Unit that records tracks with elevation

I'm pretty much convinced that my nuvi 350 will not do this. So, I'll
get a second unit that is focused on this task:
- record tracks automagically
- high granularity, ie, 10-20 feet?
- elevations of 10-20 feet resolution

Other considerations:
- cheap, since it's second unit, single purpose
- long battery life
- topo map capable
- PC comm capable
- will work on trails

Any suggestions?

tia... Bob

Bob Bailey wrote:


I'm currently using a Garmin 76Cx, 76S, and a Vista HCx to record trails. Before
you get a model with an "H", meaning it has the MediaTek chipset, you might look
at the following:

http://www.gpsmap.net/CompareHikesHCx76C76S.html

A 60Cx, 76Cx, or with an "S" has the SiRF III chipset. This chipset picks up
very weak signals so can do very well in forests/tree cover. If you are in a
canyon with a poor satellite constellation, it can pick up reflected signals
that will throw the position off - I've had the 76S record the trail more
accurately than the 76Cx under that type of condition.

If the view of satellites is limited by terrain, the GPS elevation can get way
off. My averaging software dumps records where the elevation range is greater
than 200 ft. I've seen it get into the 400 ft. range. To smooth out the GPS
elevation, you might consider a model with a barometric altimeter (an "S" model
or a Vista).

Firmware version 2.7 of the Vista Cx has a position bug. If Garmin doesn't fix
it you would be stuck with 2.6 unless you don't mind having tracks shifted by 20
to 50 ft. from where it should be.

Some models to consider: 60Cx or 76Cx and with an "S" if you want cleaner
elevations.
An older version such as the GPSmap 76 or GPSmap 76S if you don't mind the more
limited memory and if the tree cover isn't too thick. An external antenna helps
a little. {Short battery life - new units for long battery life}.

Possible disadvantage of the "S" models: I run them with auto calibration to
compensate for weather changes. I think the algorithm can delay getting to the
correct elevation when you change elevation rapidly. In other words, I calibrate
the elevation to the current/correct elevation, drive to the trailhead, check
the elevation and the sensor models are too low by perhaps 100 ft. and also
lower than the current GPS elevation. I've seen it when I've gone up or down a
steep hill but doesn't always happen. If you don't have steep hills, you will
probably be okay.

Seems to me you have already bought MapSource Topo 2008 so that would be another
reason to look at Garmin handheld models. Look under the outdoor section on
Garmin's web page.

--
Dan
(email change 2001 to 2004)
(www.gpsmap.net)

Dan Anderson wrote:

Dan, Thanks so much for reposting.

Dan Anderson wrote:

I'm a bit confused: Do I have to have a unit with an altimeter to record
tracks with elevation data? The unit does "know" what its current
elevation is but will it record that in the track.

tia... Bob