Old 9th Aug 2018, 22:07
  #186 (permalink)  
Join Date: Aug 2018
Location: West
Posts: 4
Analyzing picture in #151 with photogrammetric calculations (just in excel):

From 8 different topographic marks on the photo and using lat, lon, height values of those marks from WGS84 system in the map referenced in #157 the position/direction of the camera can be derived by mean-squared-error method:
Camera 46.902233 N, 9.224865255 E, 2639m Az 133.51 Elev 6.7
This is close to the Segnespass mountain lodge, but 12 m higher. Camera direction therefore is SE with 6.7 slightly upwards, 5 rotated clockwise.

The location of the plane shadow is where the line of sight crosses the terrain.
Shadow: 46.8987249855829 N, 9.23385 E, 2541m, distance from camera 792m

Direction of Sun at position of shadow Sat Aug 4, 16:50 local time can be derived rom several sites like sunearthtools. Of course this is the direction to the plane as well to create the shadow.
Sun: Az 252.88, Elev 38.3

Last element is to find the point were sun-shadow line crosses with line-of-sight to the plane derived from the photo:
Plane: 46.8981223562367 N, 9.2309869436985 E, 2721m, distance from camera 657m, 82m above camera
Actually the two lines are not crossing exactly, but have 15 pixel distance, which is half the planes size, likely due to sum of all small inaccuracies, which we have to be aware of.

The terrain height at the planes position is measured again from the map as 2473m. Thus the Ju52 has is in the moment of photo taken an calculated AGL of 248m.

BTW, the height of 2721m is about 100m above the lowest parts of the Segnespass ...

Last edited by MadMax9; 10th Aug 2018 at 10:46. Reason: improved accuract
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