Google Earth and Pixel Size Representation

[Opie]

I am trying to get some more updated aerial images for a project I am working on. Google Earth has some more recent images of the area, but I do not know what the individual pixel size represents. Does anyone know a way to determine that?

[bmonk]

Reviving an old post. I would also like to know this. Also is there a good way to extract the images from Google, Yahoo, MSN, or mapquest, other than 'printscreen'??

[k.baxter]

Also is there a good way to extract the images from Google, Yahoo, MSN, or mapquest, other than 'printscreen'??

I typically right click and "save image/picture as".

[bmonk]

I typically right click and "save image/picture as".

When I right click in one of those mapping applications, I only get an options window that pertains to the map, not the typical 'windows' right-click menu.

[ekubaskie]

Google Earth's images run a range of pixel resolutions, from as low as 3" up to many meters, but the served imagery resolution has little to do with the "resolution" you get when you save to a file. The image save function resamples your display to the number of pixels across that you're paying for. Free gets you 1000 pixels wide, Plus gets you 1400, and the Pro version saves at 4800 pixels across.

Since the image is resampled to 4800 pixels across, the pixel width depends on your viewing altitude. You'd probably have to overlay the image to figure that out.

If you plan to use the images in a commercial project, get Pro. The image quality is much better, but the main issue is that the Free & Plus versions are not licensed for commercial use. The $400/year fee for Pro won't even get you 2 hours of lawyer time when Google's goons knock on your door.

[margaretl]

Just a side note, Microsoft Virtual Earth sometimes has high resolution images than Google Earth. We tend to use both back and forth. Another benefit of Virtual Earth is the Bird's Eye View feature. Can look at some buildings from all four sides. Way Cool and very useful.

[mpeterson79]

Just an FYI: with Autodesk Civil3D, you can directly import both Google Earth images as well as surfaces. They come in completely georeferenced, so pixel size almost becomes a non-issue. What you measure it as in Civil3D is what is measures in the real world (accuracy issues aside, obviously). Unfortunately, the images come in as black & white, and lower quality that what you see in Google Earth itself.

[cadtag]

Remember though, you can't use the free version of Google Earth for real work. You'll need to buy the Pro license. (I'm not sure if that get's past the b/w issue or not.)

There is also the Worldwind tool from NASA, open source software using public domain, freely available and freely usable imagery.

[Opie]

Google Earth's images run a range of pixel resolutions, from as low as 3" up to many meters, but the served imagery resolution has little to do with the "resolution" you get when you save to a file. The image save function resamples your display to the number of pixels across that you're paying for. Free gets you 1000 pixels wide, Plus gets you 1400, and the Pro version saves at 4800 pixels across.

Since the image is resampled to 4800 pixels across, the pixel width depends on your viewing altitude. You'd probably have to overlay the image to figure that out.

If you plan to use the images in a commercial project, get Pro. The image quality is much better, but the main issue is that the Free & Plus versions are not licensed for commercial use. The $400/year fee for Pro won't even get you 2 hours of lawyer time when Google's goons knock on your door.

If PRO would allow me to import the image into AutoCAD accurately, I'd think about it. Until then, I'm not going to worry about using Google Earth for my needs.