Re: satellite photo showing nightfall

[paul johnson <pjohnson@SCIENCEPLACE.ORG>]

Based on the view angle, I'd say the camera was over the equator, which
implies (but doesn't require) a geosynchronous orbit. The only imaging birds
in such an orbit that I know about are the various weather satellites. But
the GSD (ground sample distance) in this image seems much smaller than in a
typical cloud cover image.

It's almost inconceivable to me that it could be a composite of images
acquired by a low-earth orbiter. The individual images would have to be
acquired at various positions along identical polar-orbit ground tracks (it
would take a week or so to synchronize the ground tracks, depending on the
bird's altitude), but it would also require the same sun angle for each
image so that the terminator line is in the same place.

Whatever, it's a glorious shot, I wonder if they have made a poster of it.

Dr. Paul O. Johnson
Senior Exhibit Developer
The Science Place
Dallas  Texas

----- Original Message -----
From: "David T. Marx" <dtmarx@SIU.EDU>
To: <PHYS-L@lists.nau.edu>
Sent: Tuesday, January 28, 2003 6:28 PM
Subject: satellite photo showing nightfall


> Please have a look at this photo of nightfall over central Europe
> that was sent to a friend of mine by a former student who is now in
> Navy satellite imagery.  Can anyone tell me if this is a single image
> or one that was pieced together using a number of images and then
> visually enhanced?
>
> http://www.siu.edu/~cafs/download/Sunset.jpg