easy calculations and adjustments 69
TARGET STRENGTH AND THE ART OF BECOMING
“RADAR-VISIBLE”
A radar signal requires a large amount of mass for good refl ectivity. It doesn’t
matter whether the mass consists of wood, paper, plastic, or metal. A large, fl at
surface that is perpendicular to the radar signal paints a sharp radar image. (Note,
however, that sails do not refl ect radar signals well.) Smaller, rounded shapes
(sailboat hulls and masts) present a poor refl ective surface to the signal.
Large ships often miss smaller targets at relatively close range. Their
high antennas send out a narrow, cone-shaped signal, skipping over these
close targets. In heavy weather, huge seas or swells hide small targets, making
detection diffi cult or impossible.
Hoist one or more radar refl ectors to make your boat visible to other
radar-equipped vessels. Refl ectors come in all sizes and shapes, from simple
plates to a vitamin-pill-shaped canister. In recent radar refl ector testing, the
trihedral-shaped refl ector took home the gold. Th is design consists of three
round plates that intersect one another at 90-degree angles. For the strongest
signal return, hoist the refl ector in a “rain catcher” position. To do this, make
sure two of the plates form a “V” shape when pointing skyward.