Winnipesaukee Forum - View Single Post - Did anyone consider radar/lasar detectors for the lake?

Woodsy · 02-09-2011, 01:45 PM

BI...

I find it hard to believe that your depth finder (sonar - sound waves) goes off when your boat was painted with radar (microwaves). Especially considering your sonar transducer is located under the waterline of the boat in either the bilge (internal) or external on the transom....

DaveR...

The LIDAR units are not well suited for marine use because of the wave motion.... if you have one of those laser pointers go outside and try to hold it steady on an object approximataly 1/8 to 1/4 mile away. The units that look like binoculars are better, but still difficult to use give wave action and rocking boats.

The handheld Radar units work pretty good and are pretty easy to use, the problem is they emit a cone of radiation and unless you are the only boat in area its hard to prove it was you.

In both instances, the Law of Cosine works in your favor. The accuracy of the unit diminishes exponentially as the angle increases. In other words the units are most accurate when you are directly approaching or departing the radar/lidar unit. As the angle increaes, the speed it records you at decreases. Thats why on the roadways they give you a minimum 5 MPH leeway and thats with an approximate 5 degree angle..... Increase that angle to 10 or 15 degrees off your heading and the accuracy rapidly diminishes!

Woodsy

02-09-2011, 01:45 PM	#5
Woodsy Senior Member Join Date: May 2004 Location: Weirs Beach Posts: 1,949 Thanks: 80 Thanked 969 Times in 432 Posts	BI... I find it hard to believe that your depth finder (sonar - sound waves) goes off when your boat was painted with radar (microwaves). Especially considering your sonar transducer is located under the waterline of the boat in either the bilge (internal) or external on the transom.... DaveR... The LIDAR units are not well suited for marine use because of the wave motion.... if you have one of those laser pointers go outside and try to hold it steady on an object approximataly 1/8 to 1/4 mile away. The units that look like binoculars are better, but still difficult to use give wave action and rocking boats. The handheld Radar units work pretty good and are pretty easy to use, the problem is they emit a cone of radiation and unless you are the only boat in area its hard to prove it was you. In both instances, the Law of Cosine works in your favor. The accuracy of the unit diminishes exponentially as the angle increases. In other words the units are most accurate when you are directly approaching or departing the radar/lidar unit. As the angle increaes, the speed it records you at decreases. Thats why on the roadways they give you a minimum 5 MPH leeway and thats with an approximate 5 degree angle..... Increase that angle to 10 or 15 degrees off your heading and the accuracy rapidly diminishes! Woodsy __________________ The only way to eliminate ignorant behavior is through education. You can't fix stupid.