I’ve been playing the past few days with a Lidar data set, just for the fun of it. Lidar is laser ranging, and here in Ohio they’ve mapped the whole state with an elevation accuracy of around 1 foot.
So I’ve made a few images by writing some software to process the data.
First up is The Octagon earthworks in Newark. These were built by Native Americans around 2000 years ago. Here is a map from an 1847 survey showing the Octagon and the Observation Circle in the upper left hand corner.
The mounds are currently about 5-6 feet high. As I mentioned in an earlier entry, the Octagon is a lunar observatory. And here is my Lidar image:
Next up is is the High Banks structure. This is down just south of Chillicothe, about 70 miles away from the Octagon. But this, too, is a lunar observatory. If you look closely, you will see that it is perpendicular to the Octagon (actually, not quite, the difference being what is needed to still line up with the moon correctly at its slightly different latitude). You will also notice that the large circles are the same diameter.
These earthworks have been plowed down pretty heavily so they don’t show up very well on the ground, but they sure show up on Lidar.
Finally, since I’ve been spending a bit of time near Conkle’s Hollow in Hocking Hills lately, I also processed the date for that site. See if you can spot Conkle’s Hollow.
The large hollow going up the top of the picture is Crane Hollow, and Conkles Hollow is the smaller one to its west. I love the way even the winding stream course shows up. Can you also figure out where Turkey Point and Airplane Rock are?
I’m marked them with arrows below.
Vulture Point is on the left and Airplane Rock is on the right. You can also get a pretty good look at Vulture Cave just to the west of Vulture Point.
I think the Lidar also does a pretty good job of highlighting the cliff areas.