A network RTK service method using virtual base station for reconstruction

Abstract

The present invention provides a network RTK service method for reconstruction using a virtual reference station, comprising the following steps: step 1: reading physical reference station information, accessing physical reference station data and parsing; step 2: performing networking and calculation on the physical reference station; step 3: reading the three-dimensional coordinates of the grid points in the area, generating all virtual grid products in RTCM format and broadcasting through network communication; step 4: reading virtual grid product communication information, accessing all virtual grid products and parsing; step 5: performing networking and calculation on the virtual grid products; step 6: performing network RTK service using the calculation results of the virtual grid products. The present invention requires a small amount of calculation; it can perform two-way communication with a service module, does not involve controlled management data, uses virtual reference station data reconstruction to perform network RTK service, and has more uniform accuracy than gridded services.

Description

Technical Field

[0001] The invention belongs to the field of communication technology, and in particular relates to a network RTK service method for reconstructing using a virtual reference station. Background Art

[0002] RTK (Real Time Kinematic) is a technology that uses carrier phase observations for real-time dynamic relative positioning. It has become a commonly used method in the field of measurement. Using RTK technology, centimeter-level positioning results can be obtained in a very short time. However, as the distance between the mobile station and the base station increases, the correlation of various errors will continue to decrease. Therefore, the distance between the mobile station and the base station cannot exceed 15km, which limits the use of this technology. To solve the above problems, relevant scholars have proposed network RTK technology, which roughly evenly arranges several base stations in a larger area, and comprehensively forms the error term of the position based on the position of the mobile station, reducing the distance limit requirements. The emergence of this technology has greatly broadened the application scenarios of RTK technology.

[0003] The Continuously Operating Reference System (CORS) currently operated by various provinces and cities is an application of network RTK technology. By establishing a number of continuously operating reference stations, long-term RTK service capabilities are formed for the coverage area.

[0004] Base station data is controlled and managed data. When using the service, users need to communicate with the CORS data processing software in both directions, which will bring the risk of base station data leakage. Therefore, most of the current services are carried out in dedicated networks, which affects the degree of promotion to the public. In order to solve this problem, relevant scholars have proposed a grid-based broadcasting method, in which the solution module communicates with the service module in one direction, which can prevent users from obtaining base station data from the solution module through the service module. However, this method is affected by the service range requirements of a single-station RTK. In order to ensure the RTK positioning accuracy, the current common grid division is generally 5km, so the grid division will be very dense, and the solution module has a constant solution amount, which is only suitable for a large number of users. When the number of users is small, the efficiency is very low. At the same time, the accuracy is affected by the distance between the user and the nearest grid point. In areas with large elevation fluctuations, the difference between the grid point elevation and the actual elevation will also affect the solution accuracy. Therefore, the present invention intends to provide a network RTK service method that utilizes virtual reference stations for reconstruction, so as to solve the problem that services must be provided in an intranet environment due to the controlled management of physical reference stations, and at the same time solve the problems of large solution volume, uneven accuracy, large elevation error, etc. caused by grid services. Summary of the invention

[0005] The technical solution adopted by the present invention to solve the problems existing in the prior art is mainly to use physical reference stations for network solution, then generate a batch of virtual grid products as virtual reference stations at fixed intervals, and finally use the virtual reference stations for re-network solution and provide network RTK (Real Time Kinematic) service. The specific technical solution is as follows:

[0006] A network RTK service method for reconstructing using a virtual reference station, characterized in that it includes the following steps:

[0007] Step 1: Read the physical reference station information, access the physical reference station data and parse it;

[0008] Step 2: Network and solve the physical reference station;

[0009] Step 3: Read the three-dimensional coordinates of the grid points in the area, generate all virtual grid products in RTCM (Radio Technical Commission for Maritime services) format and broadcast them through network communication;

[0010] Step 4: Read the communication information of virtual grid products, access all virtual grid products and parse them;

[0011] Step 5: Perform network calculation on the virtual grid product;

[0012] Step 6: Use the virtual grid product solution results to provide network RTK services.

[0013] The step 1 specifically includes:

[0014] Step 1.1: Read the coordinate information, communication information, and device information of the physical reference station, establish a connection, and access the real-time data stream of the physical reference station;

[0015] Step 1.2: Parse the real-time data stream according to the physical base station data format.

[0016] The step 3 specifically includes:

[0017] Step 3.1: According to the distribution of physical reference stations, obtain the minimum longitude and latitude and the maximum longitude and latitude from the geodetic coordinates of all reference stations to form a coverage range;

[0018] Step 3.2: According to the requirements of network RTK technology for the base station spacing, the base station spacing is 50-100km, and the grid division spacing here is set to 0.5°-1°. A batch of grid point coordinates covering the base station networking area are generated along longitude and latitude, and the longitude and latitude values ​​of each grid point coordinate are obtained;

[0019] Step 3.3: Find the nearest physical reference station according to the longitude and latitude of the grid point, and obtain the elevation of the reference station as the grid point elevation;

[0020] Step 3.4: Repeat steps 3.2 and 3.3 until the longitude, latitude and elevation three-dimensional coordinates of all points are obtained;

[0021] Step 3.5: Generate observation data of each grid point location based on the network solution results of the reference station and the three-dimensional coordinates of the grid points;

[0022] Step 3.6: Encode the observation data of all grid points according to the standard RTCM protocol;

[0023] Step 3.7: Broadcast the data generated in step 3.6 through the network communication protocol.

[0024] The step 4 specifically includes:

[0025] Step 4.1: Read the communication information of the virtual grid data product, establish a connection, and access the virtual grid product;

[0026] Step 4.2: Parse the virtual grid product to obtain observation data, coordinate data, and site ID information as the site name.

[0027] The present invention has the following advantages:

[0028] 1. Compared with the generation of gridded service products, the generation of virtual reference station data in the present invention has a larger grid spacing and requires less computational effort;

[0029] 2. The solution module of the present invention uses virtual reference station data and can communicate with the service module in a two-way manner without involving controlled management data;

[0030] 3. The present invention uses virtual reference station data reconstruction to provide network RTK services, which has more uniform accuracy compared to grid services. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The figure is a flow chart of the method of the present invention. DETAILED DESCRIPTION

[0032] The technical solution of the present invention is further described in detail below through embodiments and in conjunction with the accompanying drawings. Figure 1 As shown, a network RTK service method for reconstructing using a virtual reference station includes the following steps:

[0033] Step 1: Read the physical reference station information, access the physical reference station data and parse it;

[0034] Step 1.1: Read the coordinate information, communication information, and device information of the physical reference station, establish a connection, and access the real-time data stream of the physical reference station;

[0035] Step 1.2: Parse the real-time data stream according to the physical base station data format.

[0036] Step 2: Network and solve the physical reference station;

[0037] Step 3: Read the three-dimensional coordinates of the grid points in the area, generate all virtual grid products in RTCM format and broadcast them through network communication;

[0038] Step 3.1: According to the distribution of physical reference stations, obtain the minimum longitude and latitude and the maximum longitude and latitude from the geodetic coordinates of all reference stations to form a coverage range;

[0039] Step 3.2: According to the requirements of network RTK technology for the base station spacing, the base station spacing can be 50-100km, so the grid division spacing here can be set to 0.5°~1°, and a batch of grid point coordinates covering the base station networking area are generated along longitude and latitude, and the longitude and latitude values ​​of each grid point coordinate are obtained;

[0040] Step 3.3: Find the nearest physical reference station according to the longitude and latitude of the grid point, and obtain the elevation of the reference station as the grid point elevation;

[0041] Step 3.4: Repeat step 3.2 until the longitude, latitude and elevation three-dimensional coordinates of all points are obtained;

[0042] Step 3.5: Generate observation data of each grid point location based on the network solution results of the reference station and the three-dimensional coordinates of the grid points;

[0043] Step 3.6: Encode the observation data of all grid points according to the standard RTCM protocol;

[0044] Step 3.7: Broadcast the data generated in step 3.6 through the network communication protocol.

[0045] Step 4: Read the communication information of virtual grid products, access all virtual grid products and parse them;

[0046] Step 4.1: Read the communication information of the virtual grid data product, establish a connection, and access the virtual grid product;

[0047] Step 4.2: Parse the virtual grid product to obtain observation data, coordinate data, and site ID information as the site name.

[0048] Step 5: Perform network calculation on the virtual grid product;

[0049] Step 6: Use the virtual grid product solution results to provide network RTK services.

[0050] The key technical points of the present invention include: generating grid point observation data and broadcasting and receiving the grid point observation data, wherein:

[0051] 1. There are two steps to generate grid point observation data. The first is to obtain the grid point coordinates, and the second is to generate corresponding observation data based on the grid point coordinates.

[0052] To obtain the grid point coordinates, you first need to determine the grid point spacing. The grid point spacing can be selected based on experience. Compared with the north, the southern region has a more active ionosphere, so the spacing can be reduced. After the grid spacing is determined, the coordinates of all grid points can be obtained based on the range that the physical reference station can cover.

[0053] The generation of grid point observation data is divided into the following three steps:

[0054] a. Find the nearest reference station according to the grid point coordinates, and obtain the observation data of the reference station as the grid point observation data;

[0055] b. Calculate the position of each satellite based on the broadcast ephemeris, and thus obtain the distance between each satellite and the grid point and the distance difference to the nearest reference station. After obtaining the distance difference, it can be directly corrected to the pseudo-range value of the grid point observation data. Then, based on the distance difference and the wavelength of each satellite signal frequency point, the carrier phase difference is obtained and corrected to the carrier phase value of the observation data;

[0056] c. According to the grid point coordinates, the ionospheric and tropospheric correction data of the location are interpolated from the regional error correction model, and corrected to the pseudorange and carrier phase of the observation data to obtain the final grid point observation data.

[0057] 2. Broadcasting and receiving of grid point observation data: In order to reduce the configuration difficulty of grid broadcasting and receiving, and to meet the adaptive requirements of grid point number changes during use, the present invention will use the TCP / IP protocol to broadcast and receive all grid point observation data through a single port, and the broadcasting end uses the TCP / IP Client to push to the TCP / IP Sever at the receiving end. When broadcasting the code, each grid point is numbered according to the StaID field in the RTCM protocol, and the grid point coordinates are included in the 1005 / 1006 message; when receiving and parsing, each grid point is named and divided according to the StaID.

[0058] The protection scope of the present invention is not limited to the above-mentioned embodiments. Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the scope and spirit of the present invention. If these changes and modifications fall within the scope of the claims of the present invention and their equivalents, the present invention is intended to include these changes and modifications.

Claims

1. A network RTK service method using a virtual reference station for reconstruction, characterized in that: The steps include: Step 1: Read the physical reference station information, access the physical reference station data and parse it; Step 2: Network and solve the physical reference station; Step 3: Read the three-dimensional coordinates of the grid points in the area, generate all virtual grid products in RTCM format and broadcast them through network communication; Step 4: Read the communication information of virtual grid products, access all virtual grid products and parse them; Step 5: Perform network calculation on the virtual grid product; Step 6: Use the virtual grid product solution results to provide network RTK services; The step 3 specifically includes: Step 3.1: According to the distribution of physical reference stations, obtain the minimum longitude and latitude and the maximum longitude and latitude from the geodetic coordinates of all reference stations to form a coverage range; Step 3.2: According to the requirements of network RTK technology for the base station spacing, the base station spacing is 50-100km, and the grid division spacing here is set to 0.5°-1°. A batch of grid point coordinates covering the base station networking area are generated along longitude and latitude, and the longitude and latitude values ​​of each grid point coordinate are obtained; Step 3.3: Find the nearest physical reference station according to the longitude and latitude of the grid point, and obtain the elevation of the reference station as the grid point elevation; Step 3.4: Repeat steps 3.2 and 3.3 until the longitude, latitude and elevation three-dimensional coordinates of all points are obtained; Step 3.5: Generate observation data of each grid point location based on the network solution results of the reference station and the three-dimensional coordinates of the grid points; The generation of the observation data of the grid point position includes the following three steps: Step 3.5.1: Find the nearest reference station according to the grid point coordinates, and obtain the observation data of the reference station as the grid point observation data; Step 3.5.2: Calculate the position of each satellite based on the broadcast ephemeris to obtain the distance between each satellite and the grid point and the distance difference to the nearest reference station. Correct the obtained distance difference directly to the pseudo-range value of the grid point observation data. Then, based on the distance difference and the wavelength of each satellite signal frequency point, obtain the carrier phase difference and correct it to the carrier phase value of the observation data. Step 3.5.3: According to the grid point coordinates, the ionosphere and troposphere correction data of the location are interpolated from the regional error correction model, and corrected to the pseudorange and carrier phase of the observation data to obtain the final grid point observation data; Step 3.6: Encode the observation data of all grid points according to the standard RTCM protocol; Step 3.7: Broadcast the data generated in step 3.6 through the network communication protocol.

2. A network RTK service method for reconstructing using a virtual reference station as claimed in claim 1, characterized in that: The step 1 specifically includes: Step 1.1: Read the coordinate information, communication information, and device information of the physical reference station, establish a connection, and access the real-time data stream of the physical reference station; Step 1.2: Parse the real-time data stream according to the physical base station data format.

3. A network RTK service method for reconstructing using a virtual reference station as claimed in claim 1, characterized in that: The step 4 specifically includes: Step 4.1: Read the communication information of the virtual grid data product, establish a connection, and access the virtual grid product; Step 4.2: Parse the virtual grid product to obtain observation data, coordinate data, and site ID information as the site name.

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