Suggestion: Automatically inserting track points on contour lines

Former Member over 12 years ago

Let me illustrate an extreme case: If I create a track with two points (origin and destination), with say 9km of flat terrain and a cliff at the end, the elevation plot will be technically correct but deceiving in nature as it will show a gentle downslope. Also the resulting gpx won't be of much use when exported to tools to analyze the elevation gradient. I'd like to have the option to automatically insert points on the track at each contour line or if it's simpler every N meters of altitude change on the map.

Online you have something along those lines which works up to 300 points:

http://www.geocontext.org/publ/2010/04/profiler/en/

0 BTLAAKE over 12 years ago

You’re probably already aware of this, but if you hold down the left mouse button and drag the mouse it will lay down multiple points. The point interval will decrease as you increase the map zoom. Of course, you can switch between dragging and clicking.

All elevation data in a Garmin map comes from the DEM and not from the contour lines. Depending on the density of DEM data, it is possible to see features that exist between the contour lines and also miss the some features where there is a rapid change in elevation that the contour lines will capture. A possible limitation with Garmin mapping products is that they are designed to be used on GPS receivers which have tight memory constraints. In other words Garmin may not use best unmodified DEM available for a particular product.

I’ve noticed on my product that the DEM data does not always agree well with the contour lines, whereas in a mapping product designed for computer use the agreement is pretty good.

Your idea is still an interesting one.

0 Former Member over 12 years ago

... if you hold down the left mouse button and drag the mouse it will lay down multiple points. The point interval will decrease as you increase the map zoom. ....

Darn, didn't know that.. THANKS!!!

0 atlas_cached over 12 years ago

I didn't know this either... learn something new every day!

Garmin products have so many undocumented features and functions it drives me crazy!