Global map of forest height produced by NASA's ICESAT/GLAS, MODIS, and TRMM sensors.
Image credit: NASA/JPL-Caltech
NASA satellites pinged the surface of the Earth with 2.5 million carefully positioned laser pulses to measure the height of the world's forests. The map above shows the peak height of the canopy with a spatial resolution of 0.6 miles.
The tropics as you might expect, have a high canopy height with large areas of red for South America, south-central Africa, Indonesia, and Papua New Guinea. (Perhaps California redwoods are also appearing red.) Note the deserts of Africa and Australia have an absence of trees.
NASA scientists hope the map will assist in estimating the carbon sinks formed by the forests. It will also be a valuable record for measuring climate change.
So it measures the height of the trees. Yeah you can see why some parts are clear, if there is just grassland then nothing will show.
Posted by: ted | June 11, 2012 at 06:34 AM