A back issue of Practical Sailor said that radar returns from
sailboats are very weak without a radar reflector. So.....Useless
idea #3724

Have sailmakers put a few electrically conducting threads in the sail
every few cm so the whole thing reflects. It isnt as good as the
corner cube reflectors and will vary a lot with point of sail but, its
probably waaaaaay better than no refelctor.

Parallax wrote:

A back issue of Practical Sailor said that radar returns from
sailboats are very weak without a radar reflector. So.....Useless
idea #3724

Have sailmakers put a few electrically conducting threads in the sail
every few cm so the whole thing reflects. It isnt as good as the
corner cube reflectors and will vary a lot with point of sail but, its
probably waaaaaay better than no refelctor.


I'd say file under #3724... conductive isn't the same as reflective.

Then again, anything is better than nothing.

But the benefits of active radar on your boat far exceed relying on
ships' crew accurately setting and reading their radar AND being able to
avoid you at their speed,

--
Jere Lull
Xan-a-Deux ('73 Tanzer 28 #4 out of Tolchester, MD)
Xan's Pages: http://members.dca.net/jerelull/X-Main.html
Our BVI FAQs (290+ pics) http://homepage.mac.com/jerelull/BVI/

Jere Lull wrote:

I'd say file under #3724... conductive isn't the same as reflective.

Conductive short wires are far better than just reflective scatterers
like rocks. Ever heard of "chaff" or "window" ... short conductors
released as radar reflectors to decoy antiaircraft weapons.

Conductors can make the best reflectors. Short wires, near the
wavelength of the radar transmission act as antennas and would create a
mirror like reflection, very effective as a radar reflector.

Don't know why it can't be done. Probably some manufacturing or
durability issues. Maybe a separate mesh sheet of the material could be
hoisted just for night sailing?

Rick

Nope!
Once the sail gets wet the reflectance goes down.... Just like a radar
reflector cant be seen (attenuated radar-wise) if its shadowed by or
behind a wet sail.

Parallax wrote:
A back issue of Practical Sailor said that radar returns from
sailboats are very weak without a radar reflector. So.....Useless
idea #3724

Have sailmakers put a few electrically conducting threads in the sail
every few cm so the whole thing reflects. It isnt as good as the
corner cube reflectors and will vary a lot with point of sail but, its
probably waaaaaay better than no refelctor.

RichH wrote in message ...
Nope!
Once the sail gets wet the reflectance goes down.... Just like a radar
reflector cant be seen (attenuated radar-wise) if its shadowed by or
behind a wet sail.

Parallax wrote:
A back issue of Practical Sailor said that radar returns from
sailboats are very weak without a radar reflector. So.....Useless
idea #3724

Have sailmakers put a few electrically conducting threads in the sail
every few cm so the whole thing reflects. It isnt as good as the
corner cube reflectors and will vary a lot with point of sail but, its
probably waaaaaay better than no refelctor.


A wet sail becomes a good reflector. Actually, I once did this
experiment (I taught EE once) where we aimed a Gunn Diode (makes
microwaves) at rotating fan blades but had a wet paper towel in the
way. One set up had just tap water and one had salt water and it took
the kids forever to figger it out. A wet towel (sail) didnt attenuate
as much as expected with only fresh water. Salt water really
attenuated it.