A drone cruises over the No.90 tower of Badaling Great Wall at Yanqing district, Beijing to observe its restoration and reinforcement condition on Sunday afternoon.Photo: Li Qiao/GT

A drone climbed above the No.90 tower of the Badaling Great Wall in Yanqing district, Beijing on Sunday afternoon to survey the tower's emergency reinforcement capability. In recent years, more advanced technologies have been applied in renovating and protecting the Great Wall.

Yanqing is in the process of mapping the Badaling Great Wall's data and building an information protection system. It is the first time to use drones to capture ultra-high resolution image and refine its geographic information in the protection of the Great Wall.

Drones are used to carry out data acquisition with photographic equipment. Satellite data and laser scanning technology are used to comprehensively survey and map the Great Wall and the surrounding environment. The section of the Great Wall in Yanqing district is undergoing evaluation according to indexes such as current preservation, environmental changes and surrounding construction.

The collection of 26.6 kilometers of brick and stone wall ontology data and the construction of the centimeter-high precision three-dimensional model are almost finished. The accuracy of China's aerial surveying and mapping specification is five centimeters, but due to the particularity of the Great Wall cultural relics, the surveying and mapping precision of Yanqing district's part of the wall is less than two centimeters. 

Using this technology to collect Great Wall data, which provides more accurate data support for later repair and protection, is an important step in building the "digital Great Wall." It also serves as a model reference for the protection of the Great Wall in other provinces of China.

The National Cultural Heritage Administration has launched a pilot project in 15 provinces, autonomous regions and municipalities to protect the Great Wall by using high-tech technologies such as drones and satellite imagery, the China News Service reported.

Great Wall restoration workers pass a brick hand by hand. Photo: Li Qiao/GT

 

A worker in his 60s stirs the mortar needed to restore the Great Wall. Photo: Li Jieyi/GT

 

A mule team is carrying lime, water and other materials required for the restoration to the No.90 tower of Badaling Great Wall. Photo: Li Qiao/GT

 

The interior of No.90 tower of Badaling Great Wall being reinforced Photo: Li Qiao/GT

Two Great Wall restoration workers are rebuilding a wall. Photo: Li Qiao/GT