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periz replied to the topic ERS-2 gyroscope failure in the forum Sarproz Forum 9 years, 4 months ago
What Yuxiao says is partly not correct.
If the Doppler polynomial is precise, Sarproz does the job of resampling the image in the right way.
The problem is that those images highly probably do not have a reliable Doppler polynomial.
If this is the case, you will get lots of problems.
If on the contrary the Doppler polynomial is correct, you can…[Read more] -
Yuxiao replied to the topic ERS-2 gyroscope failure in the forum Sarproz Forum 9 years, 4 months ago
Hi Dora,
I strongly advise against using ERS-2 images after gyroscope failure. The reason is:
It is not as simple as you change the threshold for DC, the threshold are there for a reason: it is usually set between ±0.5*(doppler centroid frequency) to discard those images that might be aliased during resampling process in coresgistration process…[Read more]
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dora started the topic ERS-2 gyroscope failure in the forum Sarproz Forum 9 years, 4 months ago
Dear all,
I am processing a dataset of ERS-2 images acquired after the gyroscope failure and I increased the threshold for DC in order to have enough images for APS processing. Are there any processing options in the software I should use to deal with these images besides estimating the azimuth position?
Best regards,
Dora -
periz replied to the topic APS estimation in the forum Sarproz Forum 9 years, 4 months ago
a. UW means unwrapped.
If you check it, the sw will try to read UW interferograms. Then, the multi-temporal processing (estimation of parameters) will work using Least Squares (instead of the maximization of the periodogram).b. Ext DEM means removing the external DEM from time series.
c. the connections (temporal) coherence is calculated as…[Read more]
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seppi-santiago replied to the topic APS estimation in the forum Sarproz Forum 9 years, 4 months ago
Hello Daniele,
After having a look at timo’s notes, and the manual, I was able to get very good results for displacement in my study area. I’m really very happy with the sw.
However I still need to clear out some points of the APS processing, since I need to write a report explaining the processing I’ve carried out:
– In the processing…[Read more] -
periz replied to the topic cumulative displacement isn't accuarte in the forum Sarproz Forum 9 years, 4 months ago
the title of this post is pretty misleading.
insar is relative, but it can still be accurate.
so, deformation trend, time series, cumulative displacement and any other insar product are RELATIVE to a reference point.
unless you know whether the ref. point is stable, your measurements will always be RELATIVE to it.
the true displacement value does…[Read more] -
seppi-santiago replied to the topic Sparse points selection in the forum Sarproz Forum 9 years, 4 months ago
Indeed, you were right. Now that I’m working locally the mask loading works perfectly. Thanks!
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cnu_lee started the topic cumulative displacement isn't accuarte in the forum Sarproz Forum 9 years, 4 months ago
Hi, Professor Daniele,
The cumulative displacement value in DBF file of result are relative to the reference point. But I don’t know the cumulative displacement of reference point.So the value isn’t accurate?
How to understand the value of cumulative displacement? Whether I should plus or minus a value to obtain the true displcement value?
Thank you.
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periz replied to the topic Sparse points selection in the forum Sarproz Forum 9 years, 4 months ago
On the contrary, I believe the net disk is the major problem.
Can you check the network usage?
Or can you simply try to copy the dataset locally? Note that you do not need the SLC folder. So, I believe the rest of the folders should be quite small. -
periz replied to the topic Sparse points selection in the forum Sarproz Forum 9 years, 4 months ago
On the contrary, I believe the net disk is the major problem.
Can you check the network usage?
Or can you simply try to copy the dataset locally? Note that you do not need the SLC folder. So, I believe the rest of the folders should be quite small. -
seppi-santiago replied to the topic Sparse points selection in the forum Sarproz Forum 9 years, 4 months ago
Hello,
The file is on a net disk, so I think this should not cause major problems. Windows has more than 500 available gb, and the usage of RAM memory is about 50% when running this command. The parameter from which I’m trying to select the points is the Amplitude Stability Index (Amp. Stab. Index 1-Sigma/Mu). I enclose a screen shot, since in my…[Read more]
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periz replied to the topic Sparse points selection in the forum Sarproz Forum 9 years, 5 months ago
there is no evident reason for your problem
the file is 2.2MB, less than 1.5e6 points
loading the file in matlab takes a few seconds
I am wondering whether you could have problems affecting matlab and/or windows installation.
or maybe some problems in reading/writing operations: is the file on a local or external disk?
which kind of disk are you…[Read more] -
seppi-santiago replied to the topic Sparse points selection in the forum Sarproz Forum 9 years, 5 months ago
I am working with Windows. My dataset is not very big (ca. 3600 samples x 3100 lines). For the mask generations, I used the local maxima option (second one). You can download the Maschera.mat from here
https://www.dropbox.com/s/0arzdxjgwpizkxy/Maschera.mat?dl=0 -
anarizka replied to the topic PSInSAR Analysis in the forum Sarproz Forum 9 years, 5 months ago
Dear Prof Daniele,
I choose second area to analysis. Based on my result, have you think that it reasonable or no? Please, find attach file below.
In APS estimation, Any parameter unknown, could you explain what is “Estimated Parameters like, R r0 ds, Flatten, R and DSF” also in “Processing Parameters like Scattering Centers and Polynomial…[Read more]
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periz replied to the topic Sparse points selection in the forum Sarproz Forum 9 years, 5 months ago
the mask file is independent from the number of images
it would be nice to know how big is maschera.mat, and which is the size of your dataset (samples and lines).
by the way, which option did you use for mask generation?
are you working with windows? what’s the size of the RAM? -
periz replied to the topic Geocoding in the forum Sarproz Forum 9 years, 5 months ago
given the infos you posted,
I expect the geocoding through external DEM to work well -
Yuxiao replied to the topic Geocoding in the forum Sarproz Forum 9 years, 5 months ago
Hi Santiago,
Dan will be quite busy these days so let me try to answer your questions.
1. You can try use the external DEM in this case. There is one simple judgement to whether your geocoding went well. After geocoding, geocode your reflectivity map into Google Earth kmz file, and check in Google Earth if it is geocoded well. If it is then you…[Read more]
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seppi-santiago replied to the topic Geocoding in the forum Sarproz Forum 9 years, 5 months ago
I enclose .zip and .jpg
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seppi-santiago replied to the topic Geocoding in the forum Sarproz Forum 9 years, 5 months ago
Hello Daniele,
I’m working with an area where I find it difficult to identify a clear and reliable GCP (it’s a totally uninhabited zone) and there is not no topographic feature which could discriminate easily from its surroundings. It is more or less a flat scene at a very high altitude (more than 4000 meters) , with only one hill or peak. In…[Read more]
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seppi-santiago replied to the topic Sparse points selection in the forum Sarproz Forum 9 years, 5 months ago
Daniele,
I’m sorry, the mask zipped file exceeds the maximum allowed limit
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