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xfgvfsg Many of the satellite images we see have very different colors than the ones we are used to seeing with our own eyes.

Why do satellite images look so different?

Below are two pictures of the exact same location. The picture on the left is a "true color" image, this means that the picture shows objects in the same colors that your eyes would normally see. The picture on the right is a "false color" image, this means that the colors have been assigned to three different wavelengths that your eyes might not normally see.

Landsat 7 images of Washington D.C., Baltimore and the Chesapeake Bay area in Maryland. A true color image using ETM+ bands 3,2 and 1 is on the left and a false color image using ETM+ bands 4,3 and 2 is on the left.

To better understand this concept, it might be helpful to first study electromagnetic radiation. All objects emit radiation, albeit in various amounts and at differing wavelengths. Radiation travels in a wave-like manner and the distance between wave peaks is known as the wavelength. When organized by wavelength and frequency, these emissions collectively form the electromagnetic spectrum. Let's learn more. (continue on to the EM Spectrum)

- Download a PDF of the Landsat 7 Compositor (12.7 MB)
- Download a PDF of the Landsat 7 Compositor without answers to the questions. (12.7 MB)

References

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Goddard Space Flight Center