Steerable continuous:
Is a sensor which can be freely steerable to any intermediate position. Typically this is applicable to optical sensors mounted on board agile satellites where the full satellite platform is rolled to point to the desired looking angle.
Steerable enumerative:
Is a sensor which has a limited set of predefined looking positions.Typically this is applicable to SAR sensors, with a set of looking beams, each beam calibrated and tailored by the satellite operator.
Swath file:
Is a sensor which geometry is defined in an external “Swath Template File” file as defined by European Space Agency’s Earth Exporers File Formats.