f organi- 
eport the 
upply of 
stitute of 
last few 
etry, and 
id will pro- 
or research 
iments is 
osition of 
ic photo- 
tematical 
iscovered. 
je correc- 
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n quite a 
from the 
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By angle 
sitions of 
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ean error 
y of each 
  
  
  
  
  
  
. Fig. 1. Test field for close-up 
photogrammetry. 
By taking a great number of photographs with the same camera, infor- 
mation is obtained concerning the regular occurrence of errors such as de- 
fects in the plate's lying close to the registering frame etc. 
A similar test-field for the larger stereo-camera and the photo theodo- 
lites is under constructicn in a large court yard. Here, however, it is not 
possible to get the same ideal distribution of the control points as in the 
other case. 
Measurements for Technical Engineering Purposes. 
Volume Estimation of Coal-heaps, Sand etc. 
In No. 16 an account is given of experiments to estimate the volume of 
coal-heaps with photogrammetric methods. The photography was made 
from a crane over the heap with a photo theodclite TAL. By the aid of 
a number of control points on the ground the photographs were plotted in 
the autograph A6 to a map with contours on a scale of 1: 50 (Fig. No. 2). 
The volume was then determined by the aid of known formulae. The accu- 
racy and the speed of the photogrammetrie method is very much superior 
to the common methods. A number of practical tasks were solved with this 
method and stereoscopic cameras. Similar methods have been used to esti- 
mate the volume in gravel-pits. In one case a helicopter was employed when 
taking the photographs (T horén), as it was difficult to get sufficient insight 
from the ground. The aerial pictures were successfully plotted in the auto- 
graph A5.