Calibrating Altimeter

[+The Hokesters]

I have tried searching the forum but haven't found an answer to my question so I hope it is not an overly repeated one.

 

I have just got my hands on a Garmin Geko 301 and would like to set up the Altimeter however I have no idea how to find out my 'true elevation'?

 

Help!

 

Simesh

[jbclimber]

I don't have a Geko, but I assume that what you have to do is go to a location where the elavation is known, either by a looking at a map or having it posted someplace. For example, you are at a trailhead, and the map shows the elavation is 1000 feet, you use that value for your GPS.

[ckhd]

Go to your local municipal airport. They will be able to tell you not only the elevation, but also the current barometer setting.

[+rusty_tlc]

Benchmarks should work well for this, right?

[+dino_hunters]

go to www.topozone.com and enter in your coordinates. then read your elevation off the topo.

[+4agers]

Awesome! My 301 should be here tomorrow... I'm really looking forward to it. I planned on hitting a benchmark.

[+Prime Suspect]

Awesome! My 301 should be here tomorrow... I'm really looking forward to it. I planned on hitting a benchmark.

Unless you need extreme precision, it's really not necessary to calibrate the unit. It will perform automatic zone calibration on its own, which, in my experience, has always been correct to within 10'.

 

And while you can run out to a benchmark or the airport to calibrate your unit, keep in mind that the calibration will only be good for a matter of hours.

[+4agers]

Not that I'm questioning you... anyone would know better than I, but why only good for a few hours. Because of pressure changes?

[+Couparangus]

I've always let my GPSmap76s do the auto-calibrate thing. I was under the understanding that it uses the pressure sensor and GPS Z-axis reading to derive a quasi-differential elevation resulting in the higher accuracy.

Edited April 16, 2004 by Couparangus

[+Wrong Way Ron]

You can go to the County office in your area and tell them you want to look at the plot. Give them your address and they will

tell you the elevation of your drive way. I know this because I've done it. The elevation is 86 feet parked in my drive way.

[+The Hokesters]

Thanks to all for your replies. I tried www.topozone.com first but you have to pay $50 for a membership to get your elevation details . I am very pleased with my Geko which is probably the first usable GPS which is small enough to mount on handlebars. Well done Garmin!

 

Simesh

Edited April 16, 2004 by simesh

[edmcnierney]

No, you don't have to pay anything to follow the instructions you were given

 

You can look at the topo map and read the contour lines and interpolate your elevation. If you spend $49.95 for a TopoZone Pro subscription you get a bunch of new features, one of which is the display of the best available National Elevation Dataset (NED) elevation data in feet and meters at any spot you click. It's very likely to NOT be the same number as you read from the map.

 

For a recreational altimeter, just reading the contour lines from the topo is more than accurate enough.