Differential interferometric sar satellite-ground joint mission planning method and system

Abstract

The application provides a differential interference SAR satellite satellite-ground joint task planning method and system, which comprises the following steps: step one, task planning parameter input; step two, calculation of on-off true anomaly angle of observation area based on radar distance-Doppler equation; step three, ground generation of load work package containing on-off true anomaly angle; step four, on-satellite calculation of true anomaly angle time based on GNSS orbit prediction; and step five, on-satellite correction of load work package on-off time. The differential interference SAR satellite satellite-ground joint task planning method and system designed by the application solve the on-time inaccuracy problem faced by traditional time-based task planning, can improve the accuracy of satellite image position, and improve the differential interference application efficiency.

Description

Technical Field

[0001] This invention relates to the field of autonomous mission planning for differential interferometric SAR satellites, and more specifically, to a method and system for joint satellite-ground mission planning for differential interferometric SAR satellites. Background Technology

[0002] Currently, for differential interferometric SAR satellites performing regional coverage imaging missions, ground systems typically prepare and upload SAR payload work packages 1-3 days in advance. These work packages include radar power-on and power-off times. Because orbit prediction accuracy is insufficient at this stage, the radar power-on times in the SAR payload work package cannot guarantee that the starting positions of images acquired from two consecutive interferometric imaging sessions are consistent. This results in partial misalignment of the differential interferometric SAR images, affecting the effectiveness of differential interferometric applications. Therefore, improving the accuracy of satellite image acquisition positions has become a crucial aspect of autonomous mission planning and design for differential interferometric SAR satellites.

[0003] The paper "A SAR Satellite High-Resolution Imaging Mission Planning Method" (202211354871.4) discloses a SAR satellite high-resolution imaging mission planning method. Taking into account satellite resource constraints and the requirements of high-resolution imaging missions, it can plan multiple imaging missions at once, improving the utilization efficiency of satellite resources and the satellite's observation speed. The paper "A High-Orbit SAR Satellite Automatic Imaging System and Method Based on Ground-Based Precision Ranging" (202211354868.2) discloses a high-orbit SAR satellite automatic imaging system based on ground-based precision ranging. The ground control subsystem plans missions according to the imaging tasks, and the missions run automatically and simultaneously, improving imaging timeliness. The paper "SAR Satellite Azimuth Agile Observation Mode Multi-Target Mission Planning Method and System" (202211096304.3) discloses a SAR satellite azimuth agile observation mode multi-target mission planning method and system. This method can efficiently complete the planning and design of maximizing the multi-target observation capability in a single flight, realizing the improvement of the on-orbit observation capability and full utilization of the efficiency of high-resolution SAR satellites. The paper "A Method and System for Optimizing SAR Mission Planning for Distributed InSAR Satellite Long Strip Mapping" (202011192657.4) discloses a method and system for optimizing SAR mission planning for distributed InSAR satellite long strip mapping, which can solve problems such as sampling window offset and system performance degradation caused by long strip SAR operation. The paper "An Autonomous Mission Planning Method for Spaceborne SAR Imaging" (202011053084.7) discloses an autonomous mission planning method for spaceborne SAR imaging. This method determines a reasonable observation sequence for target areas based on the characteristics of ground target distribution, solving the problem of autonomous on-orbit imaging mission planning for spaceborne SAR under high-precision, small-swath, multi-target imaging missions.

[0004] Regarding the autonomous mission planning of differential interferometric SAR satellites, there are no publicly available technologies for joint satellite-ground mission planning of differential interferometric SAR satellites based on true anomaly angles, either domestically or internationally.

[0005] Therefore, it is necessary to design a differential interferometric SAR satellite joint mission planning method to solve the problem of inaccurate start-up time faced by traditional time-based mission planning and improve the accuracy of satellite image acquisition location. 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 planning differential interferometric SAR satellite-ground joint missions.

[0007] A differential interferometric SAR satellite joint space-ground mission planning method provided by the present invention includes:

[0008] Step S1: Input mission planning parameters into the ground system;

[0009] Step S2: Calculate the true near angle of the radar on / off switch in the observation area based on the radar range-Doppler equation;

[0010] Step S3: Add the true near-point angle of the observation area's on / off state to the existing payload work package of the ground system;

[0011] Step S4: Calculate the true perimeter time on-board based on GNSS orbit prediction;

[0012] Step S5: Based on the calculated true perimeter angle time, correct the on-board payload work package power-on and power-off time.

[0013] Preferably, step S1 includes: inputting the following parameters to the ground system: the latitude and longitude range of the observation area, reference orbit parameters, radar Doppler bandwidth, radar nearest distance and farthest distance parameters.

[0014] Preferably, step S2 employs:

[0015] Step S2.1: Calculate the current position vector p of the differential interferometric SAR satellite based on the reference orbit parameters. m and velocity vector v m ;

[0016] Step S2.2: Establish the radar range-Doppler equation based on the true near angle when the payload is powered on;

[0017] |p t,1 -p m (θ1)|=r1

[0018]

[0019] in,

[0020]

[0021] Step S2.3: Establish the radar range-Doppler equation based on the true near angle when the payload is powered off;

[0022] |p t,2 -p m (θ2)|=r2

[0023]

[0024] in,

[0025]

[0026] In the formula, p t p is the three-dimensional position vector of the ground target. m (θ) and v m (θ) represents the position and velocity vector of the antenna phase center at the true anterior angle θ, r is the slant range from the antenna center phase to the target, λ is the radar wavelength, and f d B is the center frequency of the Doppler wave. d The Doppler bandwidth is defined. All variables are defined in a fixed Earth coordinate system.

[0027] Step S2.4: Determine whether the radar distances r1 and r2 are within the imaging range when the payload is switched on or off;

[0028] Step S2.5: Using the Newton-Raphson iteration method, solve the equations to obtain the true anterior angles θ1 and θ2 corresponding to the load switching on and off.

[0029] Preferably, step S4 employs:

[0030] Step S4.1: The satellite acquires GNSS orbit prediction data at a preset time;

[0031] Step S4.2: Compare and determine whether the true anomaly angles θ1 and θ2 on the ground fall within the GNSS prediction data segment;

[0032] Step S4.3: Using the nth-order Chebyshev polynomial as the basis function, fit the satellite ephemeris during the payload startup phase and calculate the fitting polynomial within the arc segment;

[0033]

[0034] in

[0035]

[0036] In the formula, t0 is the initial epoch of the fitted arc segment; n represents the order of the Chebyshev polynomial; x(t) represents the x-axis component of the satellite position vector; y(t) represents the y-axis component of the satellite position vector; and z(t) represents the z-axis component of the satellite position vector. Represents the x-axis component of the satellite velocity vector. This represents the y-axis component of the satellite velocity vector. denoted by z, where C represents the coefficients of the fitted polynomial, and Δt represents the fitted time step.

[0037] Step S4.4: Using the interpolation approximation method, calculate the load start-up and shutdown times t1 and t2;

[0038]

[0039] Preferably, step S5 employs the following:

[0040] Step S5.1: Fill the solved load start-up and shutdown times t1 and t2 into the original load work package to obtain the on-board corrected load work package;

[0041] Step S5.2: The satellite analyzes and executes the payload work package based on time.

[0042] A differential interferometric SAR satellite-ground joint mission planning system provided by the present invention includes:

[0043] Module M1: Inputs mission planning parameters to the ground system;

[0044] Module M2: Calculates the true near angle of radar on / off in the observation area based on the radar range-Doppler equation;

[0045] Module M3: Adds the true nearest angle of power-on / off in the observation area to the existing payload work package of the ground system;

[0046] Module M4: On-board calculation of true perihelion time based on GNSS orbit prediction;

[0047] Module M5: On-board correction payload work package power-on and power-off times based on the calculated true perimeter angle time.

[0048] Preferably, the module M1 includes: inputting to the ground system parameters including: the latitude and longitude range of the observation area, reference orbit parameters, radar Doppler bandwidth, radar nearest distance and farthest distance parameters.

[0049] Preferably, the module M2 adopts:

[0050] Module M2.1: Calculates the current position vector p of the differential interferometric SAR satellite based on reference orbit parameters. m and velocity vector v m ;

[0051] Module M2.2: Establish the radar range-Doppler equation based on the true near angle when the payload is powered on;

[0052] |p t,1 -p m (θ1)|=r1

[0053]

[0054] in,

[0055]

[0056] Module M2.3: Establish the radar range-Doppler equation based on the true near angle when the payload is powered off;

[0057] |p t,2 -p m (θ2)|=r2

[0058]

[0059] in,

[0060]

[0061] In the formula, p t p is the three-dimensional position vector of the ground target. m (θ) and v m (θ) represents the position and velocity vector of the antenna phase center at the true anterior angle θ, r is the slant range from the antenna center phase to the target, λ is the radar wavelength, and f d B is the center frequency of the Doppler wave. d The Doppler bandwidth is defined. All variables are defined in a fixed Earth coordinate system.

[0062] Module M2.4: Determines whether the radar distances r1 and r2 are within the imaging range when the payload is powered on or off;

[0063] Module M2.5: The Newton-Raphson iteration method is used to solve the equations to obtain the true anterior angles θ1 and θ2 corresponding to the load switching on and off.

[0064] Preferably, the module M4 adopts:

[0065] Module M4.1: The satellite acquires GNSS orbit prediction data at a preset time;

[0066] Module M4.2: Compare and determine whether the true anomaly angles θ1 and θ2 on the ground fall within the GNSS prediction data segment;

[0067] Module M4.3: Using the nth-order Chebyshev polynomial as the basis function, the satellite ephemeris during the payload startup phase is fitted, and the fitted polynomial within the arc segment is calculated.

[0068]

[0069] in

[0070]

[0071] In the formula, t0 is the initial epoch of the fitted arc segment; n represents the order of the Chebyshev polynomial; x(t) represents the x-axis component of the satellite position vector; y(t) represents the y-axis component of the satellite position vector; and z(t) represents the z-axis component of the satellite position vector. Represents the x-axis component of the satellite velocity vector. This represents the y-axis component of the satellite velocity vector. denoted by z, where C represents the coefficients of the fitted polynomial, and Δt represents the fitted time step.

[0072] Module M4.4: The load start-up and shutdown times t1 and t2 are calculated using an interpolation approximation method;

[0073]

[0074] Preferably, the module M5 adopts:

[0075] Module M5.1: Fill the solved load start-up and shutdown times t1 and t2 into the original load work package to obtain the on-board corrected load work package;

[0076] Module M5.2: Onboard time-based parsing and execution of payload work packages.

[0077] Compared with the prior art, the present invention has the following beneficial effects:

[0078] 1. This invention adopts a satellite-ground joint mission planning method based on true near angle of arrival for differential interferometric SAR satellites, which is the first of its kind both domestically and internationally, filling a gap in existing technologies;

[0079] 2. The differential interferometric SAR satellite-ground joint mission planning method and system of the present invention adopts a technology that combines ground mission planning of true perihelion angle of strictly regressing orbit satellite with on-board autonomous planning of power-on time. It can effectively solve the problem of inaccurate power-on time faced by traditional time-based mission planning, improve the accuracy of satellite image acquisition position, and enhance user experience. Attached Figure Description

[0080] 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:

[0081] Figure 1 This is a flowchart of a differential interferometric SAR satellite-ground joint mission planning method according to the present invention. Detailed Implementation

[0082] 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.

[0083] Example 1

[0084] This invention provides a satellite-ground joint mission planning method and system for differential interferometric SAR satellites. It adopts satellite mission ground planning based on the true anomaly angle of the reference orbit and satellite on-board autonomous mission planning based on GNSS information. It solves the problem of inaccurate start-up time faced by traditional time-based mission planning, which can improve the accuracy of satellite image acquisition position and enhance the application efficiency of differential interferometric SAR.

[0085] The differential interferometric SAR satellite joint space-ground mission planning method, such as Figure 1 As shown, it includes the following steps:

[0086] Step S1: Input task planning parameters;

[0087] Step S2: Calculate the true near angle of the radar on / off switch in the observation area based on the radar range-Doppler equation;

[0088] Step S3: Generate the load work package ground including the true near point angle of power on / off;

[0089] Step S4: On-board calculation of true perihelion time based on GNSS orbit prediction;

[0090] Step S5: On-board correction of load work package power-on / off time.

[0091] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0092] This example demonstrates a strictly regressive orbit differential interferometric SAR satellite performing an observation mission over a specific region.

[0093] Specifically, step S1 involves inputting reference orbit parameters; specifically, inputting parameters such as the latitude and longitude range of the observation area, reference orbit parameters, radar Doppler bandwidth, radar closest distance, and farthest distance to the ground system.

[0094] Specifically, step S2 employs the following:

[0095] Step S2.1: Calculate the position vector p of this differential interferometric SAR satellite based on the reference orbit. m and velocity vector v m ;

[0096] Step S2.2: Establish the radar range-Doppler equation based on the true near angle when the payload is powered on;

[0097] |p t,1 -p m (θ1)|=r1

[0098]

[0099] in,

[0100]

[0101] Step S2.3: Establish the radar range-Doppler equation based on the true near angle when the payload is powered off;

[0102] |p t,2 -p m (θ2)|=r2

[0103]

[0104] in,

[0105]

[0106] In the formula, p t p is the three-dimensional position vector of the ground target. m (θ) and v m (θ) represents the position and velocity vector of the antenna phase center at the true anterior angle θ, r is the slant range from the antenna center phase to the target, λ is the radar wavelength, and f d B is the center frequency of the Doppler wave. d The bandwidth is the Doppler bandwidth. All variables are defined in a fixed Earth coordinate system.

[0107] Step S2.4: Determine whether the radar distances r1 and r2 when the load is switched on or off are within the imaging range; In this embodiment, it is found that the radar distances r1 and r2 when the load is switched on or off are both within the radar imaging range.

[0108] Step S2.5: Using the Newton-Raphson iteration method, solve the equations to obtain the true anterior angles θ1 and θ2 corresponding to the load switching on and off.

[0109] Specifically, step S3 involves adding the true anomaly angles θ1 and θ2 corresponding to the load power-on / off state to the existing payload work package format of the ground system.

[0110] Specifically, step S4 employs the following:

[0111] Step S4.1: The satellite acquires 10 minutes of GNSS orbit prediction data.

[0112] Step S4.2: Compare and determine whether the true anomaly angles θ1 and θ2 on the ground fall within the GNSS prediction data segment; In this embodiment, after comparison, it is determined that the true anomaly angles θ1 and θ2 on the ground both fall within the GNSS prediction data segment.

[0113] Step S4.3: Using the nth-order Chebyshev polynomial as the basis function, fit the satellite ephemeris during the payload startup phase and calculate the fitting polynomial within the arc segment.

[0114]

[0115] in

[0116]

[0117] In the formula, t0 is the initial epoch of the fitted arc segment; n represents the order of the Chebyshev polynomial; x(t) represents the x-axis component of the satellite position vector; y(t) represents the y-axis component of the satellite position vector; and z(t) represents the z-axis component of the satellite position vector. Represents the x-axis component of the satellite velocity vector. This represents the y-axis component of the satellite velocity vector. denoted by z, where C represents the coefficients of the fitted polynomial, and Δt represents the fitted time step.

[0118] Step S4.4: Using the interpolation approximation method, the load start-up and shutdown times t1 and t2 are calculated using the following formula.

[0119]

[0120] Specifically, step S5 employs the following:

[0121] Step S5.1: Fill the load power-on and power-off times t1 and t2 obtained in the previous step into the original load work package to obtain the on-board corrected load work package.

[0122] Step S5.2: The satellite analyzes and executes the payload work package based on time.

[0123] The differential interferometric SAR satellite-ground joint mission planning system includes:

[0124] Module M1: Input of task planning parameters;

[0125] Module M2: Calculation of the true near angle of radar on / off in the observation area based on the radar range-Doppler equation;

[0126] Module M3: Ground generation of load work package including true near-point angle for power-on and power-off;

[0127] Module M4: On-board calculation of true perihelion time based on GNSS orbit prediction;

[0128] Module M5: On-board correction for load package power-on / off time.

[0129] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0130] This example demonstrates a strictly regressive orbit differential interferometric SAR satellite performing an observation mission over a specific region.

[0131] Specifically, module M1 uses the following input: the orbital parameters are reference orbital parameters; specifically, it inputs parameters such as the latitude and longitude range of the observation area, reference orbital parameters, radar Doppler bandwidth, radar closest distance and farthest distance to the ground system.

[0132] Specifically, module M2 adopts:

[0133] Module M2.1: Calculates the position vector p of this differential interferometric SAR satellite based on the reference orbit. m and velocity vector v m Location and speed information.

[0134] Module M2.2: Establish the radar range-Doppler equation based on the true near angle when the payload is powered on;

[0135] |p t,1 -p m (θ1)|=r1

[0136]

[0137] in,

[0138]

[0139] Module M2.3: Establish the radar range-Doppler equation based on the true near angle when the payload is powered off;

[0140] |p t,2 -p m (θ2)|=r2

[0141]

[0142] in,

[0143]

[0144] In the formula, p t p is the three-dimensional position vector of the ground target. m(θ) and v m (θ) represents the position and velocity vector of the antenna phase center at the true anterior angle θ, r is the slant range from the antenna center phase to the target, λ is the radar wavelength, and f d B is the center frequency of the Doppler wave. d The bandwidth is the Doppler bandwidth. All variables are defined in a fixed Earth coordinate system.

[0145] Module M2.4: Determines whether the radar distances r1 and r2 are within the imaging range when the load is switched on or off; in this embodiment, it is found that the radar distances r1 and r2 are both within the radar imaging range when the load is switched on or off.

[0146] Module M2.5: The Newton-Raphson iteration method is used to solve the equations to obtain the true anterior angles θ1 and θ2 corresponding to the load switching on and off.

[0147] Specifically, module M3 adopts the following approach: adding the true anomaly angles θ1 and θ2 corresponding to the load power-on and power-off times to the existing payload work package format of the ground system.

[0148] Specifically, module M4 adopts:

[0149] Module M4.1: The satellite acquires 10 minutes of GNSS orbit prediction data.

[0150] Module M4.2: Compare and determine whether the true anomaly angles θ1 and θ2 on the ground fall within the GNSS prediction data segment; in this embodiment, after comparison, it is determined that the true anomaly angles θ1 and θ2 on the ground both fall within the GNSS prediction data segment.

[0151] Module M4.3: Using an nth-order Chebyshev polynomial as the basis function, the satellite ephemeris during the payload startup phase is fitted, and the fitted polynomial within the arc segment is calculated.

[0152]

[0153] in

[0154]

[0155] In the formula, t0 is the initial epoch of the fitted arc segment; n represents the order of the Chebyshev polynomial; x(t) represents the x-axis component of the satellite position vector; y(t) represents the y-axis component of the satellite position vector; and z(t) represents the z-axis component of the satellite position vector. Represents the x-axis component of the satellite velocity vector. This represents the y-axis component of the satellite velocity vector. denoted by z, where C represents the coefficients of the fitted polynomial, and Δt represents the fitted time step.

[0156] Module M4.4: The load start-up and shutdown times t1 and t2 are calculated using the following formula by interpolation approximation method.

[0157]

[0158] Specifically, module M5 adopts:

[0159] Module M5.1: Fill the load start-up and shutdown times t1 and t2 obtained in the previous step into the original load work package to obtain the on-board corrected load work package.

[0160] Module M5.2: Onboard time-based parsing and execution of payload work packages.

[0161] In summary, the differential interferometric SAR satellite-ground joint mission planning method and system of the present invention adopts a technology that combines ground mission planning based on the true perihelion angle of the satellite in a strict regression orbit with on-board autonomous planning based on the power-on time. This can effectively solve the problem of inaccurate power-on time faced by traditional time-based mission planning, improve the accuracy of satellite image acquisition position, and enhance the user experience.

[0162] Those skilled in the art will understand that, besides implementing the system and its various devices, modules, and units provided by this invention in the form of purely computer-readable program code, the same functions can be achieved entirely through logical programming of the method steps, making the system and its various devices, modules, and units of this invention function in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers. Therefore, the system and its various devices, modules, and units provided by this invention can be considered as a hardware component, and the devices, modules, and units included therein for implementing various functions can also be considered as structures within the hardware component; alternatively, the devices, modules, and units for implementing various functions can be considered as both software modules implementing the method and structures within the hardware component.

[0163] 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 joint space-ground mission planning of differential interferometric SAR satellites, characterized in that, include: Step S1: Input mission planning parameters into the ground system; Step S2: Calculate the true near angle of the radar on / off switch in the observation area based on the radar range-Doppler equation; Step S3: Add the true near-point angle of the observation area's on / off state to the existing payload work package of the ground system; Step S4: Calculate the true perimeter time on-board based on GNSS orbit prediction; Step S5: Based on the calculated true perimeter angle time, correct the on-board payload work package power-on and power-off time; Step S4 employs the following: Step S4.1: The satellite acquires GNSS orbit prediction data at a preset time; Step S4.2: Compare and determine the true near angle on the ground. , Does it fall within the GNSS forecast data segment? Step S4.3: Using the nth-order Chebyshev polynomial as the basis function, fit the satellite ephemeris during the payload startup phase and calculate the fitting polynomial within the arc segment; in In the formula, This is the initial epoch for fitting the arc segment; Denotes the order of the Chebyshev polynomial. The x-axis component represents the satellite's position vector. This represents the y-axis component of the satellite position vector. This represents the z-axis component of the satellite position vector. Represents the x-axis component of the satellite velocity vector. This represents the y-axis component of the satellite velocity vector. This represents the z-axis component of the satellite velocity vector. Represents the coefficients of the fitted polynomial. Indicates the fitting time step; Step S4.4: Calculate the load start-up and shutdown times using an interpolation approximation method. , ; 。 2. The differential interferometric SAR satellite-ground joint mission planning method according to claim 1, characterized in that, Step S1 includes: inputting the following parameters to the ground system: the latitude and longitude range of the observation area, reference orbit parameters, radar Doppler bandwidth, radar nearest distance and farthest distance parameters.

3. The differential interferometric SAR satellite-ground joint mission planning method according to claim 1, characterized in that, Step S2 employs the following: Step S2.1: Calculate the current position vector of the differential interferometric SAR satellite based on the reference orbit parameters. and velocity vector ; Step S2.2: Establish the radar range-Doppler equation based on the true near angle when the payload is powered on; in, ； Step S2.3: Establish the radar range-Doppler equation based on the true near angle when the payload is powered off; in, In the formula, This represents the three-dimensional position vector of the ground target. and These are the antenna phase center angles at the true perimeter. Position and velocity vector at time The slant range from the antenna center phase to the target. For radar wavelength, The center frequency of the Doppler wave. The Doppler bandwidth is defined; all variables are defined in a fixed Earth coordinate system. Step S2.4: Determine the radar distance when the load is switched on or off. , Is it within the imaging range? Step S2.5: Using the Newton-Raphson iteration method, solve the equations to obtain the true anterior angles corresponding to the load switching on and off. , .

4. The differential interferometric SAR satellite-ground joint mission planning method according to claim 1, characterized in that, Step S5 employs the following: Step S5.1: Solve for the load start-up and shutdown times , Fill in the original payload work package to obtain the on-board corrected payload work package; Step S5.2: The satellite analyzes and executes the payload work package based on time.

5. A differential interferometric SAR satellite-ground joint mission planning system, characterized in that, include: Module M1: Inputs mission planning parameters to the ground system; Module M2: Calculates the true near angle of radar on / off in the observation area based on the radar range-Doppler equation; Module M3: Adds the true nearest angle of power-on / off in the observation area to the existing payload work package of the ground system; Module M4: On-board calculation of true perihelion time based on GNSS orbit prediction; Module M5: On-board correction payload work package power-on / off time based on the calculated true perimeter angle time; The module M4 adopts: Module M4.1: The satellite acquires GNSS orbit prediction data at a preset time; Module M4.2: Compare and determine the true near angle on the ground. , Does it fall within the GNSS forecast data segment? Module M4.3: Using the nth-order Chebyshev polynomial as the basis function, the satellite ephemeris during the payload startup phase is fitted, and the fitted polynomial within the arc segment is calculated. in In the formula, This is the initial epoch for fitting the arc segment; Denotes the order of the Chebyshev polynomial. The x-axis component represents the satellite's position vector. This represents the y-axis component of the satellite position vector. This represents the z-axis component of the satellite position vector. Represents the x-axis component of the satellite velocity vector. This represents the y-axis component of the satellite velocity vector. This represents the z-axis component of the satellite velocity vector. Represents the coefficients of the fitted polynomial. Indicates the fitting time step; Module M4.4: The load start-up and shutdown times are calculated using an interpolation approximation method. , ; 。 6. The differential interferometric SAR satellite-ground joint mission planning system according to claim 5, characterized in that, The module M1 includes inputting the following parameters to the ground system: the latitude and longitude range of the observation area, reference orbit parameters, radar Doppler bandwidth, radar nearest distance and farthest distance parameters.

7. The differential interferometric SAR satellite-ground joint mission planning system according to claim 5, characterized in that, The module M2 adopts: Module M2.1: Calculates the current position vector of the differential interferometric SAR satellite based on reference orbit parameters. and velocity vector ; Module M2.2: Establish the radar range-Doppler equation based on the true near angle when the payload is powered on; in, ； Module M2.3: Establish the radar range-Doppler equation based on the true near angle when the payload is powered off; in, In the formula, This represents the three-dimensional position vector of the ground target. and These are the antenna phase center angles at the true perimeter. Position and velocity vector at time The slant range from the antenna center phase to the target. For radar wavelength, The center frequency of the Doppler wave. The Doppler bandwidth is defined; all variables are defined in a fixed Earth coordinate system. Module M2.4: Determines the radar range when the payload is powered on or off. , Is it within the imaging range? Module M2.5: Employs Newton's iterative method to solve equations and obtain the true anterior angle corresponding to the load switching on / off state. , .

8. The differential interferometric SAR satellite-ground joint mission planning system according to claim 5, characterized in that, The module M5 adopts: Module M5.1: Calculates the load start-up and shutdown times. , Fill in the original payload work package to obtain the on-board corrected payload work package; Module M5.2: Onboard time-based parsing and execution of payload work packages.

Images