(Roy) >>Anybody want to run LiDAR to see which of 2 peaks with same highest contour belongs on Maine P1K list? (Old Turk vs Record Hill) TLDR: I believe the nationalmap.gov viewer shows a 735 meter contour on Old Turk, and a 736 meter contour on Record Hill, making Record the winner. This work needs to be double checked (hopefully with the actual LiDAR points) before PB & LOJ are changed to make Record Hill the winner. Details below. 1. Coverage https://www.coast.noaa.gov/inventory/ shows LiDAR coverage in this part of Maine. In addition the national map 3DEP Elevation - Auto contours have "wiggles" typical of LiDAR contours. They also properly map large flat areas for wind turbine foundations found south of Record Hill. 2. nationalmap viewer procedure https://apps.nationalmap.gov/viewer/ Navigate to Old Turk Use Layer List icon to enable this layer 3DEP Elevation - Auto contours Zoom in to Level 16, the last level where the default USGS National Map basemap is visible. I believe the LiDAR contours are always in meters. We see Highest LiDAR index contour ~= 2300' = 701m Next contour above this ~= 2360' = 719m I believe this shows: LiDAR index contour = 700m LiDAR contour above this = 720m Note that we can't use the profile tool to help us, as it uses old non-LiDAR elevations. Place the cursor on the 700m contour and zoom in to Level 17 and back to 16 a few times. Do the same for the 720m contour. I believe this establishes the following for zoom level 17: LiDAR index contour = 700m LiDAR contour above this = 710m LiDAR contour above this = 720m Highest LiDAR contour = 730m Zoom in to level 18. Grab the highest index contour (725m) and drag the map and inch or so. Repeat about 10 times. You will note that sometimes there are four contours above the Index contour, and sometimes there are two. The highest contour always has the shame shape. When the dust settles I think we show that for zoom level 18: LiDAR index contour = 725m contour interval is either 2.5m or 5m Highest LiDAR contour = 735m Grab the 735m contour, zoom in to level 19, and drag the map around 10 times or so. There are three possible contour intervals - 1m, 2m, and 2.5m. On the 1m interval the 735m contour is dark, and there is no 736m contour inside it. Navigate to Record Hill. Level 17 is 700m Index, 10m contours, 730m highest. LiDAR index contour = 700m LiDAR contour above this = 710m LiDAR contour above this = 720m Highest LiDAR contour = 730m Level 18 can provide a 725m Index contour with 5m intervals. You may have to drag a the map few times to get this. Grab the 735m contour, zoom in to level 19, and drag the map around 10 times or so. You may run across a map with the 735m contour gone, and a smaller one inside. This is a 730 Index, 2 meter interval, and 736m highest contour. 3. Supporting files are at http://www.cohp.org/writers/AndyMartin/prominence/Turk_vs_Record/ With names showing Zoom, Highest Index contour, and Interval Old Turk 735m: http://www.cohp.org/writers/AndyMartin/prominence/Turk_vs_Record/Turk_19_730I_1mInterval.jpg Record Hill 736m: http://www.cohp.org/writers/AndyMartin/prominence/Turk_vs_Record/Record_19_730Index_2m_interval.jpg 4. Comments Either I'm missing a simpler way to do this, of the viewer badly needs: 1. Labeling of the contours 2. User selection of the various contour intervals