Awesome work! I'm using it to figure out the shadows cast by the Twin Towers (417 m. and 415 m., North and South towers, respectively) at different times of the day and different dates. They were truly gargantuan buildings.
As an outdoor photographer I’m constantly referring to an ephemeris[0] to check out the light situation at different times. This isn’t nearly as full featured as what I use but I love the idea of hacking something like this together with common APIs for a quick and dirty approximation.
I've got to say, as someone who lives nowhere near a city as big as NY, the view of the shadows that are cast upon Central Park throughout the day is simply mind blowing.
Very cool. Sorry for being "that guy" but I assume this doesn't take into account the earth surface curvature, just the relative sun position and then assumes a flat earth?
It probably not nearly significant enough on the scale of the use case described on the site, but a shadow on a sphere has a different shape than a shadow on a plane. Though that effect may cancel out depending on the map projection that was used.
Yup, seems to treat Earth as flat, not really useful in my area (living in the valley, surrounded by high mountains from east and west - sunrise time does not mean you're going to see sun, if it's still hiding behind a mountain).
Very neat! An idea that often came up amongst coworkers while walking to a lunch spot during the hot summers was being able to get walking directions that preferred routes in shadow. We had our own routes we came up with that didn't add much time to the total trip but had a massive increase in shade versus almost none on the fastest route.
This reminds me a lot of that, though you would need good data on building heights and shapes as well as which side of the sidewalk you would walk on (if walking on both is even possible). Would love to see that get created some day.
I actually proposed something similiar to friends at google maps, that it be interesting for walking directions to advise based on which route would be most shadowed (say in the hot summer in a non humid climate where there's a huge difference between shadowed and non shadowed paths in terms of comfort.
Wow, this is going to be great for determining ideal time of day to climb at different areas
edit: the controls really could use some work though
edit2: It doesn't appear to take elevation data into account, which might be useful. More to the point, it doesn't take shadows from surrounding terrain into account
Ah this is perfectly timed--many of the old garden-focused azimuth / altitude / persephone day calculators are defunct and never handled the problem of cast shadows very well in the first place. Nice work!
so knowing the buliding height we could figure out which time and day the aerial picture was taken?
And given time and day we could figure out how high the buildings are.
Could this be used to generate large scale 3d building models automatically?
Does anyone know whether this has been attempted?
I thought this could solve the following problem: when camping during a mountain hike, figure out where to set up the tent, by knowing at which time you will be woken up by sunlight. Unfortunately this app doesn't seem to take elevation into account -- I don't know if there is some other tool that can do it.
http://shadowcalculator.eu/#/lat/40.71136008109719/lng/-74.0...