Editing Radar cross section (section)

== Factors ==

=== Size ===
As a rule, the larger an object, the stronger its radar reflection and thus the greater its RCS. Also, radar of one band may not even detect certain size objects. For example, 10&nbsp;cm (S-band radar) can detect rain drops but not clouds whose droplets are too small.

=== Material ===
Materials such as metal are strongly radar reflective and tend to produce strong signals. Wood and cloth (such as portions of airplanes and balloons used to be commonly made) or plastic and fibreglass are less reflective or indeed transparent to radar making them suitable for [[radome]]s. Even a very thin layer of metal can make an object strongly radar reflective. [[Chaff (countermeasure)|Chaff]] is often made from metallised plastic or glass (in a similar manner to metallised foils on food stuffs) with microscopically thin layers of metal.

Also, some devices are designed to be Radar active, such as radar antennas and this will increase RCS.

==== Radar absorbent paint ====
The [[SR-71 Blackbird]] and other aircraft were painted with a special "[[iron ball paint]]" that consisted of small metallic-coated balls. Radar energy received is converted to heat rather than being reflected.

=== Shape, directivity and orientation ===
The surfaces of the [[F-117A]] are designed to be flat and very angled. This has the effect that radar will be incident at a large angle (to the [[Reflection (physics)|normal ray]]) that will then bounce off at a similarly high reflected angle; it is forward-scattered. The edges are sharp to prevent rounded surfaces which are normal at some point to the radar source. As any ray incident along the normal will reflect back along the normal, rounded surfaces make for a strong reflected signal.<ref name=":0" />

From the side, a fighter aircraft will present a much larger area than the same aircraft viewed from the front. All other factors being equal, the aircraft will have a stronger signal from the side than from the front; hence the orientation of the target relative to the radar station is important.

=== Smooth surfaces ===
The relief of a surface could contain indentations that act as [[corner reflector]]s which would increase RCS from many orientations. This could arise from open [[bomb-bay]]s, engine intakes, ordnance pylons, joints between constructed sections, etc. Also, it can be impractical to coat these surfaces with [[radar-absorbent material]]s.