Global Digital Elevation Model Profile - API?

Hi all,

I am in the process of trying to use a latitude and longitude value (of an image) to estimate it’s height via a global digital elevation model.

The use-case; I want to create elevation profiles of my Mapillary sequences (I don’t want to use the sensor reported elevation – it is corrupt).

I can’t afford Google Maps money (1,000 lookups = $5 USD). I have close to 1 million images. I don’t have $5k.

Does anyone know of any free services (or ones with a generous free tier) that expose their data via an API and could be used for this purpose?

Thanks!

Open Elevation sounds perfect for what you need. The public API can be unstable at times, but you get what you pay for as they say.

https://open-elevation.com/

I notice you also use Mapbox on Map the Paths, so their Tilequery API could be one to consider too (and benefits from a free-tier):

@nickw was playing around with something like that along those lines…

PS: among my other “wild ideas” a global covering database of all highest possible resolution data was one of those… goal: become the best resource worldwide. Got to some basic structures to store that absurd amount of data… (didn’t get much further)… would take way too much time to create a whole new way to save that amount data (and maintain it!) and was a bit too academic and theoretical… working on my GeoArchive project now :stuck_out_tongue:

PS2: the data recorded by GPS isn’t that good?

Hi @dgreenwood-trekview yes! The former Mapzen (now defunct) have provided global elevation tiles in the Terrarium PNG format on Amazon S3, which I believe is completely free/unrestricted to use (I had a message to this effect on the OSM mailing list).

See
https://registry.opendata.aws/terrain-tiles/

The elevation is encoded within the RGB channels of the PNG image; there was some documentation describing this but I’m not sure if it still exists.

Nonetheless I have a JavaScript implementation at:

which you can figure it out from.

I use this in my Hikar project and I’ve also been playing around with it for OTV.

Nick

In https://www.trekview.org/blog/2020/what-is-a-digital-elevation-model/
you link: https://www.gpsvisualizer.com/elevation

That’s a nice one. But several countries have more extensive data. For instance The Netherlands has AHN3 data (0.5 meter accuracy): https://esrinl-content.maps.arcgis.com/apps/Embed/index.html?appid=a3dfa5a818174aa787392e461c80f781#!

Etc. etc… when you would make a sport of it, you could increase the resolution by much…

I had the idea to create a new way of storing elevation data. not to use TIF (pixel) but switch to SVG (vector) I did some research and I think it’s possible, even the conversion part… but that would become a hell of a job… that way you could create something much more accurate then ever done before at a lower storage cost…

Hey @Eesger – you can always chase higher resolution. I think for the purpose of hobby mapping, resolution does not need to be very high – and why I would advise against using paid sources like Google.

That said, I think the solution on a quest to higher resolution is more simple than compiling the data yourself (to quote you; a hell of a job). Simply creating a central point with global DEM sources in a GSheet alongside their resolutions would be a massive help in pointing people to the ‘best’ available current DEM data source for an area.

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