Echo effect

Dreadnaught · 02-19-2004

I wasn't sure in which category to put this question.

I live near a lake and while using my cantenna, with it pointing towards the lake, I'm able to pick up APs that I know are behind me. Out of curiosity, I'm wondering, can a signal echo or bounce off the lake, or is there something else involved. I'm using a Senao card - haven't tried my orinoco yet.

Thorn · 02-19-2004

2.4GHz microwaves bounce and backscatter like crazy over water.

Twisted · 02-19-2004

OK an add on for this question.

If you had a building with a YAGI pointing to another YAGI across the lake, would such a directional setting be effected by the water. I had a customer mention it on a call a few weeks ago, and just thought it was one of those wacky thing customers come up with.

Mr.White · 02-19-2004

Every one of those ripples and waves acts like a mirror, scattering the signal all over the place. If you need to shoot across a substantial body of water, get both antennas way up in the air.

Thorn · 02-19-2004

Oh yeah.

With a PtP across a lake you should have a 100% Frensel Zone at a minumum, to prevent bounce. This is opposed to the standard 60-80%. 110-120% is better to allow for any wave action. Waves can produce backscatter.

Dreadnaught · 02-19-2004

Interesting. Thanks for the information.

Guess I won't be stumblin' around any water parks.

02-19-2004	#1 (permalink)
Dreadnaught Registered Member Join Date: Sep 2003 Posts: 23	Echo effect I wasn't sure in which category to put this question. I live near a lake and while using my cantenna, with it pointing towards the lake, I'm able to pick up APs that I know are behind me. Out of curiosity, I'm wondering, can a signal echo or bounce off the lake, or is there something else involved. I'm using a Senao card - haven't tried my orinoco yet.

02-19-2004	#2 (permalink)
Thorn Did you do the math? Join Date: Apr 2002 Location: Villa Straylight Posts: 10,361	2.4GHz microwaves bounce and backscatter like crazy over water. __________________ Thorn "Read Altas Shrugged. Compare it to today. Repeat as necessary"

02-19-2004	#4 (permalink)
Mr.White OH such tacos will I give Join Date: Oct 2002 Location: Minnesota Posts: 1,049	Every one of those ripples and waves acts like a mirror, scattering the signal all over the place. If you need to shoot across a substantial body of water, get both antennas way up in the air. __________________ A good way to threaten somebody is to light a stick of dynamite. Then you call the guy and hold the burning fuse up to the phone. "Hear that?" you say. "That's dynamite, baby." -Jack Handey

02-19-2004	#5 (permalink)
Thorn Did you do the math? Join Date: Apr 2002 Location: Villa Straylight Posts: 10,361	Oh yeah. With a PtP across a lake you should have a 100% Frensel Zone at a minumum, to prevent bounce. This is opposed to the standard 60-80%. 110-120% is better to allow for any wave action. Waves can produce backscatter. __________________ Thorn "Read Altas Shrugged. Compare it to today. Repeat as necessary"

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02-19-2004	#3 (permalink)
Twisted Registered Member Join Date: Dec 2003 Posts: 185	OK an add on for this question. If you had a building with a YAGI pointing to another YAGI across the lake, would such a directional setting be effected by the water. I had a customer mention it on a call a few weeks ago, and just thought it was one of those wacky thing customers come up with.

02-19-2004	#6 (permalink)
Dreadnaught Registered Member Join Date: Sep 2003 Posts: 23	Interesting. Thanks for the information. Guess I won't be stumblin' around any water parks.