Dong Guangyan, BS, Senior Engineer
2010-09
Outline
 1. Summary
 2. Basic principle & typical
specifications
 3. Comparison
with traditional surveying
technologies
 4.
Application status
 5.
Advantages & disadvantages
 6.
Expectations
1. Summary
 A fire-new technical approach
 Single point manually collecting data
continuously & automatically
acquire batch data
 Two types---airborne and ground
(according to difference of platforms)
satellite borne
2. Basic principle and specifications
of typical instrument
Transmitter
Interface
Postprocessing
Signal
processing
Target
Receiver
Figure 1 Principle sketch map of 3D laser surveying system
The hardcore is a 3D laser scanner ，which mainly consists
of the laser transmitter, receiver, scanning system and
bracket system，meanwhile, it integrates with CCD digital
camera and internal calibration systems as well.
Basic principle
 Non-contact, high speed laser measurement
mode
 Acquiring 3D data of terrain and array
geometry of surface of complicated object with
point cloud.
 TOF (Time of Flight) pulse ranging method
 Approach to calculation of 3D laser spot
coordinate for pulse ranging method
Basic principle
Calculation expressions：
X s  S cos cos 

Ys  S cos sin  

Z s  S sin 

Z
P(Xs,Ys,Zs)
S
θ
X
α
Y
Figure 2 Spatial coordinate system of 3D laser surveying system
Typical instrument
 Optech ILRIS-36D
Capture
Every
Dimension
Typical instrument
 Leica HDS3000
Typical instrument
 Mensi GX RD 200+
Main specifications of typical instrument
Manufacturer
Optech
Leica
Mensi
Products
ILRIS-36D
HDS3000
GX RD200+
Laser Security
Class 1 1500nm
Class 3
Class 3 532nm
Ranging accuracy
7mm@100m
Single point 4mm@50m Single point 7mm@100m
Positioning accuracy
8mm@100m
6mm@50m
Single point 12mm@100m
Range (min.)
1.5m
1m
1m
Range( max.)
1500,1000,800
80% 40% 20%
2600m for DR
110°V×360°H
300m@90%
134m@18%
200m-90%
350m
270°V×360°H
60°V×360°H
Scan angle of view
Built-in
6 million pixels
1 million pixels
Integrative color camera
digital camera
24°×24° 111 pictures 5.5 × optical zooming
Postprocessing software Polyworks/Inspector Cyclone
Realworks
Modeling precision
3mm
2mm
2mm
3. Comparison with traditional
surveying technologies
 Different requirements for measurement
accuracy and ambients
 Different raw data patching format
 Different data combined modes among the
sites
 Different build modes for TIN models
 Different extract modes for grains
4. Application status
 3D laser scanning system can rapidly rebuild a
3D solid model of an object.
 3D laser point cloud data can also use the
complete target data for post processing(such
as：mapping, computation, stress analysis,
finite element analysis, simulation analysis,
mission analysis, ⋯etc.)
 It is a symmetric application of all kinds of
forward engineering tools (e.g.：CATIA, UG,
CAD, PDMS, PDS, GIS, VR, 3DSMAX, MAYA,
ERP, etc.)
4. Application status
Generate data image by surveying a
target’s 3D coordinate，then process the
data to extract 3D information and
generate：
a）Digital elevation model DEM with high
accuracy, contour map and orthograph；
b）3D solid image of buildings；
c）Urban 3D diorama；
d）Height of trees, vegetation
4. Application status
Figure 3 Image of 3D laser surveying system
4. Application status
Figure 4 Buildings extracted from Figure 3
4. Application status
Fields covered：cultural relic, archaeology,
architectonics, spaceflight, aviation,
shipping, manufacture, military industries,
military, petrifaction, medicine, water
conservancy, energy sources, electric
power, traffic, machinery, movies & TV,
education, scientific research, automobile,
public security, city construction⋯⋯
Application
 Historical Preservation
Application
 Historical Preservation
Application
 Urban Planning
Application
 Urban Planning
Application
 Industrial Survey
5. Advantages & disadvantages
 Advantages：
High speed，complete measurement, accurate，multiangle-of-view observation；
Non-contact measurement，all-weather；
Shape measurement for completed surfaced object，color
revivification；
Mark and measure relative model data, such as range,
altitude difference, volume, surface area, section, 2D
picture etc.
Build all kinds of geometry shape，such as elbow, taper tube
etc.
Convert 3D model into data format of CAD system or
different software operating platforms for 3D modeling.
Advantages example
 With point cloud of intensity information，
it will support output to CAD environment
for editing and analysis.
Advantages example
 The point cloud figure with RGB information
can revert the environmental information.•
5. Advantages & disadvantages
 Disadvantages and challenges：
3D laser scanner is a black box system，it
is hard to calibrate；
Current instrument are still not perfect in
miniaturization and price，and they are
top grade equipment in market；
Longer processing time after data scan；
The scan data patch soft wares are not
perfect (lack of compatibility)。
5. Advantages & disadvantages
 Disadvantages and challenges
Lack of consideration of standardization，
Lack of soft wares both practical and
lower price；
It is hard to use the fruits of 3D modeling for
further speciality research；
3D modeling has certain subjectivity，and
the laypeople usually visually are puzzled
by virtual cartoon，surveyablity and
science of 3D model is ignored.
6. Expectations
Future works：
● Unification of term
● Establish data standard for accuracy requirement
● Data collection and post-processing requirements
● Approach to fruit accuracy assessment
3D laser scanning technique has
unexampled advantages in 3D data
rapid acquirement and build 3D model.
It is prospective with further effort.
Thanks!