4 
NORWAY 
The aerophotogrammetrical activity of the Geographical Survey was 
hampered during World War II. The German occupation prevented a further 
development. During these years one was compelled to use terrestrial photo- 
grammetry and plane table surveying. 
Since the end of the war, the Geographical Survey has supplemented 
its photogrammetrical equipment from the Wild Company (see above). For 
several years there was also a considerable lack of experienced personnel. It 
is only since 1950 that the photogrammetrical activity at the Geographical 
Survey has overcome the delay caused by World War II. 
The period 1952—1955. 
Instruments. 
1 A 5 
3 A 6 
1 A 8 purchased 1955. 
The aerial cameras used are Wild RC5, Aviogon, f-11.5 and Wild RC5, 
Aviotar f-21, both of negative size 18 x 18 cm. 
For the determination of control points, the theodolites Zeiss Th II, Wild 
T II and Wild T I are used. 
Procedure of the photogrammetrical work. 
As stated in the report of 1938, the photogrammetry in our mountainous 
terrain has to be based on stereo-compilations. The Geographical Survey 
applies vertical photography exclusively. The ground control is in most cases 
obtained by aerial triangulation. The chief map scale of the topographic maps 
of Norway is 1 : 50 000 (up to the present issued on the scale 1 : 100 000). 
In the surroundings of larger towns a map scale of 1 : 25 000 is used. The 
scale of the aerial photography varies according to the nature of the terrain. 
In areas with a higher density of population a photo-scale which permits 
compilation on a 1 : 10 000 scale is frequently applied. 
The aerial triangulation is performed in the A5 autograph, the compila 
tions in A6. The combination 3 A6 plotters to 1 A5 autograph seems to be 
well balanced. The A-8 plotter will mainly be used for compilations on the 
scale of 1 : 10 000. 
Aerial triangulation in space is executed for every second strip in a block 
of photogrammetric coverage. From these strips control points are taken 
also for the adjoint strip. Signalization of ground points prior to the aerial 
photography is not done. The compilation is performed on high quality, 
metal-mounted drawing paper. The compiled map manuscripts are always 
run through a field checking. In the field, the topographer works on a blue 
print of the original compilation. The results of the field checking are trans 
ferred to the original compilation, which is then inked. Field checking on the 
photographs prior to the stereo-compilation is in general performed only as 
far as the location of administrative boundaries, the classification of structures 
and the identification of trig, points goes.