SARPROZ ©

Please refer to this post that discussed the exact same problem

https://www.sarproz.com/groups/sarproz-group/forum/topic/sentinel-1a-co-registration-problem/

The message tries to be self-explanatory.

In some cases, one cannot achieve a perfect “burst alignment” for TOPS. Burst alignment here means the following:

Say, line no. 100 of the master image comes from burst 1; then line 100 of slave image must also come from burst 1. If it comes from burst 2 you will see noisy lines in the interferogram…[Read more]

In your data:

20161007T051857_20161007T051924 means the data is taken at 2016-10-07 05:18~05:19 UTC.

In your orbit:

20161007T112543_V20160916T225943_20160918T005943 means the orbits cover the period from 2016-09-16 22:59 UTC to 2016-09-18 00:59 UTC. 20161007 merely means the date that this orbit file is released (usually 21 days after the data…[Read more]

If it is a common shift for ALL the points, then please check well your reference point (assuming your reflectivity map is geocoded correctly).

If the shifts for different points are different, then, as discussed above, it is highly likely a height estimation error issue. The right approach should be to estimate the point height as good as…[Read more]

Did you “set orbits” again after you downloaded the orbits manually and placed in corresponding folders?

Please note that S1A(S1B) means either ORBITS/S1A/2018/05/…. or ORBITS/S1B/2019/12/….

If it still does not work please print-screen me the path of the orbits.

Q

Let me add a little bit more of my own understanding.

First of all, the shift is caused by the fact that the height of that point you try to estimate (using PSI) is not corrected. You said it is DEM error, but the better saying should be “height estimation error”.

In Sentinel-1 data, the normal baseline is very small, hence the height ambiguity…[Read more]

First of all, Sentinel-TOPS can only be processed one subswath at a time for now.

In the second place, there are always a few lines at the border that might be out of the area (just a few lines). The system will automatically adjust the area so that a common area is selected.

As long as you can extract and coregister fine you can ignore this…[Read more]

Hello,

The FTP site is working well. There is either a network blocking issue (not necessarily from your side) or there also might be a proxy issue (if for any chances you are using a proxy).

I would try to test the following to rule out problems:
1. try to connect using a client, i.e., filezilla, and check if the connection works;
2. If you…[Read more]

Could you please send me the new lasterror.mat and log regarding the orbits downloading issue? – and before that, please update to the newest version of sarproz. I see in the previous log that you are using an old version from September last year. Please make sure you are using the newest version of sarproz.

yuxiao

Hello,

Can you go to your browser and enter the following url:

ftp://johndoe:psinsar12138@128.46.174.159/data/S1A/

And see if you can connect. If you can, also try to go into the folder and randomly download a few orbits.

If you cannot connect it means something is still blocking your ftp protocol. If you can connect, then let me know and I…[Read more]

Update your software to the newest version first, please.

YQ

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

Hello Steffan,

Could you send the log of this new one to me as well? I will start to investigate from there. I will probably ask for more files but I will check see the log first for signs.

Thanks!

yuxiao

Hello Steffan,

Thanks for the post.

The first few azimuth ramps seem very likely to be caused by the initial coregistration accuracy not good enough. In the next paragraph, I will explain how to tackle this problem.

I am not sure about the ramps on the range direction, though. It might be orbital errors, but we need to check the logs.

The…[Read more]

when you have an error, post the log and lasterror.mat

Check the website manual for managing versions:
https://sarproz.com/manual/manage_version.html

Check the following tutorials for importing, coregistration and other steps:
https://www.sarproz.com/yuxiaos-tutorials/

If you are working with the LA_small sample data you don’t need to coregister; otherwise, if you are downloading SLCs of your own…[Read more]

Yes you can ignore.

The warning message there should be quite self-explanatory.

yuxiao

This bug is solved.