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This is a Space Shuttle radar (SIR-C) image of Mauna Kea volcano, which is the site of all the world famous astronomical telescopes on the Big Island. The different colors have been generated by displaying different radar wavelengths as different colors. Red corresponds to L-band (23 cm) horizontally transmit and receive (HH polarization), green is L-band horizontally transmit and vertically receive (HV polarization), and blue is C-band (5.6 cm) horizontally transmit and vertically receive (HV polarization). The strong color difference between the top right and top left parts of the image are due to variations in vegetation cover and the viewing geometry of the radar (the "look direction" is towards the right (east) in this image).


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Here is another SIR-C view of the summit of Mauna Kea, obtained in October 1994. This image has a better spatial resolution (12.5 m/pixel) than the color image because it was obtained when the radar scientists were performing a topographic mapping experiment. As a result of the limited amount of data that could be recorded in this manner, it was not possible to collect 3 wavelengths or polarizations at the same time -- which is why we only have a black and white image. However, the improvement in resolution is remarkable, since you can now see the road going to the summit, and the individual telescopes!

Copyright by P. Mouginis-Mark