OTB 8 : S1 Orthorectification using geoid file takes very long

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,

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 ?

Julien :slight_smile:

@rafgaet Any news on your side?

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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