RCP generation direct/inverde model?

adakite · February 15, 2019, 2:24pm

Hi,

I would like to know if the RPC model computed from otbgui_GenerateRPCSensorModel is a direct model or an inverse model? taking the definition from typical DIMAP/RPC xml format.

Thank you

a.

gpasero · February 18, 2019, 10:17am

Hi,

I think it is an inverse model : (line, sample) = f(lon, lat, height)

Regards,
Guillaume

adakite · February 18, 2019, 10:58am

Great Guillaume thank you.

is there any way to compute both? According to https://wiki.orfeo-toolbox.org/index.php/Sensor_Models_Support OTB can handle both direction.

A.

gpasero · February 19, 2019, 10:28am

Yes, OTB handle both direction, but I don’t think we specifically compute both models.

We always store the inverse model, and when we need to do computation in the forward direction, it is done by an iterative loop, trying to inverse the model.

Under the hood, this is currently ossimRpcModel which is used. In the near future, we have plans to rely on GDAL to do it.

Guillaume