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K.L.M. Aerocarto and the Director of the " Meetkundige Dienst" van de Rijkswaterstaat
Ir. van der Weele is assistant professor at the I. T.C. If in the near future good results will
be obtained in the Netherlands in the development of photogrammetry, this will to a large
extend be due to the close cooperation and friendly personal relations between the many
workers in the various services and institutes in Delft.
CHAPTER I. AERIAL PHOTOGRAPHY
lABLE l indicates the photography carried out for mapping between 1956 and 1960.
As can be seen from this table there exists only one organization in the Netherlands for the
production of air photographs for photogrammetric purposes: K.L.M. Aerocarto. There
is, however, in recent times a tendency for the Government photogrammetric services to
have the flying organization in their own hands, also in order to be able to carry out
experimental flights on other bases than at present. Each of the services, however, is too
small to justify the existence of their own flying organization. Therefore a pooling would
anyhow be necessary and then the advantage for each of the services would be reduced
again. From the point of view of the national economy the existing organization is the most
favourable on condition that certain requirements are fulfilled by the central commercial
organisation.
The cameras in use with K.L.M. Aerocarto are:
WidRC5 18% 18cm Aviotar 4 —% cm, film
Wild RC5a 9x 9 inch Aviogon f= 6 inch, film
Wild RC 5- 18x18cm Aviogon / 11,5 cm, film
WiIdRG 7: 15x15 em Aviotar B= 17 cm, “plates
Wild RC7_ 15x15cm Aviogon /= 10 «m, plates
Zeiss P10 18x18cm Topogon /— 19 cm, film
Zeiss 2 x RMK single and convergent 18 x 18 cm Topar 21 cm, film.
During this period the Cadastral Service and the Survey Department of the Ministry of
Transport and Waterstaat made again, as was the pre-war Netherlands practice, the use
of the Zeiss twin camera. The difference in precision between map-production from RG 7
plate negatives and from convergent film photographs can so far not be derived in a reliable
way from the Netherlands result. See for this the invited paper about this subject presented
by the author in Commission IV/1. We consider more systematic research in this respect
necessary. Since the inner orientation is much more important for convergent photography
than for near vertical, more calibration of the cameras will be necessary than carried out
so far in the Netherlands. The mechanical checking is carried out in the K.L.M. specialized
instrument departments. The camera calibration is carried out according to the gonio-
meter methods in the Geodetic Institute of the Technological University but less frequently
than necessary in my opinion.
The aircraft in use are: Dakota for the general type topographic surveys abroad and
the Havilland Domini for topographic and large scale surveys in the Netherlands. Re-
garding navigation devices the sighting pelorus visors are used for the lateral overlap. The
gyro stabilized drift sight (Pioneer B3) modified for aerial survey as mentioned already in
the report of 1956 is also used regularly for the forward line of sight. The navigation has
so far been always carried out as visual navigation using the flight instruments as auxil-
iaries. The automatic pilot is only used in the survey Dakotas. Electronic aids are not in
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