15 
obtained are still available and will be given 
hereunder: 
A picture scale of 1:30000 was prescribed for 
the individual projects which had an average 
coverage of 20 000 km 2 . With the use of the 
Zeiss-Aerotopograph camera RMK 20/3030 
this is equivalent to a flying height of 6000 m 
above the ground. The direction of the lines 
of flight was uniformly due West-East or 
East-West. The average length of the runs 
was 140 km, although there were maximum 
runs of 320 km. With a strip coverage of 
9 km, a flight line spacing of 6,5 km and an 
average of 6 runs per mission, the average 
area covered was 5000 km 2 . In several cases 
where weather conditions were particularly 
favorable, up to 10 000 km 2 have been photo 
graphed on one mission. With a time of flight 
of about 8 hours including travel to and from 
the area to be photographed, this corresponds 
to a flight path of approximately 2500 km. 
The phocographic plane was a two-engine 
Heinkel aircraft He 111 which had been 
equipped with additional tanks for long-di 
stance flights. With an absolute ceiling of 
8500 m with full load the aircraft climbed to 
about 6000 m in 45 minutes. Air speed at this 
level was 320—340 km p.h. For navigation pur 
poses, the pilot’s cockpit which afforded amp 
le visibility to all sides, was equipped with a 
Lotfe. Fligth paths and turns were flown 
with a Siemens automatic pilot. The camera 
was mounted in the middle of the fuselage 
above the entrance “blister“. The latter was 
provided with a hatch and could be opened 
during the flight. When the camera was 
lowered, the automatic Zeiss-Aerotopograph 
tilting mount permitted taking picture strips 
from horizon to horizon, if required. When 
the blister was open, a Plexiglass windbreaker 
apron attached to the camera and the magazine 
prevented the penetration of the outside air 
into the interior of the cabin. 
Navigation was based on maps with a scale 
of 1 : 2 000 000 in Mercator’s projection with 
isogones at 1-degree intervals. Occasionally, 
very poor maps at a scale of 1 : 300 000 (pro 
bably enlargements of maps 1 : 1 000 000) 
were available, which, however, were unsa 
tisfactory for pilotage. The 90 strips under 
consideration had the following deviations 
from the theoretical position: 
Maintenance of the geographial East-West- 
direction +. 
Accuracy of the flight line spacings with in 
strument-controlled turns 4^ 120 m 
Accuracy of the maintenance of flight line 
spacings along the flight paths (140—320 km) 
+ 400 m 
Control of altitude on missions flown on dif 
ferent days (use of FuG 103, geodetic con 
trol by comparative ground surveys) 
+ 15 m 
Fig. 12 
Results obtained on two missions of 6 turns each; area covered’, abt. 14000 km-, maximum 
lenghts of strips 270 km; 797 photographs. (Only the nadir point of every fifth photograph 
is marked) 
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