Problem with the interferogram

khalill · January 5, 2019, 7:54pm

I have a problem with the

A problem occurred during the target product initialization Type: operator Exception Message: interferogram Metadata Attribute ’ polarization’ not found

lveci · January 5, 2019, 8:25pm

It looks like you’re using a very old v1. Try updating to the latest SNAP 6.0.5

khalill · January 5, 2019, 8:50pm

i have done with latest SNAP 6 but that error

ABraun · January 6, 2019, 9:04am

how did you process the data until this step?

khalill · January 6, 2019, 9:25am

Hi dear
First split image sentinel1a
Second coregistration
Next interferogram
In interferogram creat error this

ABraun · January 6, 2019, 9:29am

Have you tried to use the S1 TOPS Coregistration? It combines all required steps for a proper coregistration.

khalill · January 6, 2019, 9:33am

No I don’t
I used dem assisted coregistration
And dem assisted coregistration with Xcorr

ABraun · January 6, 2019, 9:37am

Give it a try, select the subswath and bursts and use the SRTM 1ArcSec. Use BEAM DIMAP as an output format. Then apply interferogram computation, debursting at last.

khalill · January 6, 2019, 9:47am

Coregistration created but image is blank valuable, image is black

khalill · January 6, 2019, 9:48am

I think snap tools can’t download dem or orbits file

ABraun · January 6, 2019, 10:04am

this is a known problem and was fixed with the last patch. Please make sure you have installed the latest update (Menu > Help > Search for Updates)

khalill · January 6, 2019, 6:00pm

I have don but this error

image is black

ABraun · January 7, 2019, 9:46am

have you also tried the TOPS Coregistration instead?

khalill · January 7, 2019, 9:53am

yes I have
i had tried wih all coregistrations.
please help me

i have downloaded image sentinel othe but it error again

ABraun · January 7, 2019, 10:03am

I don’t have a solution, sorry.
Can you please provide the exact names of the two products you are using?

khalill · January 7, 2019, 12:10pm

i use thease images
S1A_IW_SLC__1SSV_20150421T122150_20150421T122220_005582_007243_5FC5
S1A_IW_SLC__1SSV_20150503T122143_20150503T122211_005757_007649_F885

ABraun · January 7, 2019, 12:31pm

did you consider that these scenes are shifted along-track?

grafik

That means, sub-swath 5 in image 1 (for example) covers a different area than sub-swath 5 in image 2.
The overlapping sub-swaths have different numbers. 1-6 in the first, and 4-9 in the second, for instance.

Could be a reason why the coregistration leaves an empty product.

khalill · January 7, 2019, 12:38pm

I specify IW 2 in both images

ABraun · January 7, 2019, 12:40pm

IW considers the sub-swath, but you can also select the bursts (demonstrated here). If these do not match (cover the same area), the result will be empty.

khalill · January 7, 2019, 12:44pm

i do like here too