Things like how shadows cast on oil barrows (I think)
Yep. If you have a sattelite picture of an oil tank with a floating lid, you can compare the shadow cast on the ground against the shadow cast on the lid to see how full it is.
Yep. If you have a sattelite picture of an oil tank with a floating lid, you can compare the shadow cast on the ground against the shadow cast on the lid to see how full it is.