The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Vol. XXXVII. Part B7. Beijing 2008
From the Tab. 4 we can find that the pre-filtering nearly had no
obvious impact on the coherence and interferogram because all
the indexes are almost unchanged.
4.4 Conclusion
For the interferometry, time interval and spatial perpendicular
baseline are the most important error sources. In the Tab. 2, we
can find that the temporal baseline is not long, meanwhile the
spatial baseline is also not large. Thus the decorrelation
generated by temporal and spatial baseline are nearly ignored.
Exclude the temporal and spatial decorrelation, we initially
guessed that the speckle is also an important error source which
will destroy the interferometric result. However, the result- both
the figures (Fig. 2,3, 4, 5, 6, 7 ) and the tables (Tab. 4) did not
validate what we expected that the pre-processing to the SAR
pair can improve the coherence and the quality of interferogram.
5. DISCUSSION
According to the statistics of the master and slave image, the
minimum, maximum, mean, and the standard derivation of the
amplitude make a great deal of difference, which maybe
represent the stability of the board and ground imaging system.
From the case study, we can draw a conclusion that if we
encounter the situation of great difference between
interferometric pair, the removal of speckle noise is not the first
choice to solve the problem of interferometric phase map with
low quality even although the time and space baseline are very
small. We guess that the hardware may be one of the most
fundamental causes of low coherence in this case study.
Our next work is to investigate whether the removal of speckle
noise has impact on coherence and quality of interferometric
phase on the condition of little difference between master and
slave amplitude.
ACKNOWLEDGMENTS
This work is supported by Science & Technology Commission
of Shanghai Municipality (06DZ22101), and the Knowledge
Innovation Program of the Chinese Academy of Sciences.
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