DAVIS EchoMaster Radar Reflector - Manual (Page 9)

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Plate Design. Radar reflector plates can be triangular, circular, or square. The
table below shows relative performance:
Note that a reflector with a circular plate, such as Echomaster, has four times the effective radar
cross-section as the triangular reflector, the most commonly seen type. While the square plate
design is even more effective, it is seldom used in marine systems due to its non-compatibility with
sails and rigging, which must survive in a chafe-free environment, and also due to its extra weight
and high vulnerability to windage.
The definition of
σ
m is arbitrary, and can be somewhat misleading.
σ
m increases very rapidly as
radar reflector dimensions are increased (
σ
m varies as the 4th power of dimensions). Radar
detection range, Rm, increases much more slowly (Rm varies directly with the radar reflector
dimensions). For practical purposes, however, doubling the size of the radar reflector will not usu-
ally double the detection.
Alignment of reflector plates. An essential design feature of any reflector,
one which greatly enhances the effective amount of signal returned, is the flatness of
the plates and the accuracy of the right angles formed between them. Alignment of
each angle must be within 3° of a right angle or half of the reflected signal will be
lost. A misalignment of all three plates by as much as 2° will have the same effect.
Davis Echomaster plates resist flexing and warping, and the corner latching system
ensures minimal angular distortion.
Conclusion. The use of a professional radar reflector enhances your boating fun,
knowing that safety has been part of your cruise preparation. The Davis Echomaster
utilizes advanced octahedral design for maximum effectiveness of signal return.
The plates erect quickly and easily in correct “catch rain” position—and require little
room for stowage.