Google Maps - Satellite Question

Apropos of nothing, this appears to be Nasa’s Vehicle Assembly Building at Cape Canaveral. Follow the road east to see the launch pads.

Damn, that’s a cool application! I found my apartment complex and ID’d my building, then I zoomed out, followed the freeway over to the local mall, zoomed in again, and was able to see which parking spaces had cars in them when the picture was taken. That’s awesome!

There’s no way these pictures were taken from a satellite. The Washington Monument was obviously photographed from the southeast, and the buildings just northwest of it were photographed from the north (and slightly west). It’s kind of disorienting to look at them both at once.

Wow. It really is something like an Escher drawing, isn’t it?

Google doesn’t say all the images are from satellites.

They also don’t say they aren’t. I’d really love a google-map-faq that told us what we’re looking at and where it came from.

Good point. It occurs to me these might be composites from multiple satellite images. This would explain the oddities.

I’m not trying to call Google liars, I’m just contributing something to the “are these satellite images” speculation.

I’m going to hypothesize, without knowing how to test it, that when zoomed out, the big urban brown areas are aerial photography, and the green mostly rural areas are satellite.

It’s the only reason I can think of why they’d follow such clear political division boundaries.

The brown areas are more detailed, zoomable pictures, of course.

http://www.google.com/help/maps/tour/

“Want to see what your target location looks like in real life? Check out our satellite view, which gives you access to satellite and aerial images of your locations that you can zoom in, zoom out, or pan in any direction.”

Note “satellite and aerial images”. Sounds to me like they mean “aerial” as in from the air, not space.

I’m fairly certain that the Washington DC area galt linked to has aerial and not satellite photos. If you zoom out about six or seven steps from the maximum zoom you can see that the pictures appear to be stitched together from rectangularish tiles (about 50% longer east-west than north-south), on a rectangular lattice rotated slightly counterclockwise from a north-east orientation. (This is easiest to see along the Potomac River to the south, where the reflections from the sun appear only near the southwestern corner of each tile, but you can see the lattice pattern across much of the city as well). The tile containing the Washington Monument appears to extend north to the next major road, Constitution Ave NW (just north of this the buildings are viewed from the north, so we see their north walls instead of their south walls, the Escher-effect mentioned above) and south to the obvious discontinuity in the harbor’s water color. The parallax shifts noticeably across these tiles, so that buildings farther to the south on this tile are viewed more nearly from straight overhead. This is a pretty strong hint that it’s aerial photography (assuming that each apparent tile is in fact a single-frame photographic image); satellite photos will only show noticeable perspective shifts over distances of tens to hundreds of miles.

We can estimate the height of the airplane with simple geometry. By looking at various tall buildings it seems to me that the nadir point for the camera was just west of the inflatable-looking building (just south of I-395 and Ohio Drive SW; this is close to the pushpin “D” allegedly marking, but actually nowhere near, the Lincoln Memorial–what’s up with that, anyway?). The distance from this nadir point to the base of the Washington Monument is approximately 13 times the projected length of the WM. Similar triangles then tell us that the height of the camera is about 13 times the height of the WM (555ft; thus the camera is only about 7200ft high, a fairly low-flying aircraft).

I agree with you 100% about the Washington DC photo being from a plane, Omphaloskeptic. Google is clearly using Terraserver’s photos as shown here, in which the Constitution Avenue NW “Escher effect” is even clearer since one can zoom in closer.

I too wish that they’d give more information along with each Google “satellite” image, like source (satellite or plane) with altitude if possible, date (which Terraserver does; it’s April 26 2002 for the DC image), and a linear scale in ft/yds/miles and m/km (again like Terraserver). Oh, and the pushpins are just horrible, quite apart from the inaccuracy (not only is the Lincoln Memorial wrong, but the Washington Monument itself – the supposed center of the map – is marked as being at “A”, south of the Hirschhorn Museum).

I do like the fast scrolling of the Google images however, especially using the keyboard. They seem to be preloading adjacent areas before one scrolls, which is much better than Terraserver. All in all, not bad for a Beta version.

Perhaps the Escher effect is designed to confuse terrorists, like the blurring of the US Capitol and the cartoonish coloring of the White House and Treasury roofs?

On the topic of clouds, have a look at the satellite view of Santa Barbara, CA