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Time bomb 'Old Age Underground Facilities'...Managed by 'RTK GNSS, Augmented Reality'

Various incidents and accidents continue to occur due to the deterioration of underground facilities that constitute core social infrastructure such as communication tunnels, heat transport pipes, and city gas pipes. It was difficult to accurately inspect underground facilities that had been buried for 20 to 30 years because they were buried underground and had various shapes. However, several technologies have recently emerged that help determine the exact location of underground facilities. Among these, the Global Navigation Satellite System (GNSS) based on Real-Time Kinematic (RTK) and augmented reality, which visualizes facilities without digging up the ground, are attracting attention as basic technologies to build an underground facility management system.

Underground facilities 20 to 30 years old... Various incidents have occurred

In November 2018, a fire broke out at the underground communication district of KT Ahyeon branch building in Seodaemun-gu, Seoul, causing casualties and paralyzed communication in the area.

At that time, not only Seodaemun-gu but also some parts of Goyang-si, Gyeonggi-do, had problems with mobile phones, high-speed Internet, card terminals, and point-of-sale information management systems (POSs).

In December of the same year when a fire broke out at KT's Ahyeon branch's underground communication zone, a heat pipeline ruptured near Baekseok Station in Goyang City, Gyeonggi Province, killing one person and injuring more than 50. At that time, heating was cut off in surrounding apartments.

The fire at KT's Ahyeon branch's underground communication zone and ruptured heat pipes near Baekseok Station in Goyang City, Gyeonggi Province, have all been blamed for the underground pipes that are 20 to 30 years old. Such old pipes are still buried underground. According to the Ministry of Trade, Industry and Energy's survey on the current status of infrastructure after the installation, the number of city gas pipes that are more than 20 years old amounts to 19,690 kilometers and the number of heat pipes amounts to 1,163 kilometers.

The problem is that since the facility is buried underground, it is difficult to determine the exact location and condition, making maintenance difficult. It is essential to know the exact location information because it is necessary to work precisely without touching other facilities even when digging into the ground to check the condition of underground facilities. This is why the Global Navigation Satellite System (GNSS) based on Real-Time Kinematic (RTK), which has an error range of less than 2 centimeters, is drawing attention.

RTK GNSS with error range of less than 2cm… Helps with effective underground facility management

The satellite navigation system (GNSS) is a technology used to provide precise location information of objects through satellites, but it has limitations. This is because satellite signals are distorted in the process of passing through the ionosphere and troposphere, and the signal is reflected again by obstacles such as buildings and topography, resulting in errors of up to 10 meters.

Real-time Moving Positioning (RTK) is a technology that corrects the location information error of the existing satellite navigation device to an average of 2cm through the reference station on the ground and delivers accurate location information. This is why RTK GNSS is used not only for robots that operate based on accurate location information, but also for autonomous agricultural machinery, drones, urban air transportation (UAM), and autonomous vehicles.

The RTK GNSS, which provides accurate location information through the calibration of the reference station, is also used to identify the exact location and status of underground facilities without digging the ground. Most of the RTK GNSS for surveying were imported equipment such as Trimble and Leica Geosystems, but Korean RTK GNSS developers such as Synerex are also attracting attention recently. Synerex recently developed the "SYN-RTK," a ultra-small mobile RTK GNSS device that can be installed on mobile phones.

In the past, heavy equipment had to be carried out by several people to measure underground facilities, but equipment attached to mobile phones or tablets has the advantage of being easy to use and manage, said Park Jae-deok, CEO of Synerex. "Thanks to this, we are also collaborating with public institutions to locate underground facilities."

As RTK GNSS begins to precisely determine the location of each underground facility, the development of solutions and related research to visualize underground facilities in augmented reality based on the data are also actively underway.

Visualizing underground facilities in augmented reality is expected to reduce the risk of accidents and increase work efficiency as it can be used at construction sites while looking at the location of gas pipes or water pipes without digging.

Shin Jae-seop, a senior researcher at the Korea Electric Power Technology Research Institute, said, “We are continuously developing underground spaces, but there were problems with the management of each facility being diverse and the current status information not being clearly recorded and managed.” He added, “Visualizing underground facilities in augmented reality At the same time, effective underground facility management is possible by systematically accumulating related data, so we are actively conducting related research.”

IT동아 김동진 기자 (


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