Slashdot Mirror

← Back to Stories (view on slashdot.org)

LIDAR Map Shows Height of Earth's Forests

Posted by Unknown on from the for-tax-purposes dept.

Hkibtimes writes about a recently released map of the Earth's forests. From the article: "A group of scientists from NASA and the University of Maryland have created a unique map that shows the heights of the Earth's forests. The map ... has been created using 2.5 million carefully screened and globally distributed laser pulse measurements sent from space."

9 of 47 comments (clear)

  1. First post by Anonymous Coward · · Score: 5, Funny

    http://xkcd.com/1019/

  2. Google Earth by Cinnaman · · Score: 5, Interesting

    When can we get height data with good enough resolution to show individual trees and buildings?

    1. Re:Google Earth by Anonymous Coward · · Score: 5, Informative

      You need 1m posting or better lidar data to get the individual trees and buildings. For the State of North Carolina, which was one of the first states with complete lidar coverage ( for floodplain mapping purposes), 1/3 of the state was flown at -12m posting distance and 2/3 was flown at 5m posting distance , Even at this relatively coarse resolution, there are about 26 billion x,y,z points for the State data set. You can process this as a single file using GRASS GIS or LAStools in a couple of days on a 2Ghz cpu ( single threaded). Consider that 1 m posting gives you 25 times the data points as 5 m posting and pretty soon you are talking about interesting data set sizes.
       

    2. Re:Google Earth by sgtstein · · Score: 2

      Oh, so THAT is why our GIS analysts are wanting a new 100TB Backblaze storage pod and dedicated servers. Thanks for the info!

    3. Re:Google Earth by xded · · Score: 2

      From TFA:

      The researchers augmented the ICESat data with other types of data to compensate for the sparse lidar data, the effects of topography and cloud cover. These included estimates of the percentage of global tree cover from NASA's Moderate Resolution Imaging Spectroradiometer on NASA's Terra satellite, elevation data from NASA's Shuttle Radar Topography Mission, and temperature and precipitation maps from NASA's Tropical Rainfall Measuring Mission and the WorldClim database.

      From a video with a Google Earth overlay you can find on NASA's ICESat mission website, the points from a single pass look more like 100 m apart.

  3. What happened to New Zealand? by Kittenman · · Score: 2, Insightful

    My whole country seems to have been missed (you insensitive clods!). And we're pretty much all forest down here....

    --
    "The greatest lesson in life is to know that even fools are right sometimes" - Winston Churchill
    1. Re:What happened to New Zealand? by youngone · · Score: 3, Informative

      Yeah, I noticed that too. They've also lumped us in with Australia in the article as having very tall eucalyptus forests, whcih we don't really have. (Apart from the odd commercial forest). Maybe they mean Southern Beech: http://en.wikipedia.org/wiki/Nothofagus_fusca They seem to grow to 35 metres.

  4. Interesting by retroworks · · Score: 4, Informative

    I'm from the Ozarks, and was shocked to learn as an adult that virtually the whole area of Arkansas-Missouri-Tennessee etc. was clear cut 100 years ago, and that there is more growth now than my grandparents had around them. But in Africa, saw the opposite, the clearing of forests at a frightening pace. If this can show us year-to-year how the forests are shrinking or growing, we may find out that the loss of carbon consumers is as important as the growth of carbon emitters.

    --
    Gently reply
    1. Re:Interesting by retroworks · · Score: 2

      Which is why you should not recycle paper. Recycling paper is all extra carbon emissions. .... Recycling paper is actually evil but all the anti-science fanatics assume recycling produces unicorns, kittens and puppies with no adverse affect on the environment.

      SkepticalOptimist.... I'm very much a fan of critical dialogue and questioning environmentalist, because I want environmentalism to progress with scientific method and avoid myths. With that said, well, your comment above is just wrong on many levels. Science and economics support paper recycling.

      Paper recycling has been extensively studied. American Forest and Paper Association, a group of mills, engineers, etc., who plants the trees you correctly laud, says we should recycle as much paper as possible and supports mandatory recycling http://www.afandpa.org/Recycling.aspx. Most of the recycled paper is exported overseas to places without forests in the first place. The places (like China and Japan) without forests are chopping down old growth timber in Papua New Guinea and Borneo to plant fast growing pulpwood trees. And most of it is used for toilet paper. The recycled white office paper is prized because it has been bleached (wood from trees must be bleached, and most deinking investments followed the passage of the Clean Water Act). And the energy savings from recycled paper is documented - it makes sense if you think about driving trucks into the woods to cut trees vs. trucks to collect the recycled paper. And the highest recycling rates are in free market situations - time of war, poor cities... not exactly a puppy and unicorn economy.

      So you should remain skeptical but be optimistic about why the free market loves recycling, and stop blaming unicorns and ponies for world interest in recycling. And maybe look into the Bureau of Land Management's timber and land subsidies if you need a new foil. Not to put too fine a point on it, you don't know what you are talking about and appear to be making it up as you go along.

      --
      Gently reply