Wednesday, June 26, 2013
To celebrate the sunny days of summer (in the northern hemisphere at least), we're unveiling new satellite imagery for all Google mapping products today. This stunning new imagery of the earth from space virtually eliminates clouds, includes refreshed imagery for regions of the world where high-resolution imagery is not yet available, and offers a more comprehensive and accurate view of the texture of our planet's landscape.
The new, even more beautiful global view in Maps and Earth.
In 2002 NASA released the Blue Marble, a global image of the earth with a resolution of one kilometer per pixel, based on data from NASA’s MODIS instrument. Updated in 2005 to twice the resolution, it has remained the canonical globally-uniform picture of the earth for over a decade.
With the Blue Marble as inspiration, we used Google Earth Engine technology to mine hundreds of terabytes of data from the USGS’s and NASA’s Landsat 7 satellite. The result is a seamless, globally-consistent image of the entire planet with a resolution of 15 meters per pixel, far finer than is possible with MODIS data alone.
To get a feel for the difference, here’s a comparison of the Grand Canyon, first from the Blue Marble Next Generation (courtesy NASA’s Earth Observatory), and then in our new Landsat-based imagery.
The Grand Canyon, as seen by MODIS and by Landsat 7.
Castellón, Spain: One example Landsat 7 image, and the final combined image.
Northwestern South America: before and after.
Mining data from a large number of Landsat images of each area allowed us to reconstruct cloud-free imagery even in tropical regions that are always at least partly cloudy.
We prioritized recent data when it was available, so this update also includes refreshed imagery in many regions of the world, especially in areas where high-resolution imagery is not available, including parts of Russia, Indonesia, and central Africa.
Central Papua, Indonesia: before and after.
Agricultural expansion in Saudi Arabia: before and after.
This new picture of the earth also reveals the texture of the landscape with greater clarity than ever before.
We're proud of the progress we have made, but there is always room to keep improving. For example, although we have tried to minimize the impact of the stripe artifacts in the Landsat 7 images, they are still visible in some areas. There is more good news though: the new Landsat 8 satellite, launched earlier this year, promises to capture even more beautiful and up-to-date imagery in the months and years ahead.