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COMMISSION 
Appendix to the 
| PHOTOGRAMMETRY Vol. X 
Communication to 
VIII International Congress for Photogrammetry 
Reprint from 
Svensk Lantmiteritidskrift 
Congress Number 1956 
  
Commission I 
AERIAL PHOTOGRAPHY WITH SMALL AIRCRAFT UNDER 
TROPICAL CONDITIONS 
By 
Lars Ahstrand 
Mapping project 
During 1955 the Division of Photogrammetry at the Royal Institute 
of Technology carried out aerial photography in South America, among 
other purposes for a big agriculture planning project in Ecuador: hous- 
ing, roads, drainage, cultivations, forestry etc. 
some years ago geodetic triangulations and traversing had been made 
in this area, and those measurements now had to serve as control net- 
work for the photogrammetric mapping. Signals were produced of 
different sizes: 1.4 X 1.4 metres, 1.7 X 1.7 metres and 3.0 X 3.0 
metres. 
Aircraft 
The flying was done with the Swedish fourseater Saab 91 C S'afir. 
This 1s an all-metal, low-wing aircraft, equipped with a [Lycoming 
0-435-A engine of 190 bhp, which gives a top speed of 275 km/h 
(figure 1). The plane has a wing span of 10.6 m, a length of 7.95 m, 
fuel tank capacity 150 litres, cruising range at sea level 900 km, rate of 
climb (at sea level) 4.25 m/sec. and service ceiling 5 100 m. 
Camera 
An aerial camera of type Eagle III (Ross Wide-Angle lens Xpres 
1:4 n:o 140740, 5 inches) was mounted on the place for the right, rear 
seat (see figure 2). The dismounting of the seat and mounting of this 
small and light camera only required about 15 minutes, which was of 
great importance as the plane also had to be demonstrated as a military 
trainer. 
Lf a bigger camera is wanted it may be necessary to remove the two 
t A1] 
INT. ARCHIVES OF 
lE4, 1956 
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