GPS Setup - Map Datum

I've written a short post on my blog about setting your GPS to the correct datum.

Your feedback is always welcome.

Blake

www.outdoorquest.blogspot.com

Nice article!! My son is about to take off for Boy Scout summer camp where he is going to do Geocaching Merit Badge. I'd bought him a Garmin Geko 301 a few years back, but he'd shown no real interest in it. So, I just came inside from sitting down with him and showing him some of the features of the GPS.

The first two things I showed him were (1) how to set the coordinate system displayed (D H M.M, D H M S.S, UTM, ...) AND how to select the map datum. I'm so glad you pointed out that CONUS (or on the tiny Geko CONU) is referring to the Continental US. Its so not obvious to the casual user.

Then I taught him how to create a waypoint at his current location, then how to edit the coordinates of the current location to create a waypoint for a different location.

I think he'll enjoy the merit badge.

Another topic that I myself find kind of confusing is the choice of selecting true north or magnetic north ... and what that means. Also, the difference between "bearing", "course" and "heading" on the GPS.

I wish it were easier to obtain the current magnetic declination from a GPS. I assume some might be easier than others.

BTW, I once heard from someone that the Geko 301 is coveted by many backpackers since it is so tiny and lightweight ... and no longer made.

KenK,

To answer a couple of your questions.

To keep my navigation simple, I use a declination adjustable compass such as the Silva Ranger. That way I can take into account declination and never have to worry about the math. Personally, I keep my GPS set to report in degrees true. That way both my map, GPS and compass are all on the "same page." It works for me that way. To get up to date declination info I go to www.magnetic-declination.com ; it is really simple site to use.

Bearing is your compass direction from where you are to a distant object or a direction you want to go. For example, from where I am setting right now, the South Sister mountain bears 275 degrees true; it is west of my location.

Course and heading are frequently used interchangeably. Your course is your direction of travel through the backcountry. So, if you are walking in a northerly direction (to get to your destination) your course/heading would be 000 degrees true.

There are lots of books out there to reference but one of my favorites is Staying Found by June Fleming. Also, Dick Blusts has some fine posts on land navigation (one is a post on my blog) and I frequent www.landnavigation.org too.

All the best,

Blake

www.outdoorquest.biz
www.outdoorquest.blogspot.com

Wow, great link! I'm going to study that thoroughly. I've been looking for a good online tutorial.