[GH85Carrera]

Good hump day morning all.

One of the sites we have flown since the 1970s is a plant that makes "stuff that shall be un-named" and puts it in large piles out in their plant yard. One pile is for customer A and the last pile is for customer B and they have several dozen large piles of the stuff. Of course the tax folks want their cut of the profits and the company wants internal auditing on how much stuff was made and sold. They load it on railroad cars so I am sure they know the weight of what was sold. The value of inventory on the ground is what the tax folks want a cut of.

We fly over at a prescribed time and the auditors are there to see us fly over. I guess to be sure we don't just make up numbers. We fly it in stereo and we can measure the volume of each pile of stuff and tell them how many cubic yards of stuff is in each pile.

I am always amazed at the math involved to figure out the aerial triangulation to know the exact angle each photo was taken at and calculate the tilt, tip and yaw of the camera angle. We of course try to shoot it straight down but wind and gravity make that impossible for every photo. It is controlled down to the pixel and we can generate a point cloud with a point every few inches on the ground. The exact shape of the pile shows up. With a little more math we can calculate the volume of the pile.

All of that started in WW2 by the British and US governments trying to figure our the German defenses and weapons. It was done with humans looking at the photos in 3D and hand drawing the contour lines. Now we use the same math principals and computers to be a ton faster and more accurate. It is just amazing to me how anyone figured out how to do it in the first place.