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DATA MANAGEMENT BASED ON GEOCODING INDEX AND ADAPTIVE
VISUALIZATION FOR AIRBORNE LIDAR
Xiaodong Zhi a ’ *, Keshu Zhang b , Guozhong Su b
a School of Remote Sensing Information Engineering, Wuhan University, 129 Luoyu Road, Wuhan 430079, China;
b Academy of opto-electronics, Chinese Academy of Sciences, Beijing 100080, China;
KEY WORDS: Laser scanning (LiDAR), Data management, Aerial Survey, Coding, Process modeling
ABSTRACT:
With more surveying practice and deeper application, data post-process for airborne LiDAR system has been extracted lots of
attention in data accuracy, post-process, fusion, modeling, automation and visualization. However, post-process and flexible
visualization were found to be the bottle-neck which limits the LiDAR data usage for industrial applications. The cause of above
bottle-neck problems is great capacity for LiDAR system. Thus in article a geocoding index based multivariate data management
and adaptive visualization will be studied for based on the feature of airborne LiDAR’s data to improve automatization of post
process and surveying efficiency.
1. INTRODUCTION
1.1 Development of LiDAR
LiDAR (Light Detection and Ranging) is an active detection
system of radar, which includes some techniques of laser,
Global Position System (GPS) and Inertial Navigation System
(INS). It can be used to acquire ground information and stereo
information of ground objects through the whole day. LiDAR is
the most essential techniques of information acquiring and
processing for earth observation system (EOS) plan, with image
spectrometer and synthetic aperture radar. In recent decades,
air-borne LiDAR technique has been well accepted by
developed countries, as an accurate and rapid method of
acquiring surface three dimensional information. It has been
developed and applied in terrain mapping, environment
monitoring, digital city modeling and military applications.
This technique only has been developed in several western
countries, in aspects of researching in polar region and Mars
detection.
Compared to the fast development of the hardware of LiDAR,
its data management and handling technologies lag behind
comparatively. At present, most of the LiDAR data managing
software are provided by some specific companies(like
REALM,Optech Co.). These softwares’ algorithms are covered
secretly which can’t be parsed by the users so that thay cannot
manipulate and manage those softwares. Besides, there are
some standalone universal softwares that are independent to
hardware(like LID-MAS,US and TerraSolid, Finland).Those
softwares’ data management is based on sparse file structures,
and theirs algorithms are designed according to the calculations
on every single files which are incapable of dealing with large
number of data like LiDAR.
1.2 Characters of LiDAR data
Datum acquired from Airborne LiDAR, strictly speaking,
includes position, attitude(angle), range, time, intensity in flight.
The characters of this datum are:
a) LiDAR’s data is a series of three-dimensional points
distributing in the surface of the object.
b) LiDAR’s data is in the form of a discrete data
distribution, and irregular.
c) LiDAR’s data contain too many redundant data, and
the density of points is not uneven.
d) The most important character of LiDAR’s data is too
large in size and content. This led directly to the data
organization and management inconveniently, and some
existing algorithms are not suitable for airborne LiDAR.
1.3 Example
Take AOE-LiDAR system as an example, it can generates up to
10 Gb laser data and 15 Gb image data from external digital
aerial camera per hour in one platform. Moreover, for resolving
the LiDAR data in post-process stage, large amount of
intermedia data files are created. Even further, for tuning the
data quality, use different parsing parameter for different
application purpose. This article will investigate complexity and
the way to management these complexity by using geocoding
index based multivariate data management and adaptive
visualization in post-process stage.
2. AIRBORNE LIDAR'S DATA ACQUISITION,
PROCESS MECHANISM AND DATA TYPES
2.1 The mechanism of airborne LiDAR's data acquisition
The system of airborne LiDAR includes laser scanning,
position/ attitude control system and control host. Laser
scanning launch and accept laser signals. Position/ attitude
system composed by IMU (inertial measurement unit) and
DGPS (differential GPS), which can output the position and
attitude parameters for airborne platform. Its principle is shown
in Fig below:
* Xiaodong Zhi. tuladingx@163.com, phone: 0086-1590 7718 999