Radar cross-section of large structures with complex microgeometry

From simple theoretical arguments it is shown that, when a structure is large enough and its microgeometry is also complex enough, the radar cross-section (RCS) will often be closely related to its surface area. Also in this regime, the omission of the microgeometry leads not to a first approximation for the RCS profile but to a totally different result; on the other hand, provided the microgeometry is included, the macrogeometry, or gross shape, often matters relatively little. These statements are supported by scattering calculations on demonstration two-dimensional shapes having several scales of microgeometry. It is concluded that attempted calculations of the RCS of such structures risk getting meaningless results unless approached with due regard to the dominating issues involved.