CN103558607B - A kind of active broadcasting method of ionized layer TEC of position-based information and system - Google Patents

Abstract

The present invention relates to a method and system for actively broadcasting ionospheric TEC based on location information. The method includes: the user sends the location and time information of the terminal on the user terminal through a user interaction interface or API; a virtual server transmits the information submitted by the user to the physical server; the physical server calculates the ionospheric TEC according to the preset ionospheric model and feeds it back to the virtual server; the virtual server returns the ionospheric TEC to the user terminal; the user terminal converts the ionospheric TEC into ionospheric delay correction information. Compared with the prior art, the method of the present invention separates the mathematical method of ionospheric modeling from the user, and the user only needs to receive the ionospheric TEC broadcast by the system without ionospheric model coefficients, which effectively reduces the complexity of data processing at the receiver , which promotes the unity of the data processing module at the receiver end, and the invention has the advantages of high performance, high security, scalability, controllability, universality and the like.

Description

A method and system for actively broadcasting ionospheric TEC based on location information

technical field

The invention relates to an application of location services in the field of surveying and mapping, in particular to an ionospheric TEC active broadcast method and system based on location information.

Background technique

Ionospheric delay error is the most significant error source in satellite navigation positioning. GNSS (Global Navigation Satellite System) dual-frequency receiver users can use dual-frequency ionospheric elimination combination method to eliminate most of the errors of ionospheric delay. However, for the vast number of single-frequency receiver users, it is still necessary to rely on the ionospheric model to correct the ionospheric delay. Commonly used ionospheric models include Klobuchar model, polynomial model, trigonometric model, spherical harmonic model, grid model, etc. Both GPS and Beidou broadcast Klobuchar model coefficients through broadcast ephemeris to realize ionospheric delay correction. The Klobuchar ionospheric model is simplified based on the Bent ionospheric empirical model, which can reflect the basic change characteristics of the ionosphere and ensure the reliability of the ionosphere forecast on a large scale. However, the model is difficult to take into account the local variation characteristics of the ionosphere, and the accuracy is limited. Experience has shown that the model can correct only 50-60% of the ionospheric influence, and in the best case no more than 75%. The regional ionospheric model provides high-precision ionospheric delay correction information, which is the most ideal and effective method for GNSS single-frequency receivers to correct the impact of ionospheric delay. Compared with empirical models such as Klobuchar, the regional ionospheric model can better simulate local ionospheric disturbances, and provide higher-precision ionospheric delay correction information for regional GNSS single-frequency receiver users. Many domestic scholars have achieved fruitful results in the study of regional ionospheric models, such as establishing ionospheric models by using generalized trigonometric series functions, establishing regional ionospheric models by using spherical crown harmonics, three-dimensional ionospheric models based on empirical orthogonal functions, The establishment of the grid ionospheric model and the results of trial calculations, etc. The D2 navigation message of my country's Beidou satellite navigation system includes the vertical delay parameters of the ionosphere covering a total of 320 grid points with a coverage area of 70° to 145° east longitude and 7.5° to 55° north latitude. The user only needs to interpolate the ionospheric delay at the grid point to obtain the ionospheric delay correction at the puncture point of the observation satellite, and then use the mapping function to obtain the ionospheric delay correction in the signal propagation direction. This method of using navigation messages to broadcast ionospheric delay information can meet the positioning needs of most public users (such as mobile phone users and car navigation users) in China, but it may not necessarily meet the precision measurement requirements of measuring receivers. user. For users of GNSS single-frequency receivers with precise measurements, regional ionospheric models are required to provide high-precision ionospheric delay correction information. Since the construction of each ionospheric model uses different mathematical methods, it is difficult to determine which model is better. The number and types of model coefficients required to calculate the ionospheric delay using various models are different, and the receiver data processing The ionospheric delay corrections used depend on the ionospheric model used. If the mathematical method used to construct the ionospheric model is updated or replaced, all data processing modules using this ionospheric model must be updated accordingly, which causes great difficulties in software maintenance and updating. In fact, no matter which ionospheric model is used, the receiver only needs to obtain the total electron content (Total Electron Content, TEC) of the ionosphere and then convert it to obtain ionospheric delay correction information to correct the ionospheric delay.

Contents of the invention

The object of the present invention is to provide a method and system for actively broadcasting ionospheric TEC based on location information in order to overcome the above-mentioned defects in the prior art.

The object of the present invention can be achieved through the following technical solutions: a method for active broadcasting of ionospheric TEC based on location information, characterized in that it comprises the following steps:

(1) The user sends the geographical location and time information of the terminal through the user interface or API on the user terminal;

(2) The virtual server waits for and receives the information submitted by the user;

(3) The virtual server transmits the information submitted by the user to the physical server;

(4) The physical server waits for and receives the location and time information delivered by the virtual server;

(5) After the physical server receives the position and time information, it calculates the ionospheric TEC according to the preset ionospheric model and feeds it back to the virtual server;

(6) The virtual server returns the ionospheric TEC to the user terminal through the user interaction interface or API;

(7) The user terminal receives the ionospheric TEC and converts it into ionospheric delay correction information.

An ionospheric TEC active broadcast system based on location information, characterized in that it includes a user terminal, a virtual server and a physical server, the user terminal and the virtual server are connected to each other, and the virtual server and the physical server are connected to each other, An ionospheric model is established on the physical server.

The user terminal is a mobile phone, a computer or a GNSS receiver.

The physical server is a plurality of workstations or a distributed cluster.

There are multiple virtual servers.

Compared with the prior art, the present invention has the following advantages:

1. High performance. The system of the present invention not only adopts the service architecture of Linux+Nginx+MySQL+PHP, but also adopts a server combined with "virtual and real" to separate the scientific computing part from the user interaction, give full play to the computing performance of the physical server, and can process quickly User's request, avoiding long waiting, greatly improving the performance of system services;

2. Security. The system of the present invention adopts a "virtual and real" combined server. The physical server is not directly facing the user, and the probability of being attacked is greatly reduced. At the same time, there are multiple virtual servers as backups. Once the main virtual server is attacked and goes down, it can be quickly Switch to other backup virtual servers to achieve continuous and safe operation of the platform, ensuring the safe and continuous operation of the system and the privacy of users;

3. Scalability, the virtual server can select the appropriate virtual server configuration according to the number of users, configure on demand, and save costs;

4. Controllability. For the space-time under special circumstances, the present invention can artificially add random disturbance to the calculation module in the cloud to control the TEC accuracy of the designated area;

5. Universality. The present invention can establish corresponding ionospheric models on physical servers according to requirements, and then cooperate with scalable virtual servers to serve regional or global users. It is suitable for regional, large-scale and even global ionospheric Layer TEC broadcast service;

6. Cross-terminal, users can obtain ionospheric TEC broadcast services through computers, tablet computers, mobile phones, GNSS receivers and other devices.

Description of drawings

Fig. 1 is the frame schematic diagram of the system of the present invention;

Fig. 2 is a logical schematic diagram of the method of the present invention.

detailed description

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

As shown in Figure 1, an ionospheric TEC active broadcast system is characterized in that it includes a user terminal 1, a virtual server 2 and a physical server 3, the user terminal 1 and the virtual server 2 are connected to each other, and the virtual The server 2 is connected to the physical server 3, and the ionospheric model is established on the physical server 3. The user terminal 1 is a mobile phone, a computer or a GNSS receiver. The physical server 3 is a plurality of workstations or a distributed cluster. There are multiple virtual servers 2, one of which is the main virtual server, and the rest are backup virtual servers. When the main virtual server fails, it will switch to the backup virtual server.

Present embodiment adopts Ubuntu12.04 as the operating system of the system server of the present invention, adopts Nginx+MySQL+PHP website service framework, and has adopted eight kinds of programming languages such as C++, Fortran, PHP, HTML, CSS, JavaScript, XML, XSL to complete The system of the present invention is respectively: using HTML, CSS and JavaScript languages to complete the acquisition of the user terminal user interface and terminal location and time information; using PHP language to transmit the information submitted by the user to the virtual server and feed back the calculation results to the user terminal ;Use C++ language to realize the logic processing of the main program of the virtual server and the physical server; use Fortran to realize the ionospheric model and core linear calculation part of the physical server; use XML format as the storage form of the returned result as the application programming interface; use XSL language The returned result stored in the XML format is converted into HTML and presented on the user interface of the user terminal.

As shown in Figure 2, an ionospheric TEC active broadcast method is characterized in that it comprises the following steps:

Step 101, the user sends the geographic location and time information of the terminal through the user interface or API on the user terminal;

Step 102, the virtual server waits for and receives the information submitted by the user;

Step 103, the virtual server transmits the information submitted by the user to the physical server;

Step 104, the physical server waits for and receives the location and time information delivered by the virtual server;

Step 105, after the physical server receives the position and time information, it calculates the ionospheric TEC according to the preset ionospheric model and feeds it back to the virtual server;

Step 106, the virtual server returns the ionospheric TEC to the user terminal through the user interface or API. If the user interface is used to return to the user terminal, the XML format needs to be converted into HTML format through the XSL language;

Step 107, the user terminal receives the ionospheric TEC and converts it into ionospheric delay correction information.

The system of the present invention can support three channels of Internet, mobile Internet and API to obtain ionospheric TEC. The following are the specific implementation steps for obtaining ionospheric TEC by using three channels:

A. Internet

101) Access the system home page http://iris.geodesy.cn through a browser;

102) Input the three parameters of time, latitude and longitude on the system home page, such as time: 20131007200416, latitude: 39.4792, longitude: 120.7130;

103) click on " obtain ionospheric TEC " button, submit step 102) input three parameters;

104) The virtual server receives the three parameters input in step 102), and passes them to the physical server;

105) The physical server receives step 104) the three parameters delivered by the virtual server, and calculates the value of the ionospheric TEC according to the ionospheric model to be 8.29936TECu;

106) The physical server feeds back the value of the ionospheric TEC to the virtual server;

107) The virtual server outputs the time, latitude and longitude and ionospheric TEC submitted by the user to the browser of the user terminal as a document in XML format;

108) The browser formats the XML document into HTML according to the preset XSL and presents it to the user.

B. Mobile Internet

For the mobile Internet mode, this embodiment adopts the public platform interface of the mobile communication software WeChat developed by Tencent, one of the largest integrated Internet service providers in China at present, for development. Receive the geographical location information submitted by the user through the WeChat interface, and then submit it to the cloud for calculation and push the ionospheric TEC to the user. The specific implementation steps are as follows:

201) For the first use, you need to add the WeChat account geodesy first;

202) Open the communication window after adding successfully, click "+" to pop up the function menu;

203) Select the "location" icon to load the location information;

204) Click the send button to submit the information;

205) The information submitted by the virtual server analysis step 204) is time, longitude and latitude;

206) The virtual server receives the three parameters input in step 202), and passes them to the physical server;

207) The physical server receives step 204) the three parameters delivered by the virtual server, and calculates the value of the ionospheric TEC according to the ionospheric model;

208) The physical server feeds back the value of the ionospheric TEC to the virtual server;

209) The virtual server outputs information such as the time, latitude and longitude, and ionospheric TEC values submitted by the user;

210) The Tencent WeChat server receives the output information of the virtual server and feeds it back to the WeChat window interface.

C. API method

301) Use programming language to implement socket connection API address or use wget or curl to access API address, such as http://iris.geodesy.cn/tec/? ut＝20131007202949&lat＝39.4792&lon＝-84.7130, where ut, lat, and lon respectively represent the three parameters of UT time, latitude, and longitude;

302) Using a programming language to read the XML document obtained in step 301), so as to obtain the ionospheric TEC value.

Satellite navigation and location services are still a small-scale emerging industry for the world. The development of surveying and mapping application technology and service models based on location information and cloud computing can not only meet the application needs brought by the cloud era, but also enable the surveying and mapping industry and public users to enjoy the benefits brought by technological development and service model innovation.

Claims (4)

1. the active broadcasting method of the ionized layer TEC of position-based information, is characterized in that, realized by the system comprising user terminal, virtual server and physical server, described system is the system that " actual situation " combines, and described broadcasting method comprises the following steps:

(1) user passes through geographic position and the temporal information at User Interface or API transmitting terminal place on the subscriber terminal;

(2) information that user submits to is waited for and received to virtual server;

(3) information that user submits to is passed to physical server by virtual server;

(4) position that virtual server transmits and temporal information are waited for and received to physical server;

(5), after physical server receives position and temporal information, calculate ionized layer TEC according to the ionospheric model preset and feed back to virtual server;

(6) ionized layer TEC is turned back to user terminal by User Interface or API by virtual server;

(7) user terminal receives ionized layer TEC, and is converted into Ionospheric delay correcting information.

2. the active broadcasting method of ionized layer TEC of a kind of position-based information according to claim 1, is characterized in that, described user terminal is mobile phone, computer or GNSS receiver.

3. the active broadcasting method of ionized layer TEC of a kind of position-based information according to claim 1, is characterized in that, described physical server is multiple stage workstation or distributed type assemblies.

4. the active broadcasting method of ionized layer TEC of a kind of position-based information according to claim 1, it is characterized in that, described virtual server is provided with multiple.