Wednesday, February 21, 2007

Estimating the dimension of Google Earth full resolution image

Above my home, the smallest detail I can spot on Google Earth for a pixel is about 10 cm.
The Earth equatorial circumference is about 40 000 kilometers.
This makes 40 000 * 10 000 = 400 000 000 pixels.
Assuming the Earth is spheric and the Google has all data, this makes 400 000 000 * 200 000 000 = 80 000 000 000 000 000 pixels, much more Gigapixels that I can imagine.

Of course I do not think data is available at this resolution for the whole Earth, and my estimation of precision can be wrong, but these numbers are mind-boggling.

The most precise satellite image of the Earth I have is about 1 pixel for 500 meters, this already makes a 86400 * 43200 image.

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