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Re: LiDAR Coverage for the Eastern USA

Posted: Sun Dec 03, 2017 7:17 pm
by M.W.Taylor
Bob, attached is the LiDAR for William Cullen Bryant Homestead. I downloaded the entire 1000m quad on EarthExplorer. Did I get the entire Homestead or do you need the quad further to the south too ? The units are metric for this one. Red is 40m and white is 50m. The tallest top I am getting is about 49m i.e. 160 feet. I will make a KMZ of this later this week and post so you can access directly through Google Earth.

Michael Taylor

WNTS VP

Re: LiDAR Coverage for the Eastern USA

Posted: Sun Dec 03, 2017 7:21 pm
by Erik Danielsen
Michael,

It would be fantastic to see the LiDAR for Erie County's portion of Zoar Valley MUA, which appears to be right on the border of one of NY's covered areas. It's hard work getting down to those terraces!

The other spot I'd be very curious to see would be Hudson Highlands State Park.

I made some frustrating attempts to work with the LiDAR data that's available from the earthexplorer site (though I think it's really just the same area seen here). Without a certain basic level of GIS knowledge I think this can all be pretty opaque. I was able to get two of the three required files for the tiles in question but could not for the life of me figure out which files (out of the data sets available) would work for the third (for the basic ground elevation, I think). It's also possible that I was going about the whole thing incorrectly. I was able to get the PA data to work without too much trouble, thanks to the tutorials on this site.

Thank you for any of that that you're able to get to. If in the process you get an idea of why I might have had such trouble with NY data (as opposed to the PA data) I'd love to hear how I might go about doing it successfully myself.

-Erik

Re: LiDAR Coverage for the Eastern USA

Posted: Sun Dec 03, 2017 9:12 pm
by ElijahW
Thanks for your work, Michael. Like Erik, I’ve tried to make something out of the NY data, but had a difficult time with it. The main problem is likely my lack of knowledge, but I did find the PA much easier to work with.

Elijah

Re: LiDAR Coverage for the Eastern USA

Posted: Tue Dec 05, 2017 6:43 pm
by M.W.Taylor
Erik, I have processed Zoar Valley MUA and found some very tall trees down on the benches by the river. There appears to be a few trees over 160ft and some even over 170ft. I also got multiple 230'+ hits but I can see these trees are leaning over a circular scarp or depression. Will post results on NY state section here.

Also, I have worked with a number of scientists from the BLM and Yosemite NP who did not understand how to process the LIDAR in their inventory, even after so called training. They relied strictly on automated software height estimates, which in many cases were wildly inaccurate in the case of trees leaning over hillsides. A manual inspection and manipulation of the LiDAR point cloud is necessary to get accurate estimates of hillside leaners.

Erik Danielsen wrote:Michael,

It would be fantastic to see the LiDAR for Erie County's portion of Zoar Valley MUA, which appears to be right on the border of one of NY's covered areas. It's hard work getting down to those terraces!

The other spot I'd be very curious to see would be Hudson Highlands State Park.

I made some frustrating attempts to work with the LiDAR data that's available from the earthexplorer site (though I think it's really just the same area seen here). Without a certain basic level of GIS knowledge I think this can all be pretty opaque. I was able to get two of the three required files for the tiles in question but could not for the life of me figure out which files (out of the data sets available) would work for the third (for the basic ground elevation, I think). It's also possible that I was going about the whole thing incorrectly. I was able to get the PA data to work without too much trouble, thanks to the tutorials on this site.

Thank you for any of that that you're able to get to. If in the process you get an idea of why I might have had such trouble with NY data (as opposed to the PA data) I'd love to hear how I might go about doing it successfully myself.

-Erik

Re: LiDAR Coverage for the Eastern USA

Posted: Tue Dec 05, 2017 6:44 pm
by M.W.Taylor
I have processed all of Glenn Rickets SP. I get the tallest at 151' with a few over 140'. Results to be posted in the state category shortly.
ElijahW wrote:Thanks, Michael. NY is obviously at a deficit here, but PA looks great. I would be interested in seeing what Ricketts Glen SP looks like.

Elijah

Re: LiDAR Coverage for the Eastern USA

Posted: Tue Dec 05, 2017 6:46 pm
by M.W.Taylor
Tyler, I have downloaded all of the most heavily forested areas of Congaree NP and will process tomorrow. It is a huge area so I focused on the best looking forests. I will expand the search area if I find anything super tall.

Where is Laurel Fork Heritage Preserve ? I can't get that to come up in my searches for Google Earth or the LiDAr program. What are the GPS coordinates ?
Tyler wrote:Michael,

I would be interested in any South Carolina data for Congaree National Park especially areas that are 140'+. Also if there are any 180'+ trees in Laurel Fork Heritage Preserve and surrounding areas.

Thanks,

Tyler

Re: LiDAR Coverage for the Eastern USA

Posted: Tue Dec 05, 2017 6:59 pm
by M.W.Taylor
Larry, I processed a large tract from each place of your request. For Black Creek Wilderness I get the tallest at 141' with excellent uniform height on the rest of the nearby trees (all over 120') and for Bienville NF I get the tallest at 130' and 129' respectively. Will post results shortly in the MS section. I did not know MS has 140' class trees ?

I also got a 300 foot structure in the LiDAR for Bienville NF but it looks like a radio tower. Attached are the areas I processed and height banding of that 300' structure.




Larry Tucei wrote:Michael- Wow thanks. I would like to have Tallahala Wildlife Management Area in Bienville NF and Black Creek Wilderness Area in Desoto NF. Larry

Re: LiDAR Coverage for the Eastern USA

Posted: Tue Dec 05, 2017 7:00 pm
by M.W.Taylor
The NY LiDAR has a lot of parasite pixels that need to be removed in order to process the point cloud.
ElijahW wrote:Thanks for your work, Michael. Like Erik, I’ve tried to make something out of the NY data, but had a difficult time with it. The main problem is likely my lack of knowledge, but I did find the PA much easier to work with.

Elijah

Re: LiDAR Coverage for the Eastern USA

Posted: Tue Dec 05, 2017 8:28 pm
by Tyler
Michael,

It's inside of the jocassee gorges area.
overview13.gif
overview13.gif (15.9 KiB) Viewed 707 times
Hope this helps. Looking forward to the results.

Tyler

Re: LiDAR Coverage for the Eastern USA

Posted: Tue Dec 05, 2017 9:17 pm
by Erik Danielsen
M.W.Taylor wrote:Erik, I have processed Zoar Valley MUA and found some very tall trees down on the benches by the river. There appears to be a few trees over 160ft and some even over 170ft. I also got multiple 230'+ hits but I can see these trees are leaning over a circular scarp or depression. Will post results on NY state section here.
Thanks, definitely looking forward to it. The terrain definitely makes ground-truthing essential, but the complexity of the terraces is such that some of the best stuff may still be undocumented, on less obvious or accessible shelves than the well-known ones. I visited a narrow shelf on sunday about 50' below the main rim but still 150'+ above the river and was surprised to find decent tuliptrees, basswood, and even a new maximum for cucumber magnolia. Anything over 160 in groynd truthing would genuinely surprise me, but at the same time I absolutely believe it could be there.