Development Trend of RTK
Lindsay Liu
Senior Manager ｜Antenna expert | 15 years experience |Solutions for Precision Agriculture, UAV, Autonomous Driving, GPS Antenna/5G/LORA antenna/Module, RF cable, Connector. Where there's question, there is a solution
With the rapid development of robots, unmanned lawn mowers, engineering surveying and mapping, precision agriculture, unmanned driving and drones, people have higher and higher requirements for positioning accuracy. RTK technology came into being.
1，Definition
RTK (Real-Time Kinematic) is a real-time differential technology based on carrier phase observation.
By utilizing the spatial and temporal correlation of observation errors to eliminate them, the positioning accuracy of the satellite navigation system has been greatly improved.
2，Composition
Base Station
It is a GNSS receiver installed at a known precise location. Its main function is to receive satellite signals, calculate error data and transmit it to the mobile station. It usually requires a stable power supply, a high-precision antenna , a receiver and wireless communication equipment.
Mobile Station
GNSS receivers installed on target objects that require high-precision positioning, such as self-driving cars and agricultural machinery, rely on differential data from receiving base stations to correct their own positions in real time.
Data transmission equipment
between the base station and the mobile station relies on radio stations or mobile networks (such as 4G/5G) or Wi-Fi. Due to the high real-time requirements, the stability and speed of the data transmission equipment have a significant impact on the RTK performance.
Antenna System
As a key hardware, the GNSS antenna is responsible for receiving satellite signals. Its anti-interference ability and low noise coefficient are directly related to the stability of the RTK system. At the same time, it needs to be installed in an open and unobstructed place, away from metal, transformer stations and other places to ensure the quality of signal reception.
3, Classification
Traditional RTK : A local reference station needs to be established. As the distance from the base station increases, the measurement accuracy decreases.
Network RTK : Based on the CORS system, there is no need to establish a local base station, which improves measurement accuracy and feasibility.
Single-frequency RTK : only receives satellite data in the L1 band.
Dual/Multi-frequency RTK : Receive satellite data from both L1 and L2 frequency bands simultaneously to improve measurement accuracy.
4, Features
High precision
The error range of traditional GPS positioning is usually around a few meters, while RTK technology can control the error to the centimeter level through differential correction, or even to the millimeter level in the best case.
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Real-time
The RTK system is able to make position corrections almost instantaneously after receiving correction data, which makes it particularly suitable for high-precision positioning in dynamic environments.
Anti-interference
RTK can effectively reduce the errors caused by interference factors such as signal multipath effects and atmospheric refraction through corrections made by the base station, ensuring the stability and accuracy of positioning.
Reliability
The automated operation of the RTK system greatly reduces the number of steps for manual intervention, thereby reducing the possibility of human error. For example, surveying and mapping work used to require a lot of manual calibration and control, but the introduction of RTK technology makes the measurement results more reliable.
5, Development Trend
Through the construction of a multi-base station network, network RTK technology can significantly improve signal coverage and reduce the limitations of a single base station, enabling RTK technology to achieve high-precision positioning over a larger range, especially in vast rural and mountainous areas.
Low-orbit satellites are artificial satellites operating in low-orbit orbits of the earth, usually located between 300 kilometers and 2,000 kilometers from the earth's surface.
Due to their short distance from the earth, these satellites have strong satellite signals, low transmission delays, and fast geometric distribution changes.
At present, relevant studies have proved that low-orbit satellites have a significant impact on improving positioning accuracy.
In addition, low-orbit satellites have high ground receiving signal strength and strong penetration ability, which is conducive to improving positioning performance in signal-shielded environments. Therefore, research on low-orbit satellite-enhanced RTK positioning technology will definitely be one of the future research hotspots.
The low latency and wide coverage of 5G networks provide new opportunities for RTK. In the future, RTK technology can achieve faster data transmission through 5G networks, improve real-time performance and reliability, especially in high-dynamic scenarios such as autonomous driving.
Although RTK has greatly improved the accuracy of positioning, how to reduce the multipath effect in complex urban environments and severe weather is still the focus of RTK technology research. In the face of this situation, the integration of multiple sensors such as radar, vision, IMU, etc., and the integration of multiple technologies make positioning in complex environments more accurate and reliable.
RTK technology still requires relatively high costs and technical support. As market demand increases, the production cost of RTK equipment is gradually reduced. In the future, more convenient and low-cost RTK equipment will be widely used in small businesses and individual users, promoting the popularization of RTK technology .
The development of AI technology will give RTK more intelligent functions, especially in the fields of unmanned driving and smart agriculture. Through the optimization of AI algorithms, the accuracy and autonomous decision-making capabilities of RTK can be further improved.
Conclusion
With the continuous construction and improvement of satellite navigation systems, RTK positioning technology has been widely used in the fields of multi-information fusion, low-orbit satellite enhancement,
With the popularization of network RTK, the support of 5G and the reduction of costs, RTK technology will usher in a broader application scenario in the future and become one of the core technologies to promote intelligent development.