topic Re: Make Spot Heights High and Low in Geoprocessing Questions

Make Spot Heights High and Low

forestknutsen1 — Tue, 20 Feb 2018 00:10:30 GMT

What is the best way to generate spot heights? I see that this:

Defense Mapping toolbox licensing—Help | ArcGIS Desktop

will do it. But I don't have a license. Is the only other option to generate points and extract raster values?

Re: Make Spot Heights High and Low

DanPatterson_Retired — Tue, 20 Feb 2018 00:38:00 GMT

You need the spatial analyst. SA does lack some basic tools, so you will need to determine what you want to classifiy as a 'peak'

The single highest value?
A range of high values? as an area?
As a neighborhood difference in elevation (ie difference in elevation within 1km^2 with a difference in elevation of 500m

The first option requires that you know what the highest value is http://pro.arcgis.com/en/pro-app/tool-reference/data-management/get-raster-properties.htm then you simply query the dem for it. Pretty useless since it will miss out 'peaks' that are 1 meter shorter

The second option is a bit more forgiving, except plateaus at elevation (mesas) would be considered peaks

The third option entails using an appropriate neighborhood with focal statistics or block statistics with 'range' option

http://pro.arcgis.com/en/pro-app/tool-reference/spatial-analyst/focal-statistics.htm

The options are not limited to the above, but they are starting points and can be used in combination. Of course all are way slower than taking your mouse and clicking points on a map ie humanware

Re: Make Spot Heights High and Low

forestknutsen1 — Tue, 20 Feb 2018 01:26:01 GMT

I do have SA. So I am good there.

The single highest value? - I would many values. With enough density to give people a feel for the elevation across scale levels. Maybe 1:10,000 to 1:100,000.

A range of high values? as an area? - I would like to find high and low values over a kinda large area, ~18,000 km^2.

The second option is a bit more forgiving, except plateaus at elevation (mesas) would be considered peaks - so this is the neighborhood difference? That sounds ok. I don't care if it picks up ridges and plateaus. I will give it a go.

I was surprised that this was not is SA or 3DA out of the box!

Thanks for the help Dan.