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Stellarium / stellarium

Stellarium is a free GPL software which renders realistic skies in real time with OpenGL. It is available for Linux/Unix, Windows and macOS. With Stellarium, you really see what you can see with your eyes, binoculars or a small telescope.
https://stellarium.org
GNU General Public License v2.0
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to use elevation data of osm #1393

Open qdinar opened 3 years ago

qdinar commented 3 years ago

Is your feature request related to a problem? Please describe. stellarium does not show sun set and rise time correctly taking elevation in account

Describe the solution you'd like there are 10m precise earth surface elevation map in openstreetmap bicycle map, probably it is allowed to use. it can be used to show sun and other object set and rise times.

Describe alternatives you've considered none

Additional context somebody may be interested in this type of calculation of sets and rises. for example, in islam, prayer time is with the visible sets and rises of sun, as i know.

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gzotti commented 3 years ago

Does OSM also provide a horizon polygon on the fly? Else that location elevation (which could also be retrieved from SRTM 1") alone will not be enough.

github-actions[bot] commented 3 years ago

Thank you @qdinar for suggesting this feature.

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qdinar commented 3 years ago

Does OSM also provide a horizon polygon on the fly? Else that location elevation (which could also be retrieved from SRTM 1") alone will not be enough.

i do not know. probably not. why do say it is not enough? maybe because there is not a ready published algorithm to calculate that horizon line? i tried to search "calculate horizon line from surface elevation" and i see there some appropriate results on first page of the google results, but they are texts with formulas, not schematic or programming language.

gzotti commented 3 years ago

Think again. To compute your horizon you need your own elevation and that of the point forming the horizon. You don't know in advance which point that will be, so you have to sample the terrain map multiple times into every direction (azimuth) to find out.

qdinar commented 3 years ago

and how long that job is, do you think? or how much flops or watts*hours or other units?

gzotti commented 3 years ago

See the User Guide, chapter 7, for some approaches to artificial horizons from geodata.