*3.4. Scattering*

The ability of HF radar to address a wide range of missions brings with it the need for mathematical techniques for computing the radar signatures of the diverse phenomena involved. Bistatic HF radar has been implemented in the form of operational systems since the 1960s but, for most of its history, practice has dominated theory. We can perceive four main lines of development in HF scattering theory: One for the ocean surface, one for plasma formations in the ionosphere, one for land surfaces, and one for discrete targets such as ships, aircraft, and missiles.
