A triangulation baseline positioning method and device

Abstract

This invention discloses a triangular baseline positioning method and device, belonging to the field of direction finding and positioning. The method includes the following steps: establishing a baseline combination based on equilateral triangles; measuring the three-dimensional incident angles of the target; selecting the two-dimensional incident angles with the best matching accuracy and positioning intersection degree according to different incident angles; and completing the positioning calculation based on an Earth model. This invention achieves better positioning accuracy than orthogonal baseline positioning results at different incident angles, thus improving positioning accuracy.

Description

Technical Field

[0001] This invention relates to the field of orientation and positioning technology, and more specifically, to a triangulation baseline positioning method and device. Background Technology

[0002] Direction finding and positioning technology is mature, capable of calculating target location using a single station, and is cost-effective, making it widely used in systems such as spectrum monitoring, intelligence reconnaissance, and remote sensing. For interferometer systems, the incident elevation angle β of the target signal is measured using a two-dimensional orthogonal baseline. x and azimuth β y This allows us to determine the target's incident vector. Assuming the target is located on the Earth's surface, and combining this with the platform's attitude parameters, we calculate the intersection point between the target's incident vector and the Earth's surface, thus achieving target localization. The direction-finding and localization principle of the interferometer system is as follows: Figure 1 As shown.

[0003] Factors determining positioning accuracy include the target azimuth angle β. y Measurement accuracy, pitch angle β x Measurement accuracy, the configuration of the intersection line between the azimuth cone and the Earth's surface (hereinafter referred to as the azimuth intersection line), and the configuration of the intersection line between the elevation cone and the Earth's surface (hereinafter referred to as the elevation intersection line), such as... Figure 2 , Figure 3 As shown, the higher the accuracy of azimuth and elevation angle measurements, the smaller the positioning error; the more orthogonal the azimuth and elevation intersection lines are, the smaller the positioning error.

[0004] Direction-finding-based positioning techniques have been extensively studied both domestically and internationally, mainly encompassing three types of methods. The first type is the interferometric positioning method based on the WGS-84 coordinate system, which utilizes line-of-sight (LOS) intersection to determine the target's position (see: Single-satellite DOA positioning method based on WGS-84 model, Yang Bin, Zhang Min, Li Liping; Aerospace Electronic Countermeasures, 2009). This method measures the target's azimuth and elevation angles using orthogonal azimuth and elevation baselines, respectively, and then solves for the intersection of the azimuth surface, elevation curve, and Earth model to complete the positioning. However, it does not consider the variation of the local radius of the basalt and trochoid with latitude, inevitably introducing positioning errors. The second type is also a line-of-sight (LOS) intersection positioning method based on the WGS-84 coordinate system, but it considers the differences in basalt and trochoid radii across different latitudes (see: Single-satellite direction-finding positioning method based on WGS-84 Earth model, Guo Fucheng; Journal of Astronautics, 2011). This method employs an iterative positioning technique to further improve positioning accuracy. However, it uses an interferometer system based on orthogonal baselines, which fails to address the optimal matching between the accuracy of the incident angle measurement and the configuration of the azimuth and elevation intersection lines. The third method is a geocentric coordinate system-based positioning method that uses spherical geometry to solve for the geographic latitude and longitude of ground targets (see: Simulation Study on Direction Finding and Positioning of Ground Targets on Spaceborne Platforms, Tian Minghui, Fang Qing, Niu Junqing; Radar Science and Technology, 2012). This method first calculates the target's geocentric angle and then its latitude and longitude. The calculation process only considers the local Earth radius of the nadir point. It offers high positioning accuracy for targets with small incident angles, but for targets with large incident angles, the position deviates significantly from the nadir point, leading to additional positioning errors.

[0005] In general, existing direction finding and positioning technologies are based on the incident angle results measured by two orthogonal dimensional baselines for positioning calculation, which has the problem of mismatch between the direction finding accuracy and the intersection of the incident angle cone. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a triangular baseline positioning method and device, which has better positioning accuracy than orthogonal baseline positioning results at different incident angles, with the highest positioning accuracy improved by about 20%.

[0007] The objective of this invention is achieved through the following solution:

[0008] A triangulation baseline positioning method includes the following steps:

[0009] Establish a baseline combination based on equilateral triangles and measure the incident angle of the target in three dimensions;

[0010] Select the two-dimensional incident angle that best matches the angle measurement accuracy and the positioning intersection based on different incident angles, and complete the positioning calculation based on the Earth model.

[0011] Furthermore, the Earth model includes the WGS84 Earth model.

[0012] Furthermore, the establishment of a baseline combination based on equilateral triangles for measuring the incident angle of the target in three dimensions includes the following sub-steps:

[0013] The three antenna elements A, B, and C are arranged in an equilateral triangle to form three equal-length baselines BA, AC, and CB with an included angle of 60°.

[0014] Define vector With the target incident vector The complementary angle of the included angle is the incident angle β. ba Vector With the target incident vector The complementary angle of the included angle is the incident angle β. ac Vector With the target incident vector The complementary angle of the included angle is the incident angle β. cb Z-axis unit vector With the target incident vector The included angle is the off-axis angle θ, and the incident vector is... Projection onto the XOY plane The angle between the x-axis and the x-axis is the deflection angle.

[0015] Measure the target incident angle β ba β av and β vb We can obtain three lines of intersection with the Earth's surface, and the positioning calculation can be completed by using any two lines of intersection.

[0016] Furthermore, the incident angle β of the measured target ba β ac and β cb We can obtain three lines of intersection with the Earth's surface. The positioning calculation can be completed using any two of these lines, including the following sub-steps: Based on the relationship between the incident vector and the baseline vector, we can obtain:

[0017]

[0018] Defined in the satellite body coordinate system, the baseline unit vector Incident unit vector Represented as: Therefore, the incident angle β measured from any two baselines ac β ba β cb ,available:

[0019]

[0020] According to the definition of an interferometer, the incident angle β ba β ac β cb The direction finding accuracy is as follows:

[0021]

[0022] Combining equations (2) and (3), we can obtain:

[0023]

[0024] Where λ is the signal wavelength and d is the baseline length. For phase error, in phase error With the baseline length d constant, different incident off-axis angles θ and deflection angles This leads to different incident angle measurement errors, which in turn affect the target positioning accuracy;

[0025] For a triangular baseline, the unit baseline vector

[0026] Let the target position be T(x,y,z), a be the Earth's semi-major axis, and e be the Earth's curvature. We can then obtain:

[0027]

[0028] Furthermore, the step of selecting the two-dimensional incident angle with the best matching degree between angular measurement accuracy and positioning intersection based on different incident angles, and completing the positioning calculation based on the Earth model, includes the following sub-steps:

[0029] Step 1: Measure the angle of incidence β from the three baselines. ba β ac β cb Calculate the target incident deflection angle by arbitrarily selecting two angles.

[0030] Step 2: When the target incident deflection angle When the value is within the range of [-30°, 30°], [150°, 180°], or [-180°, -150°], the measured β is used. ba With β ac The angle completes the positioning; let α = β. ba ,β=β ac , When the target incident deflection angle When the value is in the range of [90°, 150°] or [-90°, -30°], the measured β is used. ba With β cb The angle completes the positioning; let α = β. ba ,β=β cb , When the target incident deflection angle When the value is within the range of [30°, 90°] or [-150°, -90°], the measured β is used. ac With β cb The angle completes the positioning; let α = β. ac ,β=β cb ,

[0031]

[0032] Step 3: Based on the two selected incident angles β1 and β2, and their corresponding baseline unit vectors... Calculate the incident unit vector From the relationship between the incident vector and the baseline vector, we can obtain:

[0033]

[0034] Solving the equation, we get: y ot =k1x ot +b1、z ot =k2x ot +b2;

[0035] Where A = k1 2 +k2 2 +1, B=2(k1b1+k2b2), C=b1 2 +b2 2 -1

[0036]

[0037] Step 4: Change the incident unit vector Rotate from the satellite body coordinate system to the WGS-84 Earth-fixed coordinate system to obtain Where R o R is the satellite attitude rotation matrix. w This is the satellite orbit rotation matrix;

[0038] Step 5: Set the target's position (x, y) in the WGS-84 coordinate system. t ,y t ,z t ), combined with the satellite platform position (x) in the WGS-84 coordinate system s ,y s ,z s ) and incident unit vector The system of equations can be obtained as follows:

[0039]

[0040] From the above formula, we can obtain Lt 2+Mt+N=0, where: L=(1-e 2 (x) ot ′ 2 +y ot ′ 2 )+z ot ′ 2 M = 2((1-e 2 (x) s x ot ′+y s y ot ′)+z s z ot ′), N=(1-e 2 (x) s 2 +y s 2 -A 2 )+z s 2

[0041] After solving the equation to obtain T, the position (x) of the target can be calculated using equation (7). t ,y t ,z t ).

[0042] A triangulation baseline positioning device includes a processor and a memory, wherein the memory stores a computer program that, when loaded by the processor, executes the method described in any of the preceding methods.

[0043] The beneficial effects of this invention include:

[0044] This invention improves upon the baseline combination used and proposes a new direction finding and positioning method based on triangular baselines.

[0045] The triangular baseline positioning method proposed in this invention adjusts the orthogonal configuration of traditional baselines and designs an equilateral triangular antenna element layout to form three independent baselines. Different baseline combinations are selected for positioning based on different incident angles of the target, enabling simultaneous high-precision two-dimensional direction finding and optimal intersection configuration. Using the triangular baseline positioning technology of this invention, the positioning accuracy at different incident angles is superior to that of orthogonal baseline positioning, with the highest positioning accuracy improvement being approximately 20%. Therefore, this is a high-precision interferometric direction finding and positioning method. Attached Figure Description

[0046] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0047] Figure 1 This is a schematic diagram illustrating the direction finding and positioning principle of an interferometer.

[0048] Figure 2 The impact of azimuth and elevation angle measurement accuracy on positioning accuracy;

[0049] Figure 3 The influence of the configuration of the intersection line between the azimuth and elevation angle cones and the Earth's surface on positioning accuracy;

[0050] Figure 4 It is a triangular baseline array configuration;

[0051] Figure 5 This is a schematic diagram illustrating the principle of triangulation baseline positioning.

[0052] Figure 6 For β ba β ac and β cb Measurement error of angle under different deflection angles;

[0053] Figure 7 This is a comparison of the positioning errors of orthogonal baselines and triangular baselines. Detailed Implementation

[0054] All features disclosed in all embodiments of this specification, or steps in all methods or processes implied in the disclosure, may be combined and / or extended or replaced in any way, except for mutually exclusive features and / or steps.

[0055] The purpose of this invention is to solve the problem of matching the measurement accuracy of two incident angles with the positioning intersection line in an interferometer system, achieving higher positioning accuracy with the same number of array elements and array aperture. One of the core concepts is to establish a baseline combination based on equilateral triangles to measure the incident angles of the target in three dimensions. Based on different incident angles, the two-dimensional incident angles with the best matching accuracy with the positioning intersection line are selected. Positioning calculations are then performed based on the WGS84 Earth model, further improving the positioning accuracy of the interferometer system.

[0056] Orthogonal baseline direction finding and positioning systems cannot simultaneously satisfy high-precision two-dimensional direction finding and optimal intersection configuration for target signals incident from arbitrary areas. Triangulation baseline positioning technology adjusts the orthogonal configuration of the baselines, selecting different baseline combinations according to different incident angles of the target, thereby achieving both high-precision two-dimensional direction finding and optimal intersection configuration, improving the system's positioning accuracy with the same baseline length.

[0057] Triangulation baseline positioning technology adjusts the orthogonal configuration of the baselines. The three antenna elements A, B, and C are arranged in an equilateral triangle, forming three equal-length baselines BA, AC, and CB with an included angle of 60°. Figure 4 As shown.

[0058] Define vector With the target incident vector The complementary angle of the included angle is the incident angle β. ba Vector With the target incident vector The complementary angle of the included angle is the incident angle β. ac Vector With the target incident vector The complementary angle of the included angle is the incident angle β. cb Z-axis unit vector With the target incident vector The included angle is the off-axis angle θ, and the incident vector is... Projection onto the XOY plane The angle between the x-axis and the x-axis is the deflection angle.

[0059] Measure the target incident angle β ba β av and β vb This yields three intersection lines with the Earth's surface. The positioning calculation can be completed using any two of these intersection lines. Figure 5 As shown.

[0060] Based on the relationship between the incident vector and the baseline vector, we can obtain:

[0061]

[0062] Defined in the satellite body coordinate system, the baseline unit vector Incident unit vector It can be represented as: Therefore, the incident angle β measured from any two baselines ac β ba β cb ,available:

[0063]

[0064] According to the definition of an interferometer, the incident angle βba β ac β cb The direction finding accuracy is as follows:

[0065]

[0066] Combining equations (2) and (3), we can obtain:

[0067]

[0068] Where λ is the signal wavelength and d is the baseline length. This represents the phase error. It can be seen that the phase error... With the baseline length d constant, different incident off-axis angles θ and deflection angles This leads to different incident angle measurement errors, which in turn affect the positioning accuracy of the target.

[0069] For a triangular baseline, the unit baseline vector Target incident angle θ = 60°, deflection angle β varies from -180° to 180° ba β ac β cb Angle measurement error variation as follows Figure 6 As shown, and from β ba Intersection line, β ac Intersection line, β cb The simulation results of the intersection line configuration show that, regardless of the angle from which the target is incident, at least two of the intersection lines formed by the three baselines are in a better configuration.

[0070] Let the target position be T(x,y,z), a be the Earth's semi-major axis, and e be the Earth's curvature. We can then obtain:

[0071]

[0072] The steps for performing positioning calculations using this invention are as follows:

[0073] Step 1: Measure the angle of incidence β from the three baselines. ba β ac β cb Choose any two angles (e.g., β) ba and β ac ), calculate the target incident deflection angle

[0074] Step 2: When the target incident deflection angle When the value is within the range of [-30°, 30°], [150°, 180°], or [-180°, -150°], the measured β is used. ba With βac The angle completes the positioning; let α = β. ba ,β=β ac , When the target incident deflection angle When the value is in the range of [90°, 150°] or [-90°, -30°], the measured β is used. ba With β cb The angle completes the positioning; let α = β. ba ,β=β cb , When the target incident deflection angle When the value is within the range of [30°, 90°] or [-150°, -90°], the measured β is used. ac With β cb The angle completes the positioning; let α = β. ac ,β=β cb ,

[0075]

[0076] Step 3: Based on the two selected incident angles β1 and β2, and their corresponding baseline unit vectors... From the relationship between the incident vector and the baseline vector, we can obtain:

[0077]

[0078] Solving the equation, we get: y ot =k1x ot +b1、z ot =k2x ot +b2.

[0079] Where A = k1 2 +k2 2 +1, B=2(k1b1+k2b2), C=b1 2 +b2 2 -1

[0080]

[0081] Step 4: Change the incident unit vector Rotate from the satellite body coordinate system to the WGS-84 Earth-fixed coordinate system to obtain Where R o R is the satellite attitude rotation matrix. w This is the satellite orbit rotation matrix.

[0082] Step 5: Set the target's position (x, y) in the WGS-84 coordinate system. t ,y t ,z t), combined with the satellite platform position (x) in the WGS-84 coordinate system s ,y s ,z s ) and incident unit vector The system of equations can be obtained as follows:

[0083]

[0084] From the above formula, we can obtain Lt 2 +Mt+N=0, where: L=(1-e 2 (x) ot ′ 2 +y ot ′ 2 )+z ot ′ 2 M = 2((1-e 2 (x) s x ot ′+y s y ot ′)+z s z ot ′), N=(1-e 2 (x) s 2 +y s 2 -a 2 )+z s 2

[0085] After solving the equation to obtain t, the position (x) of the target can be calculated using equation (7). t ,y t ,z t ).

[0086] Using the direction-finding method of this invention, after 1000 Monte Carlo experiments, under the conditions of a longest baseline of 2 meters, a signal frequency of 3 GHz, and a system phase error of 15° root mean square, it was compared with a traditional orthogonal baseline interferometer. Figure 7 As shown, positioning accuracy can be improved by up to 20%.

[0087] Taking the detection of a target at an orbital altitude of 500km as an example, the method of satellite triangulation baseline positioning is explained based on the following conditions.

[0088] Table 1. Triangulation baseline positioning conditions

[0089]

[0090] First, according to Figure 4 By arranging the receiving antenna as a triangular baseline, the unit baseline vector can be obtained.

[0091] Choose to measure β ba and β ac Calculate the target incident deflection angle from two angles. Angle β is selected to measure two dimensions: baseline AC and baseline CB. ac With β bc Angle positioning calculation is performed.

[0092] From equation (1), the incident unit vector can be obtained. The satellite attitude rotation matrix can be obtained from the platform parameters. Satellite orbit rotation matrix Calculate the representation of this unit vector in the WGS-84 Earth-Fixed Coordinate System as follows:

[0093] According to equation (7), t = 1824.3 km is first calculated, and finally the position of the target (x) is calculated. t ,y t ,z t )=(-156.152km,-6120.709km, 1780.952km).

[0094] It should be noted that, within the scope of protection defined in the claims of this invention, the following embodiments can be combined and / or extended or replaced in any logical manner from the above specific embodiments, such as the disclosed technical principles, disclosed technical features or implicitly disclosed technical features.

[0095] Example 1

[0096] A triangulation baseline positioning method includes the following steps:

[0097] Establish a baseline combination based on equilateral triangles and measure the incident angle of the target in three dimensions;

[0098] Select the two-dimensional incident angle that best matches the angle measurement accuracy and the positioning intersection based on different incident angles, and complete the positioning calculation based on the Earth model.

[0099] Example 2

[0100] Based on Example 1, the Earth model includes the WGS84 Earth model.

[0101] Example 3

[0102] Based on Example 1, the step of establishing a baseline combination based on equilateral triangles and measuring the incident angle of the target in three dimensions includes the following sub-steps:

[0103] The three antenna elements A, B, and C are arranged in an equilateral triangle to form three equal-length baselines BA, AC, and CB with an included angle of 60°.

[0104] Define vector With the target incident vector The complementary angle of the included angle is the incident angle β. ba Vector With the target incident vector The complementary angle of the included angle is the incident angle β. ac Vector With the target incident vector The complementary angle of the included angle is the incident angle β. cb Z-axis unit vector With the target incident vector The included angle is the off-axis angle θ, and the incident vector is... Projection onto the XOY plane The angle between the x-axis and the x-axis is the deflection angle.

[0105] Measure the target incident angle β ba β ac and β cb We can obtain three lines of intersection with the Earth's surface, and the positioning calculation can be completed by using any two lines of intersection.

[0106] Example 4

[0107] Based on Example 3, the measured target incident angle β ba β ac and β cb We can obtain three lines of intersection with the Earth's surface. The positioning calculation can be completed using any two of these lines, including the following sub-steps: Based on the relationship between the incident vector and the baseline vector, we can obtain:

[0108]

[0109] Defined in the satellite body coordinate system, the baseline unit vector Incident unit vector Represented as: Therefore, the incident angle β measured from any two baselines ac β ba β cb ,available:

[0110]

[0111] According to the definition of an interferometer, the incident angle β ba β ac β cb The direction finding accuracy is as follows:

[0112]

[0113] Combining equations (2) and (3), we can obtain:

[0114]

[0115] Where λ is the signal wavelength and d is the baseline length. For phase error, in phase error With the baseline length d constant, different incident off-axis angles θ and deflection angles This leads to different incident angle measurement errors, which in turn affect the target positioning accuracy;

[0116] For a triangular baseline, the unit baseline vector

[0117] Let the target position be T(x,y,z), a be the Earth's semi-major axis, and e be the Earth's curvature. We can then obtain:

[0118]

[0119] Example 5

[0120] Based on Example 1, the step of selecting the two-dimensional incident angle with the best matching degree between angular measurement accuracy and positioning intersection according to different incident angles, and completing the positioning calculation based on the Earth model, includes the following sub-steps:

[0121] Step 1: Measure the angle of incidence β from the three baselines. ba β ac β cb Calculate the target incident deflection angle by arbitrarily selecting two angles.

[0122] Step 2: When the target incident deflection angle When the value is within the range of [-30°, 30°], [150°, 180°], or [-180°, -150°], the measured β is used. ba With β ac The angle completes the positioning; let α = β. ba ,β=β ac , When the target incident deflection angle When the value is in the range of [90°, 150°] or [-90°, -30°], the measured β is used. ba With β cb The angle completes the positioning; let α = β. ba ,β=β cb , When the target incident deflection angle When the value is within the range of [30°, 90°] or [-150°, -90°], the measured β is used. ac With β cbThe angle completes the positioning; let α = β. ac ,β=β cb ,

[0123]

[0124] Step 3: Based on the two selected incident angles β1 and β2, and their corresponding baseline unit vectors... Calculate the incident unit vector From the relationship between the incident vector and the baseline vector, we can obtain:

[0125]

[0126] Solving the equation, we get: y ot =k1x ot +b1、z ot =k2x ot +b2;

[0127] Where A = k1 2 +k2 2 +1, B=2(k1b1+k2b2), C=b1 2 +b2 2 -1

[0128]

[0129] Step 4: Change the incident unit vector Rotate from the satellite body coordinate system to the WGS-84 Earth-fixed coordinate system to obtain Where R o R is the satellite attitude rotation matrix. w This is the satellite orbit rotation matrix;

[0130] Step 5: Set the target's position (x, y) in the WGS-84 coordinate system. t ,y t ,z t ), combined with the satellite platform position (x) in the WGS-84 coordinate system s ,y s ,z s ) and incident unit vector The system of equations can be obtained as follows:

[0131]

[0132] From the above formula, we can obtain Lt 2 +Mt+N=0, where: L=(1-e 2 (x) ot ′ 2 +y ot ′ 2 )+zot ′ 2 M = 2((1-e 2 (x) s x ot ′+y s y ot ′)+z s z ot ′), N=(1-e 2 (x) s 2 +y s 2 -A 2 )+z s 2

[0133] After solving the equation to obtain T, the position (x) of the target can be calculated using equation (7). t ,y t ,z t ).

[0134] Example 6

[0135] A triangulation baseline positioning device includes a processor and a memory, wherein the memory stores a computer program that, when loaded by the processor, executes the method described in any one of Embodiments 1 to 5.

[0136] The units described in the embodiments of the present invention can be implemented in software or hardware, and the described units can also be located in a processor. The names of these units do not necessarily limit the specific unit itself.

[0137] According to one aspect of the present invention, a computer program product or computer program is provided, the computer program product or computer program including computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium, and executes the computer instructions, causing the computer device to perform the methods provided in the various optional implementations described above.

[0138] In another aspect, embodiments of the present invention also provide a computer-readable medium, which may be included in the electronic device described in the above embodiments; or it may exist independently and not assembled into the electronic device. The computer-readable medium carries one or more programs, which, when executed by the electronic device, cause the electronic device to perform the methods described in the above embodiments.

[0139] All parts not covered in this invention are the same as or can be implemented using existing technologies.

[0140] The above technical solution is only one embodiment of the present invention. For those skilled in the art, based on the application methods and principles disclosed in the present invention, it is easy to make various types of improvements or modifications, and not limited to the methods described in the above specific embodiments of the present invention. Therefore, the methods described above are only preferred and are not restrictive.

[0141] In addition to the examples above, other embodiments may be obtained by those skilled in the art based on the above disclosure or by making modifications using knowledge or technology in related fields. The features of each embodiment may be interchanged or replaced. Modifications and changes made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. A triangulation baseline positioning method, characterized in that, Includes the following steps: A baseline combination based on equilateral triangles is established to measure the incident angle of the target in three dimensions. In the satellite body coordinate system, three antenna elements A, B, and C are arranged in an equilateral triangle layout, forming three equal-length baselines BA, AC, and CB with an included angle of 60°. Vectors are defined. With the target incident vector The complementary angle of the included angle is the angle of incidence. Vector With the target incident vector The complementary angle of the included angle is the angle of incidence. Vector With the target incident vector The complementary angle of the included angle is the angle of incidence. Z-axis unit vector With the target incident vector The included angle is the off-axis angle. Incident vector Projection onto the XOY plane The angle between the x-axis and the x-axis is the deflection angle. ; Measure the angle of incidence of the target , as well as ; Select the two-dimensional incident angle that best matches the angle measurement accuracy and positioning intersection degree based on different incident angles, and complete the positioning calculation based on the Earth model; arbitrarily select two angles from the three incident angles measured by the three baselines to calculate the target incident deflection angle; when the deflection angle is within the range of [-30°, 30°], [150°, 180°], or [-180°, -150°], the measured incident angle is used. and Angle-based positioning is achieved; when the deflection angle is within the range of [90°, 150°] or [-90°, -30°], the measured angle of incidence is used. and Angle-based positioning is achieved; when the deflection angle is within the range of [30°, 90°] or [-150°, -90°], the measured angle of incidence is used. and Positioning is completed by angle measurement.

2. The triangulation baseline positioning method according to claim 1, characterized in that, The Earth model mentioned includes the WGS84 Earth model.

3. The triangulation baseline positioning method according to claim 1, characterized in that, The incident angle of the measured target , as well as We can obtain three lines of intersection with the Earth's surface. The positioning calculation can be completed using any two of these lines, including the following sub-steps: Based on the relationship between the incident vector and the baseline vector, we can obtain: (1) Defined in the satellite body coordinate system, the baseline unit vector , , Incident unit vector Represented as: Therefore, the angle of incidence measured from any two baselines , , ,available: (2) According to the definition of an interferometer, the angle of incidence... , , The direction finding accuracy is as follows: (3) Combining equations (2) and (3), we can obtain: （4） in d is the signal wavelength, and d is the baseline length. For phase error, in phase error With the baseline length d remaining constant, different incident off-axis angles Deflection angle This leads to different incident angle measurement errors, which in turn affect the target positioning accuracy; For a triangular baseline, the unit baseline vector , , ; Let the target position be T(x,y,z). For the Earth's semi-major axis, Given the curvature of the Earth, we can obtain: （5）。 4. The triangulation baseline positioning method according to any one of claims 1 or 3, characterized in that, The process of selecting the two-dimensional incident angle that best matches the angle measurement accuracy and positioning intersection based on different incident angles, and completing the positioning calculation based on the Earth model, includes the following sub-steps: Step 1: Measure the angle of incidence from the three baselines , , Calculate the target incident deflection angle by arbitrarily selecting two angles. ; Step 2: When the target incident deflection angle When the measurement is within the range of [-30°, 30°], [150°, 180°], or [-180°, -150°], the measurement method is used. and Angle-based positioning is achieved; set , , = , = When the target incident deflection angle When the measurement is within the range of [90°, 150°] or [-90°, -30°], the measurement is performed using... and Angle-based positioning is achieved; set , , = , = When the target incident deflection angle When the measurement is within the range of [30°, 90°] or [-150°, -90°], the measurement is performed using... and Angle-based positioning is achieved; set , , = , = ; Step 3: From the two selected incident angles , and its corresponding baseline unit vector , Calculate the incident unit vector ; From the relationship between the incident vector and the baseline vector, we can obtain: （6） Solving the equation, we get: , , ; in, , , 、 、 、 ； Step 4: Change the incident unit vector Rotate from the satellite body coordinate system to the WGS-84 Earth-fixed coordinate system to obtain ,in This is the satellite attitude rotation matrix. This is the satellite orbit rotation matrix; Step 5: Set the target position in the WGS-84 coordinate system Combined with the satellite platform position in the WGS-84 coordinate system and incident unit vector We can obtain the system of equations: （7） From the above formula, we can obtain ,in: , , Solving the equation yields Then, the position of the target can be calculated using equation (7). .

5. A triangulation baseline positioning device, characterized in that, It includes a processor and a memory, wherein the memory stores a computer program that, when loaded by the processor, executes the method as described in any one of claims 1 to 4.

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