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Anyone can now buy a specialized image from the Landsat 7 satellite, currently run by the USGS, which offers 15-meter-resolution black-and-white images and 30-meter color images. In general, imagery from the newer and higher-spatial-resolution satellites is more expensive than lower-resolution imagery. “Now I can download MODIS images for free.”

“In the mid-1980s, I would have given my eye-teeth to get satellite images of Madagascar,” he says. Raxworthy recalls when he first started as a biodiversity researcher, the price of satellite imagery was beyond his meager budget. As satellites and computers become more sophisticated, the costs are going down. You still have to have a muddy-boots biologist trudging through the forests.”Īnother consideration is the cost for imagery. “You just can’t look at images from space and use computers to give you the answers. “You still need to put effort into ground-truthing,” says Raxworthy. Such ‘ground-truth’ information might come from ground-based sensors, higher-resolution remote-sensing sources, like aerial photographs, or researchers in the field.

Without proper validation, satellite data should not be taken at face value. For starters, remote sensing data need to be validated, or compared with other sources of information to see if there is agreement. While these new technologies and techniques offer a far greater range of information than has ever been possible before, there are still challenges to using satellite data effectively.

There is no question that satellites and computer models are opening the door to new ways of looking at ecological issues. At the time of publication, it represented the best available science. This page contains archived content and is no longer being updated.

Call of the sea matthew turner download free