Abstract: To reduce strong diffractive fields at the baseline edge of a metal body which is reflective of electromagnetic radiation, a substrate substantially transparent to the radiation is placed contiguous to that edge. Conductive reflective elements are carried on an exposed surface of the substrate, in a pattern such that reflection decreases and transparency increases from the baseline toward the terminal edge of the substrate. Thus the diffractive field is gradually reduced.

Abstract: An air data sensor (10) for mounting on an air vehicle (14), the outer end (11) is spaced outwardly from a surface of the air vehicle (14), a mounting base (12) and an outer end (11) which is provided with sensing ports (21, 22) for sensing air data parameters, the body (32) of the sensor (10) is made so that when viewed in the bisecting plane of the body (32), the inner and outer edges (34, 36) of the body curve continuously from the outer end (11) to the base (12). These edges (34, 36) diverge from adjacent to the outer end (11) to the base (12) to provide a very smooth streamlined probe (10) which tends to reduce drag.