Magellan - What is a detection angle

The Detection Angle you should see it like the headlight beams of your car (GPS). If the beam is covering 90 or 30 degrees you "see" more or less (45 to your left and 45 to your right 45+45 = 90).

Tx Zougar. That's a simple explanation that I couldn't find anywhere.

I just saw this old trend searching for something else. I couldn't resist to post that detection angle for personal POI, at least on the Magellan 1412, is a bit dumb!

I live in front of a lake, and half a mile away from my front door, on the other margin of the lake, is a major road with stationary speed cameras on both directions. Sometimes we sit at night watching the flashes go off on some car who didn't notice the cameras until it was too late.

Anyway, my point is that every time I turn into my street, the Magellan sees the speed camera on the other side of the lake dead ahead (within the detection angle), and alarms for me. I also tried going behind a small hill close to another speed camera, and the same thing happens. So, the programming on these GPS' seems to not care for any geographical blockage or even lack of streets between your current position and the POI you're tracking. As long as it's ahead of your bearing (within the detection angle set), and within the distance set, the alarm goes off.

This the way it works for me with my NAVIGON,while using POI-Warner, I can't guarantee it will work with your Magellan GPSr.

The detection angle defines the angle in which the GPSr will give a warning for upcoming Points-of-Interest. If you choose an angle of 45°, the GPSr will warn you if it recognizes a POI-Object which is not more than 22,5° to the left and 22,5° to the right from your position towards your driving direction. Setting this value too high will probably result in false alarms, if a POI is found in a parallel street.

Yes, this is exactly the same way it works for me.

However, as I wrote, even if you have a lake, mountain, forest or canyon between your current position and the POI, the GPS will still alarm that the POI is coming "ahead"!

Absolutely correct.
That is why we need to adjust the detection angle & the warning distance trying to eliminate as many as possible false warnings. I have my detection angle set at 30 degrees and haven't yet missed a single camera ahead of me. I still from time to time get false warnings, but on the way how the system works right now that is unavoidable.

Here's a great explanation along with pictures.
http://camsahoy.com/support.html

This is a key point, if you leave it at the default of 90 degrees, you will get lots of false reports on raods running alongside a freeway, which is extremly annoying on a long trip that goes through major cities.