Have you ever wondered how
things look from outer space? Well, now is your chance to indulge
that curiosity.
We've put together
Landsat satellite images of the continental USA. At your
fingertips are images of the USA, easy to use and fun to look at.
This file is 130K, so it may take some time to load. Once
that's done, however, a whole new world will open before
you!
How to use:
1. Go to the next page, where you'll find the index map
application (requires Java).
2. A green rectangle with a dot in the middle will appear.
Move your mouse so the area you would like to see a Landsat
image of is contained by the green rectangle. To view the
Landsat image for the contained area simply click your mouse
button. It's that easy!
Note: if a red dot appears, this indicates that there are no
satellite images for that area.
*Helpful hint: use
your browser's back button to return to the image map after
looking at a satellite image.
Things to Know
Many of the satellite images are extremely colorful. The
multispectral remote sensing instruments carried on the Landsat
and other satellites measure the amount of energy reflected and
emitted in several discrete portions, or bands, of the
electromagnetic (EM) spectrum. The various visible and infrared
bands were chosen to measure reflected and emitted energy in
areas of the spectrum that correspond to known responses of the
target materials. These include specific characteristics of
land, vegetation, water, rocks, and temperature. Below is a key
of what the colors may represent. Since there are several band
combinations, the colors can represent different items
(depending on the combination that was used). Below are
materials and the colors they may represent.
- Black = water
- Green/Light Green = vegetation
- Dark Green = forested areas
- Blue = shallow water, snow, ice, certain minerals
- White = clouds, geysers, springs, snow
- Brown/Pink/Purple/Red = urban areas, concrete, asphalt,
bare soil
- Yellow = bare soil, rock
*This is not a complete list,
nor are these colors and the materials they represent the only
possibilities.
For more information,
check out the Observatorium articles titled
Landsat's Thematic
Mapper Bands and
Use of
Color Composites in Landsat TM Data.
