Pigeon Point Light Station
Californian Pacific Coast, United States
16th May, 1831 U, 10:31 local
© 2016 James Gentles, All Rights Reserved.
Lat: 37° 10' 54.55" N
Long: 123° 24' 37.2" W
Elevation: 45m (ground 15m, tower 35m AGL, camera just short of Tower)
Precision is: High. Pinpoints the exact spot.
This technique produces two hemispheres, and a different workflow in PTGui from the classic ground pano technique. This results in extra effort BUT impossible angles!
See the rig, how Kite Aerial Photography is achieved, and the workflow.
1. Technology: Nikon make a Laser Rangefinder with inclinometer. That measures range and angle with a optical sight. This means during the shoot you can work-out height and distance. But what if (as here) you dont have time, and only have the resulting image...
2. Observation: It is possible to work-out directly from the image. If interested you can prove this mathematically, it's one of those problems where the initial complexity cancels out and reduces to a simple conclusion:
WHERE THE TOWER CUTS THE HORIZON IS THE HEIGHT OF THE CAMERA
That's about 5m from the top, or 30m AGL.
This technique can be used on any image where the horizon is clearly visible and can also be used to estimate the height of an object if the height of the camera is known (the corollary of this above example).