OTB 8 : S1 Orthorectification using geoid file takes very long

OTB Usage
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Hello everyone,

since I passed to OTB 8, I am experiencing unusually long computation times when doing Orthorectification of Sentinel-1 images using both DEM and a geoid file (egm96.grd with the header file trick mentioned in the OTB doc). I did not measure exactly but we’re talking about a 50x to 100x longer time. Computation time returns reasonable (comparable to OTB 7.4) when I remove the elev.geoid parameter.

Is this a known issue? Fyi, I’m using the orthofit mode (outputs.ortho is a fully overlapping Sentinel-2 scene), and I have no significant differences in the output when using geoid file or not.

Thanks in advance,
RG

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Dear @rafgaet,

Thank you for using OTB.

We are aware of some problems related to the Orthorectification in OTB 8.0. We know if your DEM directory contains a lot of files, it takes a long time to load. But you are the first to report a problem with the geoid file. Would you share with us the logs ?

Sincerely.
Julien :slight_smile:

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@rafgaet Any news on your side?

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Hello Julien,

sorry for the delay, quite busy right now. I’ll try to relaunch the processes later today (with the release version, because I’m using a personal build) and give you more details.

Thanks again!

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