The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Vol. XXXVII. Part BI. Beijing 2008 
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2.2. Test region and test method 
There are many mountain massif landslide areas in Jingyang, 
because of natural disaster or long-term change of 
circumstance. Some landslides are more than several 
kilometers long and ten meters height. Figure 1 and Figure 2 
are the landslides of this region; Figure 2 shows the ground 
fissure because of the landslide. If the landslide is near the 
residential area, more people will be threatened. 
Figure 1: The landslide Image 
Figure2: Ground fissure because of landslides 
In this test, a typical area with 50 meters height and 100 meters 
long was chosen. It was scanned twice with a fixed station. In 
the end, it acquired the 3D point cloud and RGB images of the 
test area. In order to simulate the possibility of the landslide 
monitoring by this system, a lab assistant is considered as a 
target on the landslide area. This tested person moved about 1 
meter along landslide direction before the second scan. It is a 
simulated landslide by inspecting the position of tested person. 
The Basic parameter of the data collection is listed in the table 
2.The Figure 3 shows the image of data collection region and 
the position of the tested person. The yellow circles show the 
position of the tested person. 
Scan distance 
100 meter 
Horizontal angle 
50 
Vertical angle 
50 
Number of shots 
5453630 
Number of scan lines 
1690 
Number of points per line 
3227 
Pulse mode 
First Pulse 
Scan start position 
Lower Left 
Scan orientation 
Horizontal 
X spot spacing(counts/mm) 
8/35.2 
X spot spacing(counts/mm) 
8/35.2 
Table 2: The data collection of landslide area in Jingyang 
2.3. Purpose of test 
There are two purposes in this test. Firstly, it simulates the test 
area of landslide by the position change of the tested people 
and gains quantificational result. Secondly, it should filter 
other objects outside the tested people such as the noise and the 
vegetation, and then, we can contrast the results of two scans 
and get the accuracy of the landslide monitoring. 
Figure 3: The image of data collection region and the position 
of the tested person 
3. DATA POST PROCESSING AND RESULT 
3.1The results of the data post processing 
The original datum should be converted into pif format, this 
format data can be read by Polyworks. The datum is processed 
by Poly works and Terrascan. Terrascan is used to the point 
cloud filtering here. Polyworks is used to compare to the twi- 
scanned point cloud and gets the result of landslide. 
The datum is processed by some module of Polyworks, Data 
processing workflow is as follows (Innov Metric Software, 
2003): 
1) Firstly, the collected points should be processed to grid 
by IMalign module of Polyworks. They didn’t need align 
because of only one fixed station to scan. If the area is 
large, it should be set several stations from different angle 
and align all 3D data into unique coordinate system. 
2) Export pqk format model. 
3) The point cloud should be compared in Inspect module. 
The first scanned point cloud are the reference one. The 
second scanned point cloud are the compared one, which 
will compare with the first scanned point cloud. 
The test result is showed in Figure 4, Figure 5 and Figure 6. 
Figure 4 shows that the result of overlapping of scanned point 
cloud. Figure 5 shows the result of visualizing comparison 
results as colors mapped on the point cloud. Because the