RPC model satellite imagery support

Describe the solution you'd like

First of all, thank you very much for this great project. A really interesting feature would be support for images using RPC models, which are commonly used in satellite imagery.

Describe alternatives you've considered

We quickly forked the project to add this support, but I think it would be great if the feature were available to everyone. If test data is needed, it might be enough to take existing images / models and generate RPCs using the project https://github.com/centreborelli/rpcfit, for example.

Also, if you think this feature shouldn't be included in the project and you have a simple workaround, I'd love to hear it, too.

What do you think?

Regards David