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using Lidar to find Lost City

Posted: Wed Sep 30, 2015 7:03 pm
by Lucas

Re: using Lidar to find Lost City

Posted: Wed Sep 30, 2015 8:56 pm
by Don
Lucas-
Up here in Alaska where most of the state is more than a hundred miles from the nearest road, the latest mapping effort has been with LiDAR in conjunction with other mapping processes. Useful in mapping, the LiDAR imagery is also useful in natural resource inventory, for it's ability to "see through" the canopy to the forest floor.
More to the point, the way that LiDAR works, it's rather good at detecting forest canopy heights. When done to higher resolutions, it can make a rather fair estimate of individual mature tree heights. While it's not very good at detecting species differences (maybe conifers versus hardwoods in a general way), work is being done to 'meld' LiDAR to other remote sensing technologies that do a good job of vegetation classification.
Being a bit of a remote sensing nut, I recall earlier National Geographics with articles on finding lost cities in the deserts of the Middle East, under sand, that yielded a wealth of archeological sites, including one at the crossroads of ancient roadways.
Cool stuff!
-Don

Re: using Lidar to find Lost City

Posted: Fri Oct 02, 2015 1:38 pm
by Larry Tucei
Lucas- A very interesting article. It makes me think of the Indiana Jones movies. I wonder how large the trees would be at the T1 T2 T3 sites. Some of the Forest would be Virgin! Larry

Re: using Lidar to find Lost City

Posted: Fri Oct 02, 2015 3:21 pm
by Lucas
http://yourshot.nationalgeographic.com/ ... fe/#recent

I just noticed this where NGM asked readers to send pix of trees. They only got 17001.


Click on image to see its original size

"Photograph by Dave Yoder
Covering 20,000 square miles in Honduras and Nicaragua, Mosquitia contains the largest rain forest in Central America and some of the last areas on Earth that scientists have yet to explore. “The importance of this place can’t be overestimated,” says ethnobotanist Mark Plotkin."

That was a surprise.

Re: using Lidar to find Lost City

Posted: Sun Oct 04, 2015 11:09 am
by Lucas
For NCALM to scan just the 55 square miles of the three valleys would cost a quarter of a million dollars.
about $4500.00 / sq mile

They did it locally here a couple of years ago. I knew it was expensive but wow.

Re: using Lidar to find Lost City

Posted: Sun Nov 01, 2015 1:46 pm
by Lucas

Click on image to see its original size


Click on image to see its original size

WHAT THIS IS The Carnegie Airborne Observatory made this image of rain forest in Panama with its scanning lidar, which probes the trees’ size and shape, and a spectrometer that charts their chemical composition.

WHAT THIS TELLS US The technique allows Asner's team, flying at 7,000 feet, to identify individual trees from their chemical signatures—and even to say how healthy they are. The reddish trees here (the colors are arbitrary) are growing the fastest and absorbing the most CO₂.
PHOTOGRAPH BY GREGORY ASNER, CARNEGIE INSTITUTION FOR SCIENCE

http://ngm.nationalgeographic.com/2015/ ... lanet-text

From the Nov Nat Geo


https://en.wikipedia.org/wiki/Hyperspectral_imaging

Hyperspectral imaging + lidar likely will revolutionize tree study.

http://www.nationalgeographic.com/clima ... Art/Intro/

Also, the folding map of the Amazon has very nice graphics of tree ecology on the reverse.

http://www.nationalgeographic.com/clima ... cus=Varzea

Flooded forest, some serious water tolerance

Re: using Lidar to find Lost City

Posted: Sun Nov 01, 2015 10:08 pm
by Don
Lucas-
Yep, the shape of things to come...and for 3D, toss in SfM (Structure from Motion). An expensive solution, unless you can't get there from here...then it looks to be reasonable for high-value (not necessarily dollars, mind you) stands.
-Don

Re: using Lidar to find Lost City

Posted: Sun Nov 15, 2015 9:33 pm
by lalacurf121
I knew it was expensive but wow.
บาคาร่ามือถือ

Re: using Lidar to find Lost City

Posted: Sun Jan 31, 2016 4:36 pm
by Lucas

Re: using Lidar to find Lost City

Posted: Sun Jan 31, 2016 5:32 pm
by Lucas
http://ngm.nationalgeographic.com/2015/ ... lanet-text

"Within the next decade or so the first imaging spectrometer, similar to the ones used by Asner and Painter, could be put into Earth orbit. It would be like “Star Trek technology” compared with what’s up there now, Painter said. “We’ve orbited Jupiter, Saturn, and Mars with imaging spectrometers, but we haven’t had a committed program yet for our own planet,” he said. The view from such a device would be amazing: We’d be able to see and name individual trees from space. And we’d be reminded of the larger forest: We humans and our technology are the only hope for curing what we’ve caused."

WOW!