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THE REPORT OF THE PRESIDENT OF THE FRENCH SOCIETY
OF PHOTOGRAMMETRY
In the course of the last four years the development of Photogrammetry
is again of marked importance both in the domain of applications and of
research.
Applications
1) Private Sector:
Three mapping organizations apply photogrammetry in their work:
The Société Française de Stereotopographie (S.F.S.) which specializes in
mapping at large scales by terrestrial photogrammetry (6 plotting ma
chines).
The Société generale de Phototopographie which has established a branch
in Moroco (2 plotting machines).
The Compagnie aerienne de Photographie (C.A.P.) whose field of activity
covers all of North Africa. It uses “Gallus-Ferber” plotting machines which
have been modified during the last few years from double projection to
stereoscopic use (4 plotting machines).
2) Official Sector:
a) Cadaster — The Service du Cadastre continues to use ordinary rectifi
cation for flat terrain and plotting by rectified sectors of the photograph
in terrain with some relief. In terrain of much relief with limited fields of view
(parcels surrounded with hedges) it utilizes aerial photogrammetry successfully.
It is progressively equipping itself with Poivilliers — SOM Type B Stereotopo-
graphes (plotting machines).
b) Ministère de la Reconstruction et de l’Urbanisme (M.R.U.), Its efforts
are specialized on equipment and topographie plans of urban localities. The
precision required is not high and photographic or mechano-graphic methods
only are used. The data for plotting are furnished by a gyroscopic device in
vented by M. Dubuisson.
c) Institut Géographique National (I.G.N.). This organization has charge
of mapping France, North Africa and the territories of the French Union; a
program of about 12 million square kilometers, in the most diverse latitudes,
longitudes and climates. Aerial photogrammetry only is employed for the exe
cution of this mapping.
Escadrille.
The I.G.N. has a group of specialized aviation squadrons placed under the
orders of the chief of the photogrammetric service. This group whose home
base is at Creil is composed of four squadrons, three of four bimotor planes,
and one of 5 four-motor planes; a total of 17 photographic airplanes serviced
by 60 flying men and 60 non-flying. The photographic equipment used is com
posed of automatic plate Poivilliers SOM cameras of 125 and 150 mm focal
length and formats of 13X18 and 19X19 centimetres (10 cameras 13X18 with
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