A method, apparatus, electronic device, and readable storage medium for locating spatial targets.

Abstract

This disclosure relates to the field of relative navigation technology, and proposes a method, device, electronic device, and readable storage medium for locating a space target. The method includes: capturing an image of the space target using a space camera with imaging capabilities to obtain a spatial image and reflected light signal; determining the angular information of the space target relative to the orbital coordinate system of the probe platform based on the spatial image; determining the Fraunhofer line information of the reflected light from the space target based on the reflected light signal, and calculating the line-of-sight velocity of the space target based on the Fraunhofer line information and the solar Fraunhofer standard line; and calculating the target coordinates of the space target in the orbital coordinate system of the probe platform using a Kalman filter algorithm based on the angular information and the line-of-sight velocity. The technical solution provided by one or more embodiments of this disclosure is a passive detection method with strong concealment and anti-interference capabilities, enabling high-precision, low-power relative navigation of space targets.

Description

Technical Field

[0001] This disclosure relates to the field of relative navigation technology, specifically to a spatial target positioning method, apparatus, electronic device, and readable storage medium. Background Technology

[0002] Relative navigation is a navigation technology used to determine the relative positions of two or more spacecraft in space. It is crucial for a variety of missions, including on-orbit maintenance, formation flying, and close surveillance. Relative navigation technology allows spacecraft to cooperate autonomously without relying on external navigation systems such as GPS.

[0003] Existing relative navigation technologies for space targets (such as spacecraft and satellites) primarily rely on radar detection or active optical methods. Radar systems can achieve ranging and relative navigation by emitting electromagnetic waves and receiving the echoes, but their actively emitted signals are easily detected and jammed, resulting in poor stealth and high energy consumption. Furthermore, radar signals are significantly affected by atmospheric attenuation, limiting their ability to detect distant targets. While active optical relative navigation technologies (such as laser ranging) can achieve high-precision navigation, they require the active emission of powerful lasers, similarly facing insufficient stealth issues, and also exhibit high system complexity. Summary of the Invention

[0004] In view of this, one or more embodiments of this disclosure provide a space target positioning method, apparatus, electronic device and readable storage medium, which is a passive detection method with strong concealment and anti-interference ability, and can realize high-precision, low-power space target relative navigation.

[0005] In a first aspect, this disclosure provides a method for locating a space target, the method comprising: taking a picture of a space target using a space camera with imaging capabilities to obtain a space image and a reflected light signal of the space target; determining the angular information of the space target relative to the orbital coordinate system of a probe platform based on the space image; determining the Fraunhofer line information of the reflected light of the space target based on the reflected light signal, and calculating the line-of-sight velocity of the space target based on the Fraunhofer line information and the solar Fraunhofer standard line; and calculating the target coordinates of the space target in the orbital coordinate system of the probe platform using a Kalman filter algorithm based on the angular information and the line-of-sight velocity.

[0006] In an optional implementation, determining the angular information of the space target relative to the orbital coordinate system of the probe platform based on the space image includes: using an image processing algorithm to calculate the centroid position of the space target in the space image; calculating the camera line-of-sight direction of the space target in the camera coordinate system based on the centroid position and the camera parameters of the space camera; converting the camera line-of-sight direction into the orbital line-of-sight direction of the space target in the orbital coordinate system of the probe platform according to a preset transformation relationship between the camera coordinate system and the orbital coordinate system of the probe platform; and determining the angular information of the space target relative to the orbital coordinate system of the probe platform based on the orbital line-of-sight direction.

[0007] In an optional implementation, determining the Fraunhofer line information of the reflected light of the space target based on the reflected light signal includes: generating a local oscillator light using a local oscillator; detecting a heterodyne signal generated by mixing the local oscillator light with the reflected light signal; and determining the Fraunhofer line information of the reflected light of the space target based on the heterodyne signal.

[0008] In an optional implementation, detecting the heterodyne signal generated by mixing the local oscillator light and the reflected light signal includes: determining the heterodyne signal using the following formula;

[0009] ,

[0010] in, The heterodyne signal, The output current generated by the photodetector based on the heterodyne signal. For heterodyne efficiency, For electron charge, Photon energy, The power of the local oscillator light. The power of the reflected light signal is denoted as .

[0011] In an optional implementation, calculating the line-of-sight velocity of the space target based on the Fraunhofer line information of the reflected light and the Fraunhofer standard line of the sun includes: calculating the frequency shift of the reflected light using the Fraunhofer line information of the reflected light and the Fraunhofer standard line of the sun; and determining the line-of-sight velocity of the space target based on the frequency shift of the reflected light.

[0012] In an optional implementation, the step of calculating the frequency shift of the reflected light using the Fraunhofer line information and the solar Fraunhofer standard line includes: determining the optimal estimate of the frequency shift of the reflected light by solving the least-squares objective function of the following formula;

[0013] ,

[0014] in, for The signal intensity of the heterodyne signal at a given wavelength, wherein the heterodyne signal is generated by mixing the local oscillator light and the reflected light signal. For the solar Fraunhofer standard line, The standard center wavelength of the solar Fraunhofer standard line is... At the speed of light, The number of spectral lines of the solar Fraunhofer standard line involved in the fitting. The frequency shift of the reflected light.

[0015] In an optional implementation, the step of employing a Kalman filter algorithm to calculate the target coordinates of the space target in the orbital coordinate system of the probe platform based on the angle measurement information and the line-of-sight velocity includes: establishing the relative navigation motion equation of the space target; using the angle measurement information and the line-of-sight velocity as observations, and using the relative position and relative velocity of the space target in the orbital coordinate system of the probe platform as state variables, using the Kalman filter algorithm to solve for the relative position and relative velocity of the space target; and determining the target coordinates based on the relative position and relative velocity.

[0016] Secondly, this disclosure provides a space target positioning device, the device comprising: a signal acquisition unit, configured to capture a space target using a space camera with imaging capabilities, thereby obtaining a space image and a reflected light signal of the space target; an angle measurement unit, configured to determine the angle information of the space target relative to the orbital coordinate system of the probe platform based on the space image; a velocity measurement unit, configured to determine the Fraunhofer line information of the reflected light of the space target based on the reflected light signal, and to calculate the line-of-sight velocity of the space target based on the Fraunhofer line information and the solar Fraunhofer standard line; and a positioning unit, configured to calculate the target coordinates of the space target in the orbital coordinate system of the probe platform using a Kalman filter algorithm, based on the angle measurement information and the line-of-sight velocity.

[0017] Thirdly, this disclosure provides an electronic device, which includes a memory and a processor. The memory is used to store a computer program, and when the computer program is executed by the processor, it implements the spatial target positioning method of the first aspect described above.

[0018] Fourthly, this disclosure provides a computer-readable storage medium for storing a computer program that, when executed by a processor, implements the spatial target positioning method of the first aspect described above.

[0019] The technical solutions provided by one or more embodiments of this disclosure utilize space images captured by a space camera with imaging capabilities to effectively obtain angular information of a space target relative to the orbital coordinate system of the probe platform; by using spectral detection methods to analyze the reflected light signal of the space target, the Fraunhofer line information of the reflected light of the space target can be obtained; by using the Fraunhofer line information of the reflected light and the solar Fraunhofer standard line to calculate, the line-of-sight velocity of the space target can be inverted; based on the Kalman filtering algorithm, combined with the angular information and the line-of-sight velocity, the target coordinates of the space target in the orbital system of the probe platform can be accurately obtained, realizing high-precision and low-energy relative navigation for the space target.

[0020] The technical solution provided by one or more embodiments disclosed herein belongs to a passive detection method with strong concealment and anti-interference ability. It does not require actively emitting strong lasers at space targets, but rather integrates Doppler frequency shift information of reflected light with high-precision angle measurement information to achieve relative navigation, which has the advantage of being used without actively emitting signals. Attached Figure Description

[0021] The features and advantages of the embodiments of this disclosure will be more clearly understood by referring to the accompanying drawings, which are illustrative and should not be construed as limiting the scope of this disclosure in any way. In the drawings:

[0022] Figure 1 A schematic diagram illustrating the steps of a spatial target localization method in one embodiment of this disclosure is shown.

[0023] Figure 2 A schematic diagram of the functional modules of a space target positioning device in one embodiment of this disclosure is shown;

[0024] Figure 3 A schematic diagram of the structure of an electronic device according to one embodiment of the present disclosure is shown. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0026] Among related technologies, some passive optical relative navigation technologies (such as visible light imaging) do not require active signal transmission, but can only obtain the azimuth information of space targets and lack the ability to directly measure radial velocity and distance, which limits the accuracy of relative navigation.

[0027] This disclosure provides a space target positioning method according to one embodiment, which is applicable to space-based observation platforms (such as satellites, space stations, etc.) and can achieve high-precision passive relative navigation of space targets (such as other satellites, space debris, space fragments, etc.). It can be applied to fields such as spacecraft autonomous navigation, space situational awareness and orbital safety monitoring.

[0028] Please see Figure 1 The spatial target positioning method provided in one embodiment of this disclosure may include the following steps.

[0029] S1: Using a space camera with imaging capabilities, a space target is photographed to obtain a space image and reflected light signal of the space target.

[0030] In this embodiment, the space camera with imaging capabilities is a passive space detection device, primarily relying on the radiation characteristics (or sunlight reflection characteristics) of the space target itself to monitor the space target in real time. This imaging-capable space camera can be a composite optical payload integrating an imaging detector and signal extraction, or it can be a combination of a physically separate but optically shared or collaborative imaging camera and a device for extracting reflected light signals. In some practical applications, visible light cameras, infrared cameras, etc., can be selected for the space camera, offering advantages such as long operating range, low power consumption, and low cost.

[0031] In this embodiment, the space images acquired by the space camera can be used for subsequent analysis to provide line-of-sight information of the space target. The reflected light signals acquired by the space camera can be used for subsequent analysis to provide line-of-sight velocity information of the space target.

[0032] S2: Based on the spatial image, determine the angular information of the space target relative to the orbital coordinate system of the detection platform.

[0033] In this embodiment, an image processing algorithm is used to calculate the centroid position of the space target in the space image. Based on the centroid position and the camera parameters of the space camera (e.g., camera focal length), the camera's line-of-sight direction in the camera coordinate system can be calculated. According to a preset transformation relationship between the camera coordinate system and the probe platform's orbital coordinate system, the camera's line-of-sight direction can be converted into the orbital line-of-sight direction of the space target in the probe platform's orbital coordinate system. Based on the orbital line-of-sight direction, the angular information of the space target relative to the probe platform's orbital coordinate system can be determined.

[0034] Specifically, a space camera can acquire a sequence of space images containing a point target. Image processing algorithms can be used to calculate the centroid of the target within the image sequence. Based on this centroid, the target's line-of-sight direction in the camera coordinate system can be calculated. Using a pre-defined transformation formula between the camera and the probe's orbital coordinate system, the target's line-of-sight direction can be transformed to the probe's orbital coordinate system. The resulting transformation allows for the acquisition of the target's angular information relative to the probe's orbital coordinate system.

[0035] In this embodiment, the angle measurement information may include the viewing angle and pitch angle. With azimuth .

[0036] In a practical application example, the line-of-sight direction of the spatial target in the camera coordinate system is calculated based on the centroid position of the spatial target in the spatial image sequence. The specific formula is as follows:

[0037] ;

[0038] in, Let be the camera's line-of-sight vector of the spatial target in the camera coordinate system. ， These are the pixel coordinates of the centroid location in the image. This is the focal length of the space camera.

[0039] In a practical application example, the orbital line-of-sight direction vector The calculation can be performed by transforming quaternions. Vector of camera line of sight The calculation yields the following formula:

[0040] .

[0041] S3: Based on the reflected light signal, determine the Fraunhofer line information of the reflected light of the space target, and calculate the line-of-sight velocity of the space target based on the Fraunhofer line information and the solar Fraunhofer standard line.

[0042] In this embodiment, spectroscopic detection methods such as optical heterodyne, atomic frequency discrimination, and optical resonant cavity methods are used to process the reflected light signal, thereby determining the Fraunhofer line information of the reflected light from space targets. Space targets (such as satellites and space debris) do not emit light themselves; they reflect sunlight. When sunlight shines on the surface of a space target, some light is reflected, and this reflected light contains the spectral information of sunlight. The solar spectrum contains many dark lines, called Fraunhofer lines. Fraunhofer lines are formed by elements in the solar atmosphere (such as hydrogen, helium, and iron) absorbing light of specific wavelengths. Each element absorbs light at a specific wavelength, forming characteristic spectral lines. The light reflected by space targets also contains these Fraunhofer lines. By analyzing the reflected light with a spectrometer, the location and intensity of these Fraunhofer lines can be determined.

[0043] In this embodiment, the positions of the Fraunhofer lines in the solar spectrum are known, and these standard lines can be used as a reference. The Fraunhofer lines in the reflected light from the space target are compared with the solar Fraunhofer standard lines. If the space target is not in relative motion, the position of the Fraunhofer lines in the reflected light should coincide with the solar standard lines. However, if the space target is in relative motion, the Fraunhofer lines in the reflected light will undergo a Doppler shift. The Doppler shift principle states that when a light source (or reflecting source) is in relative motion with respect to an observer, the observed spectral lines will shift. If the space target moves closer to the observer, the wavelength of the reflected light will become shorter (blue shift); if the space target moves away from the observer, the wavelength of the reflected light will become longer (red shift). Therefore, based on the comparison between the Fraunhofer line information of the reflected light and the solar Fraunhofer standard lines, the radial velocity of the space target can be calculated and deduced.

[0044] In some embodiments, determining the Fraunhofer line information of the reflected light of the space target based on the reflected light signal includes: generating a local oscillator light using a local oscillator; detecting a heterodyne signal generated by mixing the local oscillator light with the reflected light signal; and determining the Fraunhofer line information of the reflected light of the space target based on the heterodyne signal.

[0045] Specifically, the optical heterodyne method involves two light sources: one is an external light source, such as reflected light from the sun or a space target, and the other is light generated by a local oscillator. The local oscillator is typically a stable laser source with a precisely controllable frequency. The light from the external light source is mixed with the light from the local oscillator. When the frequencies of the two beams are close, interference occurs. The frequency of the interference signal is the difference between the frequencies of the two light waves; this frequency difference is called the heterodyne frequency. The heterodyne frequency is usually a relatively low frequency relative to the external light source itself, called the intermediate frequency (IF). The IF signal contains modulation information of the external light source's spectral information (e.g., Fraunhofer line information of the reflected light). By detecting the IF signal, the spectral characteristics of the external light source can be extracted.

[0046] In some embodiments, detecting the heterodyne signal generated by mixing the local oscillator light and the reflected light signal includes: determining the heterodyne signal using the following formula;

[0047] ,

[0048] in, The heterodyne signal, The output current generated by the photodetector based on the heterodyne signal. For heterodyne efficiency, For electron charge, Photon energy, The power of the local oscillator light. The power of the reflected light signal is denoted as .

[0049] Specifically, optical heterodyne technology can detect two types of target light: coherent and incoherent light. In this embodiment, it mainly targets incoherent light, employing a high-resolution spectral analysis technique called LHR (Laser Heterodyne Radiometry) to determine the heterodyne signal and the Fraunhofer line information of the reflected light from space targets. This is because broadband light sources such as the sun and reflected light from space targets are inherently incoherent light.

[0050] Assuming that the reflected light signal and the local oscillator light excited by the local oscillator are mixed, the resulting radio frequency current in the photodetector (e.g., a square law detector) is as follows:

[0051] .

[0052] in, The frequency of the heterodyne signal. The phase of the heterodyne signal. For heterodyne efficiency, For electron charge, Photon energy.

[0053] The heterodyne receiver detects the average power of the heterodyne signal, which is proportional to the square of the radio frequency current.

[0054] For incoherent reflected light signals, the corresponding equation for heterodyne signals is:

[0055] .

[0056] The parameters of the cosine square function vary continuously between 0 and 2π. This can be displayed graphically or directly through integration. The average value of the cosine square function is 1 / 2 in the interval between 0 and 2π, thus simplifying the expression for the heterodyne signal as follows:

[0057] .

[0058] in, The power of the local oscillator light. The power of the reflected light signal is denoted as .

[0059] In some embodiments, calculating the line-of-sight velocity of the space target based on the Fraunhofer line information of the reflected light and the Fraunhofer standard line of the sun includes: calculating the frequency shift of the reflected light using the Fraunhofer line information of the reflected light and the Fraunhofer standard line of the sun; and determining the line-of-sight velocity of the space target based on the frequency shift of the reflected light.

[0060] Specifically, for light waves, the frequency change of reflected light line-of-sight velocity of space targets speed of light and the frequencies of the Sun Fraunhofer standard. The following relationship exists between them:

[0061] .

[0062] As can be seen from the above formula, the speed of light It is a known constant. Wavelengths that can be seen from the Fraunhofer standard line The solar Fraunhofer standard is calculated, and it is also prior information. By measuring the frequency shift of the reflected light, the radial velocity of a space target can be calculated.

[0063] In a practical application example, the step of calculating the frequency shift of reflected light using the Fraunhofer line information of the reflected light and the solar Fraunhofer standard line includes: determining the optimal estimate of the frequency shift of reflected light by solving the least squares objective function of the following formula;

[0064] ;

[0065] in, for The signal intensity of the heterodyne signal at a given wavelength, wherein the heterodyne signal is generated by mixing the local oscillator light and the reflected light signal. For the previously known Fraunhofer standard line of the Sun (e.g., data from the Solar Standard Spectrum Database). The standard center wavelength of the solar Fraunhofer standard line is... At the speed of light, The number of spectral lines of the solar Fraunhofer standard line involved in the fitting. The frequency shift of the reflected light.

[0066] Subsequently, based on the frequency shift The line-of-sight velocity of a space target can be calculated. .

[0067] S4: Using the Kalman filter algorithm, based on the angle measurement information and the line-of-sight velocity, calculate the target coordinates of the space target in the orbital coordinate system of the detection platform.

[0068] In this embodiment, based on the relative motion equations of the near-Earth orbit spacecraft and the Kalman filter algorithm, combined with angle measurement information and line-of-sight velocity, the target coordinates of the space target in the orbital system of the probe platform can be accurately calculated.

[0069] In some implementations, the step of employing a Kalman filter algorithm to calculate the target coordinates of the space target in the orbital coordinate system of the probe platform based on the angle measurement information and the line-of-sight velocity includes: establishing the relative navigation motion equation of the space target; using the angle measurement information and the line-of-sight velocity as observations, and using the relative position and relative velocity of the space target in the orbital coordinate system of the probe platform as state variables, using the Kalman filter algorithm to solve for the relative position and relative velocity of the space target; and determining the target coordinates based on the relative position and relative velocity.

[0070] Specifically, based on the relative motion dynamics of near-Earth orbit spacecraft, the continuous differential equations are transformed into a state-space model through discretization:

[0071] ;

[0072] Among them, state variables It includes relative position With relative velocity A six-dimensional vector; This is the state transition matrix, whose elements are determined by the orbital angular velocity. ω With discrete time interval t Decide; The process noise is calibrated using Monte Carlo simulation and can reflect the effects of thruster disturbances and orbital perturbations.

[0073] Includes angle measurement information, namely the pitch angle mentioned above. With azimuth And the line-of-sight velocity mentioned above Observations The specific mapping relationship with the state variables is as follows:

[0074] .

[0075] in, It is a Heaviside step function, when The value is 1 when < 0, and 0 otherwise. Multiplying by π achieves a 180° offset from the second and third quadrants, expanding the angular range to cover all four quadrants.

[0076] By using the Kalman filter algorithm and combining the observations with the state-space model formulas, the final result of the state variables can be calculated.

[0077] In a practical application example, the process of calculating the state variables using the Kalman filter algorithm is as follows.

[0078] Using the state transition matrix Update state prediction values With covariance :

[0079] ;

[0080] ;

[0081] in Let be the process noise covariance matrix.

[0082] Simultaneously, calculate the Kalman gain. Correct the state estimate:

[0083] ;

[0084] in, Let Jacobian matrix be the equation of observation. The observation noise covariance matrix. The final corrections for the state and covariance are:

[0085] ;

[0086] ;

[0087] After the filter converges, the output is the target's current state quantity in the orbital system, including its relative position and relative velocity. .

[0088] The technical solutions provided by one or more embodiments of this disclosure utilize space images captured by a space camera with imaging capabilities to effectively obtain angular information of a space target relative to the orbital coordinate system of the probe platform; by using spectral detection methods to analyze the reflected light signal of the space target, the Fraunhofer line information of the reflected light of the space target can be obtained; by using the Fraunhofer line information of the reflected light and the solar Fraunhofer standard line to calculate, the line-of-sight velocity of the space target can be inverted; based on the Kalman filtering algorithm, combined with the angular information and the line-of-sight velocity, the target coordinates of the space target in the orbital system of the probe platform can be accurately obtained, realizing high-precision and low-energy relative navigation for the space target.

[0089] The technical solutions provided by one or more embodiments of this disclosure belong to the passive detection method. They do not require active emission of strong lasers at space targets. Instead, they integrate Doppler frequency shift information of reflected light with high-precision angle measurement information to achieve relative navigation, which has the advantage of being used without actively emitting signals.

[0090] Please see Figure 2 This disclosure also provides a space target positioning device, the device comprising:

[0091] The signal acquisition unit 100 is used to capture a space target using a space camera with imaging capabilities, and obtain a space image and reflected light signal of the space target.

[0092] Angle measuring unit 200 is used to determine the angle measuring information of the space target relative to the orbital coordinate system of the detection platform based on the space image;

[0093] The velocity measuring unit 300 is used to determine the Fraunhofer line information of the reflected light of the space target based on the reflected light signal, and to calculate the line-of-sight velocity of the space target based on the Fraunhofer line information and the solar Fraunhofer standard line.

[0094] The positioning unit 400 is used to calculate the target coordinates of the space target in the orbital coordinate system of the detection platform based on the angle measurement information and the line-of-sight velocity using the Kalman filter algorithm.

[0095] In one embodiment, the angle measuring unit 200 is specifically used to: employ an image processing algorithm to calculate the centroid position of the space target in the space image; calculate the camera line-of-sight direction of the space target in the camera coordinate system based on the centroid position and the camera parameters of the space camera; convert the camera line-of-sight direction into the orbital line-of-sight direction of the space target in the orbital coordinate system of the probe platform according to a preset transformation relationship between the camera coordinate system and the orbital coordinate system of the probe platform; and determine the angle measuring information of the space target relative to the orbital coordinate system of the probe platform based on the orbital line-of-sight direction.

[0096] In one embodiment, the velocity measurement unit 300 includes a first velocity measurement subunit. This first velocity measurement subunit is used to: generate local oscillator light using a local oscillator; detect a heterodyne signal generated by mixing the local oscillator light with the reflected light signal; and determine the Fraunhofer line information of the reflected light from the space target based on the heterodyne signal.

[0097] In one embodiment, the first speed measuring subunit included in the speed measuring unit 300 is further configured to determine the heterodyne signal by means of the following formula;

[0098] ,

[0099] in, The heterodyne signal, The output current generated by the photodetector based on the heterodyne signal. For heterodyne efficiency, For electron charge, Photon energy, The power of the local oscillator light. The power of the reflected light signal is denoted as .

[0100] In one embodiment, the velocity measurement unit 300 includes a second velocity measurement subunit. This second velocity measurement subunit is used to calculate the frequency shift of the reflected light using the Fraunhofer line information and the solar Fraunhofer standard line; and to determine the line-of-sight velocity of the space target based on the reflected light frequency shift.

[0101] In one embodiment, the second velocity measurement subunit included in the velocity measurement unit 300 is further configured to determine the optimal estimate of the frequency shift of the reflected light by solving the least squares objective function of the following formula;

[0102] ,

[0103] in, for The signal intensity of the heterodyne signal at a given wavelength, wherein the heterodyne signal is generated by mixing the local oscillator light and the reflected light signal. For the previously known Fraunhofer standard line of the Sun (e.g., data from the Solar Standard Spectrum Database). The standard center wavelength of the solar Fraunhofer standard line is... At the speed of light, The number of spectral lines of the solar Fraunhofer standard line involved in the fitting. The frequency shift of the reflected light.

[0104] In one embodiment, the positioning unit 400 is specifically used to: establish the relative navigation motion equation of the space target; use the angle measurement information and the line-of-sight velocity as observations, and the relative position and relative velocity of the space target in the orbital coordinate system of the detection platform as state variables, and use the Kalman filter algorithm to solve for the relative position and relative velocity of the space target; and determine the target coordinates based on the relative position and relative velocity.

[0105] The various units described in the above embodiments can be implemented by a computer chip or by a product with a certain function. A typical implementation device is a computer. Specifically, the computer can be, for example, a personal computer, a laptop computer, a cellular phone, a camera phone, a smartphone, a personal digital assistant, a media player, a navigation device, an email device, a game console, a tablet computer, a wearable device, or any combination of these devices.

[0106] For ease of description, the above devices are described separately by function as various units. Of course, in implementing this application, the functions of each unit can be implemented in one or more software and / or hardware.

[0107] Please see Figure 3 This disclosure also provides an electronic device, which includes a memory and a processor. The memory is used to store a computer program, and when the computer program is executed by the processor, it implements the above-described spatial target positioning method.

[0108] This disclosure also provides a computer-readable storage medium for storing a computer program that, when executed by a processor, implements the above-described spatial target positioning method.

[0109] The processor can be a central processing unit (CPU). It can also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or combinations thereof.

[0110] Memory, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs, non-transitory computer-executable programs, and modules, such as the program instructions / modules corresponding to the methods in the embodiments of this disclosure. The processor executes various functional applications and data processing by running the non-transitory software programs, instructions, and modules stored in the memory, thereby implementing the methods in the above-described embodiments.

[0111] The memory may include a program storage area and a data storage area. The program storage area may store the operating system and applications required for at least one function; the data storage area may store data created by the processor, etc. Furthermore, the memory may include high-speed random access memory and non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, the memory may optionally include memory remotely located relative to the processor, which can be connected to the processor via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0112] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), random access memory (RAM), flash memory, hard disk drive (HDD), or solid-state drive (SSD), etc.; the storage medium can also include combinations of the above types of memory.

[0113] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, embodiments of apparatus, devices, and storage media are basically similar to method embodiments, so the descriptions are relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0114] The above description is merely an embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this application should be included within the scope of the claims of this application.

[0115] Although embodiments of the present disclosure have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present disclosure, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A method for locating a spatial target, characterized in that, The method includes: By using a space camera with imaging capabilities, a space target is photographed to obtain a space image and reflected light signal of the space target; Based on the spatial image, the angular information of the space target relative to the orbital coordinate system of the probe platform is determined, and the angular information includes the viewing angle and pitch angle. With azimuth ; Based on the reflected light signal, the Fraunhofer line information of the reflected light of the space target is determined, and based on the Fraunhofer line information and the solar Fraunhofer standard line, the line-of-sight velocity of the space target is calculated. Using the Kalman filter algorithm, the target coordinates of the space target in the orbital coordinate system of the detection platform are calculated based on the angle measurement information and the line-of-sight velocity; The method employs a Kalman filter algorithm to calculate the target coordinates of the space target in the orbital coordinate system of the probe platform based on the angle measurement information and the line-of-sight velocity. This includes: establishing the relative navigation motion equations of the space target; using the angle measurement information and the line-of-sight velocity as observations, and the relative position and relative velocity of the space target in the orbital coordinate system of the probe platform as state variables, using the Kalman filter algorithm to solve for the relative position and relative velocity of the space target; and determining the target coordinates based on the relative position and relative velocity. The step of using the angular measurement information and the line-of-sight velocity as observations, and the relative position and relative velocity of the space target in the orbital coordinate system of the probe platform as state variables, and employing the Kalman filter algorithm to solve for the relative position and relative velocity of the space target, includes: Determine the state-space model. ； Among them, state variables It includes relative position With relative velocity A six-dimensional vector; This is the state transition matrix, whose elements are determined by the orbital angular velocity. ω With discrete time interval t Decide; The process noise was calibrated using Monte Carlo simulation. Includes the angle measurement information and the line-of-sight velocity Observations The specific mapping relationship with the state variables is as follows: ； in, It is a Heaviside step function, when The value is 1 when it is less than 0, and 0 otherwise.

2. The method according to claim 1, characterized in that, The step of determining the angular information of the space target relative to the orbital coordinate system of the probe platform based on the spatial image includes: The centroid position of the spatial target in the spatial image is calculated using an image processing algorithm. Based on the centroid position and the camera parameters of the space camera, calculate the camera line-of-sight direction of the space target in the camera coordinate system; According to the preset transformation relationship between the camera coordinate system and the orbit coordinate system of the detection platform, the camera line of sight is converted into the orbital line of sight of the spatial target in the orbit coordinate system of the detection platform; Based on the orbital line of sight, the angular information of the space target relative to the orbital coordinate system of the detection platform is determined.

3. The method according to claim 1 or 2, characterized in that, The step of determining the Fraunhofer line information of the reflected light of the space target based on the reflected light signal includes: Local oscillator light is generated using a local oscillator; Detect the heterodyne signal generated by mixing the local oscillator light and the reflected light signal; Based on the heterodyne signal, the Fraunhofer line information of the reflected light of the space target is determined.

4. The method according to claim 3, characterized in that, The step of detecting the heterodyne signal generated by the mixture of the local oscillator light and the reflected light signal includes: determining the heterodyne signal using the following formula; ， in, The heterodyne signal, The output current generated by the photodetector based on the heterodyne signal. For heterodyne efficiency, For electron charge, Photon energy, The power of the local oscillator light. The power of the reflected light signal is denoted as .

5. The method according to claim 1, characterized in that, The calculation of the line-of-sight velocity of the space target based on the Fraunhofer line information of the reflected light and the Fraunhofer standard line of the sun includes: The frequency shift of the reflected light is calculated using the Fraunhofer line information of the reflected light and the solar Fraunhofer standard line. The line-of-sight velocity of the space target is determined based on the frequency shift of the reflected light.

6. The method according to claim 5, characterized in that, The step of calculating the frequency shift of reflected light using the Fraunhofer line information of the reflected light and the solar Fraunhofer standard line includes: determining the optimal estimate of the frequency shift of reflected light by solving the least squares objective function of the following formula; ， in, for The signal intensity of the heterodyne signal at a given wavelength, wherein the heterodyne signal is generated by mixing the local oscillator light and the reflected light signal. For the solar Fraunhofer standard line, The standard center wavelength of the solar Fraunhofer standard line is... At the speed of light, The number of spectral lines of the solar Fraunhofer standard line involved in the fitting. The frequency shift of the reflected light.

7. A space target positioning device, characterized in that, The device includes: The signal acquisition unit is used to capture a space target using a space camera with imaging capabilities, and obtain a space image and reflected light signal of the space target. Angle measurement unit is used to determine the angle measurement information of the space target relative to the orbital coordinate system of the probe platform based on the space image. The angle measurement information includes the viewing angle and pitch angle. With azimuth ; The velocity measurement unit is used to determine the Fraunhofer line information of the reflected light of the space target based on the reflected light signal, and to calculate the line-of-sight velocity of the space target based on the Fraunhofer line information and the solar Fraunhofer standard line. The positioning unit is used to calculate the target coordinates of the space target in the orbital coordinate system of the detection platform based on the angle measurement information and the line-of-sight velocity using the Kalman filter algorithm. The method employs a Kalman filter algorithm to calculate the target coordinates of the space target in the orbital coordinate system of the probe platform based on the angle measurement information and the line-of-sight velocity. This includes: establishing the relative navigation motion equations of the space target; using the angle measurement information and the line-of-sight velocity as observations, and the relative position and relative velocity of the space target in the orbital coordinate system of the probe platform as state variables, using the Kalman filter algorithm to solve for the relative position and relative velocity of the space target; and determining the target coordinates based on the relative position and relative velocity. The step of using the angular measurement information and the line-of-sight velocity as observations, and the relative position and relative velocity of the space target in the orbital coordinate system of the probe platform as state variables, and employing the Kalman filter algorithm to solve for the relative position and relative velocity of the space target, includes: Determine the state-space model. ； Among them, state variables It includes relative position With relative velocity A six-dimensional vector; This is the state transition matrix, whose elements are determined by the orbital angular velocity. ω With discrete time interval t Decide; The process noise was calibrated using Monte Carlo simulation. Includes the angle measurement information and the line-of-sight velocity Observations The specific mapping relationship with the state variables is as follows: ； in, It is a Heaviside step function, when The value is 1 when it is less than 0, and 0 otherwise.

8. An electronic device, characterized in that, The electronic device includes a memory and a processor, the memory being used to store a computer program that, when executed by the processor, implements the method as described in any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium is used to store a computer program that, when executed by a processor, implements the method as described in any one of claims 1 to 6.

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