Does my GPS tell direction (NWSE)?

nobb · 07-06-2007, 07:02 PM

Ive never used a GPS before and I just got the gps-500 unit (comes with Microsoft Streets and Trips). I have noticed that by rotating the unit, the arrow in iGuidance will rotate. However, it seems a bit sketchy. I am not sure how to describe. Sometimes when I point the front of the unit north, the arrow in iGuidance points north. Other times, when I keep the unit pointed north, the arrow in iGuidance points at another direction.

So what is happening here? Does the GPS unit actually tell iGuidance which way is north based on which direction the unit is pointed? Or is this just some fluke. I just want to know because I want to plan how this unit will be mounted and whether it matters which direction the unit is pointed in. I am going to mod a stuffed toy duck to house my GPS unit =)

grave · 07-06-2007, 07:11 PM

No matter with that !

direction of the arrow is given by your moves. If you don't move No fixed direction except last one.

DarquePervert · 07-06-2007, 07:46 PM

The GPS receiver simply gets signals from multiple satellites. The software interpolates your position based on the distance from at least three satellites. It's called triangulation.

The reason you see your avatar moving in your nav softare is that it's plotting the position from a satellite data string that's received right at that moment.

GPS doesn't determine direction by itself, although a vecotr can be figured out from multiple triangulations.