Coplanar constraint-based double-antenna Beidou orientation method

Abstract

The invention discloses a double-antenna Beidou orientation method based on coplanar constraint, and belongs to the technical field of satellite navigation and orientation measurement. A main antenna assembly and an observation and aiming instrument are fixedly installed, and a vertical center line structure associated with an electromagnetic receiving center of a slave antenna assembly is arranged on the slave antenna assembly; a laser light surface having a fixed geometrical relationship with a sighting vertical plane of the sighting instrument is formed by using linear laser, an alignment image of a laser line and a vertical center line is obtained through an image acquisition module, and an upper computer calculates offset and angle deviation of the laser line and the vertical center line and guides attitude adjustment, so that the problem that the laser line and the vertical center line cannot be accurately aligned in a portable application condition is solved. High-precision, quantifiable and repeatable space alignment between a double-antenna Beidou orientation axis and an aiming optical axis of an observing and aiming instrument is realized, so that the technical problem of accurately obtaining a true north orientation result is solved, the uncertainty of traditional point-to-point manual aiming is avoided, the influence of manual subjective factors on the orientation precision is greatly reduced, the structure is simple, and the use is convenient.

Description

Technical Field

[0001] This invention belongs to the field of satellite navigation and orientation measurement technology, and particularly relates to a dual-antenna BeiDou orientation method based on coplanar constraints. Background Technology

[0002] In the fields of observation and aiming instruments, surveying equipment, weaponry, and portable orientation systems, equipment typically requires high-precision azimuth information relative to true north when used in the field to achieve accurate positioning, direction finding, or aiming.

[0003] Currently, dual-antenna BeiDou orientation technology has been widely used in north-finding orientation scenarios for ships, vehicles, and fixed platforms due to its independence from magnetic field environment, strong anti-interference ability, and high orientation accuracy.

[0004] Dual-antenna BeiDou orientation technology typically involves deploying a master antenna and a slave antenna on a carrier. By utilizing the carrier phase observations received by the two antennas and the known antenna baseline length, the azimuth angle of the line connecting the electromagnetic receiving centers of the master and slave antennas relative to true north is calculated, thereby achieving high-precision orientation.

[0005] In the above technical solution, the actual output of the dual-antenna BeiDou device is the orientation result corresponding to the line connecting the electromagnetic receiving centers of the main antenna and the secondary antenna. Therefore, when the dual-antenna BeiDou device is used in combination with an observation and aiming instrument, how to accurately map this orientation result to the aiming optical axis direction of the observation and aiming instrument becomes a key factor affecting the overall orientation accuracy.

[0006] In existing technologies, when portable observation and aiming instruments are used in conjunction with dual-antenna BeiDou devices, orientation is typically achieved in the following manner: The main antenna is installed near the observation and aiming instrument, and the secondary antenna is set up at a certain distance in front of the main antenna using a tripod. The operator manually aims at the center of the secondary antenna's shape using the observation and aiming instrument, and assumes that the direction of the line connecting the main and secondary antennas is consistent with the aiming optical axis of the observation and aiming instrument. Thus, the orientation result of the dual-antenna Beidou is used as the orientation result of the observation and aiming instrument.

[0007] However, this method has at least the following shortcomings: The electromagnetic receiving center of an antenna cannot be determined visually: since antennas are usually disc-shaped or cylindrical, their electromagnetic receiving center is inside the structure. Operators can only estimate the center position by looking at the shape, which results in a large uncertainty in aiming.

[0008] The antenna's attitude is difficult to control precisely: since the antenna is set up on a tripod, its verticality and attitude usually rely on manual visual adjustment, making it difficult to ensure that the electromagnetic receiving center of the antenna is in a stable and repeatable spatial position.

[0009] Manual aiming errors significantly amplify orientation errors: In portable applications where the distance between the master and slave antennas is short, tiny manual aiming deviations will be amplified into large angular errors, which are often far greater than the orientation accuracy of the dual-antenna BeiDou device itself.

[0010] Lack of quantifiable and verifiable alignment standards: Existing methods mainly rely on subjective human judgment, which cannot quantify the spatial relationship between the direction of the connection between the master and slave antennas and the aiming optical axis of the observation and aiming instrument, making it difficult to achieve stable and repeatable high-precision orientation. Summary of the Invention

[0011] The purpose of this invention is to provide a method for dual-antenna BeiDou orientation based on coplanar constraints, which solves the technical problem of achieving high-precision, quantifiable, and repeatable spatial alignment between the dual-antenna BeiDou orientation axis and the aiming optical axis of the observation and aiming instrument under portable application conditions, thereby accurately obtaining true north orientation results.

[0012] To achieve the above objectives, the present invention adopts the following technical solution: A method for dual-antenna BeiDou orientation based on coplanar constraints includes the following steps: Step 1: The operator installs the main antenna assembly onto the main tripod, and simultaneously installs the slave antenna assembly onto the slave tripod; the main antenna assembly includes a main antenna, a sight mounting interface, a linear laser module, and an image acquisition module; the slave antenna assembly includes a slave antenna and a vertical centerline structure fixedly connected to it; Step 2: The operator adjusts the sighting device to a horizontal position on site, so that the vertical plane of the sighting device, where the vertical aiming reticle is located, is perpendicular to the horizontal plane of the ground. Step 3: The operator controls the line laser module to emit a line laser beam, so that the laser beam surface formed by the line laser beam has a fixed geometric relationship with the aiming vertical plane; Step 4: The operator adjusts the posture of the main tripod or the secondary tripod to illuminate the area where the linear laser beam is located with the secondary antenna assembly, and brings the linear laser beam and the vertical centerline structure into the field of view of the image acquisition module. Step 5: The image acquisition module acquires image data containing the line laser beam and the vertical center line structure in real time and uploads it to the host computer. The host computer identifies the relative position of the line laser beam and the vertical center line structure and calculates the positional deviation between them. Step 6: The host computer generates adjustment prompts based on the position deviation and displays them on the screen to guide the operator to continuously adjust the posture of the main tripod or the secondary tripod until the deviation is less than the preset threshold. Step 7: When the position deviation is less than the preset threshold, the host computer determines that the electromagnetic receiving center of the main antenna, the electromagnetic receiving center of the slave antenna, and the aiming optical axis of the sight are located in the same aiming vertical plane, thereby completing the transfer of orientation north-finding accuracy.

[0013] Preferably, the vertical centerline structure is a structural reference line set on the mounting reference surface of the image acquisition module. In the assembled state of the device, the structural reference line is consistent with the normal direction of the imaging plane of the image acquisition module and forms a perpendicular relationship with the horizontal direction of the imaging area of ​​the image acquisition module, and is used as a reference center line for spatial alignment of the laser beam and the image acquisition module.

[0014] Preferably, the emission center line of the linear laser emission module has a fixed geometric relationship with the vertical center line structure. Specifically, the spatial position, angle, and offset of the laser emission center line relative to the vertical center line structure remain unchanged after the equipment is assembled, and do not change relative to vibration, temperature changes, or external disturbances during the operation of the equipment.

[0015] Preferably, when the line laser emitting module is working, it is configured such that, under the constraints of the fixed geometric relationship, at least one segment of the emitted line laser beam always falls within the effective imaging area of ​​the image acquisition module within a preset working distance range, thereby allowing the line laser beam to enter the field of view of the image acquisition module and be stably acquired.

[0016] Preferably, when performing step 5, the host computer performs image preprocessing on the image data containing the linear laser beam acquired by the image acquisition module, and then extracts the pixel features of the laser line from the image data. The pixel features include at least the position distribution of the laser line in the image, the center line position, or the tilt angle information.

[0017] Preferably, when performing step 6, the host computer compares the extracted laser line pixel features with the theoretical position of the vertical center line structure in the image, and calculates the offset or angular deviation of the laser line relative to the vertical center line structure to obtain alignment deviation information between the laser beam and the image acquisition module.

[0018] Preferably, step 7 includes the following steps: Step 7-1: Based on the image data obtained in step 5, the host computer performs edge extraction and straight line fitting on the set of pixels corresponding to the line laser beam to obtain the straight line equation of the laser line in the image coordinate system, and identifies the pixel position of the vertical center line structure of the antenna component in the image to determine its corresponding theoretical vertical center line position. Step 7-2: Using the vertical centerline position of the vertical centerline structure in the image as a reference, calculate the lateral offset Δx of the line laser beam relative to the vertical centerline. The specific formula is as follows: ; Where, x i x is the x-coordinate of the laser line at the i-th image sampling point; x0 is the theoretical x-coordinate of the vertical centerline structure in the image; N is the number of laser line pixels involved in the calculation. Step 7-3: Based on the laser line fitting results, select two points (x1, y1) and (x2, y2) located at different longitudinal positions in the image, and calculate the angular deviation Δθ of the laser line relative to the vertical direction of the image. The specific formula is as follows: Δθ=arctan(|(x2-x1)÷(y2-y1)|); Wherein, Δθ represents the degree of inclination of the line laser beam relative to the vertical centerline structure; Step 7-4: Align the lateral offset Δx and the angular deviation Δθ with the preset lateral alignment threshold Δx, respectively. th and angle alignment threshold Δθ th Compare the following conditions: |Δx|≤Δx th ;|Δθ|≤Δθ th ; If the laser beam is aligned with the vertical centerline structure in the image coordinate system, the electromagnetic receiving center of the main antenna, the electromagnetic receiving center of the secondary antenna, and the aiming optical axis of the sight are located in the same aiming vertical plane. The host computer uses the orientation result output by the dual-antenna Beidou as the orientation result of the sight, thereby completing the transmission of orientation and north-finding accuracy.

[0019] This invention presents a dual-antenna BeiDou orientation method based on coplanar constraints, solving the technical problem of achieving high-precision, quantifiable, and repeatable spatial alignment between the orientation axis of the dual-antenna BeiDou and the aiming optical axis of the observation instrument under portable application conditions, thereby accurately obtaining true north orientation results. This invention introduces a linear laser and a vertical centerline structure to achieve geometric coplanar constraints between the orientation axes of the master and slave antennas and the aiming optical axis of the observation instrument, avoiding the uncertainty of traditional point-to-point manual aiming. Using an image acquisition module and a host computer algorithm, the relative position of the laser line and the centerline is quantified and determined, significantly reducing the impact of subjective human factors on orientation accuracy. Even under short-range, portable application conditions, it can still stably achieve high-precision orientation, fully utilizing the orientation performance of the dual-antenna BeiDou device. The structure is simple, easy to use, and suitable for various observation instruments and field environments, exhibiting good repeatability and engineering practicality. Attached Figure Description

[0020] Figure 1 This is the main flowchart of the present invention; Figure 2 This is a sub-flowchart of step 7 of the present invention; Figure 3 This is a schematic diagram illustrating the principle of the Beidou antenna's north-finding method in this invention; Figure 4 This is a schematic diagram of the main antenna assembly and the slave antenna assembly used in the field in this embodiment; In the diagram: 1. Main antenna; 2. Observation and aiming device; 3. Image acquisition module; 4. Linear laser module; 5. Tripod of main antenna; 6. Tripod of secondary antenna; 7. Vertical centerline structure; 8. Secondary antenna. Detailed Implementation

[0021] Depend on Figures 1-4 The method for dual-antenna BeiDou orientation based on coplanar constraints, as shown, includes the following steps: Step 1: The operator installs the main antenna assembly onto the main tripod, and simultaneously installs the slave antenna assembly onto the slave tripod; the main antenna assembly includes a main antenna, a sight mounting interface, a linear laser module, and an image acquisition module; the slave antenna assembly includes a slave antenna and a vertical centerline structure fixedly connected to it; The vertical centerline structure is a structural reference line set on the mounting reference surface of the image acquisition module. In the assembled state of the device, the structural reference line is consistent with the normal direction of the imaging plane of the image acquisition module and forms a perpendicular relationship with the horizontal direction of the imaging area of ​​the image acquisition module, and is used as a reference center line for spatial alignment of the laser beam and the image acquisition module.

[0022] The laser emission center line of the linear laser emission module has a fixed geometric relationship with the vertical center line structure. Specifically, the spatial position, angle, and offset of the laser emission center line relative to the vertical center line structure remain unchanged after the equipment is assembled, and do not change relative to vibration, temperature changes, or external disturbances during the operation of the equipment.

[0023] In this embodiment, the main antenna assembly and the slave antenna assembly are fixedly mounted on a tripod to form a rigid platform with adjustable attitude. Inside the main antenna assembly, the main antenna, the sight, the linear laser module, and the image acquisition module are designed with rigid coplanar / coaxial alignment to ensure that their spatial positions remain fixed after factory assembly.

[0024] The transmission centerline of the linear laser module forms a fixed spatial relationship with the optical axis of the sight and the electromagnetic center of the main antenna.

[0025] The vertical centerline structure set on the antenna assembly represents the electromagnetic center position of the antenna. Fixed geometric constraints ensure that the laser line and the electromagnetic center of the antenna can be quantized and aligned.

[0026] This embodiment uses a structural baseline to map the internal electromagnetic center onto a visible reference object (vertical centerline), thus solving the problem that the electromagnetic center cannot be directly observed. This allows for the indirect quantification of the spatial location of the electromagnetic center using optical methods.

[0027] like Figure 4 The schematic diagram shown in this embodiment illustrates the actual use process. The antenna assembly includes a tripod 6 for the antenna, an antenna 8, and a vertical centerline structure 7. In general use, the vertical centerline structure 7 is a vertical metal rod with a certain diameter, which allows the laser beam to be mapped onto the metal rod for easy viewing and debugging. The antenna 8, the vertical centerline structure 7, and the tripod 6 can be fixed by being arranged sequentially from top to bottom.

[0028] The main antenna assembly includes the main antenna 1, the viewing and aiming device 2, the image acquisition module 3, the linear laser module 4, and the tripod 5 of the main antenna. In general use, the image acquisition module 3 is a network camera. The main antenna 1, the viewing and aiming device 2, the image acquisition module 3, the linear laser module 4, and the tripod 5 of the main antenna are usually fixed in sequence from top to bottom.

[0029] Both the main antenna assembly and the slave antenna assembly can be assembled before leaving the factory and then applied directly in the field. During assembly before leaving the factory, the error in the position of the parts can be measured and recorded as a common error parameter.

[0030] When used in the field, the main antenna and the slave antenna can be satellite navigation receiving antennas with the same or different structural forms, and their external dimensions, structural types and installation methods are different from each other; the main antenna and the slave antenna each have a stable electromagnetic receiving center, which is the position determined after antenna structure design, calibration or model correction.

[0031] Depend on Figure 4 As can be seen, in this embodiment, the vertical centerline structure 7 is located directly below the antenna. The sighting device is aimed at the vertical centerline structure 7 for sighting. The line laser module 4 illuminates the vertical centerline structure 7 with a line laser. The image acquisition module 3 is responsible for acquiring image data on the vertical centerline structure 7.

[0032] Dual-antenna BeiDou orientation is a high-precision direction-finding technology based on two satellite signal receiving antennas mounted on a carrier. A fixed baseline vector is formed between the primary and secondary antennas. By measuring high-precision carrier phase observations and using the known baseline length, the angle between this baseline vector and true north can be calculated, thus determining the carrier's azimuth direction. The line connecting the electromagnetic receiving centers of the primary and secondary antennas is called the BeiDou orientation axis.

[0033] In portable observation and aiming instruments, to achieve the north-finding function, the aiming optical axis of the observation and aiming instrument and the Beidou orientation axis need to be aligned in the projection direction on the horizontal plane of the earth. That is, to ensure that the two directions are consistent, the observation and aiming instrument can obtain the true north direction angle α and achieve high-precision north-finding orientation.

[0034] Step 2: The operator adjusts the sighting device to a horizontal position on site, so that the vertical plane of the sighting device, where the vertical aiming reticle is located, is perpendicular to the horizontal plane of the ground. The vertical reticle of the sight determines the direction of the aiming vertical plane. By adjusting the sight to a horizontal position, the plane containing its vertical reticle is perpendicular to the horizontal plane of the ground, forming a geographical reference vertical plane. This vertical plane is equivalent to a "reference plane," and all subsequent operations (laser line, electromagnetic center of the main antenna, center line of the secondary antenna) will be based on this vertical plane to ensure controllable measurement accuracy.

[0035] Step 3: The operator controls the line laser module to emit a line laser beam, so that the laser beam surface formed by the line laser beam has a fixed geometric relationship with the aiming vertical plane; When the line laser emitting module is in operation, it is configured such that, under the constraints of the fixed geometric relationship, at least one segment of the emitted line laser beam always falls within the effective imaging area of ​​the image acquisition module within a preset working distance range, thereby allowing the line laser beam to enter the field of view of the image acquisition module and be stably acquired.

[0036] The linear laser module emits a linear beam of light according to the factory-set fixed geometric constraints, and its direction maintains a fixed angle relationship with the vertical plane of the aiming optical axis of the sight.

[0037] The laser beam forms a light surface in space, and at least a portion of it falls into the effective area of ​​the image acquisition module, ensuring that it can be captured.

[0038] Fixed geometric relationships ensure that the beam direction will not deviate within the working distance due to vibration, temperature changes or mechanical interference.

[0039] By using the principle of coplanar constraint, the laser surface is used as a "visual substitute" to reflect the spatial position of the electromagnetic center of the main antenna assembly and the optical axis of the sight.

[0040] Step 4: The operator adjusts the posture of the main tripod or the secondary tripod to illuminate the area where the linear laser beam is located with the secondary antenna assembly, and brings the linear laser beam and the vertical centerline structure into the field of view of the image acquisition module. The operator adjusts the tripod posture to ensure the laser beam illuminates the area of ​​the antenna assembly and enters the image acquisition module's field of view along the vertical centerline structure. This operation is a preliminary "coarse adjustment" on-site, ensuring the laser line falls near the reference centerline, forming a quantifiable alignment target. This embodiment combines human eye operation with machine inspection, utilizing the spatial correspondence between the laser and the vertical centerline to establish coplanar constraints between the master / slave antennas and the observation / aiming device.

[0041] Step 5: The image acquisition module acquires image data containing the line laser beam and the vertical center line structure in real time and uploads it to the host computer. The host computer identifies the relative position of the line laser beam and the vertical center line structure and calculates the positional deviation between them. When performing step 5, the host computer performs image preprocessing on the image data containing the line laser beam acquired by the image acquisition module, and then extracts the pixel features of the laser line from the image data. The pixel features include at least the position distribution of the laser line in the image, the center line position, or the tilt angle information.

[0042] The image acquisition module captures images containing laser lines and vertical centerline structures, and uploads them to the host computer for processing.

[0043] This embodiment uses pixel coordinates to represent spatial position, projects light onto the image plane, extracts the pixel features of the laser line (position, tilt angle, line distribution) and compares them with the theoretical position of the vertical center line to obtain the lateral offset and angle deviation. It uses two-dimensional projection (pixel coordinates) to indirectly quantify the three-dimensional spatial position relationship and achieve high-precision error measurement.

[0044] Step 6: The host computer generates adjustment prompts based on the position deviation and displays them on the screen to guide the operator to continuously adjust the posture of the main tripod or the secondary tripod until the deviation is less than the preset threshold. During step 6, the host computer compares the extracted laser line pixel features with the theoretical position of the vertical center line structure in the image, and calculates the offset or angular deviation of the laser line relative to the vertical center line structure to obtain alignment deviation information between the laser beam and the image acquisition module.

[0045] The host computer compares the deviation information extracted in step 5 with the preset threshold and generates adjustment prompts. The deviation information guides the operator to adjust the tripod posture, gradually reducing lateral offset and angular deviation.

[0046] Step 7: When the position deviation is less than the preset threshold, the host computer determines that the electromagnetic receiving center of the main antenna, the electromagnetic receiving center of the slave antenna, and the aiming optical axis of the sight are located in the same aiming vertical plane, thereby completing the transfer of orientation north-finding accuracy.

[0047] Step 7 includes the following steps: Step 7-1: Based on the image data obtained in step 5, the host computer performs edge extraction and straight line fitting on the set of pixels corresponding to the line laser beam to obtain the straight line equation of the laser line in the image coordinate system, and identifies the pixel position of the vertical center line structure of the antenna component in the image to determine its corresponding theoretical vertical center line position. Step 7-2: Using the vertical centerline position of the vertical centerline structure in the image as a reference, calculate the lateral offset Δx of the line laser beam relative to the vertical centerline. The specific formula is as follows: ; Where, x i x is the x-coordinate of the laser line at the i-th image sampling point; x0 is the theoretical x-coordinate of the vertical centerline structure in the image; N is the number of laser line pixels involved in the calculation. Step 7-3: Based on the laser line fitting results, select two points (x1, y1) and (x2, y2) located at different longitudinal positions in the image, and calculate the angular deviation Δθ of the laser line relative to the vertical direction of the image. The specific formula is as follows: Δθ=arctan(|(x2-x1)÷(y2-y1)|); Wherein, Δθ represents the degree of inclination of the line laser beam relative to the vertical centerline structure; Step 7-4: Align the lateral offset Δx and the angular deviation Δθ with the preset lateral alignment threshold Δx, respectively. th and angle alignment threshold Δθ th Compare the following conditions: |Δx|≤Δx th ;|Δθ|≤Δθ th ; If the laser beam is aligned with the vertical centerline structure in the image coordinate system, the electromagnetic receiving center of the main antenna, the electromagnetic receiving center of the secondary antenna, and the aiming optical axis of the sight are located in the same aiming vertical plane. The host computer uses the orientation result output by the dual-antenna Beidou as the orientation result of the sight, thereby completing the transmission of orientation and north-finding accuracy.

[0048] In this embodiment, the linear equation of the laser line is extracted through image processing, and the lateral offset and angular deviation are calculated. The measured deviation is compared with a threshold to determine whether alignment is complete. Once the deviation meets the threshold, the electromagnetic receiving center of the main antenna, the electromagnetic receiving center of the secondary antenna, and the optical axis of the sight are on the same aiming vertical plane, achieving coplanar constraint. The orientation result of the dual-antenna Beidou can then be directly used as the orientation result of the sight without manual estimation.

[0049] This embodiment transforms a three-dimensional spatial problem into a two-dimensional image coordinate analysis. Through linear fitting and deviation quantization, it achieves "quantized spatial alignment," eliminating subjective human error. The entire method follows the principle of geometric coplanar constraints and uses image feedback to form a closed-loop correction, ensuring high precision, repeatability, and engineering operability.

[0050] This invention presents a dual-antenna BeiDou orientation method based on coplanar constraints, solving the technical problem of achieving high-precision, quantifiable, and repeatable spatial alignment between the orientation axis of the dual-antenna BeiDou and the aiming optical axis of the observation instrument under portable application conditions, thereby accurately obtaining true north orientation results. This invention introduces a linear laser and a vertical centerline structure to achieve geometric coplanar constraints between the orientation axes of the master and slave antennas and the aiming optical axis of the observation instrument, avoiding the uncertainty of traditional point-to-point manual aiming. Using an image acquisition module and a host computer algorithm, the relative position of the laser line and the centerline is quantified and determined, significantly reducing the impact of subjective human factors on orientation accuracy. Even under short-range, portable application conditions, it can still stably achieve high-precision orientation, fully utilizing the orientation performance of the dual-antenna BeiDou device. The structure is simple, easy to use, and suitable for various observation instruments and field environments, exhibiting good repeatability and engineering practicality.

Claims

1. A method for dual-antenna BeiDou orientation based on coplanar constraints, characterized in that: Includes the following steps: Step 1: The operator installs the main antenna assembly onto the main tripod, and simultaneously installs the slave antenna assembly onto the slave tripod; the main antenna assembly includes a main antenna, a sight mounting interface, a linear laser module, and an image acquisition module; the slave antenna assembly includes a slave antenna and a vertical centerline structure fixedly connected to it; Step 2: The operator adjusts the sighting device to a horizontal position on site, so that the vertical plane of the sighting device, where the vertical aiming reticle is located, is perpendicular to the horizontal plane of the ground. Step 3: The operator controls the line laser module to emit a line laser beam, so that the laser beam surface formed by the line laser beam has a fixed geometric relationship with the aiming vertical plane; Step 4: The operator adjusts the posture of the main tripod or the secondary tripod to illuminate the area where the linear laser beam is located with the secondary antenna assembly, and brings the linear laser beam and the vertical centerline structure into the field of view of the image acquisition module. Step 5: The image acquisition module acquires image data containing the line laser beam and the vertical center line structure in real time and uploads it to the host computer. The host computer identifies the relative position of the line laser beam and the vertical center line structure and calculates the positional deviation between them. Step 6: The host computer generates adjustment prompts based on the position deviation and displays them on the screen to guide the operator to continuously adjust the posture of the main tripod or the secondary tripod until the deviation is less than the preset threshold. Step 7: When the position deviation is less than the preset threshold, the host computer determines that the electromagnetic receiving center of the main antenna, the electromagnetic receiving center of the slave antenna, and the aiming optical axis of the sight are located in the same aiming vertical plane, thereby completing the transfer of orientation north-finding accuracy.

2. The method for dual-antenna BeiDou orientation based on coplanar constraints as described in claim 1, characterized in that: The vertical centerline structure is a structural reference line set on the mounting reference surface of the image acquisition module. In the assembled state of the device, the structural reference line is consistent with the normal direction of the imaging plane of the image acquisition module and forms a perpendicular relationship with the horizontal direction of the imaging area of ​​the image acquisition module, and is used as a reference center line for spatial alignment of the laser beam and the image acquisition module.

3. The method for dual-antenna BeiDou orientation based on coplanar constraints as described in claim 1, characterized in that: The laser emission center line of the linear laser emission module has a fixed geometric relationship with the vertical center line structure. Specifically, the spatial position, angle, and offset of the laser emission center line relative to the vertical center line structure remain unchanged after the equipment is assembled, and do not change relative to vibration, temperature changes, or external disturbances during the operation of the equipment.

4. The method for dual-antenna BeiDou orientation based on coplanar constraints as described in claim 3, characterized in that: When the line laser emitting module is in operation, it is configured such that, under the constraints of the fixed geometric relationship, at least one segment of the emitted line laser beam always falls within the effective imaging area of ​​the image acquisition module within a preset working distance range, thereby allowing the line laser beam to enter the field of view of the image acquisition module and be stably acquired.

5. The method for dual-antenna BeiDou orientation based on coplanar constraints as described in claim 1, characterized in that: When performing step 5, the host computer performs image preprocessing on the image data containing the line laser beam acquired by the image acquisition module, and then extracts the pixel features of the laser line from the image data. The pixel features include at least the position distribution of the laser line in the image, the center line position, or the tilt angle information.

6. The method for dual-antenna BeiDou orientation based on coplanar constraints as described in claim 1, characterized in that: During step 6, the host computer compares the extracted laser line pixel features with the theoretical position of the vertical center line structure in the image, and calculates the offset or angular deviation of the laser line relative to the vertical center line structure to obtain alignment deviation information between the laser beam and the image acquisition module.

7. The method for dual-antenna BeiDou orientation based on coplanar constraints as described in claim 1, characterized in that: Step 7 includes the following steps: Step 7-1: Based on the image data obtained in step 5, the host computer performs edge extraction and straight line fitting on the set of pixels corresponding to the line laser beam to obtain the straight line equation of the laser line in the image coordinate system, and identifies the pixel position of the vertical center line structure of the antenna component in the image to determine its corresponding theoretical vertical center line position. Step 7-2: Using the vertical centerline position of the vertical centerline structure in the image as a reference, calculate the lateral offset Δx of the line laser beam relative to the vertical centerline. The specific formula is as follows: ； Where, x i x is the x-coordinate of the laser line at the i-th image sampling point; x0 is the theoretical x-coordinate of the vertical centerline structure in the image; N is the number of laser line pixels involved in the calculation. Step 7-3: Based on the laser line fitting results, select two points (x1, y1) and (x2, y2) located at different longitudinal positions in the image, and calculate the angular deviation Δθ of the laser line relative to the vertical direction of the image. The specific formula is as follows: Δθ=arctan(|(x2-x1)÷(y2-y1)|); Wherein, Δθ represents the degree of inclination of the line laser beam relative to the vertical centerline structure; Step 7-4: Align the lateral offset Δx and the angular deviation Δθ with the preset lateral alignment threshold Δx, respectively. th and angle alignment threshold Δθ th Compare the following conditions: ∣Δx∣≤Δx th ;∣Δθ∣≤Δθ th ; If the laser beam is aligned with the vertical centerline structure in the image coordinate system, the electromagnetic receiving center of the main antenna, the electromagnetic receiving center of the secondary antenna, and the aiming optical axis of the sight are located in the same aiming vertical plane. The host computer uses the orientation result output by the dual-antenna Beidou as the orientation result of the sight, thereby completing the transmission of orientation and north-finding accuracy.

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