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TRANSIENT: Helicopter
Comments
From: AndreaBT
OK, so can someone tell me why helicopters do not have the shiny "reflective" mark from the lens on the image, like airplanes do? I'm still trying to figure out this phenomenon...Thu Sep 14 10:52:04 -0700 2006 From: erwin-90
That's because of the speed.
Fri Sep 15 09:17:43 -0700 2006 I read somewhere why the planes do have a reflection, and (for instance) helicopters don't. Satellite photo's are taken twice: first a black and white one, then also color. There is just a fraction of a second between those two, but a plane goes so fast, you see a reflection. If you know what that fraction of a second was, you can calculate the speed of the plane by measuring the distance between reflection and image. |
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