HIGH OVER THE EYE

By Jeffrey Kluger

A satellite captures a powerful, poetic portrait of Hurricane Fran It's one of nature's dark ironies that the most horrific expressions of its power are also the most beautiful. Think Mount St. Helens or a Pacific tsunami. Add to these Hurricane Fran, pinwheeling toward the U.S. last Wednesday at 1:15 p.m. EDT.

At the time, Fran was on her way to claiming at least 21 lives and doing probably more than $1 billion worth of damage. What makes this portrait remarkable is not just the violence it captures but also the method of capturing it. The image was snapped by the GOES-8 weather satellite, which actually took two pictures, one black-and-white and one in the invisible infrared spectrum. These two renderings were beamed to the Goddard Space Flight Center in Maryland.

There researchers created a full-color image the way a TV set does--by combining red, green and blue versions of a single picture. The first step was to apply red and green masks to the black-and-white image, producing two muddy versions of the photo. Then a blue mask was applied to the infrared image--and things got interesting.

The intensity of infrared radiation is a measure of an object's temperature; when the heat picture sent back from space was blue-masked through the computer, it could thus be made visible, with cold features like clouds and warmer features like land appearing lighter or darker. This last image was then combined with the others, producing a full spectrum of colors.

Once this composite was created, software trickery gave it 3-D pop. One program distorted higher-altitude portions of the picture to create perspective, while another gave the image its vertiginous tilt.

With only two weather satellites keeping vigil over the U.S., GOES-8's picture-snapping ability becomes more important than ever to meteorologists trying to track a hurricane. Goddard's capacity to enhance those images may become equally important in encouraging locals to get out of a storm's path.

--By Jeffrey Kluger