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DIGITAL ELEVATION MODELS OF GREAT WALL BY A COMBINATION OF 
AIRBORNE AND TERRESTRIAL LIDAR 
Zizheng Wang 2 ’*, Yong Huang 3 , Haoyu. Yang 3 , Yanjing. Liu 3 , Zujian. Xu a , R. Kletzlib b , Tie. Xu c ,Li.Cao c , Genzhuang. Zhao c , and 
Shaoqian. Wang c . 
a Guangxi G-Energy Information Engineering Co. Ltd., No.lO,Jianzheng Road,Nanning ,guangxi, China - 
wzzlidar@gmail.com 
b Wayahead Technologies, LLC 
c Hebei Bureau Of Surveying And Mapping 
KEY WORDS: Lidar, DEM, Photogrammetry, Scanner, Accuracy, GPS. 
ABSTRACT: 
The Great Wall is one of the biggest man-made wonders of the world! The wall consists of bricks made by different dynasties and 
built on thousands of kilometers of steep mountain terrain. It has many different structures, irregular and inconsistent shapes. 
Therefore creating digital elevation models (DEMs) of the Great Wall through conventional satellite and photogrammetry stereo 
images has always been a challenge. . In this article, we will show that airborne laser scanning (LiDAR) can be used for the 
production of highly accurate DEMs of the Great Wall. In addition, a terrestrial laser scanner mounted on a tripod can also used to 
improve the terrain model, especially for the surfaces of the wall that are covered with dense vegetation. . The combined use of 
airborne and terrestrial laser scanners shows some exciting and promising advantages. The integration and fusion of data from both 
airborne and terrestrial laser scanners will be discussed. Highly accurate DEMs of the Great Wall with accuracies better than 10 cm 
have been produced. An evaluation of the accuracies achieved has been performed using either check points or trajectories obtained 
through kinematic GPS survey. 
1. INTRODUCTION 
1.1 The Project 
Shanhaiguan Great Wall, which seat in Qinhuangdao city Hebei 
province, is the beginning of Great Wall. Although the wall are 
entire the circumvallation are destroyed heavily. So national 
finance bureau and Hebei province set special funds to repair 
them before 2008 Beijing Olympic game. The current situation 
investigation of Great Wall(including space location, destroy 
and texture etc.) is the inevitable step for repair. 
This project aims at getting detailed map of shanhaiguan Great 
Wall(including guancheng, luocheng and wengcheng). So as to 
make highly accurate 3D model for the all. Which will give data 
support for Great Wall repair and construction. 
Figure LShanghaiguan Great Wall 
1.2 LiDAR Technology 
Use of LiDAR sensors and data has transitioned from the 
domain of research and development into the general 
marketplace primarily as a means of rapidly generating dense, 
accurate, digital models of the topography and vertical structure 
of a target surface. It can be said that the telecommunications 
boom in the 1990’s brought the use of LiDAR into the more or 
less mainstream with the demand for mass production of high 
accuracy digital elevation models (DEMs), digital terrain 
models (DTMs) and triangulated irregular networks (TINs). 
LiDAR elevation data is ideally suited for mapping extensive 
areas where very high accuracy elevation data is required 
rapidly. 
2. METHODS 
According domestic aerial photography and Great Wall 
mapping situation we used abroad advanced LiDAR and digital 
photography technology to finish shanhaiguan Great Wall 
project. On this basis we want to do some study and research to 
make LiDAR technology more suitable to Chinese need and 
market. 
For this project we will use airborne laser scanner, terrestrial 
laser scanner, high definition digital camera, GPS, IMU etc. to 
make highly accurate Great Wall models. We will acquire 
orthophoto and oblique texture so we can make the model more 
real. 
When using LiDAR system we will use highly accurate digital 
camera to get orthophoto at the same time. We can tell the space 
location of LiDAR and camera through LiDAR GPS and 
ground GPS. The IMU can find every second airplane’s pitch, 
roll and yaw changes. We can measure the Great Wall and 
height of Great Wall directly through Laser data. We use oblique 
camera to acquire Great Wall’s side texture to realize exact 
measurement of point, line and area.