3D map of the Czech Republic, made from 12.5cm/px imagery (2017)

Post by denhaus » Mon, Nov 07, 2022, 10:22 AM UTC

vetinari wrote: post #36

lucgommans wrote: post #12

Earlier quoted context omitted.

Indeed, something like 25cm or better is typically shot from airplanes. I don't remember what the physical limit is for image quality given a reasonably sized spy satellite (iirc it's around the 20cm mark), but commercially at least, the high quality imagery is all airplanes. Governments often commission such planes to fly ~yearly at something like 10 cm, as well as commissioning height maps[1], but the very good stu…

> but the very good stuff is not released to the public for privacy reasons. You can buy the data, the agencies responsible for these data make some decent coin. Yes, they are expensive to obtain, but that is paid by taxpayers anyways, so it is kind of double dipping. The entire area of Czech republic is available at 0,2-0,125 m per pixel for around ~100k EUR. Not unattainable for those who need it, but not hobbyist…

Post by yfbvbv » Mon, Nov 07, 2022, 11:04 AM UTC

andrewshadura wrote: post #88

Daniel_sk wrote: post #41

Earlier quoted context omitted.

Perfect for offline hiking maps in Slovakia. Google Maps are basically unusable outside of car roads.

Not for offline (unless you pre-cache), but https://Freemap.sk (which is also OSM-based) is even better for online use.

Post by carl_dr » Mon, Nov 07, 2022, 11:24 AM UTC

denhaus wrote: post #112

vetinari wrote: post #36

Earlier quoted context omitted.

> but the very good stuff is not released to the public for privacy reasons. You can buy the data, the agencies responsible for these data make some decent coin. Yes, they are expensive to obtain, but that is paid by taxpayers anyways, so it is kind of double dipping. The entire area of Czech republic is available at 0,2-0,125 m per pixel for around ~100k EUR. Not unattainable for those who need it, but not hobbyist…

As someone who doesn’t know anything about this particular data, how would I go about obtaining that Slovak republic data for free?

Post by iggldiggl » Mon, Nov 07, 2022, 2:26 PM UTC

isoprophlex wrote: post #109

lucgommans wrote: post #63

Earlier quoted context omitted.

Recently at an OSM meetup with the local government in Aachen (Germany), they mentioned that some imagery they shot was deemed too invasive and only used internally. I thought that was 10cm, but now checking what is available, looks like I was wrong! Probably it was 5-7cm then? Or maybe this was rather about the imagery available from different angles, so you can see into gardens from different directions? In iD I se…

That is indeed awful, you're right. I remember that satellietdataportaal.nl or something like that allowed access to uncompressed files, maybe they're better. I'll see if I can find my old credentials and compare. But yeah, compared to those 10 cm images, that can't be effective 7.5 cm/px. Related: Apple Maps uses some data source that is ridiculously high res for my street. They've updated the image now sadly, but f…

Post by sorenjan » Mon, Nov 07, 2022, 4:08 PM UTC

photochemsyn wrote: post #15

Why don't map sites ever publish 3D as topo lines overlaid on a flat 2D map? It's computationally much cheaper, and it's not too hard to learn to read a topo map, as long as the elevations are printed in a reasonably dense manner.