Terrain correction bug

Dear all,

with the new updates of the version 2.0 of snap I got an error when performing range-doppler TC using ANY external DEM when I use gpt or graph. You can reproduce the error by either using gpt Terrain-Correction (the operation will never end) or by creating a simple graph read terrain correction write (graphexception). The operator works fine when run from the menu or using srtm dem, though.

Any suggestions?

Thanks

same issue here ā€¦ strangely if I chose external DEM, then getting graph error, and then choose an internal DEM, the Graph processes the image with the previously chosen external DEM. Even though now it is not selected anymore. This with a new graph, not a saved xml file.

Maybe this behaviour points to the problem?

BTW I am experience some anomalies with graphs and gtpā€¦ Now the multitemporal filtering is asking as parameters the gradient threshold for Refined Lee filter Valid interval is (0, *). instead of the window sizeā€¦

Usage:
gpt Multi-Temporal-Speckle-Filter [options]

Description:
Speckle Reduction using Multitemporal Filtering

Source Options:
-Ssource= Sets source ā€˜sourceā€™ to .
This is a mandatory source.

Parameter Options:
-PgradThreshold= The gradient threshold for Refined Lee filter
Valid interval is (0, *).
Default value is ā€˜5000ā€™.
-PsourceBands=<string,string,string,ā€¦> The list of source bands.

Graph XML Format:

1.0

Multi-Temporal-Speckle-Filter

${source}


string,string,string,ā€¦
double


Dear @lveci I donā€™t know if you maybe missed this post but could you have a look at these two strange issues we experience? :slight_smile: Would be really great to fix them! Thanks again!

Yes the external dem problem has been fixed. Just waiting to issue a module update.

1 Like

I[quote=ā€œlveci, post:5, topic:1149, full:trueā€]
Yes the external dem problem has been fixed. Just waiting to issue a module update.
[/quote]

Is this the same error causing this behaviour? Graph files not working in SNAP 2.0

[quote=ā€œcarlomarin, post:1, topic:1149, full:trueā€]
ā€¦reproduce [by] using gpt Terrain-Correction (the operation will never end) [ā€¦]. The operator works fine when run from the menu or using srtm dem, though.[/quote]

Was the fixed module released in snap 3.0? Iā€™m still having the same problem whereby the range doppler terrain correction takes forever when using gpt (but works fine from the gui, including the graphbuilder gui).

We experience the same hereā€¦ even by explicitly configuring the gpt.vmoption as the in the gui the performance are poorer. I am using snap v 301 Linux Centos7 32GB 8 core.

Thanks

carlo