Image pair photos

SMEAR tower images

What is the elevation of the tower top?

Three corners of the tower give: {253.831, 253.845, 254.17} m in KKJ-system.

Is the tower tilted or does it stand vertical?

Following XY-coordinates were measured for one side of the tower (at different heights)
2515700.795, 6860103.115 (top)
2515701.209, 6860103.321 (uppermost boom)
2515701.113, 6860103.025 (2nd heighest boom)
2515701.274, 6860103.186 (3rd      "   boom)
2515701.334, 6860103.292 (4th      "   boom)
2515701.006, 6860103.257 (5th      "   boom)
==> tower stands vertical

"A hill"

What is the elevation of the highest point? Where is it in KKJ-east and north ?

The hill does not a very distinct peak. 184 a.s.l is the highest elevation (approximate)
[2516266, 6858996,184]

Hyytiälä building images

* There are two buildings in the low right corner of the images.

How high are the buildings?
What is the volume of the bigger building in m3?

Assuming that the roofs are horizontal and that there is constant elevation (flat, planar) for the terrain around the buildings:
roof corners are at elevation: 165.7 and 165.4 meters. The terrain elevations is (based on the corner of the shadow cast by the smaller building) 158.8 meters. Thus the heights are 165.7-158.8 = 6.9 and 165.4-158.8 = 6.6 meters.

The volume of the bigger building is based on the assumption that the volume is given by the equation: (area of the roof * height) = Volume.
The two side lenghts of the roof are:
SW-corner 2515352.116, 6859866.453
SE-corner 2515366.199, 6859874.781
NE-corner 2515351.511, 6859900.478
SW-SE 16.36 meters, SE-NE 29.59 m  => Volume = 16.36*29.59*6.9 = 3341 m3

* The uppermost parts of the image show a lawn field.

What is the elevation of the field (it is flat). Look at column 2746, row 10843 on the left image?

Based on the centre of the round conjugate entity seen on both images: 147.13 m

Spruce plot 1

* What is the terrain elevation in the forested part of the photo? Look for shadows cast on the ground.

Observations (X,Y missing): 169.7, 170.9, 169, 168.41 (there is a slope, the terrain visible in the upper parts of the image is slightly higher than the road).

* How high are the trees? Click a tree top on the left image and use the epipolar line to find the corresponding tree top on the right hand side image.

Observations for some tree tops: 193.2, 184.23, 180.6, 184.35, 189.14 , assuming an average terrain elevation of 169 meters, the tree heights
are in the range 11.6 - 24.2 meters (the 24.2 m high tree is a dominant birch tree, look at col 2240, row 5140 (left image)).

"Clearing image"

* there are two shadows of trees in the middle parts. What is the height of the Trees based on the shadow lengths ? (elevation of the sun is 34 degrees above the horizon, the azimuth angle is 115 degrees from KKJ-north)

Left tree: butt: 2516591.068, 6860711.327, 169.925, top (shadow):2516555.012, 6860722.175, 170.116
right tree: butt: 2516581.259, 6860726.491, 170.74, top (shadow):2516549.187, 6860736.439, 172.57

Shadow lenght: 37.65 m, height difference (top-butt) 0.19 m, angle b (degrees) 0.29,
  tree_height = 0.19 + {shadow_lenght*cos(0.29) }*tan(34-0.29) = 25.31 m

Shadow lenght: 33.63 m, height difference (top-butt) 1.83 m, angle b (degrees) 3.11
  tree_height = 1.83 + {shadow_lenght*cos(3.11) }*tan(34-3.11) = 21.91 m

shadow_lenght = sqrt(x1-x2)^2+(y1-y2)^2+(z1-z2)^2)

Measurements based on the low constrast tree tops give 197-170 = 27 m and 196-171 = 25 m
 

Kalela's stand

* what is the elevation of the log pile visible in the middle of the image?

184.368 m

* how long are the logs?

One long
2516155.662, 6860576.286
2516152.859, 6860581.171

==> 5.6 m

the logs are 4 - 6 meter in lenght!
 

Image triplets

"Konehalli images"

* measure the elevation of the roof of the buildings using different combinations of images: 1+2, 1+3, 2+3, 1+2+3

1st try  (165.98, 165.45, 164.93, 165.452)
2nd try (166.35, 166.03, 165.72, 166.036)