New Hampshire Stone Wall Project

[peakbagger]

There was article in the Concord Monitor recently about the NH Stone Wall project that linked to this site. The claim was that higher accuracy Lidar data was available for the state. When I go to site to areas in the north country with walls mapped all I see are standard Google Earth aerial photography. The claim with Lidar is that it sees through the canopy and would be of interest for finding older man made features.
https://nhgranit.maps.arcgis.com/apps/webappviewer/index.html?id=ec12d9d5583c4709be446a77115bf0a2

Has anyone played around on this site and figured out how of if the Lidar data is available? obviously I am most interested in the WMNF

 

[JoshandBaron]

In the layers list on the left I found LIDAR hillshade NE and LIDAR hillshade NW. Is that what you were looking for? Data seems unavailable for much of the Whites. Some of the Sandwich Range, Kinsmans, and exterior Pemi are there. Almost everything else between 93 and ME doesn't seem to be available.

 

[peakbagger]

When I go directly to the Granit site there is graphical overview of the state and what may be available. Much of Southern NH is covered and then its mostly western NH up to the Canadian border with some big gaps in the whites. I found some data sets available in few spots in the whites that are listed as available but the data sets are huge. Looks like a typical USGS quad sized area is over 100MB.

 

[kltilton]

The LiDAR data was flown based on watersheds. Southern NH, the Connecticut River Valley, and the Androscoggin were flown first. The Saco Valley has been flown, and is being processed. I’ve overlaid detailed on the ground surveys (at work) and the accuracy of the data is pretty impressive.

 

[Salty]

I'm pretty impressed as well just looking at my neighborhood at what it picked up. It's still missing a lot (to be expected especially on a new project, and I think it picked up a berm of dead trunks and branches I made to clear some land as well as demarcate a border.

Thanks as well for the link.

 

[peakbagger]

I guess I am missing something, when I roam around to areas of unverified stone walls all I see are aerial photos.

 

[skiguy]

I guess I am missing something, when I roam around to areas of unverified stone walls all I see are aerial photos.

Same here. Not that I tried to get into the depths of this program but is there a way to add a stonewall. For instance part of my property line is a stone wall. It would be fun to contribute.

 

[TJsName]

I guess I am missing something, when I roam around to areas of unverified stone walls all I see are aerial photos.

When you open the link, on the top left, click the 'Layer List' icon (2nd from the left), then you'll see what JoshandBaron was referencing with regards to lidar data.

 

[JoshandBaron]

I guess I am missing something, when I roam around to areas of unverified stone walls all I see are aerial photos.

It takes a minute for the LiDAR data to load over the sat imagery but it's working on Chrome.

 

[peakbagger]

Thanks for the help, I got it. It fires up with the Lidar layer off by default. Definitely looking at playing around with it now that I have it working.

 

[Jazzbo]

Oh noooo!!!!! Not another Internet time suck hole! I've been messing with it and find it fascinating. The Swipe feature is pretty interesting. Too bad they focus just on stone walls. I found the cellar holes I located last fall near Algonquin Trail. Lost North Roads in regions around Sandwich Notch Road. I was able to load my GPS tracks and they match up with lost road leading up to Wallace Homestead cellar holes. Too bad you can't save maps like you can in Caltopo. I loaded GPS tracks and they just go away when you close it unless I'm missing something. Should be interesting to look at LIDAR imagery of Hancock skidder trails.

 

[Jazzbo]

I was looking for abandoned Osceola trail from East Pond last year so I loaded my track and saw I was following the old road where I was following the wire for a while and it checks out on LIDAR imagery. Unfortunately I noticed LIDAR imagery appears to stop just south of Osceola ridge line. I also could see all of the skidder roads up by Timber Camp Trail near Mad River Notch and verified I was indeed following a skidder trail.

 

[iAmKrzys]

I wish there were a slippy tile service (see https://wiki.openstreetmap.org/wiki/Slippy_map_tilenames for details) with LIDAR layer, so that these walls could be mapped in OpenStreetMap. Unfortunately I could not find this service in documentation. Oh well...

 

[peakbagger]

Even though there is no Lidar for most of the Pemi area, the underlying aerial database is a different source than Google Earth. The Owls Head railroad spur really stands out. I am really looking forward to when Lidar coverage is available for the Pemi area.

 

[Jazzbo]

One reason NH Granit shows Owlshead RR so well is it uses Microsoft Bing Maps Imagery. I came across Bing Maps one time. MS Bing Maps seems to use mostly late winter or early spring imagery meaning no foliage. Another benefit to off trail explorers is you can tell where the hardwoods are - my favorite terrain. One way to find best terrain for off-trail routing.

 

[srhigham]

The Lidar hillshade implementation is interesting here because it's a built-in layer. Easy to use. I've used N.H., Maine, and Vermont raw Lidar data before to see things in the woods, but to do it I have to download massive data sets (last-return/ bare ground), then use QGIS freeware to convert that into 2-foot contours. It's a long process. But the drawback of this hillshade implementation seems to be that you lose the detail in the deep shade on steep slopes...unless there's a way to "rotate" the sun.

Good news that the rest of N.H. is being completed for Lidar. I've been frustrated with what's missing in the northeast quadrant of the state.

 

[srhigham]

Now I see that it does allow movement of the shade: there is a layer for NE shade and a layer for NW shade.

 

[peakbagger]

I expect real time processing of shading would burn up a lot of processor time.

 

[Fuzzy]

Are the maps still available? I wanted to check out a logging road, and can't find any of the LiDAR stuff. Was very useful earlier in the year.

 

[srhigham]

Oh yeah....the site is password protected now!