Indoor northbound reference precision evaluation method, system, equipment and medium
By combining the total station crosshair alignment method and the North Star arbitrary time angle method, the problems of low accuracy and poor reliability of traditional indoor north-oriented benchmark measurement are solved, and efficient and accurate indoor north-oriented benchmark measurement is achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-13
- Publication Date
- 2026-03-31
AI Technical Summary
Traditional indoor north-facing reference measurement methods are costly, inefficient, and have poor measurement accuracy and reliability.
The accuracy of the indoor north reference was calculated by combining the total station crosshair alignment method and the North Star arbitrary time angle method. The total station crosshair alignment method was used to adjust each station, and the North Star arbitrary time angle method was used to determine the initial true north azimuth and transfer angle. The accuracy was calculated by combining the plane distance between adjacent total stations and the meridian convergence angle correction.
It enables high-precision indoor north-oriented benchmark measurement, improves the reliability and efficiency of measurement, reduces costs, and avoids point alignment errors caused by repeated station setup.
Smart Images
Figure CN121761940A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of orientation calibration, and in particular to a method, system, equipment and medium for evaluating the accuracy of an indoor north-facing reference. Background Technology
[0002] Inertial navigation is a crucial navigation method in the fields of air, sea, and space exploration. The gyroscope is the core component of the inertial navigation system platform. Over time, gyroscopes drift in their north-finding process, requiring calibration. To calibrate the north-finding deviation of inertial navigation equipment and instruments such as gyrotheodolites, meet the calibration requirements of precision north-finding orientation equipment, and avoid interference from unstable outdoor weather conditions, it is necessary to establish a high-precision true north reference indoors. Therefore, rapid and high-precision calibration of the indoor north reference is essential.
[0003] Traditional methods for assessing the accuracy of indoor north-facing reference systems primarily employ two approaches: the dismantling-style single-station astronomical orientation observation and the collimator relay method. The dismantling-style single-station astronomical orientation involves setting up the instrument outdoors to directly observe the indoor reference target. To ensure visibility between indoor and outdoor locations and favorable conditions for outdoor astronomical observation, it is necessary to dismantle some indoor and outdoor facilities of the reference system or create skylights, significantly increasing costs and severely impacting operational efficiency. The collimator relay method uses a single theodolite paired with a temporary collimator for transition. The temporary collimator must be erected at the same height as the station and maintained strictly horizontally. The azimuth of the temporary collimator is determined first at a suitable angle, and then the station is moved to a suitable location. The azimuth transmitted by the temporary collimator is used to calibrate the indoor north-facing reference system.
[0004] This type of method has the following problems when performing measurements: High cost and low efficiency. One-stop astronomical orientation requires ensuring unobstructed indoor and outdoor visibility of the reference carrier location, which necessitates the removal of some facilities or the installation of skylights, significantly increasing costs, affecting operational efficiency, and also hindering the protection of indoor reference carriers and meeting environmental requirements.
[0005] The parallel light tube relay method requires the temporary light tube to be at the same height as the station, which is difficult to set up and level, and the aiming is time-consuming and labor-intensive. At the same time, the light tube cannot be aimed in opposite directions, which means that only one-way azimuth can be transferred. The theodolite needs to be moved to measure, and it is difficult to set up the station again. With the significant centering error that cannot be estimated and the influence of the ever-changing observation environment, the calibration accuracy is difficult to calculate and check directly.
[0006] It is evident that, for a long time, indoor true north reference measurements have had low accuracy and poor reliability. Summary of the Invention
[0007] The purpose of this application is to provide a method, system, equipment and medium for evaluating the accuracy of indoor north-pointing references, so as to solve the problems of low accuracy and poor reliability of indoor true north-pointing reference measurements.
[0008] To achieve the above objectives, this application provides the following solution: Firstly, this application provides a method for assessing the accuracy of an indoor north-facing reference, including: The total station was adjusted at each station using the crosshair alignment method. Based on the adjusted total station, the initial true north azimuth and the first standard error of the initial true north direction angle of the first total station were determined using the Polaris arbitrary time angle method. Based on the first total station, determine the transfer angles of the indoor north-facing reference and the second mean error of the transfer angles, and measure the plane distance between adjacent total stations; Calculate the meridian convergence angle correction for each station according to the indoor north-facing reference transfer sequence; Calculate the indoor north reference based on the initial true north azimuth, each transmission angle, and the meridian convergence angle correction. The accuracy of the indoor north-facing reference is assessed based on the first and second mean square errors.
[0009] Secondly, this application provides an indoor north-facing reference calibration system, comprising: The total station was adjusted at each station using the crosshair alignment method. Based on the adjusted total station, the initial true north azimuth and the first standard error of the initial true north direction angle of the first total station were determined using the Polaris arbitrary time angle method. Based on the first total station, determine the transfer angles of the indoor north-facing reference and the second mean error of the transfer angles, and measure the plane distance between adjacent total stations; Calculate the meridian convergence angle correction for each station according to the indoor north-facing reference transfer sequence; Calculate the indoor north reference based on the initial true north azimuth, each transmission angle, and the meridian convergence angle correction. The accuracy of the indoor north-facing reference is assessed based on the first and second mean square errors.
[0010] Thirdly, this application provides a computer device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the above-described method for assessing the accuracy of an indoor north-facing reference.
[0011] Fourthly, this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the above-described method for assessing the accuracy of an indoor north-facing reference.
[0012] According to the specific embodiments provided in this application, this application has the following technical effects: This application utilizes the total station crosshair alignment method to adjust the total stations at each station, achieving high-precision transfer of the short-side true north azimuth. Using the total station crosshairs as the aiming center eliminates the need for repeated station setups, thus removing the point alignment errors generated during repeated station setups. Furthermore, it combines the arbitrary time angle method based on Polaris (a star) to determine the first error of the initial true north azimuth and initial true north direction angle of the first total station, thereby determining the transfer angles of the indoor north reference and the second error of these transfer angles. It also measures the planar distance between adjacent total stations and calculates the meridian convergence angle correction for each station according to the indoor north reference transfer sequence. Based on the initial true north azimuth, transfer angles, and meridian convergence angle corrections, the indoor north reference is calculated, completing the high-precision measurement and accurate transfer of the true north azimuth. Finally, the accuracy of the indoor north reference is evaluated based on the first and second errors. This application improves the measurement accuracy of the indoor true north reference and enhances the reliability of the measurement results. Attached Figure Description
[0013] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0014] Figure 1 A flowchart illustrating an indoor north-facing reference accuracy assessment method provided in an embodiment of this application; Figure 2 A schematic diagram of indoor true north reference transfer provided for an embodiment of this application. Detailed Implementation
[0015] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0016] To make the objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0017] like Figure 1 As shown in the embodiment of this application, a method for evaluating the accuracy of an indoor north-facing reference is provided, including: S1: Use the total station crosshair aiming method to adjust the total station at each station; S2: Based on the adjusted total station, the initial true north azimuth and the first standard error of the initial true north direction angle of the first total station are determined using the Polaris arbitrary time angle method. S3: Based on the first total station, determine each transfer angle of the indoor north reference and the second mean error of the transfer angle, and measure the plane distance between adjacent total stations; S4: Calculate the meridian convergence angle correction for each station according to the indoor north-facing reference transfer sequence; S5: Calculate the indoor north reference based on the initial true north azimuth, each transmission angle, and the meridian convergence angle correction; S6: Evaluate the accuracy of the indoor north-facing reference based on the first mean square error and the second mean square error.
[0018] This application utilizes the crosshairs of a total station for high-precision transmission of the short-side true north azimuth. Stations can be freely set up according to indoor and outdoor environmental conditions without dismantling existing facilities in the reference room such as doors and windows, maximizing cost reduction and efficiency in indoor north-oriented reference calibration. Using a high-precision total station as the observation or transmission medium, this application enables elevation and depression observations of the survey line during the transmission of the true north azimuth reference. The station and aiming point do not require equal-height settings, yet the optical paths of the two total stations' line of sight remain parallel, thus completing the accurate measurement of the high-precision indoor azimuth reference.
[0019] In an exemplary embodiment, S1 specifically includes: S11: Deploy total stations to ensure line-of-sight between total stations at adjacent stations, providing the necessary conditions for the formation of optical paths for the alignment survey lines.
[0020] S12: Based on the aforementioned prerequisites, adjust the objective lenses of each total station to infinity and illuminate the crosshairs of the total station telescope field of view using an optical autocollimating light source to ensure that the crosshairs of the total stations at adjacent stations are clearly visible, providing observation conditions for forming a homing line; wherein, clear visibility means that the clarity of the total station crosshairs is higher than a set threshold.
[0021] S13: Based on the aforementioned prerequisites and observation conditions, use the first total station in the left-hand position to aim at the center of the crosshairs of the second total station, and then use the second total station in the left-hand position to aim at the center of the crosshairs of the first total station, until the crosshairs of the two total stations are clearly visible in each other's field of view, ensuring that the aiming lines of the two total stations are parallel.
[0022] This application employs a high-precision total station with crosshair alignment to achieve high-precision transfer of the short-side true north azimuth. By adjusting the telescope's focal length to infinity for alignment, the two total stations form parallel optical paths, providing a single survey line for accurate transfer of the true north azimuth. Using the total station's crosshairs as the aiming center eliminates the need for repeated station setups, thus eliminating point alignment errors that occur during repeated station setups. Setting and maintaining the focal length at infinity further reduces focusing errors during observation.
[0023] The total station allows for flexible and efficient station setup, enabling calibration operations. It can be freely set up in confined spaces, both indoors and outdoors, allowing for bidirectional and multiple short-side true north transfers. Furthermore, the use of an optical autocollimating eyepiece provides illumination while expanding its applicability to different reference carriers, ensuring image clarity and aiming accuracy.
[0024] In practical applications, in addition to the total station crosshair aiming method, the mutual aiming inner target method can also be used. That is, an inner target is installed inside the total station telescope. Generally, the installation accuracy is required to be ±4″ of the deviation from the line of sight. The mutual aiming inner target method measures the center of the instrument, so focusing observation is required. When designing the station, the distance between each station should be made as equal as possible to reduce the impact of focusing error.
[0025] An external target can also be installed on the total station telescope. The target is positioned in or near the plane formed by the instrument's line of sight and vertical axis. By using the mirror to align the aiming center with the instrument's center, the centering error can be overcome.
[0026] However, the above two methods require focusing separately in each observation direction, and the target is the center of the inner (outer) target installed on the other instrument. At the same time, there is a deviation in the installation of the target, which is time-consuming and laborious, and the accuracy is not as good as the total station crosshair aiming method of this application.
[0027] In an exemplary embodiment, S2 specifically includes: Upper half-repeat measurement: S21: Using the left-hand position of the first total station, aim at the center of the crosshairs of the second total station independently 3 times, and record the reading of the scale circle.
[0028] S22: Using the first total station, independently aim at the center position of the North Star six times, and record the aiming time and the reading of the scale.
[0029] S23: Switch the first total station to the right-hand position, independently aim at the center of the North Star six times, and record the aiming time and the circle reading.
[0030] S24: Using the right-hand position of the first total station, aim at the center of the crosshairs of the second total station independently 3 times, record the readings of the scale circle, and complete the first half of the measurement.
[0031] S25: Repeat the first half of the measurement in reverse to complete the initial true north observation of one measurement cycle.
[0032] S26: Based on the initial true north observations from multiple measurements, determine the initial true north azimuth and the first mean square error.
[0033] In an exemplary embodiment, S3 specifically includes: The process of determining the transfer angle: S31: Fix the aiming part of the first total station, use the second total station in the left-face position to aim at the center of the crosshairs of the first total station, and then use the left-face position of the first total station to aim at the center of the crosshairs of the second total station, until the crosshairs of the two total stations are clearly visible in each other's field of view, ensuring that the aiming lines of the two total stations are parallel, and completing the transfer of the aiming lines from the second total station to the first total station.
[0034] S32: Fix the aiming part of the second total station, use the second total station in the left-face position to aim at the center of the crosshairs of the third total station, and then use the third total station in the left-face position to aim at the center of the crosshairs of the second total station, until the crosshairs of the two total stations are clearly visible in each other's field of view, ensuring that the aiming lines of the two total stations are parallel, and completing the transfer of the aiming lines from the second total station to the third total station.
[0035] S33: Based on the transfer of the alignment line from the second total station to the first total station and from the second total station to the third total station, using the repetition method, with the second total station as the station, the crosshair center of the first total station as the backsight, and the crosshair center of the third total station as the foresight, multiple repetitions are observed, and the average value of the multiple repetitions is used as the first transfer angle of the indoor north reference. The second standard error of the first transfer angle is calculated.
[0036] S34: Repeat the process of determining the transfer angle multiple times, measure each transfer angle of the indoor north reference, calculate the second mean square error of each transfer angle, and measure the plane distance between adjacent total stations in sequence.
[0037] This application utilizes independent observations from multiple stations across multiple time periods, enabling multiple checks and improving the accuracy and precision of short-side azimuth transfer, thus ensuring the high reliability of the calibrated indoor north-facing reference.
[0038] In an exemplary embodiment, the meridian convergence angle correction is: in, This is the correction for the meridian convergence angle. For radians and degrees, To measure the horizontal distance from the station point to the aiming point, To measure the true azimuth from the station point to the aiming point, To measure the latitude of the station, Let be the radius of curvature of the y-axis.
[0039] In one exemplary embodiment, the indoor north-facing reference is: in, 'Using the indoor north-facing reference,' The starting true north azimuth. For the transfer angle, This is the correction for the meridian convergence angle. i This represents the number of transmitted angles.
[0040] In one exemplary embodiment, S6 specifically includes: use Assess the accuracy of the indoor north-facing reference; wherein, M This represents the mean square error of the indoor north-facing reference. This represents the first mean square error of the initial true north azimuth. This is the second error of the transmission angle.
[0041] In practical applications, the indoor north-facing reference calibration method of this application specifically includes the following steps.
[0042] Step 1: Conduct a site survey, select a suitable location to set up a high-precision total station, and ensure that the total stations of adjacent stations are in line of sight to provide the necessary conditions for the optical path interconnection of the aiming lines.
[0043] Step 2: Adjust the objective lenses of all total stations to infinity and illuminate the crosshairs of the telescope field of view with an optical autocollimating light source to ensure that the crosshairs of the total stations at adjacent stations are clearly visible, providing good observation conditions for forming the alignment line.
[0044] Step 3: After completing Steps 1 and 2, use the first total station in the left-face position to aim at the center of the crosshairs of the second total station, and then use the second total station in the left-face position to aim at the center of the crosshairs of the first total station. The two total stations aim at each other alternately until the crosshairs of the two total stations can be clearly seen in each other's field of view, so as to ensure that the aiming lines of the two total stations are parallel.
[0045] Step 4: After completing Step 3, accurately determine the initial true north using the arbitrary time angle method with Polaris (a star). The specific process is as follows: a) Using the left-face position of the first total station, aim at the center of the crosshairs of the second total station independently at least 3 times, and record the readings on the degree circle; b) Using the first total station, aim at the center of the Polaris (a star) point independently at least 6 times, and record the aiming time and the degree circle reading; c) Invert the instrument, switch the first total station to the right-face position, and aim at the center of the Polaris (a star) point independently 6 times, recording the aiming time and the degree circle reading; d) Aim at the center of the crosshairs of the second total station independently 3 times, and record the degree circle reading to complete the first half of the measurement; e) Repeat the above operations in reverse to complete one round of initial true north observation; f) Repeat processes a) to e) to perform multiple rounds of measurement to obtain a high-precision initial true north azimuth angle.
[0046] Step 5: After completing Step 4, fix the aiming part of the first total station, and use the second total station to operate according to Step 3 to complete the transfer of the aiming line from the second total station to the first total station.
[0047] Step 6: Following the steps in Step 3, determine the alignment line between the second and third total stations.
[0048] Step 7: After completing steps 5 and 6, use the repetition method, with the second total station as the station, the crosshair center of the first total station as the backsight, and the crosshair center of the third total station as the foresight, and observe for 6 repetitions. Take the average value of the 6 repetitions as the first transfer angle of the indoor north reference.
[0049] In practical applications, the first total station measures the true north azimuth between the first and second total stations, which serves as the initial true north azimuth. The second and subsequent total stations then serve as the station points or aiming points for the transfer angle measurement.
[0050] If the on-site observation conditions are poor, multiple total stations will still be needed for data transfer. Therefore, there may be situations where three or more total stations are required.
[0051] In most cases, two total stations are sufficient to complete the indoor true north reference measurement.
[0052] Step 8: Follow the steps 5 to 7 to complete the measurement of multiple transfer angles.
[0053] Step 9: After completing steps 1 to 8, measure the plane distance between adjacent total stations in sequence, accurate to 2cm.
[0054] Step 10: After completing steps 1 through 9, calculate the meridian convergence angle correction for each station according to the indoor north-facing reference transfer sequence. The calculation formula is as follows: ,in, This is the correction for the meridian convergence angle. This is the constant for converting radians to degrees (value: 206265 arcseconds). The horizontal distance (m) from the measuring station to the aiming point. To measure the true azimuth from the station point to the aiming point, To measure the latitude of the station, Let be the radius of curvature of the y-axis.
[0055] Step 11: After completing steps 1 to 10, calculate the indoor north reference azimuth. The process is as follows: 1) Based on the measurement results in step 4, accurately calculate the initial true north azimuth and its mean square error; 2) Based on the measurement results in step 8, accurately calculate each transfer angle and mean square error of the indoor north reference; 3) Using the aforementioned initial true north azimuth, each transfer angle, and the meridian convergence angle correction calculated in step 10), accurately calculate the indoor north reference. The calculation formula is: ,in, Based on the indoor north-facing reference, The starting true north azimuth. For the transfer angle, is the correction for the meridian convergence angle, and i is the number of propagation angles; Step 12: After completing Step 11, assess the accuracy of the indoor north-facing reference. According to the formula: Calculate, where M is the standard error of the indoor north-facing reference. The mean square error of the initial true north azimuth. This represents the mean square error of the transmission angle.
[0056] This application is the first to use the arbitrary time angle method of Polaris (a star) combined with the crosshair alignment method of a total station to complete the high-precision measurement and accurate transmission of true north azimuth (see steps 1 to 8 for details), which solves the long-standing problem of low accuracy and poor reliability of indoor true north azimuth benchmark measurement.
[0057] based on Figure 2 The calibration accuracy of the indoor north-facing reference calibration method of this application is verified according to Tables 1-3.
[0058] Table 1 Comparison of this application with direct observations
[0059] Table 2. Calibration data for City A
[0060] Table 3. Calibration data for City B
[0061] This application provides an indoor north-facing reference calibration system, comprising: The total station was adjusted at each station using the crosshair alignment method.
[0062] Based on the adjusted total station, the initial true north azimuth and the first mean square error of the initial true north direction angle of the first total station were determined using the Polaris arbitrary time angle method.
[0063] Based on the first total station, the transfer angles of the indoor north-facing reference and the second mean error of the transfer angles are determined, and the planar distance between adjacent total stations is measured.
[0064] Calculate the meridian convergence angle correction for each station according to the indoor northward reference transfer sequence.
[0065] The indoor north reference is calculated based on the initial true north azimuth, each transmission angle, and the meridian convergence angle correction.
[0066] The accuracy of the indoor north-facing reference is assessed based on the first and second mean square errors.
[0067] In an exemplary embodiment, a computer device is provided, including a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the steps in the above-described method embodiments. The computer device can be a server or a terminal. The computer device includes a processor, a memory, an input / output interface (I / O), and a communication interface. The processor, memory, and I / O interface are connected via a system bus, and the communication interface is connected to the system bus via the I / O interface. The processor of the computer device provides computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and computer program in the non-volatile storage medium. The database of the computer device stores data to be processed. The I / O interface of the computer device is used for exchanging information between the processor and external devices. The communication interface of the computer device is used for communicating with an external terminal via a network connection. When the computer program is executed by the processor, it implements the above-described methods.
[0068] In one exemplary embodiment, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above-described method embodiments.
[0069] In one exemplary embodiment, a computer-readable storage medium is provided storing a computer program that, when executed by a processor, implements the steps in the above-described method embodiments.
[0070] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.
[0071] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by hardware related to computer program instructions. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments described above. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM).
[0072] The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.
[0073] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0074] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.
Claims
1. A method for evaluating the accuracy of an indoor north-facing reference, characterized in that, include: The total station was adjusted at each station using the crosshair alignment method. Based on the adjusted total station, the initial true north azimuth and the first standard error of the initial true north direction angle of the first total station were determined using the Polaris arbitrary time angle method. Based on the first total station, determine the transfer angles of the indoor north-facing reference and the second mean error of the transfer angles, and measure the plane distance between adjacent total stations; Calculate the meridian convergence angle correction for each station according to the indoor north-facing reference transfer sequence; Calculate the indoor north reference based on the initial true north azimuth, each transmission angle, and the meridian convergence angle correction. The accuracy of the indoor north-facing reference is assessed based on the first and second mean square errors.
2. The method for evaluating the accuracy of an indoor north-facing reference according to claim 1, characterized in that, The total station is adjusted at each station using the crosshair alignment method, specifically including: Deploy total stations to ensure line-of-sight between total stations at adjacent stations, providing the necessary conditions for the optical path interconnection of the aiming lines; Based on the aforementioned prerequisites, the objective lenses of each total station are adjusted to infinity, and the crosshairs of the total station telescope field of view are illuminated by an optical autocollimating light source to ensure that the crosshairs of the total stations at adjacent stations are clearly visible, providing observation conditions for forming a homing line; where clear visibility means that the clarity of the total station crosshairs is higher than a set threshold. Based on the aforementioned prerequisites and observation conditions, the first total station is positioned with its face left and aimed at the center of the crosshairs of the second total station. Then, the second total station is positioned with its face left and aimed at the center of the crosshairs of the first total station, until the crosshairs of the two total stations are clearly visible in each other's field of view, ensuring that the aiming lines of the two total stations are parallel.
3. The method for evaluating the accuracy of an indoor north-facing reference according to claim 1, characterized in that, Based on the adjusted total station, the initial true north azimuth and the first standard error of the initial true north direction angle of the first total station were determined using the Polaris arbitrary time angle method, specifically including: Upper half-return measurement: Using the left-face position of the first total station, aim at the center of the crosshairs of the second total station and then independently aim 3 times, recording the readings of the scale circle; The first total station was used to independently aim at the center position of the North Star six times, and the aiming time and the reading of the scale were recorded. Switch the first total station to the right-hand position and independently aim at the center of the North Star six times, recording the aiming time and the reading of the scale circle. Using the right-hand position of the first total station, aim at the center of the crosshairs of the second total station and aim independently 3 times, record the readings of the scale circle, and complete the first half of the measurement. Repeat the first half of the measurement in reverse to complete the initial true north observation of one round; Based on multiple measurements of the initial true north azimuth, the initial true north azimuth angle and the first mean square error were determined.
4. The method for evaluating the accuracy of an indoor north-facing reference according to claim 1, characterized in that, Based on the first total station, the transfer angles of the indoor north-facing datum and the second mean square error of the transfer angles are determined, and the planar distance between adjacent total stations is measured, specifically including: The process of determining the transfer angle is as follows: Fix the aiming part of the first total station, use the second total station in the left-face position to aim at the center of the crosshairs of the first total station, and then use the left-face position of the first total station to aim at the center of the crosshairs of the second total station until the crosshairs of the two total stations are clearly visible in each other's field of view, ensuring that the aiming lines of the two total stations are parallel, thus completing the transfer of the aiming lines from the second total station to the first total station; Fix the aiming part of the second total station, use the second total station in the left-face position to aim at the center of the crosshairs of the third total station, and then use the third total station in the left-face position to aim at the center of the crosshairs of the second total station, until the crosshairs of the two total stations are clearly visible in each other's field of view, ensuring that the aiming lines of the two total stations are parallel, and complete the transfer of the aiming lines from the second total station to the third total station; Based on the transfer of the aiming line from the second total station to the first total station and from the second total station to the third total station, according to the repetition method, with the second total station as the station, the crosshair center of the first total station as the backsight, and the crosshair center of the third total station as the foresight, multiple repetitions are observed, and the average value of the multiple repetitions is used as the first transfer angle of the indoor north reference. The second standard error of the first transfer angle is calculated. Repeat the process of determining the transfer angle multiple times to measure each transfer angle of the indoor north-facing reference, calculate the second mean square error of each transfer angle, and measure the plane distance between adjacent total stations in sequence.
5. The method for evaluating the accuracy of an indoor north-facing reference according to claim 1, characterized in that, The meridian convergence angle correction is: in, This is the correction for the meridian convergence angle. For radians and degrees, The distance is the horizontal distance from the measuring station to the aiming point. The measuring station is the location where the observation instrument is set up, and the aiming point is the location where the observation target is set up. To measure the true azimuth from the station point to the aiming point, To measure the latitude of the station, Let be the radius of curvature of the y-axis.
6. The method for evaluating the accuracy of an indoor north-facing reference according to claim 1, characterized in that, The indoor north-facing reference is: in, 'Using the indoor north-facing reference,' The starting true north azimuth. For the transfer angle, Let i be the meridian convergence angle correction, and i be the number of transit angles.
7. The method for evaluating the accuracy of an indoor north-facing reference according to claim 1, characterized in that, The accuracy of the indoor north-facing reference is assessed based on the first and second mean square errors, specifically including: use Assess the accuracy of the indoor north-facing reference; wherein, M This represents the mean square error of the indoor north-facing reference. This represents the first mean square error of the initial true north azimuth. This is the second error of the transmission angle.
8. An indoor north-facing reference calibration system, characterized in that, The indoor north-facing reference calibration system performs the indoor north-facing reference calibration method according to any one of claims 1-7, and the indoor north-facing reference calibration system comprises: The total station was adjusted at each station using the crosshair alignment method. Based on the adjusted total station, the initial true north azimuth and the first standard error of the initial true north direction angle of the first total station were determined using the Polaris arbitrary time angle method. Based on the first total station, determine the transfer angles of the indoor north-facing reference and the second mean error of the transfer angles, and measure the plane distance between adjacent total stations; Calculate the meridian convergence angle correction for each station according to the indoor north-facing reference transfer sequence; Calculate the indoor north reference based on the initial true north azimuth, each transmission angle, and the meridian convergence angle correction. The accuracy of the indoor north-facing reference is assessed based on the first and second mean square errors.
9. A computer device, comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that the processor executes the computer program to implement the indoor north-facing reference accuracy assessment method according to any one of claims 1-7.
10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the computer program implements the indoor north-facing reference accuracy assessment method according to any one of claims 1-7.