Satellites monitor urban landscapes
| This is an image of the city of Houston, Texas. It was taken in 1992 using the MultiSpectral Scanner (MSS) on a Landsat satellite. This type of imagery is referred to as "false color" because the colors are different from those that would be seen with the human eye. The light blue regions are areas of high building density, such as the downtown district in the center of the image. Major freeways can also be seen, many emanating from the center of the city. Vegetation is actually colored red in this image, and water is dark blue or green. The spatial extent of this image is approximately 40 miles across. Images like this can be used to study how cities grow over the years, and what changes are made in how the land is used. |
Credit: Museums Teaching Planet Earth
For more info: http://weather.msfc.nasa.gov/urban/