Elevation profiles have been a bit of a weak area on CalTopo. You could draw a profile and get point elevation data along the path, but that was it. The profile function has now been updated with a couple key features:
- More sample points used
- Distance measurements provided for the x-axis
- Gross elevation gain and loss calculated
- Horizontal sampling interval and vertical exaggeration shown
- Climbs and descents marked with distance and elevation change
Here's an example profile:
And here's what it used to look like:
Using the data rendered for custom DEM shading, I was hoping to update the elevation profile with slope and aspect data as well. I've seen some cool circular plots of elevation v. aspect and slope angle v. aspect, and thought those would be a nice addition. However after playing with an elevation v. aspect graph, I've concluded that they're only useful for a narrow subset of routes. On ridgelines, summits and valleys the aspect can bounce around dramatically over very short distances. This leads to a graph that exaggerates aspect swings at best, or turns into a useless and confusing mess at worst.
Instead, I've incorporated that data into a "point info" feature that will give you elevation, slope and aspect readings for any spot in the continental US. I don't know how useful this will be, but it's more of a temporary bridge until I find a better way to provide this data in graph form. Note that because the point info feature uses CalTopo's elevation data and the profile graphs rely on Google's elevation service, there may be small discrepancies between the two.
|Selecting the Point Info tool.|
Not the most exciting dialog you've ever seen: