A new construction control network establishment and operation and maintenance system and establishment method

Abstract

The present invention discloses a new construction control network establishment and operation and maintenance system and an establishment method. The system consists of three major parts: a Beidou data receiving center, a Beidou data processing center, and a Beidou data transmission center. The Beidou data receiving center is composed of N Beidou satellite ground-based augmentation reference stations, which can receive Beidou satellite signals all-weather and in real time, and transmit the satellite signal data to the Beidou data processing center to provide an accurate coordinate reference for the construction control network. The Beidou data processing center can realize the functions of real-time reception, adjustment and calculation, and data result generation of satellite data of each network point of the ground-based augmentation system, and can realize real-time update and automatic correction of the coordinates of each control network point. The Beidou data transmission center can realize functions such as user online registration application, data download, and data automatic distribution, and can realize real-time scale unification of coordinate accuracy, avoiding construction quality problems caused by coordinate displacement of the control network.

Description

Technical Field

[0001] The present invention relates to the technical field of engineering surveying, and in particular to a novel construction control network establishment and operation maintenance system and establishment method. Background Art

[0002] All kinds of control networks used in engineering survey, construction and operation and maintenance stages are subject to duplication and waste of resources. In different types of control networks established by different construction units at different stages, due to different construction stages, different construction location requirements, and different levels, there are duplications in networking, which affects construction efficiency and makes it difficult to achieve multiple uses of one network. As a result, major engineering construction projects are eager to integrate control networks or explore new methods to achieve one-time construction and multi-level use.

[0003] At the same time, there is a need for changes in the construction and operation mode and technical service model of the first-level control network for engineering surveying. Compared with the new control network construction system solution, the traditional first-level control network has problems such as high overall cost, high review frequency, long re-measurement cycle, and coordinates cannot be updated in real time. In addition, the layout of the secondary encryption network or dedicated network based on the coordinates of the first-level control network points has problems such as high graphic structure requirements, long measurement cycle, and high investment in manpower and equipment resources. New methods are also urgently needed to improve or solve them. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the above-mentioned background technology and to provide a new type of construction control network establishment and operation and maintenance system and establishment method. This system is suitable for related operations of control network construction using satellite signals in the field of engineering construction measurement. It can realize multi-level utilization of one-time construction, real-time updating and transmission of coordinates, dynamic monitoring and management of coordinates, and can greatly improve the encryption efficiency of the control network, shorten the re-measurement cycle, and reduce construction and review costs.

[0005] In order to achieve the above technical features, the purpose of the present invention is achieved as follows: a new type of construction control network establishment and operation and maintenance system, the system consists of three major parts: Beidou data receiving center, Beidou data processing center, and Beidou data transmission center;

[0006] The Beidou data receiving center is composed of N Beidou satellite ground-based augmented reference stations, which can receive Beidou satellite signals in real time around the clock and transmit satellite signal data to the Beidou data processing center, providing accurate coordinate reference for the construction control network. At the same time, it can also perform joint adjustment and solution with various satellite mobile terminal data to achieve rapid encryption of control networks at all levels;

[0007] The Beidou data processing center can realize the real-time reception, adjustment and data result generation functions of satellite data of each network point of the ground-based augmentation system, and can realize the real-time update and automatic correction of the coordinates of each control network point;

[0008] The Beidou data transmission center can realize functions such as user online registration and application, data download, and data automatic distribution, and can achieve real-time scale unification of coordinate accuracy, avoiding construction quality problems caused by displacement of the control network coordinates.

[0009] The value of N is N > 4.

[0010] A construction method for establishing and operating and maintaining a new type of construction control network includes the following steps:

[0011] Step 1: In the initial stage of project design, in combination with the project requirements and the designed control network, survey the layout positions of BDS / GNSS reference stations.

[0012] Step 2: After the BDS / GNSS reference stations are established, ensure that they can compatibly receive signals in the B1, B2, B3, B1C, B2A frequency bands of BDS, the L1C / A, L2C, L2E frequency bands of the GPS system, and the L1, L2, L3 frequency bands of the GLONASS system.

[0013] Step 3: After the BDS / GNSS reference stations receive data information, through the Beidou data transmission center module, use network, optical fiber or radio communication technology to transmit the data to the Beidou data processing center; the Beidou data processing center, according to the project standards, jointly measures the BDS / GNSS reference stations with existing national plane Class B points and national second-class or above leveled points, or local control network points that meet the accuracy requirements; and automatically selects the processing steps and methods according to different requirements to perform data comprehensive adjustment calculation to obtain the plane coordinates and elevation values of the BDS / GNSS reference stations in the construction control network coordinate system.

[0014] Step 4: Before calculating the coordinate information of the BDS / GNSS reference stations, it is necessary to test the real-time kinematic positioning accuracy of the system. No less than 10 known control points should be selected as test points around the construction area; on the terminal device, through the Beidou data receiving center, set the receiving mode to the test mode; at a single test point, the system continuously collects 30 - 180 positioning information at a sampling interval of 1 s, and transmits the collected information to the Beidou data processing center through the Beidou data transmission center; the Beidou data processing center adopts corresponding processing steps according to the receiving mode to calculate the observed coordinate values of the test point, and then compares the calculation results with the known coordinate information of the control points to calculate the positioning accuracy.

[0015] Step 5: Before construction, the BDS / GNSS reference stations need to be observed for a long time and jointly adjusted with the known control points, and the average value that meets the internal consistency accuracy requirements in the joint measurement and calculation results is taken as the starting coordinates of each reference station, that is, the benchmark coordinates of the primary control network.

[0016] Step 6: After the system observes and calculates the plane coordinates and elevation values of the BDS / GNSS reference station in the construction control network coordinate system, the results are stored in the Beidou data processing center;

[0017] Step 7: In the construction and operation and maintenance applications of the primary network, the reference control points can conduct coordinate observations all-weather, complete coordinate calculations in real time, ensure the timeliness of automatic coordinate updates and transmissions, not only avoid the waste of a large amount of manpower and financial resources caused by the fixed-period review of the traditional primary control network, but also set the coordinate update and push period; users can register and apply for an account in the data transmission center and apply for the corresponding coordinate information after logging in through the PC or mobile phone.

[0018] Step 8: In the encryption applications of the secondary network or special control network, satellite observation stations are arranged at any position where encryption is required. The data sampling interval is set to 1 s, and the observation period is not less than 120 minutes. The encrypted Beidou terminal transmits the observation data to the Beidou data processing center in real time through the 5G network signal and jointly performs coordinate calculations and data storage with the satellite observation data of the reference station. Registered users can download or query the calculation results on the mobile phone through the Beidou data transmission center, and can obtain the coordinates of the encrypted points immediately after the observation is completed, greatly shortening the construction and coordinate calculation period of the encrypted network;

[0019] Step 9: In the traditional RTK layout application, users do not need to freely set up external or internal radio stations. They only need to use a mobile satellite receiving terminal to connect to the signal of the primary control network reference station through the network port to perform multi-base station network RTK coordinate layout or measurement. Compared with single-base station network CORS or single-base station radio, the accuracy is more uniform and reliable, with a plane accuracy of ±1 cm and an elevation accuracy of ±2 cm, meeting the technical requirements of construction layout and measurement.

[0020] In the above Step 1, the selection of the layout location of the BDS / GNSS reference station should meet the following requirements:

[0021] (1) It is located around the construction area and has a stable geological foundation;

[0022] (2) It has satellite visibility conditions with a horizon elevation angle of more than 10°. When the environment is complex, the elevation angle is appropriately relaxed to 25°, and the horizontal projection range of the obstacles is not more than 60°;

[0023] (3) It is more than 200 m away from large-area water areas, high-voltage line crossing areas, etc.;

[0024] (4) The number of reference stations is not less than 4 and is relatively evenly distributed.

[0025] The frequency band signals described in Step 2 specifically include pseudorange, carrier phase, Doppler frequency shift, carrier-to-noise ratio, and original navigation message information, have a perfect data reception system, and have the ability to operate continuously and automatically all-weather.

[0026] In Step 4, the positioning accuracy is measured by the internal consistency accuracy and the external consistency accuracy. The specific calculation process is as follows:

[0027] (1) Calculation of internal consistency accuracy:

[0028] Let n be the number of positioning information collected at a certain test point, l m be its m-th observation value, be the average value of the observation values at this test point. Then the internal consistency accuracy σ of the observation values at this test point is:

[0029]

[0030] The accuracy evaluation tolerance is: σ 水平 ≤1 cm, σ 垂直 ≤2 cm;

[0031] (2) Calculation of external consistency accuracy:

[0032] Let n be the number of positioning information collected at a certain test point, l m be its m-th observation value, be the true value of the observation value at this test point. Then the external consistency accuracy of this test point is:

[0033]

[0034] The accuracy evaluation tolerance is: σ 水平 ≤1 cm, σ 垂直 ≤2 cm.

[0035] In Step 5, the time for long-term observation is at least 1 month.

[0036] In Step 6, the Beidou data processing center includes a user management module, a data management module, and a data distribution module. The user management module can manage user types, permissions, and quantities. The data management module is responsible for classifying and storing data by level. The data distribution module is responsible for point-to-point encryption and transmission of data.

[0037] The specific process of automatically selecting processing steps and methods according to different requirements in Step 3 is as follows: The precise ephemeris, broadcast ephemeris, and satellite raw observation data are transmitted to the Beidou data processing center through optical fiber or network technology. The data is preprocessed and denoised by the Beidou data processing center, and then the satellite data type and frequency band are selected;

[0038] Then, post-difference data processing, static data processing, and dynamic real-time data processing are performed on the data. After post-difference data processing, non-fixed base station satellite receiving terminal data is processed, and various solution parameter settings are carried out. After the completion of various solution parameter settings, known data is input, a coordinate system is selected, and then baseline solution is performed; the data obtained through dynamic real-time data processing will enter the regional overall modeling. The data after regional overall modeling is used for differential positioning data, and then the differential positioning data is transmitted to the satellite receiving terminal through mobile, Internet, or radio. At the same time, combined with the data of the virtual reference station and the data of baseline solution, adjustment calculation is carried out, and the data after adjustment calculation is judged for accuracy. If it is qualified, the data coordinates are stored and coordinate output is performed. If it is unqualified, it returns to the initial data preprocessing step.

[0039] The present invention has the following beneficial effects:

[0040] 1. The present invention discloses a method for establishing and operating and maintaining a new construction control network system. Compared with traditional construction control network construction, it can achieve one-time construction and multi-level utilization, effectively reducing the cost of multiple-level network construction; it can realize dynamic monitoring and management of control network coordinates, improve the update frequency of control network coordinates, and shorten the control network review cycle; it can quickly and efficiently encrypt the construction control network, reducing operation costs and encryption costs; it can realize long-period automatic real-time update of coordinates, effectively ensuring the accuracy and timeliness of coordinates.

[0041] 2. By adopting the system of the present invention, it is composed of N (N>4) Beidou ground-based augmentation base stations through the Beidou data receiving center, which can receive Beidou satellite signals all-weather and in real-time, and transmit the satellite signal data to the Beidou data processing center, providing an accurate coordinate reference for the construction control network. At the same time, it can also perform adjustment calculation with various satellite mobile terminal data to realize rapid encryption of control networks at all levels. The Beidou data processing center can realize functions such as real-time reception of satellite data of each network point of the ground-based augmentation system, adjustment calculation, and generation of data results, and can realize real-time update and automatic correction of coordinates of each control network point. The Beidou data transmission center can realize functions such as user online registration application, data download, and automatic data distribution, and can realize real-time scale unification of coordinate accuracy, avoiding construction quality problems caused by coordinate displacement of the control network.

[0042] 3. By adopting the system and method of the present invention in traditional RTK layout applications, users do not need to freely set external or internal radios. They only need to use a mobile satellite receiving terminal to connect to the signal of the primary control network reference station through a network port to perform multi-base station network RTK coordinate layout or measurement. Compared with single-base station network CORS or single-base station radio, the accuracy is more uniform and reliable. After long-term verification, the planar accuracy can reach ±1 cm, and the elevation accuracy can reach ±2 cm, which can meet the general construction layout and measurement technical requirements. Description of the Drawings

[0043] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0044] Figure 1 It is a system implementation flowchart of the present invention.

[0045] Figure 2 It is a flowchart of automatically selecting processing steps and methods according to different requirements in step three of the present invention. Specific implementation manners

[0046] The embodiments of the present invention will be further described below in conjunction with the accompanying drawings.

[0047] Embodiment 1:

[0048] Refer to Figure 1-2 , a new type of construction control network establishment and operation and maintenance system, the system is composed of three major parts: a Beidou data receiving center, a Beidou data processing center, and a Beidou data transmission center; the Beidou data receiving center is composed of N Beidou satellite ground-based augmentation reference stations, which can receive Beidou satellite signals all-weather and in real time, and transmit the satellite signal data to the Beidou data processing center, providing an accurate coordinate reference for the construction control network. At the same time, it can also perform combined adjustment calculations with various satellite mobile terminal data to realize the rapid encryption of control networks at all levels; the Beidou data processing center can realize the functions of real-time receiving, adjustment calculation, and data result generation of satellite data of each network point of the ground-based augmentation system, and can realize the real-time update and automatic correction of the coordinates of each control network point; the Beidou data transmission center can realize functions such as user online registration application, data download, and automatic data distribution, and can realize real-time scale unification of coordinate accuracy, avoiding construction quality problems caused by coordinate displacement of the control network. By adopting the above control network system, it can be well applied to the related operations of using satellite signals for control network construction in the field of engineering construction survey, and can realize multi-level utilization in one construction, real-time update and transmission of coordinates, dynamic monitoring and management of coordinates, greatly improving the encryption efficiency of the control network, shortening the remeasurement cycle, and reducing the construction and review costs, etc.

[0049] Furthermore, the value of N is N > 4. By adopting multiple Beidou satellite ground-based augmentation reference stations, it is ensured that sufficient coordinate information can be collected, thereby improving the measurement accuracy.

[0050] Embodiment 2:

[0051] A construction method of a new type of construction control network establishment and operation and maintenance system includes the following steps:

[0052] Step 1: In the initial stage of project design, in combination with the project requirements and the designed control network, conduct a survey on the layout positions of BDS / GNSS reference stations;

[0053] Step 2: After the BDS / GNSS reference station is established, ensure that it can compatibly receive signals in the B1, B2, B3, B1C, B2A frequency bands of BDS, the L1C / A, L2C, L2E frequency bands of the GPS system, and the L1, L2, L3 frequency bands of the GLONASS system;

[0054] Step 3: After the BDS / GNSS reference station receives data information, through the Beidou data transmission center module, use network, optical fiber or radio communication technology to transmit the data to the Beidou data processing center; the Beidou data processing center, according to engineering standards, conducts joint measurements of the BDS / GNSS reference station with existing national plane Class B points and national second-class or above leveled points, or local control network points that meet the accuracy requirements; and automatically selects processing steps and methods according to different requirements to perform data comprehensive adjustment and calculation to obtain the plane coordinates and elevation values of the BDS / GNSS reference station in the construction control network coordinate system;

[0055] Step 4: Before calculating the coordinate information of the BDS / GNSS reference station, it is necessary to test the real-time kinematic positioning accuracy of the system. No less than 10 known control points should be selected as test points around the construction area; on the terminal device, through the Beidou data receiving center, set the receiving mode to the test mode; at a single test point, the system continuously collects 30 - 180 positioning information at a sampling interval of 1 s, and transmits the collected information to the Beidou data processing center through the Beidou data transmission center; the Beidou data processing center adopts corresponding processing steps according to the receiving mode to calculate the observed coordinate values of the test point, and then compares the calculation results with the known coordinate information of the control point to calculate the positioning accuracy;

[0056] Step 5: Before construction, the BDS / GNSS reference station needs to be observed for a long time and jointly adjusted with known control points, and take the average value that meets the internal consistency accuracy requirements in the joint measurement calculation results as the starting coordinates of each reference station, that is, the benchmark coordinates of the primary control network;

[0057] Step 6: After the system observes and calculates the plane coordinates and elevation values of the BDS / GNSS reference station in the construction control network coordinate system, store the results in the Beidou data processing center;

[0058] Step 7: In the construction and operation and maintenance applications of the primary network, the reference control network points can conduct coordinate observations all-weather, complete coordinate calculations in real time, ensure the timeliness of coordinate automatic update and transmission, which not only avoids the waste of a large amount of manpower and financial resources caused by the fixed-period review of the traditional primary control network, but also can set the coordinate update and push period; users can register and apply for an account at the data transmission center, and apply for and obtain the corresponding coordinate information after logging in through the PC or mobile phone;

[0059] Step 8: In the encryption application of the secondary network or dedicated control network, satellite observation stations are deployed at any position where encryption is required. The data sampling interval is set to 1 s, and the observation period is not less than 120 minutes. The encrypted Beidou terminal transmits the observation data to the Beidou data processing center in real time through the 5G network signal and jointly performs coordinate calculation and data storage with the satellite observation data of the reference station. Registered users can download or query the calculation results on the mobile phone through the Beidou data transmission center, and it is possible to obtain the encrypted point coordinates immediately after the observation is completed, greatly shortening the construction period of the encrypted network and the coordinate calculation period;

[0060] Step 9: In the traditional RTK layout application, users do not need to freely set external or internal radio stations. They only need to use a mobile satellite receiving terminal to connect to the signal of the primary control network reference station through the network port to perform multi-base station network RTK coordinate layout or measurement. Compared with single-base station network CORS or single-base station radio, the accuracy is more uniform and reliable, with a horizontal accuracy of ±1 cm and a vertical accuracy of ±2 cm, meeting the technical requirements of construction layout and measurement.

[0061] Furthermore, in Step 1, the selection of the layout location of the BDS / GNSS reference station should meet the following requirements:

[0062] (1) It is located around the construction area and has a stable geological foundation;

[0063] (2) It has satellite visibility conditions with a horizon elevation angle of more than 10°. When the environment is complex, the elevation angle is appropriately relaxed to 25°, and the horizontal projection range of the obstacles is not more than 60°;

[0064] (3) It is more than 200 m away from large-area water areas, high-voltage line crossing areas, etc.;

[0065] (4) The number of reference stations is not less than 4 and is relatively evenly distributed.

[0066] By adopting the above location selection, the accuracy and precision of subsequent data collection are ensured.

[0067] Furthermore, the frequency band signals in Step 2 specifically include pseudorange, carrier phase, Doppler frequency shift, carrier-to-noise ratio, and original navigation message information, and have a perfect data reception system, with the ability to operate continuously and automatically all day long.

[0068] Furthermore, the positioning accuracy in Step 4 is measured by taking the internal consistency accuracy and the external consistency accuracy. The specific calculation process is as follows:

[0069] (1) Calculation of internal consistency accuracy:

[0070] Let n be the number of positioning information collected at a certain test point, and l m be its mth observation value, Let \(\bar{x}\) be the average value of the observed values at this test point, then the internal consistency accuracy \(\sigma\) of the observed values at this test point is:

[0071]

[0072] The accuracy assessment tolerance is: \(\sigma\) 水平 \(\leq1\mathrm{cm},\sigma\) 垂直 \(\leq2\mathrm{cm}\);

[0073] (2) Calculation of external consistency accuracy:

[0074] Let \(n\) be the number of acquisition and positioning information at a certain test point, \(l\) m be its \(m\)-th observed value, be the true value of the observed values at this test point, then the external consistency accuracy of this test point is:

[0075]

[0076] The accuracy assessment tolerance is: \(\sigma\) 水平 \(\leq1\mathrm{cm},\sigma\) 垂直 \(\leq2\mathrm{cm}\).

[0077] Furthermore, the long-term observation time in step five is at least 1 month. By setting the above observation time, the stability of data acquisition is ensured.

[0078] Furthermore, the Beidou data processing center in step six includes a user management module, a data management module, and a data distribution module. The user management module can manage user types, permissions, and quantities. The data management module is responsible for classifying and storing data by level, and the data distribution module is responsible for point-to-point encryption and transmission of data. Through the above Beidou data processing center, it is possible to achieve

[0079] Furthermore, for the specific process of automatically selecting processing steps and methods in step three, please refer to Figure 2 .

[0080] The specific processing steps and methods are as follows: by transmitting precise ephemeris, broadcast ephemeris, and satellite raw observation data to the Beidou data processing center through optical fiber or network technology, preprocessing and denoising the data by the Beidou data processing center, and then selecting satellite data types and frequency bands;

[0081] Then, post-difference data processing, static data processing, and dynamic real-time data processing are performed on the data. After post-difference data processing, non-fixed base station satellite receiving terminal data is processed, and various solution parameter settings are carried out. After the completion of various solution parameter settings, known data is input, a coordinate system is selected, and then baseline solution is performed; the data processed through dynamic real-time data processing will enter the regional overall modeling. The data after regional overall modeling is used for differential positioning data, and then the differential positioning data is transmitted to the satellite receiving terminal through mobile, Internet, or radio. At the same time, combined with the data of the virtual reference station and the data of baseline solution, adjustment solution is carried out, and the data after the adjustment solution is judged for accuracy. If it is qualified, the data coordinates are stored and the coordinates are output at the same time. If it is unqualified, it returns to the initial data preprocessing step.

[0082] Embodiment 3:

[0083] By adopting the present system and method, the efficiency is improved and the cost estimation is saved.

[0084] This time, a certain medium-sized pumped storage power station construction is taken as an example for calculation. The construction period of the power station is 5 years. For details, see Table 1 Comparison Table of Control Network Construction Costs and Table 2 Comparison Chart of Control Network Efficiency:

[0085] Table 1 Comparison Table of Control Network Construction Costs

[0086]

[0087]

[0088] Table 2 Comparison Chart of Control Network Efficiency

[0089]

[0090] In summary, for a medium-sized pumped storage power station, calculated according to a 5-year construction period, the overall cost can be saved by about 11.28 million yuan; calculated according to the primary control network, the secondary encryption network, and the professional network with a review frequency of 2 times per year, the overall network construction time can be effectively saved by at least about 245 days in 5 years. It not only effectively improves the network construction efficiency, saves the network construction cost, but also speeds up the overall construction progress of the project, and the invisible benefits are inestimable.

Claims

1. A construction control network establishment and operation and maintenance system construction method, characterized in that The construction control network establishment and operation and maintenance system consists of a Beidou data receiving center, a Beidou data processing center, and a Beidou data transmission center; The Beidou data receiving center consists of N Beidou satellite ground-based augmentation reference stations, which receive Beidou satellite signals in real time all-weather, and transmit the satellite signal data to the Beidou data processing center, providing an accurate coordinate reference for the construction control network. At the same time, it also performs combined adjustment calculations with various satellite mobile terminal data to achieve rapid densification of control networks at all levels; The Beidou data processing center realizes the functions of real-time reception, adjustment calculation, and data result generation of satellite data at each point of the ground-based augmentation system, and realizes real-time update and automatic correction of the coordinates of each control point; The Beidou data transmission center realizes functions such as user online registration application, data download, and automatic data distribution, and realizes real-time scale unification of coordinate accuracy; The construction method includes the following steps: Step 1: In the initial stage of project design, in combination with the engineering requirements and the designed control network, survey the layout positions of BDS / GNSS reference stations; Step 2: After the BDS / GNSS reference station is established, ensure that it can compatibly receive signals in the B1, B2, B3, B1C, B2A frequency bands of BDS, the L1C / A, L2C, L2E frequency bands of the GPS system, and the L1, L2, L3 frequency bands of the GLONASS system; Step 3: After the BDS / GNSS reference station receives the frequency band signals, through the Beidou data transmission center module, use network, optical fiber or radio communication technology to transmit the data to the Beidou data processing center; the Beidou data processing center, according to the engineering standards, jointly measures the BDS / GNSS reference station with the existing national plane class B points and national second-class or above leveling points, or local control points that meet the accuracy requirements; and automatically selects the processing steps and methods according to different requirements for data comprehensive adjustment calculation to obtain the plane coordinates and elevation values of the BDS / GNSS reference station in the construction control network coordinate system; Step 4: Before calculating the coordinate information of the BDS / GNSS reference station, test the real-time kinematic positioning accuracy of the system. Select no less than 10 known control points around the construction area as test points; on the terminal device, through the Beidou data receiving center, set the receiving mode to the test mode; at a single test point, the system continuously collects 30 - 180 positioning information at a sampling interval of 1s, and transmits the collected information to the Beidou data processing center through the Beidou data transmission center; the Beidou data processing center adopts corresponding processing steps according to the receiving mode to calculate the observed coordinate values of the test point, and then compares the calculation results with the known coordinate information of the control point to calculate the positioning accuracy; Step 5: Before construction, the BDS / GNSS reference station conducts long-term observations and performs combined adjustment with known control points, and takes the average value that meets the internal coincidence accuracy requirements in the combined adjustment calculation results as the starting coordinates of each reference station, that is, the benchmark coordinates of the primary control network.

2. The construction method of a construction control network establishment and operation and maintenance system according to claim 1, characterized in that, It also includes the step: Step 6: After the system observes and calculates the plane coordinates and elevation values of the BDS / GNSS reference station in the construction control network coordinate system, store the results in the Beidou data processing center; Step 7: In the construction and operation and maintenance application of the primary network, the reference control points conduct coordinate observations all-weather, complete coordinate calculation in real time, ensure the timeliness of automatic coordinate update and transmission, and set the coordinate update and push cycle; users register and apply for an account at the data transmission center, and apply for corresponding coordinate information after logging in through the PC or mobile phone. Step 8: In the encryption application of the secondary network or special control network, satellite observation stations are arranged at any position where encryption is required. The data sampling interval is set to 1 s, and the observation period is not less than 120 minutes. The encrypted Beidou terminal transmits the observation data to the Beidou data processing center in real time through the 5G network signal and jointly performs coordinate calculation and data storage with the satellite observation data of the reference station. Registered users can download or query the calculation results on the mobile phone through the Beidou data transmission center, and the encrypted point coordinates can be obtained after the observation is completed. Step 9: In the traditional RTK layout application, users only need to use a mobile satellite receiving terminal to connect to the signal of the primary control network reference station through the network port to perform multi-base station network RTK coordinate layout or measurement, with a horizontal accuracy of ±1 cm and a vertical accuracy of ±2 cm, meeting the technical requirements of construction layout and measurement.

3. The construction method of a construction control network establishment and operation and maintenance system according to claim 1, characterized in that The value of N is N > 4.

4. The construction method of a construction control network establishment and operation and maintenance system according to claim 1, characterized in that In step 1, the selection of the layout position of the BDS / GNSS reference station should meet the following requirements: (1) It is located around the construction area and has a stable geological foundation; (2) It has satellite visibility conditions with a horizon elevation angle of more than 10°. When the environment is complex, the elevation angle is relaxed to 25°, and the horizontal projection range of the obstacle is not more than 60°; (3) The distance from large-area water areas and high-voltage line crossing areas is more than 200 m; (4) The number of reference stations is not less than 4 and they are evenly distributed.

5. The construction method of a construction control network establishment and operation and maintenance system according to claim 1, characterized in that, The frequency band signals described in step 2 specifically include pseudorange, carrier phase, Doppler frequency shift, carrier-to-noise ratio, and original navigation message information, and have a perfect data receiving system with the ability to operate continuously and automatically all-weather.

6. The construction method of a construction control network establishment and operation maintenance system according to claim 1, characterized in that, In step 4, the positioning accuracy is measured by taking the internal consistency accuracy and the external consistency accuracy. The specific calculation process is as follows: Calculation of internal consistency accuracy: The number of location information collected for a certain test point, For its th observed value, Is the average value of the observed values of this test point, Is the true value of the observed value of this test point, then the internal consistency accuracy of the observed value of this test point Is: The internal compliance accuracy assessment tolerance limit is: ; Calculation of external consistency accuracy: Then the external compliance accuracy of this test point is as follows: The tolerance limit for external conformity assessment is: .

7. The construction method of a construction control network establishment and operation and maintenance system according to claim 1, characterized in that In step 5, the time for long-term observation is at least 1 month.

8. The construction method of a construction control network establishment and operation and maintenance system according to claim 1, characterized in that The Beidou data processing center in step 6 includes a user management module, a data management module, and a data distribution module. The user management module can manage user types, permissions, and quantities. The data management module is responsible for classifying and storing data by level. The data distribution module is responsible for point-to-point encryption and transmission of data.

9. The construction method of a construction control network establishment and operation and maintenance system according to claim 1, characterized in that The specific process of automatically selecting the processing steps and methods according to different requirements in step 3 is to transmit precise ephemeris, broadcast ephemeris, and satellite original observation data to the Beidou data processing center through optical fiber or network technology, preprocess and denoise the data through the Beidou data processing center, and then select the satellite data type and frequency band; Perform post-difference data processing, static data processing, and dynamic real-time data processing on the data. After post-difference data processing, perform various solution parameter settings on the data of the non-fixed base station satellite receiving terminal. After completing various solution parameter settings, input known data, select a coordinate system, and then perform baseline solution; the data after dynamic real-time data processing enters the regional overall modeling. The data after regional overall modeling is used for differential positioning data, and then the differential positioning data is transmitted to the satellite receiving terminal through mobile, Internet, or radio. At the same time, combined with the data of the virtual reference station and the data of the baseline solution, perform adjustment solution, and perform accuracy judgment on the data after adjustment solution. If it is qualified, store the data coordinates and output the coordinates at the same time. If it is unqualified, return to the initial data preprocessing step.

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