Without having to visit the scene in person, you can see every brick crack on the Great Wall on the computer, understand the impact of natural phenomena such as freeze-thaw, precipitation, earthquakes on the Great Wall itself, and grasp the law of disease occurrence on the Great Wall... Recently, the Digital Display Project of the Great Wall of Huairou District (Jiankou Section) was launched and completed at the end of this year. At that time, three major centers of basic information, monitoring and protection, and scientific research will be formed to realize basic information visualization, disease and security monitoring automation, publicity and communication visualization, and the Jiankou Great Wall will also complete the "digital twin".
Assemble the equipment
Fixed-wing drones with a wingspan of nearly 2 meters, tilt photographic drones with a camera with 5 lenses, small white drones... At more than 8:00 a.m. on April 14, the reporter drove off the Jingcheng Expressway, passed through Yanqi Island, and walked more than 30 kilometers of winding mountain roads to Xizhazi Village in Yanqi Town, which is surrounded by the Great Wall of Jiankou.
Preparation before shooting
At the foot of the Great Wall in the west of the village, five drones are lined up, and technicians are assembling and debugging. On the same day, they divided their work and cooperated to shoot and collect data inside and outside the Great Wall, up and down.
"The Huairou District Great Wall Digital Display Project (Jiankou Section) project is carried out in three phases, including the basic information collection stage, the monitoring facility construction stage, and the software platform research and development stage." Zhang Tong, director of the Huairou District Cultural Relics Institute, told reporters. The data collection phase has only recently begun, and it is done before the leaves are fully grown to cover the walls.
The data collection adopts multi-source fusion and air-ground fusion technologies such as oblique photography (acquisition resolution of 1 cm), lidar (which can penetrate vegetation and obtain three-dimensional data of walls), and three-dimensional lidar to obtain high-precision three-dimensional data of the Great Wall as complete as possible. "The Great Wall rises and falls with the height of the mountain, and it is also curved from the plane. The camera mounted on the tilt photography drone has 5 lenses, according to the pre-set route, it can fly with the mountain undulating, high and low bends against the Great Wall, and the 5 cameras can shoot the wall, the ground, etc. from 5 angles at the same time, and collect more complete and accurate Great Wall data. Kang Wei, the person in charge of on-site technology, introduced. For the enemy station where the drone cannot fly, it is supplemented by manual camera shooting, and a relatively complete enemy station needs to take about 3,000 photos.
Not only is the high scientific and technological content, the scope of the data collection has also been expanded, from the Great Wall itself to the two sides of the city wall within 3 kilometers, the collection content in addition to the Great Wall itself, but also included the ancillary cultural relics on both sides, the vegetation and water system in the area where the Great Wall is located, the ecological environment, the human environment, in order to most objectively reflect the environment in which the Great Wall is located.
The second stage is the construction stage of monitoring facilities, which will lay out a variety of intelligent sensing equipment such as meteorology, environment and disasters around the Great Wall itself and the surrounding environment, and establish an intelligent monitoring system for the Great Wall itself and the surrounding environment. With the intelligent monitoring system, a little bit of wind and grass data of the Great Wall will be synchronized to the monitoring platform, which is convenient for managers to grasp the dynamics of the Great Wall in real time and make scientific disposal on demand. Moreover, data can be collected and accumulated continuously and coherently to provide a basis for scientific research.
The third stage is the research and development of the software platform, that is, how to scientifically and effectively use the monitoring data to carry out research on the protection of the Great Wall and the law of disease, repair technical standards and so on. Including through image recognition, big data analysis and combined with the Great Wall disease, historical records and other research data, to achieve a certain degree of automatic disease identification and monitoring, the establishment of the Great Wall digital protection standard system.
Upon completion of the project, three centres will be established – the Basic Information Centre, the Monitoring and Protection Centre and the Scientific Research Centre. The public can enjoy the beauty of the Great Wall through the Basic Information Center in the "Digital Museum"; the monitoring and protection center can help monitoring personnel and competent departments to improve the protection level of the Great Wall; the scientific research center to carry out research on the protection rules and technical standards of the Ming Dynasty Masonry Great Wall to demonstrate for the whole country. The three centers will realize the preservation, analysis, research, reproduction and dissemination of the Great Wall cultural relics.
A drone camera with five lenses
It is understood that as the core exhibition area of the Beijing section of the Great Wall National Cultural Park, the Jiankou section of the Great Wall has the characteristics of heavy historical and cultural value, rich landscape types and large preservation scale. In 2020, the country's first "Great Wall Protection and Restoration Practice Base" settled at the foot of the Jiankou Great Wall. At the end of 2021, the "Great Wall National Cultural Park (Beijing Section) Construction and Protection Plan" was released, and 10 landmark projects will be implemented, including 2 national projects.
The Jiankou Section Great Wall Research Protection and Repair Project is a "demonstration model project" among 10 projects, and is also one of the two national projects, which will explore new models of Great Wall protection, archaeology and research, and form replicable and popularized Great Wall protection and repair concepts and technical methods to lead the national Great Wall protection and repair action. The Digital Display Project of the Great Wall of Huairou District (Jiankou Section) is one of the construction contents of the project.
Manually shoot inside the enemy station with a camera