GPSrChive Discussion Forum

1. Does anyone know how the destination altitude is calculated ? (I am using an Open Street Map contour lines file)
2. Probably a related issue - the Vert Dist to Destination field just showed dashes.

With a route active, the GPSr's Altimeter screen shows a profile to the destination, but I didn't find it too reliable in my usage recently. (Based in what it showed, I would tell my walking companions "should be fairly flat from now on" - then we'd hit a big steep hill !).

Also, if I scrolled to the end of the altitude profile (ie the destination), the height would vary 10s of metres during the walk (which if it is getting the altitude from a contour lines file - it shouldn't change).

steerage250 wrote: Tue Jun 11, 2024 7:10 am 1. Does anyone know how the destination altitude is calculated ? (I am using an Open Street Map contour lines file)
2. Probably a related issue - the Vert Dist to Destination field just showed dashes.

The Wert dist to dest field displays the value when navigation based on track,
route or designated point on the map is turned on.
When navigating to a Waypoint, the value in the Wert Dist to Dest field may
not be displayed if the waypoint does not have an altitude entered.

Please see GPSrChive > How To... > Altimeter and reference the Altitude vs Elevation link near the end of that page.

The description for the 'Vertical Dist. to Dest.' Data Field can be found at GPSrChive > How To... > Data Fields, and reads:

The elevation distance between your current position and the final destination. You must be navigating for this data to appear.

For locations (Waypoints, POI, etc) that do not include Elevation Data, the GPSr will use information from DEM (Digital Elevation Model) maps loaded to the device.

When no DEM Data is available, Elevation values will read "---".

The OSM Contour Line Map is a visual representation of elevation change and most likely does not include any DEM data.

Visit GPSrChive > How To... > Maps and open the Garmin Map ID link to see a list of known map types and names.

Search this page for 'DEM'.

GPSrChive wrote: Tue Jun 11, 2024 4:23 pm The OSM Contour Line Map is a visual representation of elevation change and most likely does not include any DEM data.

In my opinion, there is no need for an additional map unless the base map has been removed.

The base map does not include the elevation data found in the DEM maps.

If you want this information available on your device, you will need a DEM map.

GPSrChive wrote: Tue Jun 11, 2024 4:58 pm The base map does not include the elevation data found in the DEM maps.

In the device I currently have one map without DEM data and a base map,
the altitude is displayed in the Wert Dist to Des field.
When you click on the map, the height is provided in the information about the indicated point

The devices include a Worldvide DEM Basmap basemap, which contains altitude data.

Additionally, the Garmin DEM Map is installed with the TopoActive Map.

Przekątny wrote: Tue Jun 11, 2024 5:31 pm The devices include a Worldvide DEM Basmap basemap, which contains altitude data.

The World Wide basemap does not include any altitude information. 'DEM' = Digital Elevation Model'. Altitude and Elevation are not the same thing.

The World Wide basemap is only a fraction of the size of the regional DEM maps that cover much smaller areas (46 MB vs 3.53 GB). Dedicated DEM maps are far more detailed and accurate than the WW Basemap.

And then there are the HDEM maps (>8 GB), which require several gigabytes just to cover a small portion of a DEM map region....

GPSrChive wrote: Tue Jun 11, 2024 8:20 pm Dedicated DEM maps are far more detailed and accurate than the WW Basemap.

I agree with this statement, but lower accuracy (resolution)
Worldwide Autoroute DEM Basemap,NR maps does not exclude
data from being displayed in the Vert Dist to Dest field.

The Worldwide Autoroute DEM Basemap,NR contains altitude data.

Przekątny wrote: Tue Jun 11, 2024 8:33 pm The Worldwide Autoroute DEM Basemap,NR contains altitude data.

I don't think that word means what you think it means.