A PROGRESSIVE QUALITY CONTROL TO IMPROVE THE ACCURACY OF LIDAR 
DATA PROCESSING 
Xiaodong Zhi a *, Liang Zhong a 
a School of Remote Sensing Information Engineering, Wuhan University, 129 Luoyu Road, Wuhan 430079, China 
WG 1/2 - SAR and LiDAR Systems 
KEY WORDS: LiDAR, Quality control, Accuracy analysis, Strips Adjustment 
ABSTRACT: 
Quick data acquisition using LiDAR, is a way to generate dense accurate DEM. The difference with an image recorded by a 
standard digital camera is that the LiDAR recorded points do not have a regular distribution. The quality and the true resolution 
could be variable to traditional photogrammetry. So in application of airborne LiDAR, the accuracy of LiDAR data is ambiguous. 
Actually LiDAR quality control is a vital post-process used to verify the quality of the data. The objectives of this research are, 
through analyzing the LiDAR data characteristic and the data processing flow of Airborne LiDAR, research the way to evaluate the 
LiDAR data accuracy, make clear the quality criteria, study the methods of accuracy evaluating, and bring out a working flow on 
LiDAR data processing. 
1. INTRODUCTION 
1.1 About LiDAR 
The fields of application for LiDAR are very diverse and 
include generation of digital elevation models, 3D-city 
modelling, forestry management, coastline protection, disaster 
management, erosion studies, archaeology, monitoring of 
corridors such as powerlines, pipelines, railways and roads. The 
technology offers short data acquisition time, highly detailed 
detection of the earth surface and the accuracy fits the needs of 
many applications. 
But from an end user perspective, they need the quality criteria, 
the methods of evaluating to examine performance of LiDAR 
and evaluate the accuracy of point clouds. These problems are 
studied in following chapters. 
1.2 Coordinates calculated mathematical model 
X 
X' 
X* 
y 
= 
Yo 
+ ^WGS-M(p y o y k)^Rc/(IMU) 
y l 
z 
WGS-84 
A. 
WGS-84 
A. 
Where x, y, z is Ground coordinates of the object point 
,7 0 ,Z 0 is Ground coordinates of the GPS 
antenna phase center 
x L , Y l ,Z l is Laser Scanner coordinates of the 
object point with calibration parameters 
R r ef(iMU) ' s R° tat i° n matrix that needs to be 
applied to the laser unit coordinate system to make it parallel to 
the reference coordinate system 
R*-wgs-M(p ok) * s Rotation matrix that needs to be 
applied to the reference coordinate system to make it parallel to 
the WGS-84 coordinate system 
Figure 1. The coordinates of the LiDAR system 
1.3 LIDAR quality 
LiDAR quality control is an important post-process used to 
verify the quality of the produced data. The objectives of this 
research are to develop new methods and tools for LiDAR 
quality control. 
Before talking about quality, quality criteria, we have a look at 
the definition of the term quality. In IS09000 (ISO, 2000) 
quality is defined as "degree to which a set of inherent 
characteristics fulfils requirements". 
In geodesy, the term quality is mostly used synonymous to 
accuracy. 
Accuracy is the degree to which information on a map or in a 
digital database matches true or accepted values. Accuracy is an 
issue pertaining to the quality of data and the number of errors 
contained in a dataset or map. 
Generally, the comparison analysis among the various datasets 
(e.g., LiDAR and photogrammetric DTM, LIDAR and GPS 
check points, LiDAR and GIS vector data) was performed using 
different approaches as point to point comparison, point vs