Target refraction error high-precision compensation method based on three-dimensional time difference positioning and detection equipment

Abstract

The invention relates to the technical field of passive positioning, and discloses a target refraction error high-precision compensation method based on three-dimensional time difference positioning, and the method comprises the steps: obtaining a troposphere atmosphere refractive index distribution profile, the actual measurement time delay inequality and station position of each receiving station, and the distance between the initial radiation source position and each receiving station; according to the troposphere atmospheric refractive index distribution profile, the apparent distance of each grid point position and distance errors corresponding to different apparent distances are obtained; performing refraction compensation on the actually measured delay inequality of each receiving station according to the distance between the initial radiation source position and each receiving station, the apparent distance of each grid point position and distance errors corresponding to different apparent distances to obtain the delay inequality of each receiving station; and performing refraction compensation on the initial radiation source position according to the station position of each receiving station and the delay inequality to obtain a target radiation source position. The invention further discloses detection equipment.

Description

Technical Field

[0001] The present application relates to the field of passive positioning technology, for example, to a high-precision compensation method and detection equipment for target refraction error based on three-dimensional time difference positioning. Background Art

[0002] The current positioning system mainly includes two types of target positioning methods: active positioning and passive positioning. Active positioning uses active equipment to transmit high-power signals to receive the echo signal returned by the target to detect the target; passive positioning does not transmit signals to the target, but only determines the target's position by receiving electromagnetic waves radiated, reflected and scattered by the radiation source (He You, Xiu Xiujuan, Tang Xiaoming, et al. Over-the-horizon target positioning and tracking based on time difference information [J], Journal of Electronics, 2003, 31(12)). The level of advancement of future weapon systems is increasingly dependent on the level of advancement of their electronic information systems. Faced with the rapid development of electronic countermeasures and stealth technology, traditional active positioning systems are prone to expose themselves due to their active signal transmission. Passive positioning, due to its non-signal transmission and one-way transmission, has the advantages of good concealment and long detection distance, and has occupied an increasingly important position in modern warfare (Xu Kehui. Time difference positioning method and its engineering implementation [D]. Master's thesis of University of Electronic Science and Technology of China, 2015). Current passive positioning systems mainly use time difference of arrival (TDOA) technology for target positioning. This technology assumes that electromagnetic waves propagate in a straight line at the speed of light. By measuring the time difference of the signal arriving at different stations and multiplying it by the speed of light, the distance difference between the radiation source and the monitoring station can be obtained. Through this distance difference, a hyperbolic equation can be obtained. By selecting appropriate monitoring stations, a hyperbolic equation group can be obtained. By solving the hyperbolic equation group, the position of the radiation source can be obtained (Zhao Guangwei, Li Li, Wang Kui. Analysis of the influence of channel delay in passive time difference positioning system [J]. Electronic Information Countermeasures Technology, 2015, 30(2)).

[0003] Li Ting (Li Ting, The influence of station layout mode on the accuracy of four-station time difference positioning [J], Ship Electronic Countermeasures, 2021, 44 (4)) studied the influence of station layout mode on the accuracy of four-station time difference positioning through theoretical analysis and simulation methods, which has a good guiding significance for engineering applications. Niu Xinliang et al. (Niu Xinliang, Zhao Guoqing, Liu Yuanhua et al., High-precision passive time difference positioning method for low-altitude targets [J], Journal of Xidian University, 2009, 36 (5)) proposed an improved passive time difference positioning method to address the shortcomings of the traditional passive time difference positioning method in not being able to locate low-altitude targets well. This method adds the measurement of the target elevation angle at the main station to form a redundant positioning system consisting of three subsystems, which achieves better performance than the traditional passive time difference positioning method. Liao Haijun (Liao Haijun, Accuracy Analysis and Related Technology Research of Multi-station Passive Positioning [D], Master's Thesis of University of Electronic Science and Technology of China, 2008.5) conducted an in-depth and specific study on the principle and positioning accuracy of multi-station positioning technology in passive positioning technology, including various positioning methods of multi-station passive positioning technology, positioning accuracy and error distribution of corresponding positioning algorithms, multi-station network error registration, etc., providing the necessary theoretical basis and key technologies for the system design and application of multi-station network positioning technology. Zhang Yuxi et al. (Zhang Yuxi, Tong Yuliang, Zhang Xia et al., Analysis of the Impact of Time-sharing Time Difference Positioning Technology on System Positioning Accuracy [J], 2023.43(3)) proposed a new time difference positioning method to solve the problem that a detection station of a distributed time difference positioning system in actual engineering fails to receive the target signal in a short period of time and cannot complete the continuous positioning and tracking task. The method uses the time difference pairing of two stations at different times to complete the positioning task. Wu Peng (Wu Peng, Multi-station Passive Positioning Based on TDOA [D], Master's Thesis of National University of Defense Technology, 2019.10) conducted research on the three key technologies of multi-station passive positioning based on TDOA: non-cooperative signal recognition of target radiation source, high-precision estimation of time delay and multi-station passive positioning solution method. Lei Wenying et al. (Lei Wenying, Chen Boxiao, Yang Minglei et al., Three-dimensional Passive Target Positioning Method Based on TOA and TDOA [J], Systems Engineering and Electronic Technology, 2014, 36(5)) proposed a passive positioning method for high-precision three-dimensional positioning of targets by an aerial moving platform based on arrival time TOA and TDOA. This method uses the TOA of the signals from three auxiliary stations to the aerial moving platform and the position of the auxiliary station to determine the position of the aerial moving platform itself, and then determines the position of the target based on the TDOA of the target scattered echo arriving at each auxiliary station and the aerial moving platform. This algorithm has higher accuracy than the classic TDOA positioning algorithm and does not have positioning ambiguity, thereby verifying the effectiveness and correctness of the passive positioning method for the aerial moving platform to the target.

[0004] A common shortcoming of the aforementioned literature is that they fail to consider the influence of refraction in the actual tropospheric atmospheric environment during time-of-day positioning. They treat electromagnetic waves as propagating in a straight line at the speed of light in free space, completely ignoring the delay error caused by atmospheric refraction. If atmospheric refraction is ignored and the target's transmitted signal is assumed to propagate in a vacuum, the difference in path length between the target reaching receiving station A and receiving station B can be calculated based on spatial geometry, and the differential delay is a fixed value. However, the actual atmosphere is complex, and the spatial and temporal distribution of the tropospheric refractive index is uneven, causing the atmospheric refraction error on the two paths to continuously vary in space and time. Consequently, the differential delay on the two paths also varies and is no longer a fixed value. This leads to differential delay errors in passive positioning systems, and the greater the environmental variation, the lower the time-of-day accuracy. With the continuous advancement of modern signal processing synchronization technology and the timing performance of electronic systems, current reconnaissance equipment has placed higher demands on the positioning accuracy of targets, especially those at long distances. The delay error caused by atmospheric refraction cannot be ignored and is gradually becoming a major source of error in target positioning in time-of-day positioning systems.

[0005] Dong Xiang et al. (Dong Xiang, Ci Ying, Sheng Wugang et al., Influence of atmospheric waveguide on the differential delay accuracy of passive positioning [J]. Journal of Radio Science, 2020, 35(6)) used the Taylor series approximation ray tracing algorithm to simulate the propagation path modeling and calculation of the time difference positioning system for beyond-horizon targets, analyzed the differential delay error and multipath relative delay under different waveguide environments, and evaluated the delay difference accuracy of the time difference positioning system for atmospheric waveguide beyond-horizon targets, providing environmental protection and technical support for the working performance and parameter design of the passive time difference positioning system. Zhu Qinglin et al. (Zhu Qinglin, Sun Fang, Yao Shanfeng et al., Refraction Correction Technology for Time-of-Sight Positioning under Beyond-Horizon Propagation Mechanism [J]. Systems Engineering and Electronic Technology, 2024.12) proposed a refraction correction technology for time-of-sight positioning under beyond-horizon propagation mechanism based on the ray tracing algorithm, targeting the propagation path characteristics of electromagnetic waves in atmospheric ducts and troposcatter environments. They also evaluated the accuracy of the correction results using the principle of geometric dilution of precision. The evaluation results fully verified the effectiveness and accuracy of the correction technology, and the use of this technology can significantly improve the positioning accuracy of passive time-of-sight positioning systems for beyond-horizon targets. Zhou Meiru (Zhou Meiru, Distributed Beyond-Horizon Time-of-Sight Positioning Technology Based on Tropospheric Scatter Propagation [D]. Master's Thesis, Xidian University, 2022.6) proposed a distributed beyond-horizon time-of-sight positioning method based on tropospheric scatter propagation. This method not only compensates for the shortcomings of existing tropospheric scatter path models and atmospheric duct path models, but also determines the channel type of the target signal received by the ground monitoring station, thereby achieving accurate positioning of distant targets. Zhang Shuqiang (Zhang Shuqiang, Guo Fucheng, Zhang Min, et al., Influence and correction of atmospheric refraction on time difference positioning error under elevation constraint [J]. Systems Engineering and Electronic Technology, 2020.42(3)) proposed a time difference positioning error correction algorithm based on iteration and then improved particle swarm optimization under atmospheric refraction conditions, and verified the effectiveness of the correction algorithm.

[0006] Although the above-mentioned literature has fully considered the impact of atmospheric refraction on the accuracy of time-of-day positioning, there are still some shortcomings: First, most of them are aimed at the impact of atmospheric waveguides and tropospheric scattering over-the-horizon environments on sea surface targets in shore-to-ship and ship-to-ship combat scenarios, and adopt a three-station two-dimensional time-of-day positioning method, which can only give a two-dimensional plane refraction error and cannot calculate the height error of high-altitude targets at sea; second, in the calculation of refraction error, empirical models such as segmented models or equivalent earth radius methods are used to obtain the atmospheric refractive index profile, which can only reflect the statistical average value of atmospheric refraction parameters. No high-precision real-time acquisition method of atmospheric refraction parameters suitable for engineering practice is given. The low prediction accuracy of the atmospheric environment will directly lead to low compensation accuracy of refraction error; third, in the refraction correction process, it is necessary to repeatedly iteratively approximate the measured value to obtain the true target distance. This method is time-consuming and computationally inefficient, and will be subject to certain limitations in actual engineering reconnaissance scenarios such as large areas and multiple targets. Summary of the Invention

[0007] In order to provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. The summary is not an extensive review, nor is it intended to identify key / critical elements or delineate the scope of protection of these embodiments, but rather serves as a prelude to the detailed description that follows.

[0008] The embodiments of the present disclosure provide a high-precision compensation method and detection equipment for target refraction errors based on three-dimensional time-difference positioning, so as to improve the positioning accuracy of the time-difference positioning system for large areas and multiple targets at high altitudes.

[0009] In some embodiments, the method includes: obtaining the tropospheric atmospheric refractive index distribution profile and the measured time delay difference and site location of each receiving station, and the distance between the initial radiation source position and each receiving station; obtaining the apparent distance of each grid point position and the distance error corresponding to different apparent distances based on the tropospheric atmospheric refractive index distribution profile; performing refraction compensation on the measured time delay difference of each receiving station based on the distance between the initial radiation source position and each receiving station, the apparent distance of each grid point position and the distance error corresponding to different apparent distances to obtain the time delay difference of each receiving station; performing refraction compensation on the initial radiation source position based on the site location and time delay difference of each receiving station to obtain the target radiation source position.

[0010] In some embodiments, the refractive index distribution profile of the tropospheric atmosphere is obtained in the following manner: historical sounding data, measured ground data and measured brightness temperature data are obtained; wherein the measured ground data include ground temperature, ground humidity and atmospheric pressure; based on the historical sounding data and the measured ground data and the measured brightness temperature data, a network inversion is performed using a neural network deep inversion algorithm to obtain the refractive index distribution profile of the tropospheric atmosphere.

[0011] In some embodiments, the apparent distance of each grid point position and the distance errors corresponding to different apparent distances are obtained based on the tropospheric atmospheric refractive index distribution profile, including: obtaining a coarsening stratification principle; wherein the coarsening stratification principle includes that the altitude interval gradually increases with increasing altitude, and / or the elevation angle interval gradually increases with increasing elevation angle; based on the tropospheric atmospheric refractive index distribution profile and the coarsening stratification principle, the detection area is gridded to determine the position of each grid point; based on the tropospheric atmospheric refractive index distribution profile, the apparent distance of different grid point positions and the distance errors corresponding to different apparent distances are obtained through spherical layered ray tracing technology.

[0012] In some embodiments, based on the atmospheric refractive index distribution profile of the tropospheric atmosphere, the apparent distances of different grid point positions and the distance errors corresponding to the different apparent distances are obtained by a spherical layered ray tracing technique, including: obtaining the spherical Snell's law constant term and the observation station altitude and the earth's radius, the target altitude, and the refractive index at the current integration height; wherein the target altitude represents the altitude corresponding to each grid point position; determining the apparent distances of different grid point positions based on the spherical Snell's law and the spherical Snell's law constant term, the lower integration limit, and the upper integration limit; wherein the lower integration limit represents the sum of the observation station altitude and the earth's radius, and the upper integration limit represents the sum of the target altitude and the earth's radius; determining the geocentric angle between the observation station and different grid points based on the refractive index at the current integration height and the spherical Snell's law constant term, the lower integration limit, and the upper integration limit; determining the true distance of different grid point positions based on the law of cosines and the target altitude, the lower integration limit, and the geocentric angle between the observation station and different grid points; and determining the difference between the apparent distance and the true distance of each grid point position to obtain the distance error corresponding to each apparent distance.

[0013] In some embodiments, the receiving station includes a main receiving station and three secondary receiving stations; refraction compensation is performed on the measured time delay difference of each receiving station according to the distance between the initial radiation source position and each receiving station, the apparent distance of each grid point position, and the distance error corresponding to different apparent distances to obtain the time delay difference of each receiving station, including: obtaining the initial distance error between the initial radiation source position and each receiving station using a bilinear interpolation algorithm according to the apparent distance of each grid point position and the distance error corresponding to different apparent distances; error compensation is performed on the initial distance error between the initial radiation source position and each receiving station to obtain the actual distance between each secondary receiving station and the main receiving station; and the time delay difference of each receiving station is obtained according to the actual distance between each secondary receiving station and the main receiving station.

[0014] In some embodiments, a bilinear interpolation algorithm is used to obtain the initial distance error between the initial radiation source position and each receiving station based on the apparent distance of each grid point position and the distance error corresponding to the different apparent distances, including: obtaining the apparent distance between the target radiation source and the main receiving station and the apparent distance between the target radiation source and each secondary receiving station based on the distance equation; using the apparent elevation angle and apparent distance of different grid point positions and the distance error matrix, a bilinear interpolation algorithm is used to obtain the initial distance error between the initial radiation source position in the current grid position and the four receiving stations.

[0015] In some embodiments, obtaining the initial radiation source position includes: constructing a position difference matrix based on the site position of each receiving station; obtaining an initial radiation source position estimate based on a distance equation; substituting the initial radiation source position estimate into the distance equation to obtain the apparent distance between the target radiation source and the main receiving station; and obtaining the initial radiation source position based on the apparent distance between the target radiation source and the main receiving station and the radiation source estimate equation.

[0016] In some embodiments, the device includes a processor and a memory storing program instructions, and the processor is configured to execute the aforementioned high-precision compensation method for target refraction error based on three-dimensional time difference positioning when running the program instructions.

[0017] In some embodiments, the detection device includes: a detection device body; and a target refractive index error compensation device based on three-dimensional time difference positioning as described above, which is installed on the detection device body.

[0018] In some embodiments, the storage medium stores program instructions, which, when executed, enable a computer to execute the aforementioned high-precision target refraction error compensation method based on three-dimensional time difference positioning.

[0019] The high-precision target refraction error compensation method and detection device based on three-dimensional time-of-day positioning provided by the embodiments of the present disclosure can achieve the following technical effects:

[0020] In order to solve the problem that the positioning accuracy of high-altitude targets decreases significantly with increasing distance due to the failure to consider the atmospheric refraction effect in the CHAN algorithm, the influence of atmospheric refraction is fully considered. For large-area and multi-target reconnaissance application scenarios, the atmospheric refraction error distribution prediction is obtained through the tropospheric atmospheric refraction index profile. Combined with the CHAN algorithm, the refraction error of the main and secondary receiving stations of the measured target radiation source of the four-station three-dimensional time difference positioning system is compensated. This can efficiently and significantly improve the positioning accuracy of the time difference positioning system for large-area and multi-target high-altitude positioning.

[0021] The above general description and the following description are exemplary and explanatory only and are not intended to limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] One or more embodiments are exemplarily described by corresponding drawings. These exemplary descriptions and drawings do not limit the embodiments. Elements with the same reference numerals in the drawings are shown as similar elements. The drawings do not constitute a scale limitation. In addition,

[0023] Figure 1 This is a schematic diagram of a target detection system using a four-station passive reconnaissance time difference positioning system according to an embodiment of the present disclosure;

[0024] Figure 2This is a diagram showing the principle of hyperbolic positioning using the CHAN algorithm provided by an embodiment of the present disclosure;

[0025] Figure 3 This is a comparison of atmospheric refractive index profiles at a certain time in a coastal area obtained by different detection methods provided by the embodiments of the present disclosure; wherein the detection methods include empirical model prediction and microwave radiometer inversion;

[0026] Figure 4 is a schematic diagram of the ray description process used in the spherical layered ray tracing technology provided in an embodiment of the present disclosure;

[0027] Figure 5 1 is a schematic diagram of a high-precision compensation method for target refraction error based on three-dimensional time difference positioning provided by an embodiment of the present disclosure;

[0028] Figure 6 is a schematic diagram of another high-precision compensation method for target refraction error based on three-dimensional time difference positioning provided by an embodiment of the present disclosure;

[0029] Figure 7 is a schematic diagram of another high-precision compensation method for target refraction error based on three-dimensional time difference positioning provided by an embodiment of the present disclosure;

[0030] Figure 8 is a schematic diagram of another high-precision compensation method for target refraction error based on three-dimensional time difference positioning provided by an embodiment of the present disclosure;

[0031] Figure 9 is a schematic diagram of another high-precision compensation method for target refraction error based on three-dimensional time difference positioning provided by an embodiment of the present disclosure;

[0032] Figure 10-1 This is an example of comparing the three-dimensional coordinates of the target position before and after compensation for the atmospheric refraction error during the test provided by the embodiment of the present disclosure;

[0033] Figure 10-2 is the target positioning accuracy before and after atmospheric refraction error compensation provided by the embodiments of the present disclosure;

[0034] Figure 11 It is a schematic diagram of a target refractive index error compensation device based on three-dimensional time difference positioning provided by an embodiment of the present disclosure. DETAILED DESCRIPTION

[0035] In the description and claims of the embodiments of the present disclosure, as well as in the accompanying drawings, the terms "first," "second," and the like are used to distinguish similar items and are not necessarily used to describe a particular order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate to describe the embodiments of the present disclosure herein. In addition, the terms "including," "having," and any variations thereof are intended to cover non-exclusive inclusions.

[0036] Unless otherwise stated, the term "plurality" means two or more.

[0037] In the embodiment of the present disclosure, the character " / " indicates that the preceding and following objects are in an "or" relationship. For example, A / B means: A or B.

[0038] The term "and / or" describes an association between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or A and B.

[0039] The term "correspondence" may refer to an association relationship or a binding relationship. The correspondence between A and B means that there is an association relationship or a binding relationship between A and B.

[0040] Combine Figure 1 As shown in the figure, the four-station passive reconnaissance time-difference positioning system (hereinafter referred to as the time-difference positioning system) includes receiving stations, meteorological sensors, and microwave radiometers. The receiving stations include a primary receiving station and four secondary receiving stations. ☆ represents the location of the primary receiving station, while measurement stations 1, 2, and 3 are the three secondary receiving stations. The four receiving stations constitute the four-station passive reconnaissance time-difference positioning system. △ represents the location of the target emitter. The system locates the target emitter by receiving the time delay difference between the target emitter and the four receiving stations.

[0041] In the disclosed embodiment, the CHAN algorithm represents a positioning algorithm based on TDOA (Time Difference of Arrival) technology. Its core idea is to measure the time difference between the target signal arriving at multiple base stations, combine the base station coordinate information, construct a set of hyperbolic equations, and then solve the target position. The hyperbolic positioning principle of the CHAN algorithm in time difference positioning technology is as follows: Figure 2 The CHAN algorithm is a non-recursive method for solving hyperbolic equations with an analytical expression. Its key features are high positioning accuracy and minimal computational effort when the measurement error follows an ideal Gaussian distribution. Furthermore, the algorithm's accuracy can be improved by increasing the number of base stations. The algorithm is based on the assumption that the measurement error is a zero-mean Gaussian random variable. However, its performance degrades significantly for measurements with large errors in real-world environments, such as those with non-line-of-sight errors.

[0042] Meteorological sensors are used to measure ground temperature, humidity, and atmospheric pressure. Microwave radiometers utilize the atmospheric brightness temperature in the microwave band to remotely invert atmospheric parameters. Due to transitions in electronic, vibrational, and rotational energy levels within matter, the atmosphere can radiate electromagnetic waves or absorb electromagnetic radiation of corresponding frequencies over a wide frequency band. Similarly, due to differences in their physical and chemical properties, different atmospheric molecules emit and transmit electromagnetic signals containing characteristic information within specific frequency bands. Ground-based microwave radiometers enable high-precision, real-time inversion of key atmospheric parameters such as tropospheric temperature profiles, water vapor density profiles, refractive index profiles, integrated water vapor content, and liquid water content. This allows for the study of the atmospheric's spatiotemporal characteristics and supports applications in various fields, including high-precision orbit determination, navigation positioning, and weather forecasting.

[0043] Figure 3 This is a comparison of atmospheric refractive index profiles at a certain time in a coastal area obtained by different detection methods provided by the embodiment of the present disclosure. The climate characteristics of the above coastal area are that the water vapor fluctuates violently, the atmospheric refractive index changes significantly in time and space, and atmospheric refractive effects such as super refraction and anomalous refraction often occur within the low-altitude sea-air boundary. Figure 3 As shown in Figure 1, the atmospheric refractivity predicted using empirical models is generally a statistical average, which cannot accurately reflect the local, real-time atmospheric refractivity environment. Using the atmospheric refractivity profiles obtained from meteorological parameters measured by sounding balloons at the regional meteorological stations as the true values, the error between the microwave radiometer-derived profiles and the profiles predicted by the segmented model was compared. The comparison results show that the real-time refractivity error of the microwave radiometer-derived refractivity is much smaller than that predicted by the segmented model, with a clear technical advantage at altitudes below 5 km.

[0044] The time difference positioning system calculates the apparent distance of different grid points and the distance error corresponding to different apparent distances through the spherical layered ray tracing technology. The ray description process used in the spherical layered ray tracing technology is as follows: Figure 4 As shown. Combined Figure 4 As shown in the figure, the ray tracing technology starts from the ray equation, based on the assumption of spherical stratification, uses the principles of geometric optics, according to the atmospheric refractive index profile, the geometric relationship between the radar and the target, and based on the strict mathematical derivation of the spherical Snell's law to derive the calculation formula of the refraction error. It is the model algorithm with the highest calculation accuracy in the field of refraction correction so far.

[0045] Based on the above time difference positioning system, combined with Figure 5 As shown, the embodiment of the present disclosure provides a high-precision compensation method for target refraction error based on three-dimensional time difference positioning, including:

[0046] S01, the detection equipment obtains the distribution profile of the atmospheric refractive index in the troposphere and the measured time delay difference of each receiving station and the station position, and the distance between the initial radiation source position and each receiving station.

[0047] S02, the detection equipment obtains the apparent distance of each grid point and the distance error corresponding to different apparent distances based on the distribution profile of the atmospheric refractive index in the troposphere.

[0048] S03, the detection equipment performs refraction compensation on the measured time delay difference of each receiving station based on the distance between the initial radiation source position and each receiving station, the apparent distance of each grid point position, and the distance error corresponding to different apparent distances to obtain the time delay difference of each receiving station.

[0049] S04: The detection device performs refraction compensation on the initial radiation source position according to the site position and time delay difference of each receiving station to obtain the target radiation source position.

[0050] The high-precision compensation method for target refraction error based on three-dimensional time-of-day positioning provided by the embodiment of the present disclosure is adopted. The embodiment of the present disclosure addresses the problem that the positioning accuracy of high-altitude targets decreases significantly with increasing distance due to the failure to consider the atmospheric refraction effect in the CHAN algorithm. By fully considering the influence of atmospheric refraction, for large-area, multi-target reconnaissance application scenarios, the atmospheric refraction error distribution prediction is obtained through the tropospheric atmospheric refractive index profile, and the refraction error of the main and secondary receiving stations of the measured target radiation source of the four-station three-dimensional time-of-day positioning system is compensated in combination with the CHAN algorithm. This can efficiently and significantly improve the positioning accuracy of the time-of-day positioning system for large-area, multi-target high-altitude areas.

[0051] Optionally, the detection device obtains the tropospheric atmospheric refractive index distribution profile in the following manner:

[0052] The detection equipment obtains historical sounding data, measured ground data, and measured brightness temperature data. The measured ground data includes ground temperature, ground humidity, and atmospheric pressure.

[0053] The detection equipment performs network inversion based on historical sounding data, measured ground data, and measured brightness temperature data using a neural network deep inversion algorithm to obtain the tropospheric atmospheric refractive index distribution profile.

[0054] In this way, the disclosed embodiment combines historical sounding data, measured ground data and measured brightness temperature data to perform neural network inversion, which can obtain high-precision atmospheric refractive index distribution profiles in real time, providing data support for subsequent target radiation source positioning.

[0055] As an example, the detection equipment uses a neural network deep inversion algorithm to perform network inversion based on historical sounding data, measured ground data, and measured brightness temperature data to obtain the tropospheric atmospheric refractivity distribution profile, including:

[0056] S101: The detection equipment selects historical sounding data for sample data according to the latitude, longitude and altitude of different receiving stations, calculates the atmospheric pressure, ground temperature and water vapor pressure at the specified altitude layer based on basic parameters, and obtains atmospheric refractive index profile data based on the atmospheric refractive index formula and measured ground data.

[0057] In this step, the atmospheric refractive index formula is: Where P is atmospheric pressure (hPa), e is water vapor pressure (hPa), and T is absolute temperature (K). The absolute temperature is determined by the ground temperature.

[0058] S102: The detection equipment calculates and obtains the measured brightness temperature data based on the atmospheric radiation transfer equation.

[0059] In this step, the detection device calculates and obtains the measured brightness temperature data according to the atmospheric radiation transfer equation. Specifically, the detection device defines a general expression for the brightness temperature in the zenith direction according to the atmospheric radiation transfer equation. The general expression is:

[0060]

[0061] in, represents the brightness temperature in K. T(r) represents the atmospheric temperature at height r in K. k e =k a +k s , which represents the volume attenuation coefficient of the medium (i.e., volume extinction coefficient) and is equal to the sum of the volume absorption coefficient and the volume scattering coefficient, unit: N p ·m -1 . It represents the optical thickness of the atmosphere in the zenith direction between the ground and the height r, and the unit is N p .

[0062] The detection equipment calculates the downward radiation brightness temperature of the atmosphere measured by the microwave radiometer when observing upward based on the atmospheric radiation transfer equation and determines the radiation brightness temperature as the measured brightness temperature data.

[0063] In this step, the radiant brightness temperature is:

[0064]

[0065] Where θ represents the zenith angle, T EXTRA Indicates the brightness temperature of outer space. When the frequency is greater than 5GHz, it is usually considered that its T EXTRA Equal to the cosmic background temperature of 2.73K. z represents the altitude (km). k a (z) represents the atmospheric absorption coefficient (N pThe atmospheric absorption coefficient is primarily composed of absorption by oxygen and water vapor, as well as absorption by liquid water, and is correlated with the atmospheric temperature, humidity, and pressure at that altitude. T(z) represents the physical temperature of the atmosphere (K). It should be noted that in the radiation brightness temperature formula, the zenith angle and outer space brightness temperature, the atmospheric absorption coefficient, and the physical temperature of the atmosphere are all determined from historical sounding data.

[0066] S103, the detection equipment uses the historical sounding data trained by the neural network to establish an inversion network between the measured brightness temperature data, the measured ground data, the atmospheric refractivity profile data and the inversion parameters according to the mean square error requirement.

[0067] At step S104, the detection device obtains the mean square error (MSE), completes network training if the MSE meets the MSE requirement, and determines that the output of the neural network is the atmospheric refractivity profile. It is understood that in this step, if the MSE does not meet the MSE requirement, network training continues until the updated MSE meets the MSE requirement.

[0068] Optionally, combined Figure 6 As shown in the figure, the detection equipment obtains the apparent distance of each grid point and the distance error corresponding to different apparent distances based on the tropospheric atmospheric refractive index distribution profile, including:

[0069] S11, the detection device obtains a coarsening stratification principle, wherein the coarsening stratification principle includes gradually increasing the height interval as the height increases, and / or gradually increasing the elevation angle interval as the elevation angle increases.

[0070] S12, the detection equipment divides the detection area into grids based on the tropospheric atmospheric refractive index distribution profile and the coarse stratification principle, and determines the position of each grid point.

[0071] S13, based on the refractive index distribution profile of the tropospheric atmosphere, the detection equipment obtains the apparent distances of different grid point positions and the distance errors corresponding to different apparent distances through the spherical layered ray tracing technology.

[0072] In this way, since the refractive error is directly related to the refractive index and the gradient of the height profile, the greater the refractive index and the refractive index gradient, the greater the distance error integrated along the ray path, and the characteristic of the atmospheric refractive index profile is that it decreases exponentially along the height. Based on the above situation, in the detection area with low altitude and small elevation angle, the distance error changes greatly, and conversely, the distance error changes less. According to the distribution characteristics of the atmospheric refractive error, taking into account the error correction accuracy and the calculation amount of the correction coefficient, the embodiment of the present disclosure adopts an unequal interval division method, that is, a smaller height interval is selected at low elevation angles and low altitudes, and the height interval tends to increase with the increase of elevation angle and altitude. By adopting the above-mentioned coarsening and stratification principle, it can be ensured that the distance error matrix calculation of the flight area is carried out in advance without affecting the calculation accuracy, so that the apparent distance and distance error of different grid point positions at high altitude can be quickly obtained.

[0073] In a specific embodiment, the coarsening layering principle refers to Table 1 and Table 2.

[0074] Table 1 Example of height interval division

[0075] Height (unit, km) Height interval (unit, m) (0，1] 10 (1，3] 20 (3，5] 50 (5，10] 100 (10，20] 150 (20，60] 250

[0076] Table 2 Example of elevation interval division

[0077] Elevation angle (unit, °) Elevation angle interval (unit, °) (0，3.0] 0.1 (3.0，5.0] 0.2 (5.0，6.0] 0.5 (6.0，8.0] 1.0 (8.0，12.0] 2.0 (12.0，30.0] 3.0 (30.0，40.0] 5.0 (40.0，60.0] 10.0 (60.0，90.0] 15.0

[0078] Optionally, combined Figure 7 As shown in the figure, the detection equipment uses the spherical layered ray tracing technology based on the tropospheric atmospheric refractive index distribution profile to obtain the apparent distances at different grid points and the distance errors corresponding to different apparent distances, including:

[0079] S21, the detection device obtains the spherical Snell's law constant, the observation station altitude, the radius of the earth, the target altitude, and the refractive index at the current integrated altitude. The target altitude represents the altitude corresponding to each grid point position.

[0080] S22: The detection equipment determines the apparent distances at different grid points based on Snell's law, the constant term, the lower limit of integration, and the upper limit of integration. The lower limit of integration represents the sum of the observation station's altitude and the Earth's radius, and the upper limit of integration represents the sum of the target's altitude and the Earth's radius.

[0081] S23, the detection equipment determines the geocentric angle between the observation station and different grid points based on the refractive index at the current integration height and the constant term of Snell's law on the spherical surface, the lower limit of integration, and the upper limit of integration.

[0082] S24, the detection equipment determines the true distances of different grid points based on the law of cosines, the target altitude, the lower limit of integration, and the geocentric angle between the observation station and the different grid points.

[0083] S25, the detection device determines the difference between the apparent distance and the actual distance of each grid point position, and obtains the distance error corresponding to each apparent distance.

[0084] In this way, combining the atmospheric refractive index profile and the CHAN algorithm to compensate for the refraction error of the main and auxiliary receiving stations of the four-station three-dimensional time difference positioning system's measured target radiation source can efficiently and significantly improve the positioning accuracy of the time difference positioning system for large areas and multiple targets at high altitudes.

[0085] As an example, the detection device obtains the apparent distances at different grid points and the distance errors corresponding to the different apparent distances through spherical layered ray tracing technology based on the tropospheric atmospheric refractive index distribution profile. Specifically, the following steps are performed:

[0086] S201: The detection device obtains the constant term of the spherical Snell's law, the observation station altitude h0, the earth radius a, the target altitude, and the refractive index n at the current integration height. The constant term of the spherical Snell's law is:

[0087] A0=n0r0cosθ0

[0088] In the above formula, n0 represents the refractive index at the time difference positioning system observation station. r0 = a + h0, where a = 6371 km, h0 represents the altitude of the observation station, and θ0 represents the ray elevation angle at the observation station.

[0089] S202: The detection device derives the apparent distances of different grid point positions according to Snell's law on the spherical surface.

[0090] Among them, the apparent distances at different grid point positions are:

[0091]

[0092] In the above formula, the upper limit of the integral is r T =a+h T , h T Indicates the target altitude, r0 indicates the upper limit of integration. r=a+h, where h is the current integration altitude.

[0093] S203: The detection equipment derives the geocentric angle between the observation station and different grid points based on Snell's law on the spherical surface. Among them, the geocentric angle Expressed as:

[0094]

[0095] S204: The detection equipment determines the true distances of different grid points based on the law of cosines, the target altitude, the lower limit of integration, and the geocentric angle between the observation station and the different grid points. The true distances of different grid points are:

[0096]

[0097] S203: The detection device calculates the difference between the apparent distance and the actual distance at each grid point to obtain the distance error corresponding to each apparent distance. The distance error ΔR is expressed as:

[0098] ΔR=R e -R0.

[0099] Optionally, combined Figure 8 As shown in the figure, the detection equipment performs refraction compensation on the measured delay difference of each receiving station based on the distance between the initial radiation source position and each receiving station, the apparent distance of each grid point position, and the distance error corresponding to different apparent distances, and obtains the delay difference of each receiving station, including:

[0100] S31, the detection device uses a bilinear interpolation algorithm to obtain the initial distance error between the initial radiation source position and each receiving station according to the apparent distance of each grid point position and the distance error corresponding to different apparent distances.

[0101] In this step, the detection device uses a bilinear interpolation algorithm to obtain the initial distance error between the initial radiation source position and each receiving station based on the apparent distance of each grid point position and the distance error corresponding to different apparent distances, including:

[0102] The detection equipment obtains the apparent distance R0 between the target radiation source and the main receiving station and the apparent distance R0 between the target radiation source and each secondary receiving station according to the distance equation. i .

[0103] The detection equipment uses the apparent elevation angle, apparent distance, and distance error matrix of different grid point positions, and uses a bilinear interpolation algorithm to obtain the initial distance error ΔR between the initial radiation source position in the current grid position and the four receiving stations. t .

[0104] Among them, the initial distance error ΔR t for:

[0105]

[0106] In the above formula, k represents the grid point number, θ k represents the apparent elevation angle sequence composed of the apparent elevation angles at different grid point positions, R i The apparent distance sequence corresponding to the apparent distances at different grid point positions, ΔR i,kRepresents the distance error matrix composed of distance errors corresponding to different apparent distances.

[0107] It should be noted that the apparent elevation angles at different grid points are determined by the elevation angles in steps S11 and S12 of the aforementioned embodiment. As an example, the apparent elevation angle at a particular grid point is equal to the sum of the elevation angle at that grid point and the correction angle. The correction angle is preset by the spatiotemporal positioning system.

[0108] S32, the detection device performs error compensation on the initial distance error between the initial radiation source position and each receiving station, and obtains the actual distance between each secondary receiving station and the main receiving station.

[0109] In this step, the detection equipment compensates for the initial distance error between the initial radiation source position and each receiving station to obtain the actual distance between each secondary receiving station and the main receiving station, including:

[0110]

[0111] Among them, r true0 represents the actual distance between the target radiation source and the main receiving station after error compensation, r truei It represents the actual distance between the target radiation source and the i-th secondary receiving station after error compensation.

[0112] S33, the detection device obtains the delay difference of each receiving station according to the actual distance between each secondary receiving station and the main receiving station.

[0113] In this step, the detection equipment compensates for the initial distance error between the initial radiation source position and each receiving station to obtain the actual distance between each secondary receiving station and the main receiving station, including:

[0114] The detection device calculates the difference between the actual distance between the target radiation source and the i-th secondary receiving station after error compensation and the actual distance between the target radiation source and the primary receiving station after error compensation to obtain the true distance difference.

[0115] The detection equipment compares the actual distance difference with the speed of light to obtain the delay difference of each receiving station. The delay difference of each receiving station includes Δt' 10 and Δt' 20 , Δt' 30 , which includes:

[0116]

[0117] In this way, the disclosed embodiment combines the CHAN algorithm and the bilinear interpolation algorithm to compensate for the refraction error of the time delay difference between the main and secondary receiving stations of the measured target radiation source of the four-station three-dimensional time difference positioning system, which can efficiently and significantly improve the positioning accuracy of the time difference positioning system for large areas and multiple targets at high altitudes.

[0118] Optionally, the detection device performs refraction compensation on the initial radiation source position according to the site position and delay difference of each receiving station to obtain the target radiation source position, including: the detection device inputs the delay difference to the CHAN algorithm for target positioning to obtain the target radiation source position.

[0119] Optionally, combined Figure 9 As shown, the detection device obtains the initial radiation source position, including:

[0120] S41: The detection device constructs a position difference matrix A based on the site location of each receiving station. The position difference matrix A is a 3×3 matrix. The first column represents the difference between the horizontal coordinate of the site location of the primary receiving station and the horizontal coordinate of the site location of each secondary receiving station. The second column represents the difference between the vertical coordinate of the site location of the primary receiving station and the vertical coordinate of the site location of each secondary receiving station. The third column represents the difference between the depth coordinate of the site location of the primary receiving station and the depth coordinate of the site location of each secondary receiving station.

[0121] S42, the detection device obtains an initial radiation source position estimate based on the distance equation. The distance equation is:

[0122]

[0123] Among them, (x, y, z) represents the coordinates of the radiation source, (x0, y0, z0) represents the coordinates of the main receiving station, (x1, y1, z1), (x2, y2, z2), (x3, y3, z3) represent the coordinates of the three secondary receiving stations. R0 represents the apparent distance between the target radiation source and the main receiving station, R i Indicates the apparent distance between the target radiation source and each secondary receiving station. c represents the speed of light, Δt i It represents the time difference between the radiation source signal reaching the primary receiving station and the i-th secondary receiving station, i=1,2,3.

[0124] S43, the detection device substitutes the initial radiation source position estimate into the distance equation to obtain the apparent distance R0 between the target radiation source and the main receiving station.

[0125] S44, the detection device obtains the initial radiation source position according to the apparent distance R0 between the target radiation source and the main receiving station and the radiation source estimated value equation.

[0126] In this step, the radiation source estimation equation is:

[0127] in:

[0128] In this way, the embodiment of the present disclosure uses a four-station three-dimensional time difference positioning technology based on the CHAN algorithm to obtain the initial radiation source position before the target refraction error compensation through the three-dimensional coordinates of the four receiving stations and the time delay difference from the three secondary receiving stations to the main receiving station, thereby ensuring the positioning accuracy of the initial radiation source.

[0129] In a specific embodiment, considering the three-dimensional positioning requirement, the CHAN algorithm uses four base stations to participate in positioning. Figure 1 As shown in the figure, the radiation source is positioned in three-dimensional space. The space-time system is configured with a main receiving station A (x0, y0, z0), three secondary receiving stations B (x1, y1, z1), C (x2, y2, z2), and D (x3, y3, z3). Assuming that the position of the radiation source is (x, y, z), the distance difference is based on A.

[0130] Let the distance equation be:

[0131]

[0132] In the above formula, c represents the speed of light, Δt i is the time difference between the radiation source signal reaching the primary receiving station and the i-th secondary receiving station, i = 1, 2, 3. After rearranging the above formula, we can get:

[0133] (x0-x i )·x+(y0-y i )·y+(z0-z i )·z=k i +R0·Δr i

[0134] in,

[0135]

[0136] The above formula can form a system of equations. To solve the system of equations, first consider R0 as a known quantity, and we can get:

[0137] AX=F

[0138] Where A represents the position difference matrix, and A and F are expressed as:

[0139]

[0140] In the four-station time difference positioning, if rank(A)=3, the initial radiation source position estimate is

[0141]

[0142] That is, the initial radiation source position estimate can be expressed as the following radiation source estimate equation:

[0143]

[0144] in:

[0145]

[0146] Substituting the estimated value of the initial radiation source position into equation (1), we have:

[0147]

[0148] Among them, the coefficients of the radiation source estimation equation are:

[0149]

[0150] After solving equation (2) to obtain the apparent distance R0 between the target radiation source and the main receiving station, substitute it into the radiation source estimation equation to obtain the initial radiation source position.

[0151] In practical applications, Figure 10-1 This is an example of comparing the three-dimensional coordinates of the target position before and after compensation for the atmospheric refraction error during the test provided by the embodiment of the present disclosure. Figure 10-2 It is the target positioning accuracy before and after the atmospheric refraction error compensation provided by the embodiment of the present disclosure.

[0152] Combine Figure 10-1 The target position coordinates shown in the figure are obtained using refraction error compensation technology during the test, when the aircraft target flight trajectory was detected using the time difference positioning system. The target position before compensation and the actual position coordinates are shown. It can be seen that the target position after compensation is very consistent with the actual position, and positioning performance has been greatly improved.

[0153] Combine Figure 10-2 As shown in the figure, the time difference positioning accuracy before refraction error compensation decreases rapidly as the distance between the target and the main receiving station increases. The positioning error at long distances can reach more than 2000m, while the positioning error after compensation is only on the order of tens of meters. The positioning accuracy is improved by more than 96%, and the positioning performance is greatly improved.

[0154] Combine Figure 11As shown, an embodiment of the present disclosure provides a target refractive index error compensation device 70 based on three-dimensional time difference positioning, including a processor 700 and a memory 701. Optionally, the device 70 may also include a communication interface 702 and a bus 703. The processor 700, the communication interface 702, and the memory 701 can communicate with each other through the bus 703. The communication interface 702 can be used for information transmission. The processor 700 can call the logic instructions in the memory 701 to execute the high-precision target refractive index error compensation method based on three-dimensional time difference positioning of the above embodiment.

[0155] In addition, the logic instructions in the memory 701 can be implemented in the form of software functional units and can be stored in a computer-readable storage medium when sold or used as an independent product.

[0156] Memory 701, as a computer-readable storage medium, can be used to store software programs and computer-executable programs, such as program instructions / modules corresponding to the methods in the embodiments of the present disclosure. Processor 700 executes the program instructions / modules stored in memory 701 to perform functional applications and data processing, thereby implementing the high-precision target refraction error compensation method based on three-dimensional time-of-day positioning in the above-mentioned embodiments.

[0157] The memory 701 may include a program storage area and a data storage area. The program storage area may store an operating system and at least one application required for a function; the data storage area may store data generated based on the use of the terminal device. Furthermore, the memory 701 may include high-speed random access memory and non-volatile memory.

[0158] The embodiment of the present disclosure provides a detection device, comprising: a detection device body, and the above-mentioned target refractive index error compensation device 100 based on three-dimensional time difference positioning. The target refractive index error compensation device 100 based on three-dimensional time difference positioning is installed on the detection device body. The installation relationship described here is not limited to placement inside the detection device body, but also includes installation connections with other components of the detection device, including but not limited to physical connections, electrical connections or signal transmission connections, etc. Those skilled in the art will understand that the target refractive index error compensation device 100 based on three-dimensional time difference positioning can be adapted to a feasible product body, thereby realizing other feasible embodiments.

[0159] An embodiment of the present disclosure provides a computer-readable storage medium storing computer-executable instructions, wherein the computer-executable instructions are configured to execute the above-mentioned high-precision compensation method for target refraction error based on three-dimensional time difference positioning.

[0160] The technical solutions of the embodiments of the present disclosure may be embodied in the form of a software product, which is stored in a storage medium and includes one or more instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in the embodiments of the present disclosure. The aforementioned storage medium may be a non-transitory storage medium, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, among other media capable of storing program code.

[0161] The above description and the accompanying drawings fully illustrate the embodiments of the present disclosure so that those skilled in the art can practice them. Other embodiments may include structural, logical, electrical, process and other changes. The embodiments represent only possible variations. Unless explicitly required, individual components and functions are optional, and the order of operations may vary. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. Moreover, the words used in this application are only used to describe the embodiments and are not used to limit the claims. As used in the description of the embodiments and claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to also include plural forms. Similarly, the term "and / or" as used in this application refers to any and all possible combinations of one or more associated listings. In addition, when used in this application, the term "comprise" and its variations "comprises" and / or comprising refer to the presence of stated features, wholes, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or groups of these. In the absence of further restrictions, an element defined by the sentence "comprising a..." does not exclude the presence of other identical elements in the process, method or device that includes the element. In this article, each embodiment may focus on the differences from other embodiments, and the same and similar parts between the various embodiments can be referenced to each other. For the methods, products, etc. disclosed in the embodiments, if they correspond to the method part disclosed in the embodiments, then the relevant parts can be found in the description of the method part.

Claims

1. A high-precision compensation method for target refraction error based on three-dimensional time difference positioning, characterized in that: include: Obtain the distribution profile of the atmospheric refractivity in the troposphere, the measured time delay difference of each receiving station, the station location, and the distance between the initial radiation source location and each receiving station; According to the distribution profile of the atmospheric refractivity in the troposphere, the apparent distance of each grid point and the distance error corresponding to different apparent distances are obtained; The measured time delay difference of each receiving station is refraction-compensated based on the distance between the initial radiation source and each receiving station, the apparent distance of each grid point, and the distance error corresponding to different apparent distances to obtain the time delay difference of each receiving station. The initial radiation source position is refraction compensated according to the site location and time delay difference of each receiving station to obtain the target radiation source position.

2. The method according to claim 1, characterized in that The tropospheric atmospheric refractivity profile is obtained as follows: Acquire historical sounding data, measured ground data, and measured brightness temperature data; among them, measured ground data include ground temperature, ground humidity, and atmospheric pressure; Based on historical sounding data, measured ground data and measured brightness temperature data, network inversion is performed using a neural network deep inversion algorithm to obtain the tropospheric atmospheric refractive index distribution profile.

3. The method according to claim 1, characterized in that According to the tropospheric atmospheric refractivity distribution profile, the apparent distance of each grid point and the distance error corresponding to different apparent distances are obtained, including: Obtaining a coarsening stratification principle; wherein the coarsening stratification principle includes gradually increasing the height interval as the height increases, and / or gradually increasing the elevation angle interval as the elevation angle increases; Based on the distribution profile of the atmospheric refractive index in the troposphere and the principle of coarse-sparse stratification, the detection area is gridded and the position of each grid point is determined; Based on the atmospheric refractive index distribution profile of the troposphere, the apparent distances at different grid points and the distance errors corresponding to different apparent distances are obtained through the spherical layered ray tracing technique.

4. The method according to claim 3, characterized in that Based on the atmospheric refractive index distribution profile of the troposphere, the apparent distances at different grid points and the distance errors corresponding to different apparent distances are obtained through spherical layered ray tracing technology, including: Obtain the spherical Snell's law constant, the observation station altitude, the Earth's radius, the target altitude, and the refractive index at the current integration altitude; the target altitude represents the altitude corresponding to each grid point position; Determine the apparent distances at different grid points based on Snell's law for spherical surfaces, its constant, the lower limit of integration, and the upper limit of integration. The lower limit of integration represents the sum of the observation station's altitude and the Earth's radius, and the upper limit of integration represents the sum of the target's altitude and the Earth's radius. Determine the geocentric angle between the observation station and different grid points based on the refractive index at the current integration height, the constant term of Snell's law on the spherical surface, the lower limit of integration, and the upper limit of integration; Determine the true distances between different grid points based on the law of cosines, target altitude, lower limit of integration, and the geocentric angle between the observation station and different grid points. Determine the difference between the apparent distance and the true distance at each grid point, and obtain the distance error corresponding to each apparent distance.

5. The method according to any one of claims 1 to 4, characterized in that The receiving stations include a main receiving station and three secondary receiving stations. Refraction compensation is performed on the measured time delay difference of each receiving station based on the distance between the initial radiation source and each receiving station, the apparent distance of each grid point, and the distance error corresponding to different apparent distances. The time delay difference of each receiving station is obtained, including: According to the apparent distance of each grid point and the distance error corresponding to different apparent distances, the initial distance error between the initial radiation source position and each receiving station is obtained using the bilinear interpolation algorithm; Compensate the initial distance error between the initial radiation source position and each receiving station to obtain the actual distance between each secondary receiving station and the main receiving station; According to the actual distance between each secondary receiving station and the main receiving station, the time delay difference of each receiving station is obtained.

6. The method according to claim 5, characterized in that Based on the apparent distance of each grid point and the distance error corresponding to different apparent distances, the bilinear interpolation algorithm is used to obtain the initial distance error between the initial radiation source position and each receiving station, including: According to the distance equation, the apparent distance between the target radiation source and the main receiving station and the apparent distance between the target radiation source and each secondary receiving station are obtained; The apparent elevation angles, apparent distances, and distance error matrices at different grid point locations are used to obtain the initial distance errors between the initial radiation source position and the four receiving stations within the current grid location using a bilinear interpolation algorithm.

7. The method according to claim 5, characterized in that Get the initial radiation source position, including: According to the site location of each receiving station, a position difference matrix is ​​constructed; According to the distance equation, the estimated value of the initial radiation source position is obtained; Substitute the estimated value of the initial radiation source position into the distance equation to obtain the apparent distance between the target radiation source and the main receiving station; The initial radiation source position is obtained according to the apparent distance between the target radiation source and the main receiving station and the radiation source estimated value equation.

8. A detection device, characterized in that: include: Detection equipment body; And a high-precision compensation device for target refraction error based on three-dimensional time difference positioning, comprising a processor and a memory storing program instructions, wherein the processor is configured to execute the high-precision compensation method for target refraction error based on three-dimensional time difference positioning as described in any one of claims 1 to 7 when running the program instructions.

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