Mapping GPS & their altimeters

I have a Garmin Colorado GPS and it says that it has a "barometric altimeter". Barometric altimeters are OK if you can reset them every day at the exact altitude you're at but that's a hassle.

Why the heck can't we have altimeter readings from the GPS sattelite constellation??? Today while backpacking in the Spring Mountains north of 'Vegas my Colorado altimeter said 9,860 ft. and my buddy's altimeter said 9,780 ft. and we both wondered why Garmin uses a barometer for an altimeter.

Eric

The Colorado can determine elevation by satellite or barometer. If you don't know your exact elevation you can set the barometer altimeter by your satellite elevation. See this for more info.

Yep, it's a hassle to constantly recalibrate barometric altimeters from known elevations but they're a good gadget to have in many situations.

Thanks Trailrunner. That link is interesting.
Do you know if there are any sites that have trail maps that can be downloaded onto my Colorado?

I have the 300 model(so I could have the map CD to print out topo maps of areas I want). I think it's a bit more versatile than the pre-loaded Colorado 400t.
With a 4 Gb Ultra SD card that I bought you can load a LOT of maps and then load more on another card, if necessary. I have all the western U. S. to the Mississippi on that one card.

I've noticed a friend's Oregon doesn't seem to have the ability to get satellites in canyons as well as my Colorado. Seems my older tech "Quad Helix" antenna is better than his ceramic antenna.

Eric

I get my maps here but it sounds like you already have those and more.

I use a Vista HcX and I'm very happy with it. It acquires and locks very well even indoors and under clouds/trees. Battery life is excellent. Initially it did not record movement at < 2MPH but a software upgrade fixed that. Now it's the cat's meow and a quantum leap from my old Magellan 315.