Newbie question: 2d vs 3d

[Guest Mr_Macaw]

My 315 has two settings for 'elevation': 2D and 3D. It says in the manual that in 3D mode it calculates elevation itself, whereas in 2D mode you simply enter an elevation to use for everything. It also states that it requires fewer satellites to get a lock in 2D mode than in 3D mode.

 

Now, I'm not worried about getting an elevation from the GPS, so I thought that I should set it to 2D mode so I could more easily get a lock. However, I am concerned that in 2D mode the unit might use the elevation I enter as part of its position calculation, and therefore give me less accurate reading.

 

Is this the case, and are there any other factors I should consider?

 

Thanks.

[Guest Rubberhead]

Garmin has a great guide called GPS for beginners located on their website. It's in Adobe format. Here's the address: http://www.garmin.com/aboutGPS/manual.html

 

This guide explains 2D vs. 3D navigation. However, it usually only takes 4 satelites to get a 3D lock. Any less than that, the accuracy will suffer anyway.

 

To be most accurate, try to get as many satelites as possible.

 

All GPS satelites are continually moving (except for the new WAAS satelites) so, four satelites that are close together in the sky won't give you as accurate a position as four satelites that are spread out.

 

Good luck.

[Guest c_oflynn]

Hi,

 

2D mode only needs 3 satillites, 3D needs 4 or more. I would just go with 3D mode, the mag315 will easily pick up the 4 satillites needed. Also, the more satillites you get the better.

 

Colin

[Guest c_oflynn]

looks like rubberhead got in a reply while I was still typing