Here’s a little GIT (geographic information trivia) showcasing some local history and modern spatial data shared by John W. Barge of the Adirondack Park Agency on March 17, 2017.

“On this day [March 17] in 1776, the British army evacuates Boston. It was the culmination of an American effort that had begun many months earlier.

The City of Boston had been under siege by the Americans since April 1775. As the months wore on, a colonel in George Washington’s army, Henry Knox, had an idea: Why not retrieve the British cannons and artillery that could be found at Forts Ticonderoga and Crown Point? Those forts had been captured by the Americans, and the cannons were available, assuming someone could make the trip with them.”see article

Using new USGS 1 meter DEM’s (Thanks, USGS and GIS Program Office!) and Esri’s Multi-Directional Hillshade function here are some views of the Crown Point Ruins and Fort Ticonderoga both at 1:4000 scale with a little transparency showing the NYS 2013 Orthoimagery beneath.

Crown Point:

 

 

 

 

 

 

 

 

 

 

 

Fort Ticonderoga:

 

 

 

 

 

 

 

 

 

 

I never used multi-directional hillshading before testing with these areas. I like the results on the Crown Point image. The Ticonderoga landscape is a little harder to figure out what’s up and what’s down based on the shadows. The hillshading we’re used to seeing has light coming from one direction casting shadows generally in the lower right of the image. With multi-directional hillshading, the light and shadows reveal subtle textures in the surface. If you want to dig deeper on the topic, here’s a link to a short description on the Multi-Directional Oblique-Weighted hillshade approach.

These two spots are great places to visit. Get out and enjoy. Happy mapping.

John W. Barge
Adirondack Park Agency
PO Box 99, 1133 State Route 86, Ray Brook, NY 12977
www.apa.ny.gov