On ArcGis Desktop help, it is stated that GeoEye and DigitalGlobe RPC files are supported
"Images from DigitalGlobe store RPC information in a <file name>.rpb file, and GeoEye offers images with RPC information stored in a <file name>_rpc.txt file."
Does anyone have examples of these text file, I'm not interested in the actual coefficients, rather in how the file is structured (formatted).