponds to the edge vector L4 O We obtain it from the following formula:

[0084]

[0085] A4(2) represents the second element of the included angle matrix A4; A4(1) represents the first element of the included angle matrix A4;

[0086] Module M2.3.2: Based on satellite position, velocity, and time information, it converts the edge vector direction into a description in the Earth-fixed coordinate system;

[0087] Module M2.3.3: The Earth is equivalent to an ellipsoid, and the ellipsoid equation is obtained by describing it in the Earth-fixed coordinate system; the spatial straight line is determined according to the satellite position coordinates and the direction of the edge vector; the problem of solving the field of view range is transformed into solving the intersection point of the spatial straight line and the ellipsoid.

[0088] Module M2.3.4: After obtaining the coordinates of the ellipsoidal intersection point of the spatial line and the ellipsoid, the coordinates are converted into latitude and longitude descriptions to obtain the imaging areas of the two star formations described by latitude and longitude.

[0089] Preferably, it further includes:

[0090] Module M4: Analyzes the overlap rate of the imaging region after adding engineering errors.

[0091] Compared with the prior art, the present invention has the following beneficial effects:

[0092] 1. This invention addresses the need for deformation correction in satellite on-orbit images. During the analysis, it considers the real-time guidance of the satellite's on-orbit attitude. By utilizing the position, attitude, and imaging wavefront information of the two satellites, it can effectively analyze, predict, and evaluate the spatial synchronization effect, closely approximating the actual on-orbit state.

[0093] 2. This invention takes into account engineering practice and can guide the design of space synchronization and the control of various errors in actual development, effectively supporting the demonstration and analysis of indicators such as the space synchronization rate of formation SAR satellites.

[0094] 3. The present invention has a wide range of applications, including the indicator analysis and demonstration stage, the research and development testing stage, and the long-term on-orbit operation stage. Moreover, the input parameters involved in the present invention are all conventional parameters of satellite orbit attitude and SAR payload, which have universality.

[0095] 4. This invention achieves space synchronization through satellite attitude adjustment, making it applicable to large phased array antennas that cannot be directly driven in orbit. Attached Figure Description

[0096] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0097] Figure 1 This is a schematic diagram illustrating the concepts of spatial synchronization and synchronization rate analysis in this invention.

[0098] Figure 2 This is a schematic diagram of the three-dimensional attitude guidance calculation process for satellite space synchronization in this invention.

[0099] Figure 3 This diagram illustrates the variation of spatial synchronization rate of formation satellites with latitude angle when using the present invention.

[0100] Figure 4 This diagram illustrates the variation of spatial synchronization rate of satellite formations with geographical latitude using the present invention. Detailed Implementation

[0101] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0102] like Figure 1 As shown, this invention discloses a method for calculating and analyzing the spatial synchronization rate of formation SAR satellites, addressing the requirements of spatial synchronization interferometric imaging for formation satellites. It involves a method for calculating the spatial synchronization rate of two satellites based on their positions, attitudes, and imaging beam information. First, the attitude guidance angles of the two satellites are calculated based on their respective orbital parameters at the analysis time. Then, the imaging regions of each satellite are calculated based on their positions, attitudes, and beam information. Finally, the spatial synchronization rate of the two satellites is analyzed based on their imaging regions, taking into account various effects of engineering errors.

[0103] like Figure 2 As shown, a method for calculating and analyzing the spatial synchronization rate of SAR satellite formations according to the present invention includes:

[0104] Step S1: Calculate the attitude guidance angles of the binary stars based on their respective orbital parameters at the analysis time in the source data. Step S1 specifically includes the following steps:

[0105] Step S1.1: Calculate the yaw guidance angle ψ:

[0106]

[0107]

[0108] Where: i is the orbital inclination, u is the latitudinal argument, and ω s ω represents the satellite's real-time angular velocity in orbit. e This is the Earth's rotational angular velocity.

[0109] Step S1.2: Calculate the pitch guidance angle θ:

[0110]

[0111] Where: e is the orbital eccentricity, and f is the true anomaly angle.

[0112] Step S1.3: Obtain the satellite attitude guidance angle based on the yaw guidance angle ψ and the pitch guidance angle θ. in Indicates the rolling direction guide angle.

[0113] Step S2: Calculate the imaging regions of the two stars based on the attitude guidance angle and the range beamwidth and azimuth beamwidth in the source data. Step S2 specifically includes the following steps:

[0114] Step S2.1: Select the wave position to be analyzed and determine the beam pointing angle α and range beamwidth β of that wave position. W azimuth beamwidth β L The wave positions to be analyzed preferably cover the near-end wave position, the central wave position, and the far-end wave position.

[0115] Step S2.2: Based on the beam pointing angle α and range beamwidth β of the stated wave position... W azimuth beamwidth β L Determine the range of the conical field of view:

[0116]

[0117]

[0118]

[0119]

[0120] Where A1, A2, A3, and A4 represent the angle matrix between the four edges of the SAR conical field of view and the center line, respectively.

[0121] Step S2.3: Based on information such as the attitude guidance angle and the range of the conical field of view, calculate the ground imaging area, that is, sequentially determine the intersection points of the four edges of the conical field of view with the Earth. Step S2.3 includes:

[0122] Step S2.3.1: Based on the attitude guidance angle and edge field of view angles A1, A2, A3, and A4, obtain the edge vector direction in the orbital coordinate system according to the specified transformation sequence;

[0123] Where A1 corresponds to the edge vector L1 O We obtain it from the following formula:

[0124]

[0125] Where rotx, roty, and rotz represent the transformation matrices corresponding to rotations around the x, y, and z axes, respectively.

[0126] A1(2) represents the second element of the included angle matrix A1; A1(1) represents the first element of the included angle matrix A1.

[0127] The other three edges are calculated using the same method, namely:

[0128] Where A2 corresponds to the edge vector L2 O We obtain it from the following formula:

[0129]

[0130] A2(2) represents the second element of the included angle matrix A2; A2(1) represents the first element of the included angle matrix A2.

[0131] Where A3 corresponds to the edge vector L3 O We obtain it from the following formula:

[0132]

[0133] A3(2) represents the second element of the included angle matrix A3; A3(1) represents the first element of the included angle matrix A3.

[0134] Where A4 corresponds to the edge vector L4 O We obtain it from the following formula:

[0135]

[0136] A4(2) represents the second element of the included angle matrix A4; A4(1) represents the first element of the included angle matrix A4.

[0137] Step S2.3.2: Based on the satellite position, velocity, and time information, convert the edge vector direction to a description in the Earth-fixed coordinate system;

[0138] Step S2.3.3: Equivalently represent the Earth as an ellipsoid and describe the ellipsoid equation in the Earth-fixed coordinate system; determine the spatial straight line based on the satellite position coordinates and the direction of the edge vector; transform the problem of solving the field of view range into solving the problem of finding the intersection point of the spatial straight line and the ellipsoid;

[0139] Step S2.3.4: After obtaining the coordinates of the ellipsoidal intersection point of the spatial line and the ellipsoid, convert the position coordinates into latitude and longitude descriptions, thus obtaining the imaging areas of the two star formations described by latitude and longitude.

[0140] Step S3: Calculate the overlap rate of the imaging areas of the two stars based on their respective imaging regions, and complete the analysis and calculation of the spatial synchronization rate.

[0141] Step S4: Analyze the overlap rate of the imaging region after adding engineering errors. Specifically, by superimposing information such as the position error of the two satellites, attitude determination error, and beam pointing error onto the source data, analyze and determine the achievable spatial synchronization rate and the impact of each error on spatial synchronization.

[0142] like Figure 3 , Figure 4 As shown, Figure 3 The following is a schematic diagram illustrating the variation of spatial synchronization rate with latitude angle for calculating the formation satellites using this invention. Figure 4 A schematic diagram illustrating the variation of spatial synchronization rate of a satellite formation with geographical latitude using this invention is provided. The spatial synchronization rate of this satellite formation is better than 96.5%.

[0143] The present invention also provides a system for calculating and analyzing the spatial synchronization rate of formation SAR satellites. Those skilled in the art can implement the system by executing the process steps of the method for calculating and analyzing the spatial synchronization rate of formation SAR satellites. That is, the method for calculating and analyzing the spatial synchronization rate of formation SAR satellites can be understood as a preferred embodiment of the system for calculating and analyzing the spatial synchronization rate of formation SAR satellites.

[0144] Those skilled in the art will understand that, in addition to implementing the system, apparatus, and their modules provided by this invention in purely computer-readable program code, the same program can be implemented in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers by logically programming the method steps. Therefore, the system, apparatus, and their modules provided by this invention can be considered a hardware component, and the modules included therein for implementing various programs can also be considered structures within the hardware component; alternatively, modules for implementing various functions can be considered both software programs implementing the method and structures within the hardware component.

[0145] Specifically, according to the present invention, a system for calculating and analyzing the spatial synchronization rate of SAR formation satellites includes:

[0146] Module M1: Obtains the satellite attitude guidance angles of the two satellites;

[0147] Module M2: Calculates the imaging areas of the two satellites respectively based on the satellite attitude guidance angle;

[0148] Module M3: Calculates the overlap rate of the imaging areas of the two stars based on their respective imaging regions, and completes the analysis and calculation of the spatial synchronization rate.

[0149] Preferably, module M1 calculates the satellite attitude guidance angles of the two satellites based on their respective orbital parameters at the analysis time in the source data, including:

[0150] Module M1.1: Calculate the yaw guidance angle ψ:

[0151]

[0152]

[0153] Where: i is the orbital inclination, u is the latitudinal argument, and ω s ω represents the satellite's real-time angular velocity in orbit. e This is the Earth's rotational angular velocity;

[0154] Module M1.2: Calculate the pitch guidance angle θ:

[0155]

[0156] Where: e is the orbital eccentricity, and f is the true anomaly angle;

[0157] Module M1.3: Based on the yaw guidance angle ψ and pitch guidance angle θ, obtain the satellite attitude guidance angle. in Indicates the rolling direction guide angle.

[0158] Preferably, module M2 calculates the imaging regions of the two satellites based on the satellite attitude guidance angle and the range beamwidth and azimuth beamwidth in the source data, including:

[0159] Module M2.1: Select the waveform to be analyzed and determine the beam pointing angle α and range beamwidth β of that waveform. W azimuth beamwidth β L Among them, the wave positions to be analyzed cover the proximal wave position, the central wave position, and the distal wave position;

[0160] Module M2.2: Based on the beam pointing angle α and range beamwidth β of the stated wave position W azimuth beamwidth β L Determine the range of the conical field of view:

[0161]

[0162]

[0163]

[0164]

[0165] Where A1, A2, A3, and A4 represent the angle matrix between the four edges of the SAR conical field of view and the center line, respectively;

[0166] Module M2.3: Calculate the ground imaging area based on the satellite attitude guidance angle and the range of the conical field of view angle, that is, determine the intersection points of the four edges of the conical field of view with the Earth in sequence.

[0167] Preferably, module M2.3 includes:

[0168] Module M2.3.1: Based on the attitude guidance angle and edge field of view angles A1, A2, A3, A4, obtain the edge vector direction in the orbital coordinate system according to the specified transformation sequence;

[0169] Where A1 corresponds to the edge vector L1 O We obtain it from the following formula:

[0170]

[0171] Where rotx, roty, and rotz represent the transformation matrices corresponding to rotations around the x, y, and z axes, respectively.

[0172] A1(2) represents the second element of the included angle matrix A1; A1(1) represents the first element of the included angle matrix A1;

[0173] Where A2 corresponds to the edge vector L2 O We obtain it from the following formula:

[0174]

[0175] A2(2) represents the second element of the included angle matrix A2; A2(1) represents the first element of the included angle matrix A2;

[0176] Where A3 corresponds to the edge vector L3 O We obtain it from the following formula:

[0177]

[0178] A3(2) represents the second element of the included angle matrix A3; A3(1) represents the first element of the included angle matrix A3;

[0179] Where A4 corresponds to the edge vector L4 O We obtain it from the following formula:

[0180]

[0181] A4(2) represents the second element of the included angle matrix A4; A4(1) represents the first element of the included angle matrix A4;

[0182] Module M2.3.2: Based on satellite position, velocity, and time information, it converts the edge vector direction into a description in the Earth-fixed coordinate system;

[0183] Module M2.3.3: The Earth is equivalent to an ellipsoid, and the ellipsoid equation is obtained by describing it in the Earth-fixed coordinate system; the spatial straight line is determined according to the satellite position coordinates and the direction of the edge vector; the problem of solving the field of view range is transformed into solving the intersection point of the spatial straight line and the ellipsoid.

[0184] Module M2.3.4: After obtaining the coordinates of the ellipsoidal intersection point of the spatial line and the ellipsoid, the coordinates are converted into latitude and longitude descriptions to obtain the imaging areas of the two star formations described by latitude and longitude.

[0185] Preferably, it further includes:

[0186] Module M4: Analyzes the overlap rate of the imaging region after adding engineering errors.

[0187] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A method for computing and analyzing the spatial synchronization rate of a formation of SAR satellites, characterized in that, include: Step S1: Obtain the satellite attitude guidance angles of the two satellites; Step S2: Calculate the imaging areas of the two satellites respectively based on the satellite attitude guidance angle; Step S3: Calculate the overlap rate of the imaging areas of the two stars based on their respective imaging regions, and complete the analysis and calculation of the spatial synchronization rate. In step S2, the imaging regions of the two satellites are calculated based on the satellite attitude guidance angle and the range beamwidth and azimuth beamwidth in the source data, including: Step S2.1: selecting a wave position to be analyzed, determining the beam pointing angle a, the range beam width of the wave position w , the azimuth beam width L ; wherein the wave position to be analyzed covers the near-end wave position, the center wave position, and the far-end wave position; Step S2.2: Determine a cone of view angle range based on the beam pointing angle a of the wave position, the range-wise beam width w , the azimuth-wise beam width L , the azimuth-wise beam width Where A1, A2, A3, and A4 represent the angle matrix between the four edges of the SAR conical field of view and the center line, respectively; Step S2.3: Calculate the ground imaging area based on the satellite attitude guidance angle and the range of the conical field of view angle, that is, determine the intersection points of the four edges of the conical field of view with the Earth in sequence; Step S2.3 includes: Step S2.3.1: Based on the attitude guidance angle and edge field of view angles A1, A2, A3, and A4, obtain the edge vector direction in the orbital coordinate system according to the specified transformation sequence; wherein A1 corresponds to an edge vector L 1 o is obtained from the equation wherein rotx, roty, rotz respectively represent the corresponding transformation matrices for rotation about x, y, z the x-axis, y-axis and z-axis respectively; is the yaw steering angle, θ is the pitch steering angle and φ represents the roll direction steering angle. Step S2.3.2: Based on the satellite position, velocity, and time information, convert the edge vector direction to a description in the Earth-fixed coordinate system; Step S2.3.3: Equivalently represent the Earth as an ellipsoid and describe the ellipsoid equation in the Earth-fixed coordinate system; determine the spatial straight line based on the satellite position coordinates and the direction of the edge vector; transform the problem of solving the field of view range into solving the problem of finding the intersection point of the spatial straight line and the ellipsoid; Step S2.3.4: After obtaining the coordinates of the ellipsoidal intersection point of the spatial line and the ellipsoid, convert the position coordinates into latitude and longitude descriptions to obtain the imaging areas of the two star formations described by latitude and longitude.

2. The method of claim 1, wherein the method is characterized by, Step S1 involves calculating the satellite attitude guidance angles of the two satellites based on their respective orbital parameters at the analysis time in the source data, including: Step S1.1: Calculate yaw guidance angle :

3. The method of claim 1, wherein the method is characterized by, Also includes: Step S4: Analyze the overlap rate of the imaging region after adding engineering errors.

4. A system for computing and analyzing the spatial synchronization rate of a formation of SAR satellites, characterized in that, include: Module M1: Obtains the satellite attitude guidance angles of the two satellites; Module M2: Calculates the imaging areas of the two satellites respectively based on the satellite attitude guidance angle; Module M3: Calculates the overlap rate of the imaging areas of the two stars based on their respective imaging regions, and completes the analysis and calculation of the spatial synchronization rate; Module M2 calculates the imaging regions of the two satellites based on the satellite attitude guidance angle and the range beamwidth and azimuth beamwidth in the source data, including: Module M2.1: Select the waveform to be analyzed and determine the beam pointing angle α and range beamwidth of that waveform. w azimuth beamwidth L Among them, the wave positions to be analyzed cover the proximal wave position, the central wave position, and the distal wave position; Module M2.2: Based on the beam pointing angle α and range beamwidth of the stated wave position w azimuth beamwidth L Determine the range of the conical field of view: Where A1, A2, A3, and A4 represent the angle matrix between the four edges of the SAR conical field of view and the center line, respectively; Module M2.3: Calculate the ground imaging area based on the satellite attitude guidance angle and the range of the conical field of view, that is, determine the intersection points of the four edges of the conical field of view with the Earth in sequence; The module M2.3 includes: Module M2.3.1: Based on the attitude guidance angle and edge field of view angles A1, A2, A3, A4, obtain the edge vector direction in the orbital coordinate system according to the specified transformation sequence; Where A1 corresponds to the edge vector L 1 O We obtain it from the following formula: in rotx, roty, rotz They represent circumference respectively. x, y, z The transformation matrix corresponding to axis rotation. For yaw guidance angle, θ For pitch guidance angle, φ Indicates the rolling direction guide angle; A4(2) represents the second element of the included angle matrix A4; A4(1) represents the first element of the included angle matrix A4; Module M2.3.2: Based on satellite position, velocity, and time information, it converts the edge vector direction into a description in the Earth-fixed coordinate system; Module M2.3.3: The Earth is equivalent to an ellipsoid, and the ellipsoid equation is obtained by describing it in the Earth-fixed coordinate system; the spatial straight line is determined according to the satellite position coordinates and the direction of the edge vector; the problem of solving the field of view range is transformed into solving the intersection point of the spatial straight line and the ellipsoid. Module M2.3.4: After obtaining the coordinates of the ellipsoidal intersection point of the spatial line and the ellipsoid, the coordinates are converted into latitude and longitude descriptions to obtain the imaging areas of the two star formations described by latitude and longitude.

5. The system for calculating and analyzing the spatial synchronization rate of formation SAR satellites according to claim 4, characterized in that, The module M1 calculates the satellite attitude guidance angles of the two satellites based on their respective orbital parameters at the analysis time in the source data, including: Module M1.1: Calculate yaw guidance angle : in: For the track inclination angle, Argument of latitude This refers to the satellite's real-time angular velocity in orbit. This is the Earth's rotational angular velocity; Module M1.2: Calculate pitch guidance angle : in: For orbital eccentricity, It is a true near point angle; Module M1.3: Based on the yaw guidance angle Pitch guidance angle The satellite attitude guidance angle is obtained. ,in , Indicates the rolling direction guide angle.

6. The system for calculating and analyzing the spatial synchronization rate of SAR satellite formations according to claim 4, characterized in that, Also includes: Module M4: Analyzes the overlap rate of the imaging region after adding engineering errors.

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