A Brief Introduction to GPS-RTK Technology and Its Applications

This article mainly introduces the working principle and work content of GPS-RTK measurement technology, the application of RTK technology in project measurement, and the relevant issues that need to be paid attention to during RTK operations. GPS-RTK is widely used in landscape surveying, map surveying, engineering project stakeout and other measurements due to its high accuracy, faster speed and low deviation.

The Global Positioning System, commonly known as GPS, is a new generation of satellite navigation system and mobile phone positioning system developed in the United States in the early 1970s. It brings together the most cutting-edge indoor space technology, communication technology and microelectronics technology. It is a kind of technology that can The website navigation designated by the Time Calibration and Laser Ranging Space Fair can provide continuous, real-time, high-precision 3D position, 3D speed and duration information to global customers.

(Beitian high-end GPS receiver)

How RTK works

RTK (Real Time Kinematic) dynamic measurement system software is a fusion of GPS measurement technology and data transmission technology. It is a new improvement in GPS measurement technology. It subverts the traditional measurement method and can provide centimeter-level positioning accuracy at any time. Remote transmission of two-dimensional coordinates under blocked viewing conditions. RTK measurement technology is a real-time differential signal GPS measurement technology based on carrier phase measurement that combines carrier phase measurement and transmission data technology. The RTK system is mainly composed of three parts: a base station receiver, a data link and a mobile receiver. Generally, more than two GPS receivers are used to receive signals at the same time, and one of them is placed on a known point for measurement. point, and the other is used to measure the coordinates of an unknown point, called the mobile station. The base station can calculate the distance correction number between other communication satellites based on the precise coordinates of this point and send this correction number to the mobile station. The mobile station calculates the distance based on the distance correction. The calculation corrects the positioning conclusion, greatly improving the positioning accuracy, so that the three-dimensional positioning conclusion of the measuring site in the specified coordinate system can be given instantly with cm-level accuracy.

(Beitian centimeter-level high-precision positioning board)

The normal operation of the RTK system software requires three conditions: first, the base station and the mobile station receive more than 5 GPS signals at the same time; second, the base station and the mobile station receive signals and audio from the standard station port at the same time. signal. Third, the mobile station must continue to receive GPS signals and audio signals from the base station.

Compared with other measurement methods, RTK technology has the advantages of high precision positioning, measurement automation technology, high degree of integration, strong data analysis capabilities, and ease of use.

The application of RTK in measurement work

(1) RTK measurement technology is used to manipulate measurements

Because the standard accuracy of RTK measurement positioning point plan within 20km is 3cm, and the positioning point deviation of Class I conductor points according to the control measurement standards is 5cm, technically RTK measurement is sufficient to meet the technical specifications of conductor points below the industrial level. Conventional control measurements, such as transmission line measurement, require visibility between points, which is time-consuming and uneven in accuracy. GPS static data measurement, although there is no need for visibility between points and high accuracy, requires three simultaneous observations. It takes a long time to process the data later, and the positioning results cannot be understood in real time. If the industry data finds that the accuracy does not meet the requirements, it will need to be repaired. And using RTK technology for control measurement has great advantages in terms of operation accuracy and operation efficiency.

(Beitian quickly enters RTK mode demonstration)

(2) RTK measurement technology is used to measure map fragments

Because RKT measurement has high accuracy and faster speed, when measuring parts of the map, it is not necessary to carry out control measurements of the map root points, but to measure each part point directly based on some basic datum points distributed in the survey area.

When RTK performs part measurement, it first calculates the transformation parameters based on the WGS-84 coordinates and local coordinate system coordinates of more than two known points, and then adjusts the base station and weighing station to perform part measurement. If Equipped with more professional landform and terrain surveying software, intelligent terrain surveying can be realized by recording directly from the electronic handbook.

(3) RTK measurement technology is used for engineering construction stakeout

Construction stakeout is the whole process of measuring the target point of the point corresponding to the read coordinate according to the coordinates of the known point and using the experimental instrument. The RTK stakeout process is to first enter the known point coordinates into the RTK engineering survey control panel. When setting out, follow the arrows on the control panel screen to indicate the offset and offset direction, and move it up, down, left, and right until the measurement accuracy is reached. Setting out with basic equipment usually requires 2-3 people, and the target needs to be moved back and forth frequently. The work is very complicated. The setting out process also requires good visibility from point to point. The efficiency is not very high under various conditions. . RTK only requires one person to complete the entire stakeout measurement process. Because RTK has the characteristics of shorter observation time, higher precision, and no need for visual inspection, RTK stakeout is simpler, more convenient, more reliable, and more convenient than the basic method. The efficiency has been greatly improved, so RTK is becoming more and more popular among consumers in project stakeout measurement, and its application is becoming more and more common.

(4) RTK surveying technology is used for land surveying and boundary surveying

RTK technology can measure the coordinates of boundary points in real time, clarify the scope of land use boundaries, and calculate the construction area. When classifying ten places and surveying ownership, RTK technology can be used to measure ownership boundaries and land classification and surveying in real time, which improves the measurement speed. and precision

(5) RTK is used for distribution line alignment measurement

For long-distance line alignment measurements, RTK has the irreplaceable advantage of basic measurement technology. RTK technology is easy to use and has flexible working methods. Line alignment can be carried out continuously, and it can be started from any point on the line at any time, with the convenience of several instruments and equipment. Collaborative work.

(6) RTK is used for measurement in various aspects

RTK technology can also be applied to various aspects such as overall planning and construction setting out of housing construction, cross-sectional measurement, real estate measurement, sea area measurement, pipeline measurement, etc.

Things to note when using RTK operations

(1) Because RTK operations need to receive more than 5 signals at any time and at any time for proper correction, it is most appropriate to choose a wider area for mobile station operations. Therefore, RTK operations should avoid large-scale sea areas, high and large areas Houses, buildings and tall trees are not.

(2) Because RTK uses VHF ultra-high frequency electromagnetic waves as data links, it is easily affected by telecommunication network signal transmission towers, relay stations, high-voltage lines, etc., as well as the requirements of terrain fluctuations. Therefore, interference signals should be avoided as much as possible during operation. .

(3) In thunder and lightning weather, in order to avoid being struck by lightning, RTK outdoor operations should be completed on standby.

RTK dynamic measurement technology has not only gradually become an indispensable measurement tool for all surveyors, but also has become an indispensable measurement tool for all surveyors due to its characteristics of high accuracy, convenient operation, faster speed, high work efficiency, strong practicality, and no need to look. It is gradually recognized and widely used in the industry. The marketing and promotion accompanying the application of RTK technology will inevitably produce significant economic benefits for various industries.