How to produce elevation profiles on screen?

[giaruso]

I use my Garmin GPS eTrex Vista HCx on a bicycle I ride in Southern California.  I want to be able to build routes within maps on my computer and view the elevation profiles before I attempt the rides/routes.  After creating a route (using "California TOPO," "PC Basemap," "Ibycus USA 2.01, and "SouthWest USA TOPO, all downloaded from the GPSFileDepot) in Garmin MapSource/BaseCamp (latest versions A/O 11-02-2010), I cannot get the maps to show an elevation profile.  The "Show Profile" button is always grayed out in "Route Properties" of MapSource or I get an error message in BaseCamp.  As I research this question myself, I understand the maps must be Digital Elevation Model (DEM) GPS Maps.  Are those maps downloaded from GPSFileDepot, mentioned above, not DEM?  So far, I have only found that the Garmin's MapSource TOPO! US 24k West has the DEM capability.  Is this correct?  Can anyone here help me find the MAP(s) that I can use to develop elevation profiles?  Should I get the aforementioned Garmin Map?  Thank you very much.

Denny G.   

[Boyd]

I believe you can configure your unit to use the internal altimeter instead of map data - see page 32 in the manual: http://static.garmincdn.com/pumac/eTrexLegendHCx_OwnersManual.pdf

This isn't a function I have used much myself, and I also find it a bit confusing. Garmin's 24k topo maps have high resolution DEM data. Garmin's US Topo 100k also has DEM data, but lower resolution. So you have to choose whether you want the whole US at lower resolution with 100k or just a couple high resolution states at 24k - each option costs about $100.

Unfortunately, there are no tools available for us mapmakers to put DEM into our maps; I wish we could. Third party maps here are almost all created with a shareware compiler that was reverse engineered from Garmin maps. Garmin has never published their format and considers it proprietary.

To use DEM in a map you need to be accepted as one of their partners and use their own software. This is very tightly controlled, and they will not grant a license to anybody who creates maps for areas they also serve. So that puts all of us in the US out; I applied and got a polite rejection. Heh, if you are accepted then you are granted the privilege of paying $5,000 for a software license.

[giaruso]

Thanks, Boyd.  Well I guess that answers my question.  I'll just go ahead and purchase Garmin's MapSource TOPO! US 24k West and be done with it.  Thanks again for your feedback.

Denny G.