LIDAR Map Shows Height of Earth's Forests 47
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."
First post (Score:5, Funny)
http://xkcd.com/1019/
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This is Slashdot (Score:2)
What is this "peer consensus" thing of which you speak?
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What is this "peer consensus" thing of which you speak?
This is slashdot. You know, it thing where lots of people get together and decide as a group the thing they want to believe in, which is usually factually wrong, unsubstantiated in any way, or just flat out stupid. Its more commonly known as a cluster fuck.
Lasers? (Score:1)
Shooting forests with lasers from space? I think we now know who is responsible for both the recent crop of large scale forest fires and global warming as a whole.
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Yes, but can we make popcorn with one?
No, you need a laser on a B-1 bomber to make popcorn.
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(Now that we've got that one out of the way, we're back to our regular discussion)
Google Earth (Score:5, Interesting)
When can we get height data with good enough resolution to show individual trees and buildings?
Re:Google Earth (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.
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You're not a very good geek. There doesn't have to be a reason to get new hardware like that...
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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 [nasa.gov] you can find on NASA's ICESat mission website, the points from a single pass look more like 100 m apart.
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Very close, MODIS (Terra) resolution is ~90m if I remember right. SRTM is 3 arc-sec (~90m latitude) 60N-60S but 1" (~30m latitude, same as LANDSAT) over the USA. In reality it's only very reliable at 90m though.
(props to Prof Mitasova @ NCSU!)
What happened to New Zealand? (Score:3, Insightful)
Re:What happened to New Zealand? (Score:4, Informative)
Interesting (Score:5, Informative)
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Which is why you should not recycle paper. Recycling paper is all extra carbon emissions. With less demand on paper, paper companies have no incentive to plant more trees (tree are managed just like farms, farmers do not grow more product then the market can bear). Increase demand on paper, more trees planted, more carbon is taken out of the air and less carbon is produced trucking paper back to recycling plants to re-process the paper back into more paper. Recycling paper is actually evil but all the a
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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 a
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This isn't the first or only way to measure/visualize forestation. Visible light and infrared imaging have been used for this purpose for decades now (and spectrography can tell us stuff like what species we're looking at), so we already have a pretty good idea of how many carbon consumers are lost over time.
They're in space now?! (Score:1)
What are laser-wielding sharks doing in space? Thank goodness they're just taking orders from NASA!
Can we detect this stuff FROM THE GROUND? (Score:2)
With all this remote sensing and especially with the now (more) common use of ACTIVE sensors, is there any way the average, non-James Bond citizen can know what exactly he's being scanned with?
Sort of like a radar detector for the 21st century; some sort of gadget that would tell you when some space-borne laser is strobing you or some military radar is illuminating you or you're walking through someone's microwave beam spillover? Or is that way beyond being practical now?
It might be interesting to know whi
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With all this remote sensing and especially with the now (more) common use of ACTIVE sensors, is there any way the average, non-James Bond citizen can know what exactly he's being scanned with?
No, the average citizen cannot know that. The reason is that the emitter is usually not constrained by cost, and emitters exist only in small quantities. For example, that TSA scanner van may exist in quantity one, but the whole population of the USA may be required to be on the lookout for it.
Those emitters also
My colleagues weren't joking... (Score:2)
I said I'd like to try the train up from Helsinki. They said, "Why bother? All you'll see is trees, just shorter trees as you go north."
And, from the low-resolution map at least, they seem to be right.
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Any word from Mitt Romney... (Score:1)
LIDAR (Score:2)