Satellite calibration method, device, apparatus and storage medium
By using multi-angle data acquisition and self-calibration methods, the problem of satellite calibration relying on high-cost ground facilities and low-precision external data has been solved, achieving high-precision and low-cost satellite interferometric system calibration and improving the system's measurement accuracy and practicality.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- BEIJING WEINA STAR TECH CO LTD
- Filing Date
- 2026-03-12
- Publication Date
- 2026-06-12
AI Technical Summary
Existing satellite calibration technologies rely on high-cost ground facilities and low-precision external data, making it difficult to meet the needs of high-precision interferometry.
By receiving echo data from multiple radar satellites and utilizing data acquisition from different angles, the elevation error influencing factor and fitting function are determined, enabling self-calibration and eliminating systematic errors and dependence on ground calibration fields and external data.
It significantly improved the elevation measurement accuracy of the satellite interferometry system, reduced implementation costs and time, achieved low-cost and high-precision calibration, and enhanced the system's engineering applicability.
Smart Images
Figure CN122194074A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of radar signal processing technology, and in particular to a satellite calibration method, apparatus, device, and storage medium. Background Technology
[0002] Spaceborne systems based on synthetic aperture radar interferometry can achieve large-scale surface deformation monitoring and digital elevation model acquisition. The accuracy of their measurements is highly dependent on the accuracy of the system calibration.
[0003] Currently, the calibration of spaceborne SAR interferometric systems mainly relies on two technical approaches: one is to use prior external DEM data as a reference for geometric calibration, and the other is to use ground-based corner reflectors or a dedicated calibration field for active or passive calibration.
[0004] However, the above methods all have significant limitations in practical applications: external DEM data are often limited by the accuracy of their acquisition and the grid sampling density, making it difficult to meet the stringent requirements of high-precision interferometry for reference benchmarks; and the construction, long-term maintenance, and customization of high-precision corner reflectors of the ground calibration field not only incur huge economic costs but also have a lengthy implementation cycle. Summary of the Invention
[0005] This invention provides a satellite calibration method, apparatus, device, and storage medium to solve the problems of limited accuracy and high cost in satellite calibration.
[0006] In a first aspect, the present invention provides a satellite calibration method, comprising: The system receives multiple sets of radar data transmitted by radar satellites and uses these multiple sets of radar data to determine the initial ground elevation. Each set of radar data is the echo data received by the radar satellite at the acquisition location. The acquisition locations and viewing angles of different sets of radar data are different. Determine the elevation error influence factor of the initial ground elevation, and determine the elevation error fitting function corresponding to the elevation error influence factor, wherein the elevation error influence factor is a factor affecting the accuracy of ground elevation, and the elevation error fitting function is a function that includes the elevation error influence factor; The deviation between the initial ground elevations at different acquisition locations is determined, and the elevation error influence factor value is determined with the goal of minimizing the difference between the deviation and the elevation error fitting function value. Then, the radar satellite is calibrated based on the elevation error influence factor value.
[0007] In a second aspect, the present invention provides a satellite calibration device, comprising: The initial elevation determination module is used to receive multiple sets of radar data sent by radar satellites and use the multiple sets of radar data to determine the initial ground elevation. Each set of radar data is the echo data received by the radar satellite at the acquisition location. The acquisition locations and acquisition angles of different sets of radar data are different. The function determination module is used to determine the elevation error influence factor of the initial ground elevation and to determine the elevation error fitting function corresponding to the elevation error influence factor, wherein the elevation error influence factor is a factor affecting the accuracy of ground elevation, and the elevation error fitting function is a function that includes the elevation error influence factor. The calibration module is used to determine the deviation between the initial ground elevations of different acquisition locations, and to determine the elevation error influence factor value with the goal of minimizing the difference between the deviation and the elevation error fitting function value. Then, the radar satellite is calibrated based on the elevation error influence factor value.
[0008] Thirdly, the present invention provides an electronic device comprising: At least one processor; and memory that is communicatively connected to at least one processor; The memory stores a computer program that can be executed by at least one processor, which enables the at least one processor to perform the satellite calibration method of the first aspect described above.
[0009] Fourthly, the present invention provides a computer-readable storage medium storing computer instructions for causing a processor to execute the satellite calibration method of the first aspect described above.
[0010] The satellite calibration scheme provided by this invention acquires multiple sets of interferometric data pairs from different angles using radar, and obtains elevation error fitting functions for different acquisition locations through elevation error fitting. Then, aiming to minimize the difference between the initial ground elevation deviations at different acquisition locations and the values of the elevation error fitting functions, the elevation error influence factor is calculated. This factor value can then be used to calibrate the radar satellite. This scheme can accurately isolate the systematic error components affecting elevation accuracy, eliminate the uncertainty caused by insufficient accuracy of external data, significantly improve the elevation measurement accuracy of the spaceborne SAR interferometric system, and eliminate dependence on the ground calibration field, greatly reducing implementation costs and time. Through a data-driven multi-angle self-calibration method, it successfully bypasses the constraints of traditional calibration techniques on expensive ground facilities and low-precision external data, achieving low-cost and high-precision satellite interferometric system calibration, significantly improving the system's engineering practicality.
[0011] It should be understood that the description in this section is not intended to identify key or essential features of the invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description
[0012] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0013] Figure 1 This is a flowchart of a satellite calibration method provided in Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of radar satellite scanning waveforms provided in Embodiment 1 of the present invention; Figure 3 This is a flowchart of a satellite calibration method provided in Embodiment 2 of the present invention; Figure 4 This is a schematic diagram of error distribution provided according to Embodiment 2 of the present invention; Figure 5 This is a schematic diagram of tilt angle error distribution provided in Embodiment 2 of the present invention; Figure 6 This is a schematic diagram of phase error distribution provided in Embodiment 2 of the present invention; Figure 7 This is a schematic diagram of a satellite calibration device according to Embodiment 3 of the present invention; Figure 8 This is a schematic diagram of the structure of an electronic device provided according to Embodiment 4 of the present invention. Detailed Implementation
[0014] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.
[0015] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. In the description of this invention, unless otherwise stated, "a plurality of" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist; for example, A and / or B can represent: A alone, A and B simultaneously, and B alone. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or devices.
[0016] Example 1 Figure 1 The flowchart of a satellite calibration method provided in Embodiment 1 of the present invention is applicable to the case of calibrating satellites. The method can be executed by a satellite calibration device, which can be implemented in hardware and / or software. The satellite calibration device can be configured in an electronic device, which can be composed of two or more physical entities or a single physical entity.
[0017] like Figure 1 As shown, the satellite calibration method provided in Embodiment 1 of the present invention specifically includes the following steps: S101. Receive multiple sets of radar data sent by radar satellites, and use the multiple sets of radar data to determine the initial ground elevation respectively. Each set of radar data is the echo data received by the radar satellite at the acquisition location. The acquisition locations and acquisition angles of different sets of radar data are different.
[0018] In this embodiment, the radar satellite can be a synthetic aperture radar (SAR) satellite. The radar satellite can collect a set of echo data at each acquisition location, and the acquisition angles of different sets are different. Using this radar data, a low-precision ground elevation, i.e., the initial ground elevation, can be obtained.
[0019] S102. Determine the elevation error influence factor of the initial ground elevation, and determine the elevation error fitting function corresponding to the elevation error influence factor, wherein the elevation error influence factor is a factor affecting the accuracy of ground elevation, and the elevation error fitting function is a function that includes the elevation error influence factor.
[0020] In this embodiment, the factors affecting the accuracy of the initial ground elevation, i.e., the elevation error influence factors, can be determined first. Different elevation error influence factors correspond to different elevation error fitting functions, and the corresponding elevation error fitting function can be determined according to the type of the factor.
[0021] S103. Determine the deviation between the initial ground elevations of different acquisition locations, and with the goal of minimizing the difference between the deviation and the elevation error fitting function value, determine the elevation error influence factor value, and then calibrate the radar satellite based on the elevation error influence factor value.
[0022] In this embodiment, the deviation between the initial ground elevations at different acquisition locations can be determined first, and then the difference between the elevation error fitting function values of the initial ground elevations at different acquisition locations can be determined. With the goal of minimizing the deviation and the difference, the elevation error influence factor value is calculated. Finally, the elevation error influence factor value can be used to calibrate the radar satellite.
[0023] The technical solution of this invention involves acquiring multiple sets of interferometric data pairs from different angles using radar. Elevation error fitting functions for different acquisition locations are obtained through elevation error fitting. The goal is to minimize the difference between the initial ground elevation deviations at different acquisition locations and the values of the elevation error fitting functions, thereby calculating the elevation error influence factor. This factor value can then be used to calibrate the radar satellite. This solution accurately isolates the systematic error components affecting elevation accuracy, eliminates the uncertainty caused by insufficient accuracy of external data, significantly improves the elevation measurement accuracy of the spaceborne SAR interferometric system, and eliminates dependence on the ground calibration field, greatly reducing implementation costs and time. Through a data-driven multi-angle self-calibration method, it successfully bypasses the constraints of traditional calibration techniques, which rely on expensive ground facilities and low-precision external data, achieving low-cost and high-precision satellite interferometric system calibration and significantly improving the system's engineering practicality.
[0024] Optionally, each set of radar data includes echo data from multiple regions received by the radar satellite at the acquisition location, and the acquisition location of each set of radar data is at a different distance from the multiple regions.
[0025] For example, if the acquisition locations include a and b, and the regions include c and d, then the first set of radar data includes the echo data of c and d received by the radar satellite at a, and the second set of radar data includes the echo data of c and d received by the radar satellite at b.
[0026] Optionally, receiving multiple sets of radar data transmitted by the radar satellite includes receiving three sets of radar data transmitted by the radar satellite; wherein, the first set of radar data includes echo data of a first region, a second region, and a third region received by the radar satellite at a first acquisition position and from a first viewing angle; the second set of radar data includes echo data of a fourth region, a fifth region, and a sixth region received by the radar satellite at a second acquisition position and from a second viewing angle; and the third set of radar data includes echo data of a seventh region, an eighth region, and a ninth region received by the radar satellite at a third acquisition position and from a third viewing angle; the first acquisition position, the second acquisition position, and the third acquisition position are all different from each other; the distances from the first acquisition position to the first region, the fourth region, and the seventh region are in the order of near to far; the distances from the second acquisition position to the second region, the fifth region, and the eighth region are in the order of near to far; and the distances from the third acquisition position to the third region, the sixth region, and the ninth region are in the order of near to far; the first viewing angle, the second viewing angle, and the third viewing angle are all different from each other.
[0027] For example, Figure 2 This is a schematic diagram of a radar satellite scanning waveform. Figure 2 In the diagram, T1, T4, and T7 represent the imaging beams of the radar satellite under forward-looking conditions at the first acquisition position; T2, T5, and T8 represent the imaging beams of the radar satellite under intermediate-looking conditions at the second acquisition position; and T3, T6, and T9 represent the imaging beams of the radar satellite under back-looking conditions at the third acquisition position. T1 to T3 represent the observation center times for scanning T4, T5, and T6. Parallel rectangular blocks represent the primary and secondary stars.
[0028] Specifically, T1, T2, and T3 correspond to the first, second, and third regions, respectively; T4, T5, and T7 correspond to the fourth, fifth, and sixth regions, respectively; and T7, T8, and T9 correspond to the seventh, eighth, and ninth regions, respectively. Regions one, two, and three are near-end (irradiated) regions; regions four, five, and six are mid-end (irradiated) regions; and regions seven, eight, and nine are far-end (irradiated) regions.
[0029] Optionally, after determining the acquisition location of the radar satellite, it is also necessary to calculate the working sequence of the calibration scenario.
[0030] Specifically, this may include: Based on the principles of avoiding nadir interference and transmitted pulse interference, as well as the geometric relationship between the satellite and the scene, the pulse repetition frequency (PRF) and inter-pulse timing of each beam are obtained through the following constraints: Where i is the pulse number. The near-end slant range of each beam. The slant distance at the far end of the scene. For the protection time of sending and receiving, For launch bandwidth, denoted as nadir echo width, H as distance between the satellite and Earth, and c as speed of light.
[0031] Calculate the beam dwell time in the calibration scenario: Number of pulses per independent beam It can be much smaller than the Doppler main lobe bandwidth, i.e., the dwell time of a single beam. Much smaller than the synthetic aperture time. The dwell time of each beam is also significantly shorter. The ratio of dwell pulse number to repetition frequency (PRF): Where i represents the beam count.
[0032] Optionally, determining the initial ground elevation using the multiple sets of radar data includes: performing incomplete focusing signal processing on the multiple sets of radar data to obtain incomplete focusing data for each set of radar data, wherein the radar satellite includes a primary satellite and a secondary satellite; performing registration and resampling on the incomplete focusing data of the primary satellite and the incomplete focusing data of the secondary satellite to obtain registration data for the radar satellite; and determining the initial ground elevation for each set of radar data based on the registration data.
[0033] Specifically, after performing range-matched filtering on single-beam radar data, Doppler center correction can be performed based on satellite attitude parameters. After azimuth demodulation, a weighted Fourier transform is performed to obtain a partially focused image after complete range compression and Doppler sharpening. It can be assumed that within a short dwell time, the random phase error of a single sampled data is independently distributed across each frame in the azimuth direction; therefore, the equivalent optimization of the signal-to-random noise power ratio under partially coherent processing is... for: Then, the incompletely focused data of the primary satellite and the incompletely focused data of the secondary satellite are registered and resampled to obtain the registration data of the radar satellite. The range-axis registration amount depends on the relative value of the slant range delay between the two satellites and the pixel offset. It can be represented as: Where ΔR is the relative value of the slant range delay between the two stars. This represents the range resolution.
[0034] The azimuth registration can be expressed as the center beam position deviation along the time baseline of the flight path: in, This represents the pixel offset in the azimuth direction. Along the baseline of the flight path, This is the equivalent speed.
[0035] The interferometric elevations of each beam after resampling and registration are as follows: Where Phase is the phase extraction function and DEM is the elevation calculation function. and These represent the complex signals corresponding to the same ground target in the primary satellite registration data and the secondary satellite registration data, respectively. The above formula yields the low-precision interferometric elevation information, i.e., the initial ground elevation, for each set of registration data.
[0036] Optionally, the radar satellite includes a primary satellite and a secondary satellite, the elevation error influence factor includes at least the baseline tilt error and phase error, and the elevation error fitting function is a sinusoidal comprehensive modulation error function that includes the tilt error function and the phase error function.
[0037] Specifically, the dip and phase errors of the baseline will create a sinusoidal modulation of the interferometric elevation error on the observation slant plane: in, Baseline tilt error The resulting elevation error The sensitivity of elevation h to baseline inclination angle α, The slant distance from the primary star to the target. It is the sine of the angle of incidence. Due to interference phase error The resulting elevation error The sensitivity of elevation to phase is commonly referred to as elevation ambiguity or scaling factor. For radar wavelength, This is the effective vertical baseline.
[0038] The elevation error fitting function is a sinusoidal comprehensive modulation error function that includes the tilt error function and the phase error function, expressed as: Example 2 Figure 3 This is a flowchart of a satellite calibration method provided in Embodiment 2 of the present invention. The technical solution of the present invention is further optimized based on the above optional technical solutions, and a specific method for calibrating satellites is given.
[0039] Optionally, the step of performing non-perfect focus signal processing on the multiple sets of radar data to obtain non-perfect focus data for each set of radar data includes: if each set of radar data includes echo data from multiple regions received by the radar satellite at the acquisition location, and the acquisition location of each set of radar data is at a different distance from the multiple regions, then non-perfect focus signal processing is performed on the echo data of each region in each set of radar data to obtain non-perfect focus data; wherein, the step of determining the initial ground elevation for the registration data of each set of radar data includes: determining the initial ground elevation for the non-perfect focus data of each region in each set of radar data.
[0040] Optionally, determining the deviation between the initial ground elevations of different acquisition locations, and aiming to minimize the difference between the deviation and the elevation error fitting function value, and determining the elevation error influence factor value includes: determining the deviation between the initial ground elevations of different acquisition locations; and aiming to minimize the difference between the deviation and the corresponding elevation error fitting function value, and determining the elevation error influence factor value.
[0041] like Figure 3 As shown in Embodiment 2 of the present invention, a satellite calibration method specifically includes the following steps: S201: Receive three sets of radar data transmitted by radar satellites.
[0042] The radar data includes the following: the first set of radar data includes echo data from the first, second, and third regions received by the radar satellite at the first acquisition position from the first viewing angle; the second set of radar data includes echo data from the fourth, fifth, and sixth regions received by the radar satellite at the second acquisition position from the second viewing angle; and the third set of radar data includes echo data from the seventh, eighth, and ninth regions received by the radar satellite at the third acquisition position from the third viewing angle. The first, second, and third acquisition positions are all different. The distances from the first, fourth, and seventh regions from the first acquisition position are in the order of near to far; the distances from the second, fifth, and eighth regions from the second acquisition position are in the order of near to far; and the distances from the third, sixth, and ninth regions from the third acquisition position are in the order of near to far. The first, second, and third viewing angles are all different. The radar satellite includes a primary satellite and a secondary satellite. The elevation error influence factor includes at least the baseline tilt error and phase error. The elevation error fitting function is a sinusoidal comprehensive modulation error function that includes both tilt error and phase error functions.
[0043] S202. Perform incomplete focusing signal processing on the echo data of each region in each group of radar data to obtain incomplete focusing data.
[0044] Specifically, in the three sets of radar data mentioned above, each set of radar data includes echo data from multiple regions received by the radar satellite at the acquisition location, and the distance between the acquisition location and the multiple regions is different for each set of radar data.
[0045] S203. Register and resample the incompletely focused data of the primary satellite and the incompletely focused data of the secondary satellite to obtain the registration data of the radar satellite, and determine the initial ground elevation for the incompletely focused data of each region in each group of radar data.
[0046] S204. Determine the elevation error influence factor of the initial ground elevation, and determine the elevation error fitting function corresponding to the elevation error influence factor.
[0047] S205. Determine the deviation between the initial ground elevations of different acquisition locations; determine the elevation error influence factor value with the objective of minimizing the difference between the deviation and the corresponding elevation error fitting function value; calibrate the radar satellite based on the elevation error influence factor value.
[0048] Specifically, initial ground elevation It can be represented as: in, To provide accurate and error-free ground elevation. This is the elevation error fitting function. This includes systematic and random errors in other modulation formats.
[0049] For example, such as Figure 2 In the example shown, the deviation C between the initial ground elevations at different data collection locations can be calculated first: Wherein, the deviation C between the initial ground elevations is a known deviation value calculated from the observed values.
[0050] The difference between the elevation error fitting function values corresponding to C1 is ; The difference between the elevation error fitting function values corresponding to C2 is ; The difference between the elevation error fitting function values corresponding to C3 is .
[0051] Solve for the condition with the objective of minimizing the difference between C and F: You can get and The value of is the elevation error influence factor value.
[0052] For example, simulation experiments can be conducted on the above method, and the simulation indicators are shown in Table 1 below, including: Table 1 Simulation Indicators The distribution of tilt and phase errors can be obtained through simulation. Figure 4 This is a schematic diagram of an error distribution. Figure 4 The content shown represents the overall error distribution effect of tilt and phase errors. The left horizontal axis represents the relative position in the vertical direction of the flight path, the right horizontal axis represents the relative position in the direction of the flight path, and the vertical axis represents the ground elevation error caused by tilt and phase errors. Figure 5 The diagram shows the inclination error distribution obtained from the fitting. The horizontal axis represents the coordinates along the flight path, the vertical axis represents the inclination error, the red line represents the estimated value obtained using this method, and the black line represents the input value of this method. Figure 6 The diagram shows the phase error distribution obtained from the fitting. The horizontal axis represents the coordinates along the flight path, the vertical axis represents the phase error, the red line represents the estimated value obtained using this method, and the black line represents the input value of this method.
[0053] The satellite calibration method provided in this invention utilizes multi-view echo data acquired by the radar satellite at three different acquisition locations. In the calibration process, a comprehensive modulation error function including tilt and phase error functions is introduced. This decouples the previously intertwined and indistinguishable geometric and electrical errors, achieving precise source tracing and quantification of elevation errors. Furthermore, by constructing a system containing... and The cost function f is optimized by minimizing the inconsistency between elevation observations under different observation geometries, and the error influence factor value is solved in reverse. This mathematical processing method of "seeking accuracy through deviation" effectively suppresses the interference of systematic errors and random noise from other modulation forms, significantly improves the calculation accuracy and stability of calibration parameters, and achieves self-decoupling and self-correction of systematic errors.
[0054] Example 3 Figure 7 This is a schematic diagram of a satellite calibration device provided in Embodiment 3 of the present invention. Figure 7 As shown, the device includes: an initial elevation determination module 301, a function determination module 302, and a calibration module 303, wherein: The initial elevation determination module is used to receive multiple sets of radar data sent by radar satellites and use the multiple sets of radar data to determine the initial ground elevation. Each set of radar data is the echo data received by the radar satellite at the acquisition location. The acquisition locations and acquisition angles of different sets of radar data are different. The function determination module is used to determine the elevation error influence factor of the initial ground elevation and to determine the elevation error fitting function corresponding to the elevation error influence factor, wherein the elevation error influence factor is a factor affecting the accuracy of ground elevation, and the elevation error fitting function is a function that includes the elevation error influence factor. The calibration module is used to determine the deviation between the initial ground elevations of different acquisition locations, and to determine the elevation error influence factor value with the goal of minimizing the difference between the deviation and the elevation error fitting function value. Then, the radar satellite is calibrated based on the elevation error influence factor value.
[0055] The satellite calibration device provided in this invention acquires multiple sets of interferometric data pairs from different angles using radar, and obtains elevation error fitting functions for different acquisition locations through elevation error fitting. Then, aiming to minimize the difference between the initial ground elevation deviations at different acquisition locations and the values of the elevation error fitting functions, the elevation error influence factor is calculated. This factor value can then be used to calibrate the radar satellite. This device can accurately isolate systematic error components affecting elevation accuracy, eliminate the uncertainty caused by insufficient accuracy of external data, significantly improve the elevation measurement accuracy of the spaceborne SAR interferometric system, and eliminate dependence on the ground calibration field, greatly reducing implementation costs and time. Through a data-driven multi-angle self-calibration method, it successfully bypasses the constraints of traditional calibration techniques on expensive ground facilities and low-precision external data, achieving low-cost and high-precision satellite interferometric system calibration, significantly improving the system's engineering practicality.
[0056] Optionally, each set of radar data includes echo data from multiple regions received by the radar satellite at the acquisition location, and the acquisition location of each set of radar data is at a different distance from the multiple regions.
[0057] Optionally, the initial elevation determination module includes: The data receiving unit is used to receive three sets of radar data transmitted by a radar satellite. The first set of radar data includes echo data from a first region, a second region, and a third region received by the radar satellite at a first acquisition position and from a first viewing angle. The second set of radar data includes echo data from a fourth region, a fifth region, and a sixth region received by the radar satellite at a second acquisition position and from a second viewing angle. The third set of radar data includes echo data from a seventh region, an eighth region, and a ninth region received by the radar satellite at a third acquisition position and from a third viewing angle. The first, second, and third acquisition positions are all different. The distances from the first, fourth, and seventh regions from the first acquisition position are in the order of near to far; the distances from the second, fifth, and eighth regions from the second acquisition position are in the order of near to far; and the distances from the third, sixth, and ninth regions from the third acquisition position are in the order of near to far. The first, second, and third viewing angles are all different.
[0058] Optionally, the initial elevation determination module includes: A processing unit is used to perform incomplete focusing signal processing on the multiple sets of radar data to obtain incomplete focusing data for each set of radar data, wherein the radar satellite includes a primary satellite and a secondary satellite; The registration unit is used to register and resample the incompletely focused data of the primary satellite and the incompletely focused data of the secondary satellite to obtain the registration data of the radar satellite. The initial elevation determination unit is used to determine the initial ground elevation for each set of radar data registration data.
[0059] Furthermore, the step of performing non-perfectly focused signal processing on the multiple sets of radar data to obtain non-perfectly focused data for each set of radar data includes: if each set of radar data includes echo data from multiple regions received by the radar satellite at the acquisition location, and the acquisition location of each set of radar data is at a different distance from the multiple regions, then non-perfectly focused signal processing is performed on the echo data of each region in each set of radar data to obtain non-perfectly focused data; wherein, the step of determining the initial ground elevation for the registration data of each set of radar data includes: determining the initial ground elevation for the non-perfectly focused data of each region in each set of radar data.
[0060] Optionally, the radar satellite includes a primary satellite and a secondary satellite, the elevation error influence factor includes at least the baseline tilt error and phase error, and the elevation error fitting function is a sinusoidal comprehensive modulation error function that includes the tilt error function and the phase error function.
[0061] Optional, the calibration module includes: The deviation determination unit is used to determine the deviation between the initial ground elevations at different acquisition locations; The influence determination unit is used to determine the elevation error influence factor value with the objective of minimizing the difference between the deviation and the corresponding elevation error fitting function value.
[0062] The satellite calibration device provided in the embodiments of the present invention can execute the satellite calibration method provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the execution method.
[0063] Example 4 Figure 8 A schematic diagram of an electronic device 40 that can be used to implement embodiments of the present invention is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices (e.g., helmets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the invention described and / or claimed herein.
[0064] like Figure 8 As shown, the electronic device 40 includes at least one processor 41 and a memory, such as a read-only memory (ROM) 42 or a random access memory (RAM) 43, communicatively connected to the at least one processor 41. The memory stores computer programs executable by the at least one processor. The processor 41 can perform various appropriate actions and processes based on the computer program stored in the ROM 42 or loaded from storage unit 48 into the RAM 43. The RAM 43 may also store various programs and data required for the operation of the electronic device 40. The processor 41, ROM 42, and RAM 43 are interconnected via a bus 44. An input / output (I / O) interface 45 is also connected to the bus 44.
[0065] Multiple components in electronic device 40 are connected to I / O interface 45, including: input unit 46, such as keyboard, mouse, etc.; output unit 47, such as various types of monitors, speakers, etc.; storage unit 48, such as disk, optical disk, etc.; and communication unit 49, such as network card, modem, wireless transceiver, etc. Communication unit 49 allows electronic device 40 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.
[0066] Processor 41 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of processor 41 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. Processor 41 performs the various methods and processes described above, such as satellite calibration methods.
[0067] In some embodiments, the satellite calibration method may be implemented as a computer program tangibly contained in a computer-readable storage medium, such as storage unit 48. In some embodiments, part or all of the computer program may be loaded and / or mounted on electronic device 40 via ROM 42 and / or communication unit 49. When the computer program is loaded into RAM 43 and executed by processor 41, one or more steps of the satellite calibration method described above may be performed. Alternatively, in other embodiments, processor 41 may be configured to perform the satellite calibration method by any other suitable means (e.g., by means of firmware).
[0068] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), system-on-a-chip (SoC) systems, complex programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.
[0069] Computer programs used to implement the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when executed by the processor, the computer programs cause the functions / operations specified in the flowcharts and / or block diagrams to be performed. The computer programs may be executed entirely on a machine, partially on a machine, or as a standalone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.
[0070] The computer equipment provided above can be used to execute the satellite calibration method provided in any of the above embodiments, and has the corresponding functions and beneficial effects.
[0071] Example 5 In the context of this invention, a computer-readable storage medium may be a tangible medium, wherein the computer-executable instructions, when executed by a computer processor, are used to perform a satellite calibration method, the method comprising: The system receives multiple sets of radar data transmitted by radar satellites and uses these multiple sets of radar data to determine the initial ground elevation. Each set of radar data is the echo data received by the radar satellite at the acquisition location. The acquisition locations and viewing angles of different sets of radar data are different. Determine the elevation error influence factor of the initial ground elevation, and determine the elevation error fitting function corresponding to the elevation error influence factor, wherein the elevation error influence factor is a factor affecting the accuracy of ground elevation, and the elevation error fitting function is a function that includes the elevation error influence factor; The deviation between the initial ground elevations at different acquisition locations is determined, and the elevation error influence factor value is determined with the goal of minimizing the difference between the deviation and the elevation error fitting function value. Then, the radar satellite is calibrated based on the elevation error influence factor value.
[0072] In the context of this invention, a computer-readable storage medium can be a tangible medium that may contain or store a computer program for use by, or in conjunction with, an instruction execution system, apparatus, or device. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination thereof. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.
[0073] The computer equipment provided above can be used to execute the satellite calibration method provided in any of the above embodiments, and has the corresponding functions and beneficial effects.
[0074] It is worth noting that in the above-described embodiments of the satellite calibration device, the various units and modules included are only divided according to functional logic, but are not limited to the above division, as long as the corresponding functions can be achieved; in addition, the specific names of each functional unit are only for easy differentiation and are not used to limit the scope of protection of the present invention.
[0075] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.
Claims
1. A satellite calibration method, characterized in that, include: The system receives multiple sets of radar data transmitted by radar satellites and uses these multiple sets of radar data to determine the initial ground elevation. Each set of radar data is the echo data received by the radar satellite at the acquisition location. The acquisition locations and viewing angles of different sets of radar data are different. Determine the elevation error influence factor of the initial ground elevation, and determine the elevation error fitting function corresponding to the elevation error influence factor, wherein the elevation error influence factor is a factor affecting the accuracy of ground elevation, and the elevation error fitting function is a function that includes the elevation error influence factor; The deviation between the initial ground elevations at different acquisition locations is determined, and the elevation error influence factor value is determined with the goal of minimizing the difference between the deviation and the elevation error fitting function value. Then, the radar satellite is calibrated based on the elevation error influence factor value.
2. The method according to claim 1, characterized in that, Each set of radar data includes echo data from multiple regions received by the radar satellite at the acquisition location, and the acquisition location of each set of radar data is at a different distance from the multiple regions.
3. The method according to claim 1 or 2, characterized in that, The multiple sets of radar data received from the radar satellite include: Receives three sets of radar data transmitted by radar satellites; The radar data consists of three sets: a first set of radar data including echo data from a first acquisition position and a first viewing angle of a first region; a second set of radar data including echo data from a second acquisition position and a second viewing angle of a fourth region; and a third set of radar data including echo data from a third acquisition position and a third viewing angle of a seventh region, an eighth region, and a ninth region. The first, second, and third acquisition positions are all different from each other. The distances from the first, fourth, and seventh regions from the first acquisition position are in the order of near to far; the distances from the second, fifth, and eighth regions from the second acquisition position are in the order of near to far; and the distances from the third, sixth, and ninth regions from the third acquisition position are in the order of near to far. The first, second, and third viewing angles are all different from each other.
4. The method according to claim 1, characterized in that, The process of determining the initial ground elevation using the multiple sets of radar data includes: The multiple sets of radar data are subjected to incomplete focusing signal processing to obtain incomplete focusing data for each set of radar data, wherein the radar satellite includes a primary satellite and a secondary satellite; The incompletely focused data of the primary satellite and the incompletely focused data of the secondary satellite are registered and resampled to obtain the registration data of the radar satellite; The initial ground elevation was determined for each set of radar data registration data.
5. The method according to claim 4, characterized in that, The process of performing non-perfectly focused signal processing on the multiple sets of radar data to obtain non-perfectly focused data for each set of radar data includes: If each set of radar data includes echo data from multiple regions received by the radar satellite at the acquisition location, and the acquisition location of each set of radar data is at a different distance from the multiple regions, then non-perfectly focused signal processing is performed on the echo data of each region in each set of radar data to obtain non-perfectly focused data. The process of determining the initial ground elevation for each set of radar data registration data includes: The initial ground elevation is determined for each region of the incompletely focused data in each set of radar data.
6. The method according to claim 1, characterized in that, The radar satellite includes a primary satellite and a secondary satellite. The elevation error influence factor includes at least the baseline tilt error and phase error. The elevation error fitting function is a sinusoidal comprehensive modulation error function that includes the tilt error function and the phase error function.
7. The method according to claim 1, 2, or 5, characterized in that, The process of determining the deviation between the initial ground elevations at different acquisition locations, and aiming to minimize the difference between the deviation and the elevation error fitting function value, includes determining the elevation error influence factor value, including: Determine the deviation between the initial ground elevations at different data collection locations; The elevation error influence factor value is determined with the goal of minimizing the difference between the deviation and the corresponding elevation error fitting function value.
8. A satellite calibration device, characterized in that, include: The initial elevation determination module is used to receive multiple sets of radar data sent by radar satellites and use the multiple sets of radar data to determine the initial ground elevation. Each set of radar data is the echo data received by the radar satellite at the acquisition location. The acquisition locations and acquisition angles of different sets of radar data are different. The function determination module is used to determine the elevation error influence factor of the initial ground elevation and to determine the elevation error fitting function corresponding to the elevation error influence factor, wherein the elevation error influence factor is a factor affecting the accuracy of ground elevation, and the elevation error fitting function is a function that includes the elevation error influence factor. The calibration module is used to determine the deviation between the initial ground elevations of different acquisition locations, and to determine the elevation error influence factor value with the goal of minimizing the difference between the deviation and the elevation error fitting function value. Then, the radar satellite is calibrated based on the elevation error influence factor value.
9. An electronic device, characterized in that, The electronic device includes: At least one processor; and a memory communicatively connected to the at least one processor; The memory stores a computer program that can be executed by the at least one processor, which is then executed by the at least one processor to enable the at least one processor to perform the satellite calibration method according to any one of claims 1-7.
10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions that cause a processor to execute the satellite calibration method according to any one of claims 1-7.