Sail Magazine, August, 2000 Issue

For many sailors a radar reflector is as much a talisman as a piece
of functional equipment.

     Because fiberglass boats are nearly invisible to radar, 
prudence requires that reflectors be displayed, but few pretend 
they do much good.  In the real world, where boats are heeled and 
surrounded by water and waves that absorb radar signals and
generate clutter, a prayer may sometimes seem just as effective. 
  Unfortunately, technology in this area has been very static.  
Almost all reflectors currently available are iterations of the 
simple aluminum trihedral corner reflector, and independent tests 
have shown that the crudest example, an octahedral reflector 
(consisting of eight large trihedral pockets) hoisted in a rig in 
the proverbial "catch-rain" position, is still the best bet for 
increasing radar visibility.
  
  The Tri-Lens Reflector, new on the market this spring, promises 
to shake things up a bit.  It consists of a trio of Luneberg lenses, 
which have been the radar reflectors of choice in military 
applications for several years.  Each lens is a sphere composed 
of layers of material with varying indexes of refraction that focus
incoming radar signals onto a reflector cap at the back of the 
sphere and bounce them back to their source. The great advantage 
of a spherical lens is that its signal-return signature is broader and 
much more consistent than that of an angular corner reflector, which 
is characterized by dramatic peaks and valleys.
  
  The Tri-Lens is not the first Luneberg device on the market, 
but it is significantly different from its predecessor, a 
single-lens apparatus known as the Lensref.  The distinction 
between the two is in the placement of the reflector that 
receives and returns incoming radar signals.  The Lensref is a 
"belly-band" lens, with its reflector girding its waist like a 
belt.  This allows for a seamless 360 degrees of horizontal 
coverage, but when the lens is vertically heeled at a sufficient 
angle (18 degrees or more, according to one independent lab 
test), the focal point of the incoming signals is shifted off the 
reflector and the device ceases to function.

The Tri-Lens, with a cap reflector at the back of the lens, is by 
comparison reported to be fully effective when heeled to 45 
degrees and can beheeled all the way to 90 degrees before 
it fails to return a signal at all.  While a single lens provides only 
limited horizontal coverage, the three lenses together purportedly 
provide 330 degrees of coverage, with only three shallow valleys 
in which signal return is significantly reduced.

   Best of all, the Tri-Lens is a small, discrete unit.  The 
full-size version measures just 6 by 12 inches and weighs only 5 ½ 
pounds.  The Mini Tri-Lens is 4 by 8 inches and weighs just 2 
pounds. Both have a durable exterior surface of smooth UV resistant 
ABS plastic and can easily be mounted atop a masthead, 
where they will not only be entirely out of the way, but also 
give optimum performance —clear of the mast’s shadow and well 
above the water.

  Rozendal Associates, creator of the Tri-lens, has 
been manufacturing high-tech reflectors, antennas, and radomes 
for the U.S. military since 1983.  This is their first foray into 
the recreational marine market, and one can’t help but  wonder 
what took them so long.

Rozendal Associates, Santee, California
tel. 619-562-5596, www.tri-lens.com
--Charles J. Doane

Sail Magazine, May, 2001 Issue

Radar reflectors have been long considered a critical
piece of safety equipment, but a truly effective passive
device that can be easily mounted on a sailboat has 
yet to appear on the market. Our judges thought this
new reflector from Rozendal Associates was a step
in the right direction. A key military contractor in the
field, Rozendal brought its acumen to bear on the 
recreational marine market and produced a simple, yet 
innovative, trio of stepped-index Luneberg lenses that
is both inexpensive and unobtrusive. First introduced
to the public in these pages (Tech Notes, August 2000)
the Tri-Lens produces a broader cross-section return
signal at much wider angles of heel than conventional
reflectors and should improve the radar visibility of
fiberglass sailboats.

Rozendal Associates, Santee, California
tel. 619-562-5596, www.tri-lens.com