Sensor model

The class otb::SensorTransformBase is the base class for sensor models. It inherits from otb::Transform, which inherits from itk::Transform. It is templated over the data type, and input and output dimentions. All sensor model classes should inherit from it, and implement the methods:

  • SetMetadataModel that takes a boost::any object representing the model;
  • IsValidSensorModel that returns true if the model is correctly set;
  • TransformPoint that process the transformation.

RPC sensor model

The structure otb::Projection::RPCParam is used to store the parameters of the RPC model. It is based on GDAL’s RPC structure.

The RPC model is stored in the otb::ImageMetadata object, using the key MDGeom::RPC. The classes otb::RPCTransformBase, otb::RPCForwardTransform and otb::RPCInverseTransform are used to perform forward and inverse transformation using this model.

The abstract class otb::RPCTransformBase contains the implementation of the SetMetadataModel method, which receives the RPC description from the otb::ImageMetadata and instantiates an otb::GDALRPCTransformer.

The classes otb::RPCForwardTransform and otb::RPCInverseTransform each implement a version of the TransformPoint method which uses the otb::GDALRPCTransformer.