The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Vol. XXXVII. Part Bl. Beijing 2008
360
Fig.2 Distribution of GCPs and Pass Points
Image
X
Mean Square Error(m)
Y Z horizontal
1321-01
2.9
3.4
1.9
4.5
1309-40
2.9
3.4
1.9
4.5
1321-08
2.2
2.4
2.8
3.3
1309-33
2.2
2.4
2.8
3.3
Averag
e
2.6
2.9
2.4
3.9
Table 1. Combined Adjustment Accuracy
Image
X
Mean Square Error(m)
Y Z horizontal
0701-71
1.9
2.1
0.9
2.8
0831-06
1.8
2.5
0.8
3.1
0629-06
0.7
1.3
1.9
1.5
0701-76
1.1
1.6
2.3
1.9
0701-82
1.4
1.6
2.9
2.1
0701-87
1.0
0.8
3.8
1.3
0831-11
1.1
1.2
3.0
1.6
0831-16
1.6
1.2
2.4
2.0
0831-22
1.5
0.7
3.9
1.7
0629-12
1.3
1.4
1.7
1.9
0629-18
1.2
1.3
2.1
1.8
Averag
e
1.3
1.4
2.3
2.0
Table 2. Combined Adjustment Accuracy
In the two experiments, the GCPs and the Pass Points are
distributed rationally in each image. The two experimental
results show that the coordinate accuracy of Pass Points is
feasible for 1:10 000 scale ortho-image making and topographic
map updating. There are four images in the first experiment,
and nine GCPs and ten Pass Points are used. There are eleven
images in the second experiment, and nine GCPs and thirty Pass
Points are used. The second experimental result is better than
the first one. Because the Pass Points are twice overlap in the
first experiment and the most Pass Points are more than twice
overlap in the second one.
4. CONCLUSIONS
The experimental results show as follows:
Firstly, this method can satisfy accuracy requirement of 1:10,
000 scale image ortho-rectification and map updating.
Secondly, compared with conventional ortho-rectification of
single image, the number of GCPs has decreased greatly based
on this method.
Thirdly, when computing ground coordinates of pass points, the
elevation value is obtained from 1:50,000 scale DEM. The
experimental results show that the accuracy of pass point is
improved enormously used this method.
Fourthly, this method can apply to multi-photo combined
adjustment of any airborne SAR image, such as different
temporal, different side-looking-orientation, different flight
height, different resolution.
According to functions above, this method can also apply in
multi-photo spacebome SAR images and spacebome SAR
images with airborne ones, but time and data is limited, this
method will be researched with more kinds of data later.
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ACKNOWLEDGEMENT
This work was supported by State Bureau of Surveying and
Mapping Key Laboratory of Geographic Information
Engineering Foundation of Researches, No 200731.