Method and system for measuring the flight movement of a spacecraft in a target airspace

Abstract

The application discloses a kind of target airspace in the process of spacecraft flight movement measurement method and system, it is related to deep space measurement technical field, method includes: in the preset time period, real-time determination with target region as bottom surface and with target ground-based antenna as vertex solid cone in target airspace, obtain the target airspace of each preset time in the preset time period, in the preset time period, control target ground-based antenna to reference point is tracked;In the tracking process, at each preset time, the downlink signal of spacecraft in target airspace is tracked and measured by target ground-based antenna, and the downlink signal measured by tracking is processed, and the flight movement data of spacecraft is obtained.The application can complete the radio open-loop measurement of spacecraft flight movement process in target airspace, and the flight state of spacecraft can be further evaluated according to the obtained flight movement data.

Description

Technical Field

[0001] This invention relates to the field of deep space measurement technology, and in particular to a method and system for measuring the flight motion of a spacecraft within a target airspace. Background Technology

[0002] For measuring the motion of spacecraft in orbit, common techniques include ground-based radar measurement and ground-based / space-based optical measurement. However, both ground-based radar and ground-based / space-based optical measurements face numerous challenges and limitations in practical applications. Ground-based radar measurement suffers from limitations such as limited range, high operating costs, poor timeliness, and low measurement sensitivity. Specifically:

[0003] Ground-based optical measurements are significantly affected by weather conditions and are typically only available during dawn, dusk, and night, limiting their operational time. For spacecraft measurements in lunar gravitational space, when the observed spacecraft is far away, it is difficult to rapidly measure information such as orbital maneuvers and attitude adjustments using ground-based optical methods. Spacecraft in orbit almost always transmit downlink signals during orbital maneuvers and attitude adjustments to monitor the effects of these maneuvers in real time. This provides the necessary conditions for measuring the orbital and attitude changes of target spacecraft using ground-based radio measurements. Spacecraft measurements targeting a specific region of interest on the Moon have important applications, such as determining whether a spacecraft is performing lunar landings or orbital maneuvers within that area—invaluable information.

[0004] In summary, how to use relevant design schemes and methods to measure the flight motion of spacecraft in the target airspace is a technical issue worthy of in-depth research. Summary of the Invention

[0005] The technical problem to be solved by this invention is to address the shortcomings of existing technologies, specifically by providing a method and system for measuring the flight motion of a spacecraft within a target airspace, as detailed below:

[0006] 1) In a first aspect, the present invention provides a method for measuring the flight motion of a spacecraft within a target airspace, the specific technical solution of which is as follows:

[0007] Within a preset time period, the target airspace within a three-dimensional cone with the target area as the base and the target ground-based antenna as the vertex is determined in real time, and the target airspace at each preset moment within the preset time period is obtained. The target area is the beam coverage area calculated based on the beamwidth of the target ground-based antenna, and the center of the beam coverage area is the reference point selected on the moon.

[0008] Within a preset time period, control the target ground-based antenna to track the reference point;

[0009] During the tracking process, at each preset time, the downlink signal of the spacecraft in the target airspace is tracked and measured through the target ground-based antenna, and the tracked and measured downlink signal is processed to obtain the spacecraft's flight motion data.

[0010] The beneficial effects of the method for measuring the flight motion of a spacecraft within a target airspace provided by this invention are as follows:

[0011] During the process of controlling the target ground-based antenna to track the reference point, the downlink signal of the spacecraft in the target airspace is tracked and measured by the target ground-based antenna. This enables the completion of open-loop radio measurement of the spacecraft's flight motion process in the target airspace. Based on the obtained flight motion data, the flight status of the spacecraft can be further evaluated.

[0012] Based on the above scheme, the method for measuring the flight motion process of a spacecraft in the target airspace of the present invention can be further improved as follows.

[0013] Furthermore, within a preset time period, the target ground-based antenna is controlled to track the reference point, including:

[0014] Based on the position of the target ground-based antenna at each preset time and the position of the reference point at each preset time within a preset time period, the azimuth and elevation angles of the target ground-based antenna at each preset time are calculated.

[0015] Based on the azimuth and elevation angles of the target ground-based antenna at each preset time, control the target ground-based antenna to track the reference point.

[0016] Furthermore, the position of the target ground-based antenna is characterized by its coordinates in the Earth-fixed coordinate system, and the position of the reference point is characterized by its coordinates in the Moon-fixed coordinate system.

[0017] Furthermore, the downlink signals detected by tracking are processed, including:

[0018] An open-loop velocity measurement analysis method is used to process the downlink signal that has been tracked and measured, and to generate frequency detection results and carrier-to-noise ratio detection results of the spacecraft with matching time stamps.

[0019] 2) In a second aspect, the present invention also provides a measurement system for the flight motion process of a spacecraft within a target airspace, the specific technical solution of which is as follows:

[0020] It includes a target airspace determination module, a tracking module, a tracking measurement module, and a signal processing module;

[0021] The target airspace determination module is used to: determine the target airspace within a three-dimensional cone with the target area as the base and the target ground-based antenna as the vertex in real time within a preset time period, and obtain the target airspace at each preset moment within the preset time period. The target area is the beam coverage area calculated based on the beamwidth of the target ground-based antenna, and the center of the beam coverage area is the reference point selected on the moon.

[0022] The tracking module is used to control the target ground-based antenna to track the reference point within a preset time period;

[0023] The tracking and measurement module is used to: during the tracking process, at each preset time, track and measure the downlink signal of the spacecraft in the target airspace through the target ground-based antenna;

[0024] The signal processing module is used to process the downlink signals measured by tracking to obtain the spacecraft's flight motion data.

[0025] Based on the above scheme, the measurement system for the flight motion process of a spacecraft in the target airspace of the present invention can be further improved as follows.

[0026] Furthermore, the tracking module is specifically used for:

[0027] Based on the position of the target ground-based antenna at each preset time and the position of the reference point at each preset time within a preset time period, the azimuth and elevation angles of the target ground-based antenna at each preset time are calculated.

[0028] Based on the azimuth and elevation angles of the target ground-based antenna at each preset time, control the target ground-based antenna to track the reference point.

[0029] Furthermore, the position of the target ground-based antenna is characterized by its coordinates in the Earth-fixed coordinate system, and the position of the reference point is characterized by its coordinates in the Moon-fixed coordinate system.

[0030] Furthermore, the signal processing module is specifically used to: use an open-loop velocity analysis method to process the downlink signal that has been tracked and measured, and generate the spacecraft's frequency detection results and carrier-to-noise ratio detection results with matching time stamps.

[0031] 3) In a third aspect, the present invention also provides an electronic device, the electronic device including a processor coupled to a memory, the memory storing at least one computer program, the at least one computer program being loaded and executed by the processor, so that the electronic device realizes the method for measuring the flight motion process of a spacecraft in any of the above-mentioned target airspace.

[0032] 4) In a fourth aspect, the present invention also provides a computer-readable storage medium storing a computer program, wherein when the computer program is executed by a processor, a method for measuring the flight motion process of a spacecraft within the airspace of any of the above objectives is implemented.

[0033] It should be noted that the beneficial effects of the technical solutions of the second to fourth aspects of the present invention and their corresponding possible implementations can be found in the above description of the technical effects of the first aspect and its corresponding possible implementations, and will not be repeated here. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below:

[0035] Figure 1 This is a flowchart illustrating a method for measuring the flight motion of a spacecraft within a target airspace, according to an embodiment of the present invention.

[0036] Figure 2 A flowchart for the acquisition and recording of downlink signals from spacecraft within the target airspace;

[0037] Figure 3 A flowchart illustrating the process of tracking and measuring downlink signals;

[0038] Figure 4 A flowchart illustrating the process of spacecraft flight status assessment;

[0039] Figure 5 This is a schematic diagram of the structure of a measurement system for the flight motion process of a spacecraft within a target airspace, according to an embodiment of the present invention.

[0040] Figure 6 This is a schematic diagram of the structure of an electronic device according to an embodiment of the present invention. Detailed Implementation

[0041] The principles and features of the present invention are described below. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0042] The technical solution of the present invention and how the technical solution of the present invention solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of the present invention will now be described with reference to the accompanying drawings.

[0043] like Figure 1 As shown in the figure, a method for measuring the flight motion of a spacecraft within a target airspace according to an embodiment of the present invention includes the following steps:

[0044] S1. Within a preset time period, the target airspace within a three-dimensional cone with the target area as the base and the target ground-based antenna as the vertex is determined in real time, and the target airspace at each preset moment within the preset time period is obtained. The target area is the beam coverage area calculated based on the beamwidth of the target ground-based antenna, and the center of the beam coverage area is the reference point selected on the moon.

[0045] S2. Within a preset time period, control the target ground-based antenna to track the reference point;

[0046] S3. During the tracking process, at each preset time, the downlink signal of the spacecraft in the target airspace is tracked and measured through the target ground-based antenna, and the tracked and measured downlink signal is processed to obtain the spacecraft's flight motion data.

[0047] Optionally, in S2, within a preset time period, the target ground-based antenna is controlled to track the reference point, including:

[0048] S20. Based on the position of the target ground antenna at each preset time and the position of the reference point at each preset time within the preset time period, calculate the azimuth and elevation angles of the target ground antenna at each preset time.

[0049] S21. Based on the azimuth and elevation angles of the target ground antenna at each preset time, control the target ground antenna to track the reference point.

[0050] Optionally, in the above technical solution, the position of the target ground-based antenna is characterized by the coordinates of the target ground-based antenna in the Earth-fixed coordinate system, and the position of the reference point is characterized by the coordinates of the reference point in the lunar-fixed coordinate system.

[0051] Optionally, in S3, the downlink signal measured by tracking is processed, including:

[0052] S30. An open-loop velocity measurement analysis method is used to process the downlink signal that has been tracked and measured, and to generate the spacecraft's frequency detection results and carrier-to-noise ratio detection results with matching time stamps.

[0053] The following embodiments illustrate a method for measuring the flight motion of a spacecraft within a target airspace, specifically including the following steps:

[0054] S101. Select a reference point on the lunar surface:

[0055] A reference point can be selected from the key areas of interest. For example, the reference point could be a crater, or it could be the predetermined landing location of any lunar spacecraft known in advance. The position of the reference point can be represented by its coordinates in the lunar-fixed coordinate system.

[0056] S102. Determine the target ground-based antenna:

[0057] According to the work plan of the ground-based antenna resources, the ground-based antenna that can be called up within the specified time period is selected as the target ground-based antenna. It should be noted that when there are multiple ground-based antennas that can be called up within the target working time period, one ground-based antenna is selected as the target ground-based antenna. The position of the target ground-based antenna is represented by the coordinates of the target ground-based antenna in the ground-fixed coordinate system.

[0058] S103. Determine the target airspace for each preset time, specifically including:

[0059] S1030. Calculate the beam coverage area based on the beamwidth of the target ground-based antenna, specifically:

[0060] During the design of radio measurements in the target airspace (also known as the designated lunar airspace), it is necessary to estimate the beamwidth of the target ground-based antenna in order to determine whether the spacecraft signal in the target airspace is within the antenna beamwidth range (beam coverage area).

[0061] The half-beamwidth of the target ground-based antenna is calculated using the first formula, which is:

[0062]

[0063] Where, θ 0.5 λ is the half-beamwidth of the target ground-based antenna in degrees, λ is the wavelength of the radio frequency signal received by the target ground-based antenna in meters, and D is the antenna aperture of the target ground-based antenna in meters.

[0064] S1031, Based on the half-beamwidth θ of the target ground-based antenna 0.5 The Earth-Moon distance (the distance between the Earth and the Moon) allows us to calculate the beam coverage area of ​​the target ground-based antenna on the Moon. The center of the beam coverage area is a reference point selected on the Moon. The beam coverage area can be a region on the lunar surface or a planar region on the lunar cross-section obtained with the reference point as the tangent point.

[0065] For example, when the beamwidth of the target ground-based antenna is 0.066° and the radio frequency signal received by the target ground-based antenna belongs to the X-band, the beam coverage area of ​​the target ground-based antenna with a radius of about 220km centered on the crater can be calculated. For the S-band, the beam coverage area of ​​the target ground-based antenna with a radius of about 820km centered on the Atlas crater can be calculated.

[0066] The duration between two adjacent preset times can be set according to the actual situation. The shorter the duration, the higher the accuracy of the target ground antenna in tracking the reference point. The longer the duration, the lower the accuracy of the target ground antenna in tracking the reference point. Combining S1030 and S1031, the target airspace at each preset time within the preset time period can be obtained.

[0067] S104. Generate ground-based antenna boot file:

[0068] Based on the transformation relationship between the Earth-fixed coordinate system and the Moon-fixed coordinate system, and combined with the rotation laws of the Earth and the Moon, the azimuth and elevation angles of the target ground-based antenna at each preset time are calculated, thereby obtaining the ground-based antenna guidance file (the ground-based antenna guidance file includes the azimuth and elevation angles of the target ground-based antenna at each preset time).

[0069] The lunar-fixed coordinate system includes the principal axes (PA) and the mean-earth / mean-rotation frame (MER). The invention adopts the principal axes coordinate system. The vector r in the lunar-fixed coordinate system... PA Vector r in Earth-fixed coordinate system J2000 The transformation relationship between the Earth-fixed coordinate system and the Moon-fixed coordinate system is established using Euler angles. The three Euler angles corresponding to the Moon's rotation are obtained through numerical integration. The transformation relationship between the Earth-fixed coordinate system and the Moon-fixed coordinate system is as follows:

[0070] r J2000 =R3(90°+α0)R1(90°-β0)R3(W)r PA

[0071] Where W represents the difference in longitude between the intersection of the lunar equator and the zero-degree meridian at the current moment and the intersection with the ICRF equatorial plane, and α0 and β0 represent the right ascension and declination of the lunar axis poles, respectively.

[0072] The lunar-fixed coordinate system and the Earth-fixed coordinate system involve the geocentric coordinates of the Moon, which can be obtained in two ways: one is through a high-precision numerical ephemeris, and the other is through a lower-precision analytical ephemeris. The guidance method in this invention obtains the geocentric coordinates of the Moon through a numerical ephemeris, and then translates the Earth-fixed coordinate system to the lunar-fixed coordinate system. Specifically, the Earth-fixed coordinate system is corrected for precession and nutation to obtain an instantaneous true equatorial coordinate system. Then, the X-axis of the instantaneous true equatorial coordinate system is rotated around the Z-axis by one Greenwich Mean Time (GMT) to obtain a quasi-Earth-fixed coordinate system. Finally, polar motion correction is applied to obtain the coordinate data of the lunar reference point used for guidance in the Earth-fixed coordinate system.

[0073] S105. According to the ground-based antenna guidance file, control the target ground-based antenna to track the reference point. During the tracking process, at each preset time, track and measure the downlink signal of the spacecraft in the target airspace through the target ground-based antenna, and process the tracked and measured downlink signal to obtain the spacecraft's flight motion data.

[0074] In this process, multiple channels are set up in the target ground-based antenna's frequency band according to the frequency band coverage matching relationship, enabling the target ground-based antenna to passively receive downlink signals (which can be radio signals) from spacecraft within the target area. Downlink signals from spacecraft in the target airspace are acquired and recorded using acquisition and recording equipment adapted to the target ground-based antenna. The center frequency, sampling bandwidth, quantization bits, and acquisition channels of the target ground-based antenna can be set according to actual conditions. The downlink signal recording format can refer to standard VLBI scientific receivers, ensuring that the frequency band range of the multiple channels covers the ITU-recommended deep space X-band range of 8.4 GHz to 8.5 GHz and S-band range of 2.2 GHz to 2.3 GHz, and the number of acquisition channels is set in conjunction with specified prior information.

[0075] The process for acquiring and recording downlink signals from spacecraft within the target airspace is as follows: Figure 2 As shown, it specifically includes:

[0076] The parameters of the ground antenna acquisition and recording equipment are set based on prior arc-segment time information, prior frequency information, and specified frequency band coverage analysis. The prior arc-segment time information is determined based on the visibility period of the spacecraft from the ground antenna. The prior frequency information is determined by the pre-established downlink signal frequency information of the spacecraft. The specified frequency band coverage analysis considers full-band or key-band coverage of the pre-established downlink signal frequencies of the spacecraft. If prior frequency information is unavailable, multi-channel acquisition is used to cover as wide a frequency range as possible to ensure reception of downlink signals from spacecraft within the target airspace. Specific parameter settings for the ground antenna acquisition and recording equipment include: center frequency, sampling bandwidth, quantization bit depth, and number of signal acquisition channels. For example, for observation of a lunar lander, four channels can be used. The center frequency covers the lander's main carrier frequency, subcarrier frequency, and two sets of DOR frequencies. Considering the Doppler motion relationship between the lander and the ground-based antenna, an on setting of 200kHz is used. Considering the impact of the signal recording quantization bit depth on measurement signal processing, an 8-bit quantization setting is used. Finally, according to the preset observation time, the downlink signals of the spacecraft were collected and recorded according to the above-mentioned ground antenna acquisition and recording equipment parameter settings.

[0077] The process of processing the downlink signal obtained through tracking and measurement involves using spectrum analysis to screen out channel signals with downlink signals within the observation arc. These signals are then analyzed, with a focus on using open-loop velocimetry analysis to acquire frequency and carrier-to-noise ratio (CNR) values, generating spacecraft frequency and CNR detection results with matched time stamps. The most crucial information in this open-loop velocimetry is the reconstruction of the local model signal based on the frequency estimation results obtained from the carrier signal spectrum analysis. This reconstruction is then cross-correlated with the received signal to obtain the residual correlation phase, and subsequently the residual frequency, resulting in a high-precision open-loop measurement frequency estimation result. The specific process of signal processing using the open-loop velocimetry analysis method is as follows: Figure 3 As shown, specifically:

[0078] ① Read in the downlink signal that has been tracked and measured, and perform format parsing on the acquired and recorded spacecraft downlink signal according to the standard VLBI scientific receiver (VSR) format;

[0079] ② Fourier Transform Coarse Estimation: Perform Fourier transform on the tracked downlink signal and use the mature Fast Fourier Transform (FFT) algorithm to extract the carrier frequency of the spacecraft's downlink carrier signal;

[0080] ③CZT spectrum refinement: The signal obtained in ② is subjected to linear frequency modulation Z-transform (CZT) spectrum refinement. The general CZT algorithm is used to obtain the carrier frequency result with higher frequency resolution. At the same time, the carrier frequency at the maximum amplitude is found based on the CZT method. Then, the general carrier-to-noise ratio estimation method is used to obtain the carrier-to-noise ratio detection result of the signal with matching time scale.

[0081] ④ Signal processing segmentation: The signal obtained in ③ is segmented according to time. It is generally recommended to use 5, 10 or 20 segments.

[0082] ⑤ Generating a piecewise latency model from frequency: A piecewise latency model can be obtained by fitting the latency using the least squares polynomial method.

[0083]

[0084] in, Let K be the time delay rate fitting model for the i-th signal segment, where K is the number of signal segments, i represents the count of the sub-segments, and t is the time delay rate fitting model for the i-th signal segment. i Δf represents the time scale of the i-th signal segment. i Let f be the differential frequency of the i-th signal segment, i.e., the carrier frequency estimate obtained by the CZT algorithm. czt Subtract the spacecraft's downlink theoretical frequency f sky , where n is the least squares fitting order, p1, p2, ..., p n+1The coefficients are the fitting coefficients, and min indicates the calculation of the least squares value.

[0085] ⑥ Integrate to obtain the piecewise delay model, which is as follows:

[0086]

[0087] ⑦ Reconstruct the local signal model. The mathematical expression for the reconstructed local model signal is:

[0088] y cons (t i )=cos(2πf sky (t i -τ(t i ))-2πf loc t i )

[0089] Among them, y cons (t i f represents the locally reconstructed signal of the i-th segment of the signal. sky f is the theoretical downlink frequency of the spacecraft. loc Let τ(t) be the local oscillator frequency of the station. i () represents the latency model obtained.

[0090] ⑧ Cross-correlation phase generation and linearization detection: Cross-correlation calculation is performed between the local signal model and the carrier signal actually received by the station. The correlation phase φ with the maximum number of frequency values ​​in the cross-correlation spectrum is calculated. max Each relevant phase is arranged according to time.

[0091] ⑨ Obtaining the residual frequency of the signal: residual frequency f res By analyzing the cross-correlation phase φ max Obtained by least squares linear fitting.

[0092] ⑩ Signal carrier frequency acquisition: The estimated spacecraft wave frequency is equal to the residual frequency plus the model frequency. The model frequency is the carrier frequency at the midpoint time mark during each FFT operation.

[0093] Doppler frequency estimation: The Doppler frequency is equal to the estimated spacecraft wave frequency minus the theoretical downlink frequency of the spacecraft, thus obtaining the Doppler frequency detection result with a matching time scale.

[0094] S106, Spacecraft flight status assessment, such as Figure 4 As shown:

[0095] ① Read in the spacecraft's external frequency measurement results and the spacecraft's external signal carrier-to-noise ratio results. Both the spacecraft's external frequency measurement results and the signal carrier-to-noise ratio results are obtained from the above signal processing procedure.

[0096] ② External frequency differential processing. Based on the spacecraft's external frequency measurement results, external frequency differential processing is performed. The differential processing process involves calculating the difference between the external carrier frequency values ​​at consecutive time points (e.g., 1 second apart), i.e., subtracting the frequency of the previous time point from the frequency of the later time point. If the spacecraft undergoes orbital changes or attitude adjustments during this process, these will be highlighted through differential frequency processing.

[0097] ③ Spectrum analysis and periodic feature extraction. Spectrum analysis and periodic feature extraction are performed on the external frequency differential processing results and the spacecraft external signal carrier-to-noise ratio results, respectively. Obvious spectral line structures are identified from the spectrum analysis. If obvious spectral line results exist in the spectrum, it indicates that the spacecraft's motion is periodic. Its periodic features are extracted, and the reciprocal of the frequency corresponding to the strongest spectral line in the spectrum is obtained. Then, the spacecraft's attitude and orbital periodic changes are detected and evaluated.

[0098] ④ Based on the carrier-to-noise ratio (CNR) and frequency results of the spacecraft's external measurement signals, the measurement characteristics are matched with the empirical flight motion state. For example, a rapid change in frequency or CNR within a short period of time may correspond to a spacecraft orbital maneuver, while a periodic change in frequency or CNR may correspond to a spacecraft attitude adjustment.

[0099] ⑤ Based on the results of attitude and orbital period change detection and evaluation, and the matching results of measurement characteristics with experienced flight motion states, a comprehensive assessment and judgment of the spacecraft's flight status is conducted.

[0100] In the above embodiments, although the steps are numbered S1, S2, etc., they are only specific embodiments given by the present invention. Those skilled in the art can adjust the execution order of S1, S2, etc. according to the actual situation, which is also within the protection scope of the present invention. It can be understood that in some embodiments, some or all of the above embodiments may be included.

[0101] like Figure 5 As shown, an embodiment of the present invention provides a measurement system 200 for the flight motion process of a spacecraft within a target airspace, comprising a target airspace determination module 201, a tracking module 202, a tracking measurement module 203, and a signal processing module 204.

[0102] The target airspace determination module 201 is used to: determine the target airspace within a three-dimensional cone with the target area as the base and the target ground antenna as the vertex in real time within a preset time period, and obtain the target airspace at each preset moment within the preset time period. The target area is: the beam coverage area calculated based on the beamwidth of the target ground antenna, and the center of the beam coverage area is the reference point selected on the moon.

[0103] The tracking module 202 is used to: control the target ground-based antenna to track the reference point within a preset time period;

[0104] The tracking and measurement module 203 is used to: during the tracking process, at each preset time, track and measure the downlink signal of the spacecraft in the target airspace through the target ground-based antenna;

[0105] The signal processing module 204 is used to process the downlink signals measured by tracking to obtain the spacecraft's flight motion data.

[0106] Optionally, in the above technical solution, the tracking module 203 is specifically used for:

[0107] Based on the position of the target ground-based antenna at each preset time and the position of the reference point at each preset time within a preset time period, the azimuth and elevation angles of the target ground-based antenna at each preset time are calculated.

[0108] Based on the azimuth and elevation angles of the target ground-based antenna at each preset time, control the target ground-based antenna to track the reference point.

[0109] Optionally, in the above technical solution, the position of the target ground-based antenna is characterized by the coordinates of the target ground-based antenna in the Earth-fixed coordinate system, and the position of the reference point is characterized by the coordinates of the reference point in the lunar-fixed coordinate system.

[0110] Optionally, in the above technical solution, the signal processing module 204 is specifically used to: process the downlink signal tracked and measured by adopting an open-loop velocity analysis method to generate the spacecraft's frequency detection result and carrier-to-noise ratio detection result with matching time stamp.

[0111] It should be noted that the beneficial effects of the spacecraft flight motion measurement system 200 in the target airspace provided in the above embodiments are the same as those of the spacecraft flight motion measurement method in the target airspace described above, and will not be repeated here. Furthermore, the system provided in the above embodiments is only illustrated by the division of the above functional modules. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the system can be divided into different functional modules according to the actual situation to complete all or part of the functions described above. In addition, the system and method embodiments provided in the above embodiments belong to the same concept, and their specific implementation process is detailed in the method embodiments, and will not be repeated here.

[0112] The measurement system for the spacecraft flight motion process within the target airspace of the present invention can be a computer program (including program code) running on a computer device. For example, the measurement system for the spacecraft flight motion process within the target airspace of the present invention is an application software that can be used to execute the corresponding steps in the measurement method for the spacecraft flight motion process within the target airspace of the present invention.

[0113] In some embodiments, the measurement system for the spacecraft flight motion process within the target airspace of the present invention can be implemented using a combination of hardware and software. As an example, the measurement system for the spacecraft flight motion process within the target airspace of the present invention can be a processor in the form of a hardware decoding processor, which is programmed to execute the measurement method for the spacecraft flight motion process within the target airspace of the present invention. For example, the processor in the form of a hardware decoding processor can employ one or more application-specific integrated circuits (ASICs), DSPs, programmable logic devices (PLDs), complex programmable logic devices (CPLDs), field-programmable gate arrays (FPGAs), or other electronic components.

[0114] The modules described in the embodiments of this invention can be implemented in software or hardware. The names of the modules are not, in some cases, limiting the scope of the module itself.

[0115] An electronic device according to an embodiment of the present invention includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the measurement method for the flight motion process of a spacecraft within any of the aforementioned target airspaces. That is, an electronic device according to an embodiment of the present invention may include, but is not limited to: a processor and a memory; the memory is used to store the computer program; the processor is used to execute the measurement method for the flight motion process of a spacecraft within any of the target airspaces shown in any embodiment of the present invention by calling the computer program.

[0116] In one alternative embodiment, an electronic device is provided, such as Figure 6 As shown, Figure 6 The illustrated electronic device 4000 includes a processor 4001 and a memory 4003. The processor 4001 and the memory 4003 are connected, for example, via a bus 4002. Optionally, the electronic device 4000 may further include a transceiver 4004, which can be used for data interaction between the electronic device and other electronic devices, such as sending and / or receiving data. It should be noted that in practical applications, the transceiver 4004 is not limited to one type, and the structure of the electronic device 4000 does not constitute a limitation on the embodiments of the present invention.

[0117] Processor 4001 may be a CPU (Central Processing Unit), a general-purpose processor, a DSP (Digital Signal Processor), an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. It can implement or execute the various exemplary logic blocks, modules, and circuits described in conjunction with the disclosure of this invention. Processor 4001 may also be a combination that implements computational functions, such as a combination of one or more microprocessors, a combination of a DSP and a microprocessor, etc.

[0118] Bus 4002 may include a path for transmitting information between the aforementioned components. Bus 4002 may be a PCI (Peripheral Component Interconnect) bus or an EISA (Extended Industry Standard Architecture) bus, etc. Bus 4002 can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 6 The bus 4002 is represented by only one thick line, but this does not mean that there is only one bus or one type of bus.

[0119] The memory 4003 may be ROM (Read Only Memory) or other types of static storage devices capable of storing static information and instructions, RAM (Random Access Memory) or other types of dynamic storage devices capable of storing information and instructions, or EEPROM (Electrically Erasable Programmable Read Only Memory), CD-ROM (Compact Disc Read Only Memory) or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital universal optical discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but not limited thereto.

[0120] The memory 4003 stores the application code (computer program) for executing the present invention, and its execution is controlled by the processor 4001. The processor 4001 executes the application code stored in the memory 4003 to implement the content shown in the foregoing method embodiments.

[0121] Among them, electronic devices can also be terminal devices, which can be any device that can install applications, including at least one of smartphones, tablets, laptops, desktop computers, smart speakers, smartwatches, smart TVs, and smart in-vehicle devices.

[0122] It should be noted that, Figure 6 The electronic device shown is merely an example and should not be construed as limiting the functionality and scope of use of the embodiments of the present invention.

[0123] An embodiment of the present invention provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements a method for measuring the flight motion process of a spacecraft within any of the aforementioned target airspace.

[0124] Alternatively, the computer-readable storage medium may be a read-only memory (ROM), a random access memory (RAM), a compact disc read-only memory (CD-ROM), magnetic tape, a floppy disk, and an optical data storage device, etc.

[0125] In an exemplary embodiment, a computer program product or computer program is also provided, which includes computer instructions stored in a computer-readable storage medium. A processor of an electronic device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the electronic device to perform the measurement method for the spacecraft's flight motion within any of the aforementioned target airspaces.

[0126] Computer program code for performing the operations of this invention can be written in one or more programming languages ​​or a combination thereof. These programming languages ​​include object-oriented programming languages—such as Java, Smalltalk, and C++—and conventional procedural programming languages—such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0127] It should be understood that the flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of methods and computer program products according to various embodiments of the present invention. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0128] The computer-readable storage medium provided in this invention can be, but is not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of a computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EEPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this invention, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0129] The aforementioned computer-readable storage medium carries one or more programs, which, when executed by the electronic device, cause the electronic device to perform the method shown in the above embodiments.

[0130] The above description is merely a preferred embodiment of the present invention and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of disclosure in this invention is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this invention.

[0131] It should be noted that the terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and represent a limitation on a specific order or sequence. Where appropriate, the order of use for similar objects can be interchanged so that the embodiments of this application described herein can be implemented in an order other than that shown or described.

[0132] Those skilled in the art will recognize that this invention can be implemented as a system, method, or computer program product. Therefore, this invention can be specifically implemented in the following forms: it can be entirely hardware, entirely software (including firmware, resident software, microcode, etc.), or a combination of hardware and software, generally referred to herein as a "circuit," "module," or "system." Furthermore, in some embodiments, this invention can also be implemented as a computer program product contained in one or more computer-readable media, which includes computer-readable program code.

[0133] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for measuring the flight motion of a spacecraft within a target airspace, characterized in that, include: Within a preset time period, the target airspace within a three-dimensional cone with the target area as the base and the target ground-based antenna as the vertex is determined in real time, and the target airspace at each preset moment within the preset time period is obtained. The target area is the beam coverage area calculated based on the beamwidth of the target ground-based antenna, and the center of the beam coverage area is a reference point selected on the moon. The half-beamwidth of the target ground-based antenna is calculated using the first formula, which is: in, The half-beamwidth of the target ground-based antenna. The wavelength of the radio frequency signal received by the target ground-based antenna. Given the antenna aperture of the target ground-based antenna, based on the half-beamwidth of the target ground-based antenna. The beam coverage area of ​​the target ground-based antenna on the moon is calculated based on the Earth-Moon distance. During the preset time period, the target ground-based antenna is controlled to track the reference point; During the tracking process, at each preset time, the downlink signal of the spacecraft in the target airspace is tracked and measured through the target ground-based antenna, and the tracked and measured downlink signal is processed to obtain the spacecraft's flight motion data.

2. The method for measuring the flight motion of a spacecraft within a target airspace according to claim 1, characterized in that, During the preset time period, controlling the target ground-based antenna to track the reference point includes: Based on the position of the target ground-based antenna at each preset time and the position of the reference point at each preset time within the preset time period, the azimuth and elevation angles of the target ground-based antenna at each preset time are calculated. Based on the azimuth and elevation angles of the target ground-based antenna at each preset time, the target ground-based antenna is controlled to track the reference point.

3. A method for measuring the flight motion of a spacecraft within a target airspace according to claim 1 or 2, characterized in that, The position of the target ground-based antenna is characterized by its coordinates in the Earth-fixed coordinate system, and the position of the reference point is characterized by its coordinates in the Moon-fixed coordinate system.

4. A method for measuring the flight motion of a spacecraft within a target airspace according to claim 1 or 2, characterized in that, Processing the downlink signal detected by tracking, including: An open-loop velocity measurement analysis method is used to process the downlink signal that has been tracked and measured, and to generate frequency detection results and carrier-to-noise ratio detection results of the spacecraft with matching time stamps.

5. A measurement system for the flight motion of a spacecraft within a target airspace, characterized in that, It includes a target airspace determination module, a tracking module, a tracking measurement module, and a signal processing module; The target airspace determination module is used to: determine the target airspace within a three-dimensional cone with the target area as the base and the target ground-based antenna as the vertex in real time within a preset time period, and obtain the target airspace at each preset moment within the preset time period. The target area is: the beam coverage area calculated based on the beamwidth of the target ground-based antenna, and the center of the beam coverage area is a reference point selected on the moon. The half-beamwidth of the target ground-based antenna is calculated using the first formula, which is: in, The half-beamwidth of the target ground-based antenna. The wavelength of the radio frequency signal received by the target ground-based antenna. Given the antenna aperture of the target ground-based antenna, based on the half-beamwidth of the target ground-based antenna. The beam coverage area of ​​the target ground-based antenna on the moon is calculated based on the Earth-Moon distance. The tracking module is used to: control the target ground-based antenna to track the reference point within the preset time period; The tracking and measurement module is used to: during the tracking process, at each preset time, track and measure the downlink signal of the spacecraft in the target airspace through the target ground-based antenna; The signal processing module is used to process the downlink signals measured by tracking to obtain the spacecraft's flight motion data.

6. The measurement system for the flight motion process of a spacecraft within a target airspace according to claim 5, characterized in that, The tracking module is specifically used for: Based on the position of the target ground-based antenna at each preset time and the position of the reference point at each preset time within the preset time period, the azimuth and elevation angles of the target ground-based antenna at each preset time are calculated. Based on the azimuth and elevation angles of the target ground-based antenna at each preset time, the target ground-based antenna is controlled to track the reference point.

7. A measurement system for the flight motion of a spacecraft within a target airspace according to claim 5 or 6, characterized in that, The position of the target ground-based antenna is characterized by its coordinates in the Earth-fixed coordinate system, and the position of the reference point is characterized by its coordinates in the Moon-fixed coordinate system.

8. A measurement system for the flight motion of a spacecraft within a target airspace according to claim 5 or 6, characterized in that, The signal processing module is specifically used to: process the downlink signal tracked and measured using an open-loop velocity analysis method, and generate frequency detection results and carrier-to-noise ratio detection results of the spacecraft with matching time stamps.

9. An electronic device, characterized in that, The device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the method for measuring the flight motion of a spacecraft within a target airspace as described in any one of claims 1 to 4.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, which, when executed by a processor, implements a method for measuring the flight motion of a spacecraft within a target airspace as described in any one of claims 1 to 4.

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