GNSS Signal Blocked? Try This IoT-Assisted Rapid Re-survey Method for Engineering Control Networks – Millimeter-Level Accuracy & Doubled Efficiency
2025-04-14
Friends in surveying and engineering must have encountered the same frustrating problem – control network re-survey, especially in scenarios with severe GNSS signal obstruction (such as mountainous areas, factories, and dam surroundings), which is simply “an arduous task”!
Control networks are like the “eyes” of a project. Regular re-survey is essential to ensure the reliability of subsequent construction and monitoring. However, common re-survey methods on the market either have limited application scenarios or are inefficient to the point of frustration. Today, I will share a practically proven solution – an IoT-assisted rapid re-survey method for engineering control networks, which achieves millimeter-level accuracy and doubles efficiency in actual tests!
IoT-Assisted Rapid Re-survey Method for Engineering Control Networks System Architecture
Perception layer: The protagonist is the “remote-controlled prism” – we have modified ordinary prisms to adjust their orientation remotely, eliminating the need for manual adjustment at control points, which is the key to improving efficiency;
Network transmission layer: LoRa technology is adopted. You may not be familiar with this technology, but its advantages are obvious – long transmission distance and strong anti-interference ability. Even in complex environments such as mountainous areas and dams, it can stably transmit control signals. It is worth mentioning that all Toknav’s RTK devices have the same advantages as LoRa technology and can also achieve stable transmission in complex surveying scenarios. For more information, you can check out
Application layer: It is the control software we operate, with a simple interface. It can remotely control the prism orientation, view measurement data, and realize full-process visualization, making operation very simple.
The entire re-survey process is also very simple: deploy remote-controlled prisms at each control point, the operator operates the total station at a fixed position, remotely adjusts the prism orientation through the application layer software, and the total station automatically completes angle and distance measurement. No need to travel back and forth between control points, completing the task in one step.
Actual Test Verification: Accuracy Uncompromised, Efficiency Doubled!
Talking the talk is not enough; walking the walk is. We conducted an experiment on an actual project (the plane control network of a hydropower station dam), comparing the re-survey effects of the “IoT-assisted method” and the “total station only” method. The results were really surprising!
Accuracy: The re-survey accuracy of the two methods is completely consistent, reaching sub-millimeter level, which fully meets the re-survey requirements of engineering control networks, so there is no need to worry about accuracy degradation;
Efficiency: Taking working hours as the indicator, the efficiency of the IoT-assisted method is about 107% higher than that of using only the total station – simply put, a re-survey task that used to take two days can now be completed in one day, saving half the time directly!
More importantly, this method does not rely on GNSS signals. As long as there is line of sight between control points (a basic requirement for traditional total station measurement), it can work normally no matter how severe the surrounding obstruction is. Many actual engineering control networks are laid out as angle-distance networks, which are just suitable for this method, with broad application prospects.
Summary & Future Outlook
In summary, this IoT-assisted rapid re-survey method for engineering control networks perfectly solves the pain points of traditional methods: “low efficiency, tiring labor, and limited scenarios”:
No manual trips to control points to adjust prisms, with full automation, reducing labor costs and safety risks;
The accuracy is consistent with that of traditional total stations, reaching sub-millimeter level, meeting engineering needs;
It does not rely on GNSS signals and can easily handle scenarios with severe obstruction, with a wider scope of application;
Efficiency is increased by 107%, greatly shortening the re-survey period.
Of course, this method still has a small regret – it has not been applied in complex terrain (such as high mountain canyons) or ultra-large-scale control networks. In the future, we will continue to improve, and strive to verify it in more complex scenarios, so that this method can help more friends in engineering and surveying.
If your project also encounters problems of GNSS signal obstruction and low re-survey efficiency, you may wish to try this method – it has been proven useful in actual tests! If you have any related questions, you can also leave a message in the comment area to communicate~
Reference: [1] Zhou Jianguo, Gan Youhuizi, Chen Yanchong. IoT-Assisted Rapid Re-survey Method and System for Engineering Control Networks[J]. Science of Surveying and Mapping, 2026, 51(02): 33-40. DOI:10.16251/j.cnki.1009-2307.2026.02.004.
