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Hi Paul,
there is a high number of factors that can cause the difference in the results. One of them is the reference point. Then one should check all options you used for processing. Also the outcome of the APS processing plays an important role on the final result. The topic is too broad to be treated here in a single answer. I suggest you to…[Read more]

Hi Daniele,

Thank you very much for the suggestions. The coregistration works well now.
I did process the external DEM in SAR coordinates, but i did not choose ‘orthorectified’ in data export process, which is important. Besides, the data i am using is Sentinel data.

Have a great day,
Paul

Hi Paul,
you are missing the most important things:
1. you have to process the external DEM in SAR coordinates
2. you have to choose the “orthorectified” output, in the extended data export
You also miss to tell us which satellite data you are using.
If it is not Sentinel, probably you need to select a GCP manually.
Also, search in the forum,…[Read more]

Please take the time to read this https://www.sarproz.com/groups/sarproz-group/forum/topic/forum-general-rules/
if you want we understand what you are talking about, paste pictures, logs, messages, all possible information you can find.

Hi,

try to draw the angle to the piece of paper. You will realize that the value -129.6 deg is not the heading of the satellite track, while the value from SARPROZ is really heading angle of the satellite from the North (azimuth angle).

best,

M.

TerraSAR stripmap doesn’t require deramping.

If you are working with TerraSAR ScanSAR/TOPS mode, I don’t think sarproz support those formats yet.

YQ

For Sentinel, Deramp is automatically done (during coregistration).

yuxiao

Thank you for the information.

It is sentinel-1A data. One interesting thing is that in Site Processing – APS estimation, i generated the graph, and it gives me 25 auto point, and i chose a ‘best’ point with good distribution. Then, i moved to Site Processing -Sparse point processing. When i checked the distribution of the parameters, there is a…[Read more]

By looking at your results again, I notice that the deviation of the estimated height is particularly high: is this Sentinel? If so, the estimated residual height is not very accurate, because the normal baselines are very small. Do not get crazy with the ref point selection.
The suggested ref points are chosen also considering their phase…[Read more]

Thank you so much for the suggestion.

About the reference point choosing, i still have a question. When i read the SARPROZ tutorial ‘Demo: APS Estimation Multitemporal analysis with Sarproz’, it says that best reference point should reflects that both velocity and residual height distribution peak at 0. However, in the Site Processing – APS…[Read more]

hi linweicheng,
sorry for the late answer. You are trying to import Alternating Polarization Envisat images. At the moment this particular Envisat Mode is not supported. We will include it in the near future.
Best

first of all,
velocity and residual height are two different parameters belonging to two different physical characteristics, very different from each other and usually not correlated.
then, even if the majority of radar reflections would be higher than the ground level, still, reflections would be at different height values. Unless you are in an…[Read more]

Sorry that I forgot to upload my attachment……

I’ve also tried to import another Envisat files, but I still met the same problem.

Problems can be solved by doing things step by step from the beginning.

Step 0: read this https://www.sarproz.com/groups/sarproz-group/forum/topic/forum-general-rules/
In particular for what concerns files to include when one encounters errors

best