I'm a complete novice at GIS. My project is to find the highest peaks in each Antarctic territory, and compare the results with the international gazetteer to find which peaks are and aren't named.

I'm trying QGIS Desktop with Grass with the 200m resolution radar altitude DEM raster file. Locations are (x,y) from the south pole in metres.


The Gazetteer is https://data.aad.gov.au/aadc/gaz/scar/download.cfm and is available as CSV, GeoJSON (whatever that is) and KML formats. Locations are in latitude and longitude to the nearest minute of arc, which is not accurate enough.

Territories are given by longitude range in Wikipedia

I've succeeded in opening the DEM with QGIS. I could find peaks manually one at a time using colours and the "identify features" button.

But is there a better way?

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    First you need to define your question more completely. How would you define a peak? Is the top of a gentle rise a peak? What about a mountain with two sharp points and a narrow 100m valley in between - is that two peaks or one? – Simbamangu Jan 1 '17 at 14:53
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    Wikipedia has some notes about "topographic prominence" en.wikipedia.org/wiki/List_of_highest_mountains_on_Earth – Spacedman Jan 2 '17 at 22:16
  • I'm distinguishing between "mountains" and "peaks". One mountain may have many peaks. For the definition of "mountain", I stick to the usage in the international gazetteer, no problems there. For peaks, I don't want to miss any so use a topographic prominence of 20 metres, which means that many of the objects I find as a "peak" will actually be labeled as "ridge, bastion, nunatak, heights, bluff, etc." in the gazetteer as well as "peak" and "mountain". – mollwollfumble Jan 2 '17 at 22:55
  • On a different aspect of the same topic - how does QGIF "save as image" work? Is there an image format that doesn't lose any raster data - retains the full height range of 0 to 5022 metres and has one pixel for each of the 28680*24580 datapoints - and has a utility that can change it to csv? I have software that can manipulate csv to find peaks if the csv is (i,j) ordered. – mollwollfumble Jan 2 '17 at 23:08
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    200m seems rather large for this task, that could contain allot of height variance. – AnserGIS Jan 3 '17 at 8:17