Do GPS units display actual headings?

[wannabe]

I have never owned a GPS unit, but am looking to get a Garmin Etrex based on user feedback on this forum as well as user reviews.

 

I was looking at the Etrex user manual available online and something is not clear that someone here might be able to clear up:

 

When you select GOTO and pick a waypoint, the manual says the Etrex will show you how far to the waypoint as well as display the "pointer" on the screen which after a few steps will line up with the desired waypoint.

 

Does the unit also give you an actual heading (mag or true) on the screen so I can dial that into my magnetic compass, put away the GPS unit, and then navigate to the next point by mag compass alone (my preference)?

 

The Etrex user manual seems to indicate that the only heading info comes from the "pointer".

 

Thanks for the feedback.

[trad_guy]

Hello wannabe-

The $100 eTrex is a great choice.

 

The "GoTo" window has the name of the Waypoint and the distance there to.

 

Below the pointer circle there is a window that can be changed with the cursor buttons to show many different screens: Bearing, Course, speed, distance covered, etc.

 

Google -best GPS for mountaineering- (without the dashes) to learn more.

 

You can select Set Up, North Refernce, True North, Enter to make your GPS match your map.

 

Use the UTM Coordinant Grid and NAD27 to match your Quad maps.

--trad_guy

 

 

[gslater]

 

Note the terminology that trad_guy used in his response. He said that the GoTo function gives you the BEARING to the other waypoint, which is what you want for navigating via compass as you described. This is the correct terminology. I'm sure that's what you meant when you asked about "heading", but heading and bearing are not the same thing.

[OlympicMtnBoy]

I still love my Geko 301 with the built in barometric altimeter, but yeah, I think the screen is just about exactly the same. It'll show you bearing (the direction you want to go to get to your waypoint from where you are), and you can find your heading (the direction your headed) as well.

[wannabe]

Wow, thanks for the replies!

 

I showed my navigation ignorance too. I always got by with "dead reckoning" in the past, but I know my luck with that would run out at some point.

 

Looking to buy that unit this week I hope.

 

On a side note, I found some webpages where people detailed a home-built data cable for the Etrex:

 

http://www.geocities.com/eTrexkb/cable.htm?20076

 

and

 

http://www.aac.uc.pt/~seabra/etrex.html

 

and

 

http://www.pfranc.com/projects/g45contr/emap/diy/

 

and

 

http://www.jens-seiler.de/etrex/datacable.html

 

[catbirdseat]

Note the terminology that trad_guy used in his response. He said that the GoTo function gives you the BEARING to the other waypoint, which is what you want for navigating via compass as you described. This is the correct terminology. I'm sure that's what you meant when you asked about "heading", but heading and bearing are not the same thing.

A Heading is a magnetic bearing towards a destination. A map bearing is a true bearing. GPS units can be programmed to give magnetic bearings or headings.

 

Most GPS units do not have internal compasses. Hence it can't point in the direction you should go with an arrow, unless you are moving. Then it can sense the direction it has been moving in and hence its orientation.

 

Some units have internal compasses. In that case, the unit knows which way it is facing and can tell you not only the bearing, but point an arrow in the direction you should go, even if you have been standing there for some time.

[gslater]

A Heading is a magnetic bearing towards a destination. A map bearing is a true bearing. GPS units can be programmed to give magnetic bearings or headings.

 

Not quite. "Heading" is the direction in which you're "pointing" (for lack of a better term) at a given moment. "Bearing" is the direction from one point (typically your current point) to another point. Both headings and bearings can be either magnetic or true.

 

And then there's "track", which is the direction you're actually "going" over the ground at a given moment. In an airplane, your bearing, heading, and track enroute to a given point rarely are aligned.

Edited March 7, 2007 by gslater