DougPaul
Well-known member
Some GPSes have magnetic sensors which drive the compass display when it is stationary*. (This is part of Garmin's "sensors" feature. Don't know what other brands might call it.) When you are moving info from the GPS drives the compass display (whether or not you have a magnetic sensor). GPSes without magnetic sensors cannot determine compass directions when stationary.I discovered that the compass feature on my GPS is useless unless I'm moving at a good clip (and thus not watching where I'm going)
* You must calibrate the magnetic sensor every time you change (or disturb) the batteries or the magnetic sensor directions will be inaccurate.
Note that you can set the GPS to give either true or magnetic directions. (It does not matter which you use as long as you use the same one on your map, compass, and GPS.)
???and also that the screen on my GPS that I thought was giving me bearings to waypoints I set actually changes back to the compass bearing if I select the waypoint (I thought the screen had actually selected the point and was guiding me toward it when in fact it was just escaping to the compass screen). I knew from my actual compass and map that the GPS was not telling me what I thought it was telling me so that was a good learning experience. Trips after that were much better.
A GPS can be set to give either the bearing or the course to the next waypoint. (A bearing is the direction to a waypoint, a course is the straight-line direction between the last and next waypoints.) When following a route (sequence of waypoints), it will automatically switch to the next waypoint as one passes the last.
A GPS is a wonderful device, but it requires that the user know how to use it properly. (Actually much of it is pretty obvious if you know point-to-point navigation.)
Doug