Three-dimensional passive positioning system and method for air mobile target based on single-satellite enhancement

Abstract

A three-dimensional passive positioning system and method for airborne maneuvering targets based on single-satellite enhancement is disclosed. The system, comprising a satellite receiving subsystem and a shore-based receiving subsystem, receives electromagnetic radio frequency signals emitted by the airborne maneuvering target. After preprocessing, it analyzes the obtained radiation source data to acquire signal segment data, along with the measured azimuth and elevation angles of the current radiation source position relative to the shore-based receiving subsystem. Simultaneously, it combines real-time satellite position data with signal segment data for airborne target radiation source positioning, obtaining the three-dimensional coordinate information of the airborne maneuvering target. This allows for complete positioning and tracking of the airborne target's maneuvering process, meeting the requirements of airborne target positioning missions.

Description

Technical Field

[0001] This invention relates to a three-dimensional passive positioning system and method for aerial maneuvering targets based on single-satellite enhancement, belonging to the field of space microwave remote sensing technology. Background Technology

[0002] Space electronic reconnaissance utilizes satellite-based reconnaissance equipment to detect and locate electromagnetic signals emitted by radar and communication radiation sources that are difficult to intercept from land, sea, and air platforms. It boasts a wide coverage area, is unrestricted by national borders or geographical conditions, and possesses a degree of concealment, making it a crucial component of military intelligence systems. Space electronic reconnaissance employs a multi-sampling single-satellite-to-ground direction finding cross-location or a multi-satellite measurement system combined with Earth equations for positioning. Its reconnaissance targets primarily include low-elevation radiation sources such as ground-based and sea-based targets. However, when facing high-value aerial targets such as early warning aircraft, reconnaissance planes, and reconnaissance airships, the positioning accuracy is degraded or even fails due to the target's flight altitude and maneuverability, making it difficult to meet the urgent requirements of aerial target positioning. This necessitates long-term accumulation and iterative analysis to approximate the target's true location, or the construction of multiple (≥4) observation stations for three-dimensional observation and positioning. However, this faces challenges such as the difficulty in converging positioning information due to the modulation of aerial target maneuverability, and the drastic increase in the scale and cost of building multiple observation stations, resulting in excessively high engineering complexity and cost for spaceborne aerial moving target positioning methods. Summary of the Invention

[0003] The technical problem solved by this invention is: addressing the lack of engineering technology for spaceborne airborne moving target positioning methods in the current technology, this invention proposes a three-dimensional passive positioning system and method for airborne moving targets based on single-satellite enhancement.

[0004] The present invention solves the above-mentioned technical problem through the following technical solution:

[0005] A three-dimensional passive positioning system for aerial maneuvering targets based on single-satellite augmentation includes a satellite receiving subsystem and a shore-based receiving subsystem, wherein:

[0006] The satellite receiving subsystem receives electromagnetic radio frequency signals from radiation sources transmitted by aerial maneuvering targets, performs filtering, amplification, and AD sampling processing to obtain signal segment data one, and sends signal segment data one and the satellite's current position data to the shore-based receiving subsystem.

[0007] The shore-based receiving subsystem receives electromagnetic radio frequency signals from the airborne maneuvering target, performs filtering, amplification, and AD sampling processing to obtain signal segment data two and the measured azimuth and elevation angles of the airborne maneuvering target's current radiation source position relative to the shore-based receiving subsystem. Simultaneously, it receives signal segment data one and satellite current position data from the satellite receiving subsystem. Based on all the data and the shore-based receiving subsystem equipment position data, it performs radiation source localization and obtains the three-dimensional coordinate information of the airborne maneuvering target.

[0008] The shore-based receiving subsystem includes a data processing module, a mutual fuzzy function module, a time difference equation module, a direction-finding ray module, and a three-dimensional positioning module, wherein:

[0009] The data processing module filters, amplifies, and performs AD sampling on the electromagnetic radio frequency signal from the radiation source to obtain signal segment data two, and acquires the measurement azimuth and elevation angle information of the current position of the airborne maneuvering target radiation source relative to the shore-based receiving subsystem.

[0010] The mutual ambiguity function module constructs a mutual ambiguity function, uses signal segment data one and signal segment data two to characterize the time difference of received data between the satellite receiving subsystem and the shore-based receiving subsystem, and calculates the time difference of received data based on the current position si of the satellite and the position sa of the shore-based receiving subsystem.

[0011] The time difference equation module constructs time difference equations for the location of the radiation source of an aerial maneuvering target;

[0012] The direction finding ray module determines the direction finding ray equation based on the measured azimuth and elevation angles of the current radiation source position relative to the shore-based receiving subsystem, as well as the radiation source position parameters, and defines the three-dimensional positioning parameters based on the direction finding ray equation.

[0013] The three-dimensional positioning module determines the direction-finding ray scaling factor based on the three-dimensional positioning parameters and time difference equation, and then determines the three-dimensional coordinate information of the aerial maneuvering target based on the direction-finding ray scaling factor to complete the radiation source positioning.

[0014] The signal segment data is a signal segment x1 with a data length of N and a sampling rate of fs;

[0015] Signal segment data 2: Signal segment x2, data length N, sampling rate fs;

[0016] The location of the shore-based equipment remains unchanged at sa:[xa ya za], the initial location of the satellite is s0:[x0 y0 z0], and the location of the satellite at any time is si:[xi yi zi]. The satellite position is obtained by satellite measurement based on the selected time.

[0017] In the mutual fuzziness function module, the mutual fuzziness function is specifically:

[0018]

[0019] In the formula, A is the mutual ambiguity function matrix, delta_t is the received data time difference, delta_f is the Doppler frequency difference, x1 is signal segment data one, x2 is signal segment data two, n is any integer from 0 to N-1, [.]* indicates taking the conjugate, and j is the imaginary part sign of the complex number.

[0020] In the time difference equation module, the time difference equation is specifically as follows:

[0021] ka=((xi^2+yi^2+zi^2)+(xa^2+ya^2+za^2)+delta_r^2) / 2;

[0022] lx = xi-xa; ly = yi-ya; lz = zi-za;

[0023] In the formula, (lx, ly, lz) are the three-dimensional coordinates of the satellite receiving subsystem position relative to the shore-based receiving subsystem position, i.e., normalized coordinates, ka is the distance correction amount, delta_r is the distance difference between the satellite receiving subsystem and the shore-based receiving subsystem, delta_r=C×delta_t, and the speed of light C=3×10^8m / s.

[0024] In the direction-finding ray module, the method for defining intermediate variables for 3D positioning based on the direction-finding ray direction is as follows:

[0025] Based on the azimuth and elevation angles of the radiation source target obtained by the shore-based receiving subsystem, and converted to the Earth-fixed coordinate system, the azimuth and elevation angles are transformed into three-dimensional direction-finding ray equations. Using the current position of the shore-based receiving subsystem [xa yaza], a point m is randomly selected along the azimuth and elevation direction-finding ray direction, where m: [xm ym zm]. Three-dimensional positioning parameters A, B, and C are defined, where:

[0026] A=lx×(xi-xm)+ly×(yi-ym)+lz×(zi-zm);

[0027] B = lx × xi + ly × yi + lz × zi;

[0028]

[0029] The calculation method for the direction-finding ray scaling factor k in the three-dimensional positioning module is as follows:

[0030] k = (ka - B) / (A ± C);

[0031] The calculation method for the three-dimensional coordinate information (x_estimate, y_estimate, z_estimate) of an aerial maneuvering target is as follows:

[0032] x_estimate = xi + k × (xi - xm);

[0033] y_estimate = yi + k × (yi - ym);

[0034] z_estimate = zi + k × (zi - zm).

[0035] A three-dimensional passive localization method for airborne maneuvering targets based on single-satellite augmentation, implemented according to a three-dimensional passive localization system for airborne maneuvering targets, includes:

[0036] The satellite receiving subsystem receives electromagnetic radio frequency signals from radiation sources and preprocesses them to obtain signal segment data one. Then, the signal segment data one and the satellite's current position data are forwarded to the shore-based receiving subsystem.

[0037] The shore-based receiving subsystem receives electromagnetic radio frequency signals from a maneuvering aerial target, performs filtering, amplification, and AD sampling to obtain signal segment data two, and obtains azimuth and elevation information about the target from the shore-based receiving subsystem. At the same time, it receives signal segment data one and satellite current position data from the satellite receiving subsystem.

[0038] A mutual ambiguity function is constructed using the mutual ambiguity function module, and the time difference between the received data of the satellite receiving subsystem and the shore-based receiving subsystem is calculated using signal segment data one and signal segment data two.

[0039] The normalized coordinates and range corrections for the position of the radiation source of an aerial maneuvering target are constructed using the time difference equation module.

[0040] The direction finding ray module is used to determine the direction finding ray direction by measuring the azimuth and elevation angles of the satellite with respect to the radiation source position based on the satellite's current position, and to define three-dimensional positioning parameters based on the direction finding ray direction.

[0041] The three-dimensional positioning module uses three-dimensional positioning parameters and time difference equations to determine the direction finding ray ratio coefficient, and then uses the direction finding ray ratio coefficient to determine the three-dimensional coordinate information of the aerial maneuvering target, thus completing the radiation source positioning.

[0042] During the calculation of the received data time difference, the received data time difference changes in real time according to the satellite's current position si and the shore-based receiving subsystem's position sa at the selected time.

[0043] In the process of calculating the three-dimensional positioning of the radiation source target, the direction finding ray scaling factor is determined based on the three-dimensional positioning parameters and time difference equation, the ray scaling factor is constructed, and the three-dimensional coordinate information of the aerial maneuvering target is obtained.

[0044] The advantages of this invention compared to the prior art are:

[0045] (1) The present invention provides a three-dimensional passive positioning system and method for airborne maneuvering targets based on single-satellite enhancement. The system includes a satellite receiving subsystem and a shore-based receiving subsystem. It receives electromagnetic radio frequency signals emitted by the airborne maneuvering target. After preprocessing, it obtains signal fragment data by analyzing the obtained radiation source data. The real-time position data of the satellite and the signal fragment data are used for radiation source positioning to obtain the three-dimensional coordinate information of the airborne maneuvering target. It is suitable for single-satellite reconnaissance. Based on a wide-area distributed ground-based reconnaissance platform and its angle measurement positioning system, it forms a satellite-ground single-sided time difference and direction finding intersection positioning application mode, which meets the requirements of three-dimensional positioning of airborne targets. This enables single-satellite reconnaissance to have three-dimensional positioning capability of airborne targets, and the wide-area distributed ground-based reconnaissance angle measurement positioning system to have ranging capability, thus meeting the requirements of high-precision three-dimensional positioning of airborne targets.

[0046] (2) Based on the proposed space-based satellite and ground-based receiving equipment, this invention only involves the basic application unit of a single satellite combined with a widely distributed ground-based equipment platform, which can meet the mission requirements of locating targets from airborne radiation sources. By further expanding the scope and increasing the number of satellites or airborne platforms (aircraft, airships, etc.), the accuracy of airborne target positioning can be further improved, the application range can be enhanced, and it has broad market application prospects.

[0047] (3) This invention proposes a three-dimensional passive positioning system and method for aerial maneuvering targets based on single-satellite enhancement. It involves cross-domain re-integration of resources, utilizing my country's satellite and ground reconnaissance resources and equipment. This is beneficial for the full utilization and realization of the value of satellite reconnaissance data, and can solve the problem of high-precision three-dimensional positioning of high-value aerial targets around my country. On the basis of almost no increase in system cost, it forms a new quality capability for innovative application of satellite-ground collaborative reconnaissance. It has important practical significance for tapping the application potential of my country's existing reconnaissance equipment system, and can locally enhance the traditional space-based electronic reconnaissance and positioning system to meet the urgent need for reconnaissance and positioning of aerial maneuvering targets. It can conduct cross-system collaborative reconnaissance through satellite and widely distributed reconnaissance platforms such as shore-based, sea-based, air-based, and stratosphere-based platforms, and has great flexibility in terms of application. Attached Figure Description

[0048] Figure 1 A schematic diagram of a passive positioning system for a heterogeneous aerospace platform provided for the invention;

[0049] Figure 2 A schematic diagram of the mutual fuzzy function provided for the invention;

[0050] Figure 3 The positioning accuracy GDOP distribution provided for the invention Figure 1 ;

[0051] Figure 4 The positioning accuracy GDOP distribution provided for the invention Figure 2 ;

[0052] Figure 5 The positioning accuracy GDOP distribution provided for the invention Figure 3 ;

[0053] Figure 6 The positioning accuracy GDOP distribution provided for the invention Figure 4 ;

[0054] Figure 7 The positioning accuracy GDOP distribution provided for the invention Figure 5 ;

[0055] Figure 8 The positioning accuracy GDOP distribution provided for the invention Figure 6 ;

[0056] Figure 9 A schematic diagram of the aerial maneuvering target positioning and tracking results provided for the invention; Detailed Implementation

[0057] A three-dimensional passive positioning system and method for airborne maneuvering targets based on single-satellite enhancement is disclosed. The system includes a satellite receiving subsystem and a shore-based receiving subsystem. It receives electromagnetic radio frequency signals emitted by the airborne maneuvering target, preprocesses the signals, analyzes the received radiation source data to obtain signal segment data, and uses the real-time satellite position data and signal segment data to locate the radiation source and obtain the three-dimensional coordinate information of the airborne maneuvering target.

[0058] In the three-dimensional passive localization system for aerial maneuvering targets, the satellite receiving subsystem receives the electromagnetic radio frequency signals from the radiation source, preprocesses them, and then forwards them to the shore-based receiving subsystem. The shore-based receiving subsystem receives the preprocessed data and performs non-cooperative radiation source localization against the electromagnetic radio frequency signals from the radiation source, wherein:

[0059] The satellite receiving subsystem receives electromagnetic radio frequency signals from radiation sources transmitted by aerial maneuvering targets, performs filtering, amplification, and AD sampling processing to obtain signal segment data one, and transmits the signal segment data and the satellite's current position data to the shore-based receiving subsystem.

[0060] The shore-based receiving subsystem receives electromagnetic radio frequency signals from the airborne moving target, performs filtering, amplification, and AD sampling processing to obtain signal segment data 2. At the same time, it receives signal segment data and satellite current position data from the satellite receiving subsystem. Based on all the data and the position data of the shore-based receiving subsystem equipment, it performs radiation source localization and obtains the three-dimensional coordinate information of the airborne moving target.

[0061] Specifically, the shore-based receiving subsystem includes a data processing module, a mutual fuzzy function module, a time difference equation module, a direction-finding ray module, and a three-dimensional positioning module, among which:

[0062] The data processing module performs filtering, amplification, and AD sampling on the electromagnetic radio frequency signal from the radiation source to obtain signal segment data two.

[0063] The mutual ambiguity function module constructs a mutual ambiguity function, uses signal segment data one and signal segment data two to characterize the time difference of received data between the satellite receiving subsystem and the shore-based receiving subsystem, and calculates the time difference of received data based on the current position si of the satellite and the position sa of the shore-based receiving subsystem.

[0064] The time difference equation module constructs the time difference equation and intermediate variables for the location of the radiation source of the aerial maneuvering target;

[0065] The direction finding ray module measures the azimuth and elevation angles of the satellite with respect to the position of the radiation source based on the satellite's current position, determines the direction finding ray direction, and defines intermediate variables for three-dimensional positioning based on the direction finding ray direction.

[0066] The three-dimensional positioning module determines the direction-finding ray scaling factor based on the intermediate variables of three-dimensional positioning, the time difference equation, and the intermediate variables of the location of the airborne maneuvering target radiation source. Based on the direction-finding ray scaling factor, it determines the three-dimensional coordinate information of the airborne maneuvering target and completes the radiation source positioning.

[0067] Signal segment data 1 is signal segment x1, with a data length of N and a sampling rate of fs;

[0068] Signal segment data 2: Signal segment x2, data length N, sampling rate fs;

[0069] The location of the shore-based equipment remains unchanged at sa:[xa ya za], the initial location of the satellite is s0:[x0 y0 z0], and the location of the satellite at any time is si:[xi yi zi]. The satellite position is obtained by satellite measurement based on the selected time.

[0070] In the mutual ambiguity function module, the mutual ambiguity function is specifically as follows:

[0071]

[0072] In the formula, A is the mutual ambiguity function matrix, delta_t is the received data time difference, delta_f is the Doppler frequency difference, x1 is signal segment data one, x2 is signal segment data two, n is any integer from 0 to N-1 as the sampling point, * indicates taking the conjugate, and j is the imaginary part sign of the complex number.

[0073] In the time difference equation module, the time difference equation is specifically as follows:

[0074] ka=((xi^2+yi^2+zi^2)+(xa^2+ya^2+za^2)+delta_r^2) / 2;

[0075] lx = xi-xa; ly = yi-ya; lz = zi-za;

[0076] In the formula, (lx, ly, lz) are the three-dimensional coordinates of the satellite receiving subsystem position relative to the shore-based receiving subsystem position, i.e., normalized coordinates, ka is the distance correction amount, delta_r is the distance difference between the satellite receiving subsystem and the shore-based receiving subsystem, delta_r=C×delta_t, and the speed of light C=3×10^8m / s.

[0077] In the direction-finding ray module, the method for defining intermediate variables for 3D positioning based on the direction-finding ray direction is as follows:

[0078] Based on the azimuth and elevation angles of the radiation source target obtained by the shore-based receiving subsystem, the coordinates are transformed from the conventional antenna coordinate system and the body coordinate system to the ground-fixed coordinate system. The azimuth and elevation angles are then converted into three-dimensional direction-finding ray equations. Using the current position of the shore-based receiving subsystem [xa ya za], a point m is randomly selected along the azimuth and elevation direction-finding ray direction, where m: [xm ym zm]. Three-dimensional positioning intermediate variables A, B, and C are defined, where:

[0079] A=lx×(xi-xm)+ly×(yi-ym)+lz×(zi-zm);

[0080] B = lx × xi + ly × yi + lz × zi;

[0081]

[0082] The calculation method for the direction-finding ray scaling factor k in the three-dimensional positioning module is as follows:

[0083] k = (ka - B) / (A ± C);

[0084] The calculation method for the three-dimensional coordinate information (x_estimate, y_estimate, z_estimate) of an aerial maneuvering target is as follows:

[0085] x_estimate = xi + k × (xi - xm);

[0086] y_estimate = yi + k × (yi - ym);

[0087] z_estimate = zi + k × (zi - zm).

[0088] The specific steps of the three-dimensional passive localization method for aerial maneuvering targets based on single-satellite enhancement are as follows:

[0089] The satellite receiving subsystem receives electromagnetic radio frequency signals from radiation sources, preprocesses them to obtain signal segment data one, and forwards the signal segment data and the satellite's current position data to the shore-based receiving subsystem.

[0090] The shore-based receiving subsystem receives electromagnetic radio frequency signals from airborne mobile targets, performs filtering, amplification, and AD sampling to obtain signal segment data 2, and simultaneously receives signal segment data and satellite current position data from the satellite receiving subsystem.

[0091] A mutual ambiguity function is constructed using the mutual ambiguity function module, and the time difference between the received data of the satellite receiving subsystem and the shore-based receiving subsystem is calculated using signal segment data one and signal segment data two.

[0092] The time difference equation and intermediate variables for the location of the radiation source of the aerial maneuvering target are constructed using the time difference equation module.

[0093] The direction finding ray module is used to determine the direction finding ray direction by measuring the azimuth and elevation angles of the satellite with respect to the radiation source position based on the satellite's current position, and to define intermediate variables for three-dimensional positioning based on the direction finding ray direction.

[0094] The three-dimensional positioning module uses intermediate variables of three-dimensional positioning, time difference equation, and intermediate variables of the position of the airborne maneuvering target radiation source to determine the direction finding ray ratio coefficient. Based on the direction finding ray ratio coefficient, the three-dimensional coordinate information of the airborne maneuvering target is determined, and the radiation source is located.

[0095] During the calculation of the received data time difference, the received data time difference changes in real time according to the satellite's current position si and the shore-based receiving subsystem's position sa at the selected time.

[0096] In the process of calculating the three-dimensional positioning of the radiation source target, the direction finding ray scaling coefficient is determined based on the intermediate variables of the three-dimensional positioning, the time difference equation, and the intermediate variables of the position of the airborne maneuvering target radiation source. The ray scaling coefficient is then constructed to obtain and determine the three-dimensional coordinate information of the airborne maneuvering target.

[0097] The following description, in conjunction with the accompanying drawings and preferred embodiments, provides further details:

[0098] In the current embodiment, such as Figure 1 As shown, the three-dimensional passive positioning system for airborne maneuvering targets mainly includes a satellite receiving subsystem and a shore-based receiving subsystem. The satellite receiving subsystem forwards the received radiation source data to the shore-based receiving subsystem to complete the non-cooperative radiation source positioning. Its core lies in the positioning processing stage of the shore-based receiving subsystem, which includes a mutual fuzzy function module, a time difference equation module, a direction-finding ray module, and a three-dimensional positioning module.

[0099] This invention provides a passive positioning system for aerospace heterogeneous platforms, the steps of which are as follows:

[0100] (1) Satellite receiving subsystem: mainly includes several links such as receiving antenna, broadband receiver, AD sampling, signal preprocessing, and data transmission and forwarding. Its main purpose is to receive electromagnetic radio frequency signals from non-cooperative radiation sources received by the satellite, filter, amplify and AD sample them to obtain signal segment x1(1:1:N), N=1024 is the data length, the sampling rate is fs=500e6, and send it to the shore-based receiving subsystem along with the satellite's current position s0:[6878137 0 0].

[0101] (2) Shore-based receiving subsystem: mainly includes receiving antenna, broadband receiver, AD sampling, signal preprocessing, and positioning processing. Its main purpose is to receive electromagnetic radio frequency signals from non-cooperative radiation sources from shore-based equipment, filter, amplify and AD sample them to obtain signal segment x2 (1:1:N), where N = 1024 is the data length, the sampling rate is fs = 500e6, and the current shore-based equipment position sa: [6378137 0 0]. Combined with the data segment x1 (1:1:N) and data position s0 sent by the satellite receiving subsystem, the non-cooperative radiation source calculation is completed in the positioning processing stage.

[0102] (3) Positioning Processing Stage: This stage mainly includes the mutual fuzzy function module, time difference equation module, direction finding ray module, and three-dimensional positioning module;

[0103] 1) Mutual ambiguity function module: This module calculates the time difference delta_t and Doppler frequency difference delta_f based on the data received by the satellite receiving subsystem and the shore-based receiving subsystem. The mutual ambiguity function is constructed as follows: Figure 2 The following is stated:

[0104]

[0105] Where [.]* indicates taking the conjugate, calculate the corresponding time difference delta_t=6.00751×1e-4 and Doppler frequency difference delta_f=4.022×1e4 for the data received by the satellite receiving subsystem and the shore-based receiving subsystem, and combine them with the corresponding positions s0 and s1 of the data segment, and send them into the positioning equation module;

[0106] The time difference equation module mainly constructs a time difference equation and its intermediate variables about the radiation source location u based on the very long observation baseline formed by the satellite receiving subsystem and the shore-based receiving subsystem.

[0107] Assuming the speed of light C = 3 × 10^8 m, and the distance difference delta_r = C × delta_t, construct the intermediate matrix variables:

[0108] ka = 3.3 × 1e12;

[0109] lx = 5.0 × 1e5;

[0110] ly = 0.0;

[0111] lz = 0.0;

[0112] The direction-finding ray module constructs the direction-finding ray equation based on the azimuth and elevation angles of the radiation source position u obtained from satellite measurements.

[0113] By taking any collinear point on the direction-finding ray, the direction-finding ray can be determined, specifically: point 1: [6878137 00], point 2: [6341660-500270-493598]. Define intermediate variables:

[0114] A = 2.6 × 1e11;

[0115] B = 3.4 × 1e12;

[0116] C = -1.5 × 1e11;

[0117] The three-dimensional positioning module mainly solves for the direction finding ray scaling factor k based on the constructed time difference equation and direction finding ray equation, thereby obtaining the target's three-dimensional coordinate information [x_estimate y_estimate z_estimate]. The specific process is as follows:

[0118] k = -0.9987;

[0119] The target location is as follows:

[0120] x_estimate = 6342315;

[0121] y_estimate = -499660;

[0122] z_estimate = -492995;

[0123] The above examples illustrate single-point radiation source positioning. Similarly, to verify the positioning performance of the patented system, a comparison of positioning performance between satellite and shore-based equipment within a ±500km coverage area is presented below.

[0124] Analysis conditions for patent positioning system:

[0125] Satellite position: [6878.137; 0; 0] km, orbital altitude: 500 km, position measurement error: 5 m, velocity: [0.13; -6.85; -1.88] km; shore-based equipment position: [6378.137; 0; 0] km, measurement error: 2 m, velocity: [0; 0; 0] m; three experiments were conducted in three aspects: synchronization accuracy at different times and tracking of aerial maneuvering targets, to evaluate the positioning performance of the method proposed in the patent.

[0126] Experiment 1: With a time synchronization accuracy of 10µs and a direction finding accuracy of 0.2°, conduct 100 Monte Carlo experiments and statistically analyze the distribution pattern of positioning accuracy within ±500km.

[0127] The GDOP distribution of positioning accuracy with a direction finding error of 0° and a synchronization accuracy of 10µs is as follows: Figure 3 As shown;

[0128] The GDOP distribution of positioning accuracy with a direction finding error of 0.2° and a synchronization accuracy of 0µs is as follows: Figure 4 As shown;

[0129] The GDOP distribution of positioning accuracy with a direction finding error of 0.2° and a synchronization accuracy of 10µs is as follows: Figure 5 As shown.

[0130] Analysis of the two influencing factors, direction-finding error and time synchronization error, shows that, in this case, the impact of time synchronization error on positioning accuracy is greater than that of direction-finding accuracy. Figure 5 The positioning accuracy error distribution shown in the figure mainly comes from the contribution of time difference synchronization error.

[0131] Experiment 2: With a time synchronization accuracy of 1µs and a direction finding accuracy of 0.2°, conduct 100 Monte Carlo experiments and statistically analyze the distribution pattern of positioning accuracy within ±500km.

[0132] The GDOP distribution of positioning accuracy with a direction finding error of 0° and a synchronization accuracy of 1µs is as follows: Figure 6 As shown;

[0133] The GDOP distribution of positioning accuracy with a direction finding error of 0.2° and a synchronization accuracy of 1µs is as follows: Figure 7 As shown;

[0134] The GDOP distribution of positioning accuracy with a direction finding error of 0.2° and a synchronization accuracy of 1µs is as follows: Figure 8 As shown.

[0135] Analysis of the two influencing factors, direction finding error and time synchronization error, shows that, in this case, the impact of direction finding synchronization error on positioning accuracy is greater than that of time synchronization error. Figure 8 The positioning accuracy error distribution shown in the figure mainly comes from the contribution of direction finding error.

[0136] Experiment 3: With a direction-finding system error of 0.2° and a time synchronization accuracy of 1µs, analyze the results of airborne maneuvering target localization and tracking as follows: Figure 9 As shown, the method proposed in the patent can completely locate and track the maneuvering process of aerial targets, thus meeting the requirements of aerial target positioning missions.

[0137] A three-dimensional passive positioning system and method for airborne maneuvering targets based on single-satellite enhancement. This system re-integrates and utilizes my country's satellite and ground reconnaissance resources and equipment, which not only facilitates the full utilization and realization of the value of satellite reconnaissance data but also solves the problem of high-precision three-dimensional positioning of high-value airborne targets around my country. It forms a new quality capability for innovative applications of satellite-ground collaborative reconnaissance with almost no increase in system cost. This has significant practical implications for tapping the application potential of my country's existing reconnaissance equipment system, locally enhancing the traditional space-based electronic reconnaissance and positioning system, and meeting the urgent need for reconnaissance and positioning of airborne maneuvering targets. Through satellite and widely distributed reconnaissance platforms such as shore-based, sea-based, airborne, and stratosphere reconnaissance, it can conduct cross-system collaborative reconnaissance, offering significant flexibility in application.

[0138] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

[0139] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A three-dimensional passive positioning system for aerial maneuvering targets based on single-satellite augmentation, characterized in that: Includes a satellite receiving subsystem and a shore-based receiving subsystem, among which: The satellite receiving subsystem receives electromagnetic radio frequency signals from radiation sources transmitted by aerial maneuvering targets, performs filtering, amplification, and AD sampling processing to obtain signal segment data one, and sends signal segment data one and the satellite's current position data to the shore-based receiving subsystem. The shore-based receiving subsystem receives electromagnetic radio frequency signals from the radiation source transmitted by the airborne maneuvering target, performs filtering, amplification, and AD sampling processing, and obtains signal segment data two and the measured azimuth and elevation angle information of the current radiation source position of the airborne maneuvering target relative to the shore-based receiving subsystem. At the same time, it receives signal segment data one transmitted by the satellite receiving subsystem and the current position data of the satellite. Based on all the data and the position data of the shore-based receiving subsystem equipment, the radiation source is located and the three-dimensional coordinate information of the airborne maneuvering target is obtained. The shore-based receiving subsystem includes a data processing module, a mutual fuzzy function module, a time difference equation module, a direction-finding ray module, and a three-dimensional positioning module, wherein: The data processing module filters, amplifies, and performs AD sampling on the electromagnetic radio frequency signal from the radiation source to obtain signal segment data two, and acquires the measurement azimuth and elevation angle information of the current position of the airborne maneuvering target radiation source relative to the shore-based receiving subsystem. The mutual ambiguity function module constructs a mutual ambiguity function, uses signal segment data one and signal segment data two to characterize the time difference of received data between the satellite receiving subsystem and the shore-based receiving subsystem, and calculates the time difference of received data based on the current position si of the satellite and the position sa of the shore-based receiving subsystem. The time difference equation module constructs time difference equations for the location of the radiation source of an aerial maneuvering target; The direction finding ray module determines the direction finding ray equation based on the measured azimuth and elevation angles of the current radiation source position relative to the shore-based receiving subsystem, as well as the radiation source position parameters, and defines the three-dimensional positioning parameters based on the direction finding ray equation. The three-dimensional positioning module determines the direction-finding ray scaling factor based on the three-dimensional positioning parameters and time difference equation, and then determines the three-dimensional coordinate information of the aerial maneuvering target based on the direction-finding ray scaling factor to complete the radiation source positioning.

2. The three-dimensional passive positioning system for aerial maneuvering targets based on single-satellite enhancement according to claim 1, characterized in that: The signal segment data is a signal segment x1 with a data length of N and a sampling rate of fs; Signal segment data 2: Signal segment x2, data length N, sampling rate fs; The location of the shore-based equipment remains unchanged at sa:[xa ya za], the initial location of the satellite is s0:[x0 y0 z0], and the location of the satellite at any time is si:[xi yi zi]. The satellite position is obtained by satellite measurement based on the selected time.

3. The three-dimensional passive positioning system for aerial maneuvering targets based on single-satellite enhancement according to claim 1, characterized in that: In the mutual fuzziness function module, the mutual fuzziness function is specifically: In the formula, A is the mutual ambiguity function matrix, delta_t is the received data time difference, delta_f is the Doppler frequency difference, x1 is signal segment data one, x2 is signal segment data two, and n is the sampling point. The sign indicates conjugate, and j is the symbol for the imaginary part of the complex number.

4. A three-dimensional passive positioning system for aerial maneuvering targets based on single-satellite enhancement according to claim 3, characterized in that: In the time difference equation module, the time difference equation is specifically as follows: ka=((xi^2 + yi^2 + zi^2) + (xa^2 + ya^2 + za^2) + delta_r^2) / 2; lx=xi-xa; ly=yi-ya; lz=zi-za; In the formula, (lx, ly, lz) are the three-dimensional coordinates of the satellite receiving subsystem position relative to the shore-based receiving subsystem position, i.e., normalized coordinates, ka is the distance correction amount, delta_r is the distance difference between the satellite receiving subsystem and the shore-based receiving subsystem, delta_r=C×delta_t, and the speed of light C=3×10^8m / s.

5. A three-dimensional passive positioning system for aerial maneuvering targets based on single-satellite enhancement according to claim 4, characterized in that: In the direction-finding ray module, the method for defining intermediate variables for 3D positioning based on the direction-finding ray direction is as follows: Based on the azimuth and elevation angles of the radiation source target obtained from the shore-based receiving subsystem, and converted to the Earth-fixed coordinate system, the azimuth and elevation angles are transformed into three-dimensional direction-finding ray equations. Using the current position of the shore-based receiving subsystem [xayaza], a point m is randomly selected along the azimuth and elevation direction-finding ray direction, where m: [xmymzm]. Three-dimensional positioning parameters A, B, and C are defined, where: A=lx×(xi-xm) + ly×(yi-ym) + lz×(zi-zm); B = lx × xi + ly × yi + lz × zi; 。 6. A three-dimensional passive positioning system for aerial maneuvering targets based on single-satellite enhancement according to claim 5, characterized in that: The calculation method for the direction-finding ray scaling factor k in the three-dimensional positioning module is as follows: k = (ka - B) / (A ± C); The calculation method for the three-dimensional coordinate information (x_estimate, y_estimate, z_estimate) of an aerial maneuvering target is as follows: x_estimate = xi + k × (xi - xm); y_estimate = yi + k × (yi - ym); z_estimate = zi + k × (zi - zm).

7. A three-dimensional passive localization method for airborne maneuvering targets based on single-satellite augmentation, applied to a three-dimensional passive localization system for airborne maneuvering targets based on single-satellite augmentation as described in claim 1, characterized in that... include: The satellite receiving subsystem receives electromagnetic radio frequency signals from radiation sources and preprocesses them to obtain signal segment data one. Then, the signal segment data one and the satellite's current position data are forwarded to the shore-based receiving subsystem. The shore-based receiving subsystem receives electromagnetic radio frequency signals from a maneuvering aerial target, performs filtering, amplification, and AD sampling to obtain signal segment data two, and obtains azimuth and elevation information about the target from the shore-based receiving subsystem. At the same time, it receives signal segment data one and satellite current position data from the satellite receiving subsystem. A mutual ambiguity function is constructed using the mutual ambiguity function module, and the time difference between the received data of the satellite receiving subsystem and the shore-based receiving subsystem is calculated using signal segment data one and signal segment data two. The normalized coordinates and range corrections for the position of the radiation source of an aerial maneuvering target are constructed using the time difference equation module. The direction finding ray module is used to determine the direction finding ray direction by measuring the azimuth and elevation angles of the satellite with respect to the radiation source position based on the satellite's current position, and to define three-dimensional positioning parameters based on the direction finding ray direction. The three-dimensional positioning module uses three-dimensional positioning parameters and time difference equations to determine the direction finding ray ratio coefficient, and then uses the direction finding ray ratio coefficient to determine the three-dimensional coordinate information of the aerial maneuvering target, thus completing the radiation source positioning.

8. A three-dimensional passive localization method for aerial maneuvering targets based on single-satellite enhancement according to claim 7, characterized in that: During the calculation of the received data time difference, the received data time difference changes in real time according to the satellite's current position si and the shore-based receiving subsystem's position sa at the selected time.

9. A three-dimensional passive localization method for aerial maneuvering targets based on single-satellite enhancement according to claim 7, characterized in that: In the process of calculating the three-dimensional positioning of the radiation source target, the direction finding ray scaling factor is determined based on the three-dimensional positioning parameters and time difference equation, the ray scaling factor is constructed, and the three-dimensional coordinate information of the aerial maneuvering target is obtained.

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