A new kind of list

[John Kirk]

I've been looking for a good alternative measure to "Spire Measure" where peaks that would seem to have spire-like characteristics end up on the list. For example, with the currently accepted "Spire Measure" involving average slope and relief, Lizard Head misses the list, where El Diente makes it.

Prominence divided by distance to saddle yields some more intuitive results, ranking Curecanti Needle, The Sharkstooth, Peak Fifteen, and Independence Monument in the top ten. Lizard Head makes the top 56. Elbert is last on the list of all 4356 ranked CO peaks.

This is far from a great dataset, however, since the measure doesn't consider how steep it is between the summit and saddle other than from an average perspective. So for example a peak with ten miles of only 100' of rise from saddle to its lower flanks before it rises 1000' up a sheer face would not be recognized as such. This is why Lizard Head isn't in the top 10, as its saddle is a comparatively long way from the base of the summit tower.

To be continued...

[RyanSchilling]

That's a creative application of the dataset, John!

Does anyone have a picture of Curecanti Needle? I've not driven up SH-92, but it looks like it'd impressive from Pioneer Lookout Point.

[John Kirk]

...The next progression to arrive at the "intuitive spire measure" is to collect elevations in ascending distance intervals from summit lat/lon using dem data. So, at 1/3 of a second intervals in eight cardinal directions from the summit, what are the elevations? The delta between the summit elevation and max elevation of the eight will yield a spire rise. Then the maximum factor (rise/distance from summits) from the intervals will be used. This should build a better candidate pool, from which more precise measurements can be made as to the max height and radius factor of spire-like summits, using the base of a spire as the starting point rather than the peak's prominence saddle.



Now the challenge is finding/building a database with elevation for each possible lat/lon in 1/3 seconds. Then the process is automated with rounding and lookups in excel.

[DSunwall]

now your getting somewhere John.

[TWorth]

I've considered a measure similar to this "intuitive spire measure", where only a radius of 1/2 mile and/or 1 mile around the summit is considered. Take elevation readings at ascending distances from the summit, say (for the 1 mile radius plan) 25m,50m,100m,200m,400m,800m,1200m,1600m. By looking at distances in a discrete manner such as this, the drop values closer to the summit can be given greater weight in the formula. This seems to differ from the current Spire Measure, which looks at drop in a continuous manner by using integration.

Might as well look at all 360 degrees/2 pi radians rather than the 8 cardinal directions. Many more calculations would be performed, but the formula used would be the same.

First thing needed would be set of "radius coordinates" for each peak at given distance intervals. Second requirement would be an "elevation lookup" for each coordinate pair. Might have to use 1/9 second resolution, which I believe is available from the new NED digital dataset. It would be nice if lookup software already exists for this dataset, rather than having to build a retrieval program from scratch.

I never did any work on this idea, since the SRTM data was in my experience not very reliable. However, reports are that this new NED dataset is much more accurate, so perhaps this idea is worth revisiting. Sounds like a winter project....