Internet World Sunlight Map

[Bj]

This is cool

http://www.die.net/earth/

How it works

I start with cloudless images of the earth during the day (from a pair of NASA satellites) and night (from a DoD program to map city lights). Every 3 hours, I download a composite cloud image based on data from weather satellites all over the world. And every half hour, these images are composited and mapped onto a sphere by xplanet according to the relative position of the sun. The flat maps are post-processed by ImageMagick to cut off the 15 degrees nearest the north and south poles where cloud data is unavailable.

 

[Notebook]

I don't get it, if the Earth is flat, why is the sunlight narrower at the top? Is the Sun conical?

Nice map though.

N.

 

[garyw]

I don't get it, if the Earth is flat, why is the sunlight narrower at the top? Is the Sun conical?

Seasons. You'll see the same with Orbitron and NASA orbital maps, the width of the "beam" of sunlight is the amount of sunlight in one day, obviously during winter it's a lot less.

Have a look at something like orbitron. set the date for 22dec and see how narrow the cone is at the top then set the date for 22jun and see how wide it is.

 

[cjp]

Seasons. You'll see the same with Orbitron and NASA orbital maps, the width of the "beam" of sunlight is the amount of sunlight in one day, obviously during winter it's a lot less.

Have a look at something like orbitron. set the date for 22dec and see how narrow the cone is at the top then set the date for 22jun and see how wide it is.

I wanted to say that too, but you're faster than I.

When it's winter in the northern hemisphere, it's summer down under, and the map looks like this. When it's summer in the northern hemisphere, it's the other way around, and the light part on the map will be wider at the top and narrower on the bottom side of the map.

So, this map shows both day/night and seasons.

 

[SiberianTiger]

Does it actually show a real-time cloud cover at entire Earth? If yes, it's really useful in real life, and I believe it smells like an idea for an Orbiter addon.

Would also be nice if it also shown snow/ice cover and vegetation intensity, to get a good feeling of what's season is out there. Placing custom markers or drawing could also be nice.

 

[tblaxland]

Seasons. You'll see the same with Orbitron and NASA orbital maps, the width of the "beam" of sunlight is the amount of sunlight in one day, obviously during winter it's a lot less.

garyw/cjp: sense of humour not kicked in this morning yet? I think you missed this bit:

I don't get it, if the Earth is flat...

:rofl:

 

[cjp]

garyw/cjp: sense of humour not kicked in this morning yet? I think you missed this bit:

:rofl:

It was a long evening yesterday, trying to repair my bicycle. There probably still is some water in the chain, because it tends to become hard in the freezing weather we have now. But at least the rust is away now and it has some new oil.

:humorsense:

If the world is flat, then the light clearly shows that the sun is a conical light source, which illuminates the earth from the north.

This may not be surprising for you down under, but for me that's a whole new perspective.
:lol:

 

[garyw]

garyw/cjp: sense of humour not kicked in this morning yet? I think you missed this bit:

:rofl:

I did see it but brain and eyes are not talking to each other right now... :lol:

 

[Notebook]

Not the reaction I was expecting, but still good

Looks like I'll have to add a "Joke Approaching" icon...

N.

 

[Linguofreak]

If the Earth is flat, why isn't it either day or night everywhere on the planet at once?

 

[Unstung]

Which is caused by the tilt, the seasons and sunlight. I didn't read all of the posts, so I may have missed it.
Anyways, the site's cool. I'm bookmarking it.

 

[Bj]

Does it actually show a real-time cloud cover at entire Earth? If yes, it's really useful in real life, and I believe it smells like an idea for an Orbiter addon.

Yep it does, it updates every 3 hours.

Its amazing, it puts it into perspective how big the earth really is. Also most amazing, clouds seem to be scarce around the equator and more abundant around the poles. I wonder why that is... I also notice we are again getting a nice rain storm, but that's what you get for living in the wettest place in USA right?

 

[tblaxland]

Does it actually show a real-time cloud cover at entire Earth? If yes, it's really useful in real life, and I believe it smells like an idea for an Orbiter addon.

There is this: [ame="http://www.orbithangar.com/searchid.php?ID=3271"]Tutorial - Generating A Realtime Cloud Texture[/ame]


Otherwise, the texture processing could be automated without too much trouble, IMHO, but I don't think we can update planet textures without restarting the simulation session (someone please correct me if I am wrong there).

An alternative could be a script that grabs the latest cloud texture and processes it before starting the sim.

clouds seem to be scarce around the equator and more abundant around the poles. I wonder why that is...

It is mostly an artefact of the projection (Mercator?), as far as I can tell, although there is some increase in density at high latitudes due to the polar jet streams (notice also lack of cloud cover due to the subtropical jet streams).

 

[Bj]

It is mostly an artefact of the projection (Mercator?), as far as I can tell, although there is some increase in density at high latitudes due to the polar jet streams (notice also lack of cloud cover due to the subtropical jet streams).

Oh yes, I forgot about the stretching effect at the polls.

When you look from this view

http://www.die.net/earth/hemisphere.html

it appears more spread out. Though still high latitudes are 'foggy'

 

[cjp]

Otherwise, the texture processing could be automated without too much trouble, IMHO, but I don't think we can update planet textures without restarting the simulation session (someone please correct me if I am wrong there).

You could disable Orbiter's default cloud layer, and abuse the vessel API to add your own clouds, in the same way as Orulex and OrbiterProcTer add terrain.

Disadvantages of this approach are that cloud shadows will not be present, and you may have visual artifacts when viewing this from high orbit, due to z-buffer fighting.

Besides, how are you going to handle time acceleration, and non-present simulation dates?

An advantage would be that many other effects become possible as well. Clouds can be made to look much more realistic, and even based on real weather, e.g. through on-line weather station data. Also think of multi-layer clouds, and more realistic gas giants.

 

[tblaxland]

^ Good ideas.

Disadvantages of this approach are that cloud shadows will not be present

Vessels make shadows on the ground in Orbiter. Am I missing something?

Other disadvantages include big hardware loads. I've never been able to use volumetric clouds in any flight sim software on my PC because it pretty much grinds to a halt.

Besides, how are you going to handle time acceleration, and non-present simulation dates?

I wasn't thinking so much of a real-time effect (ie, showing historically accurate cloud formations), more something so you just have different clouds each time you start the sim.

 

[cjp]

Vessels make shadows on the ground in Orbiter. Am I missing something?

:idk::idk::idk::idk:

Yes, vessels make shadows. But somehow the landscape vessels don't make shadows. So, I'm confused a bit.

I guess it may have something to do with the altitude of the vessel. Landscape vessels (Orulex, OrbiterProcTer) have their center high above the ground, as a work-around for certain visual artifacts. Maybe Orbiter doesn't render vessel shadows beyond a certain altitude threshold.

In that case, our advanced clouds probably wouldn't cast any shadows either.

Besides, for rendering clouds, you often use textures with an alpha channel. IIRC, Orbiter uses stencil buffering for vessel shadows, which can not use information from the texture alpha channel. If you manage to let your clouds cast shadows, they'll probably look really bad.

Now that I think of it, I don't know how Orbiter generates shadows from exhaust particles. More confusion...
:idk::idk::idk::idk: