by Vas Mylko

Recently we have engineered features for a new ML module for Curiosio, and one of the features was elevation. The elevation of a geographic location is its height above or below a mathematical model of the Earth’s sea level. The task sounded as easy as writing a “Hello World” in unknown programming language.

Hello World

I prepared a list of ~70 manually sampled locations, and started to pull their elevations from the OSM, Wikidata, and Wikipedia. Almost instantly I noticed diversity how/where the elevation data was present. It resembled me the diversity of the naming the basic things in different spoken languages (e.g. dog, rain, food) because they evolved independently. Elevation was present under different names and forms in them all, but in most cases it was absent at all:

OSM has Key:ele

Wikidata has elevation above sea level (P2044)

Wikipedia has {{Infobox… elevation_m=… }} for meters and {{Infobox… elevation_ft=… }} for feet

Wikipedia has elevation in free form text on the page

I decided to link more data sets, so looked in the GeoNames. Elevation was supposed to be there, it was there, but not for all locations from the sampled list:

GeoNames has geoname table with elevation column

Here I felt that this mission was not even close to the “Hello World” by complexity and notified Roman about potential surprises with the elevation data point… He found the data. What to do in such situations? Raise abstraction level. How high? Until it starts working for our problem. So we have raised the bar by ~240 kilometers (150 miles) above the Earth to Space.

Space Tech

The Shuttle Radar Topography Mission (SRTM) was an international project spearheaded by the National Imagery and Mapping Agency and NASA, with participation of the German Aerospace Center DLR. Its objective was to obtain the most complete high-resolution digital topographic database of the Earth. SRTM consisted of a specially modified radar system that flew onboard Endeavour during its 11-day mission in February 2000. This radar system gathered around 8 terabytes of data to produce high-quality 3D images of the Earth’s surface.