REPORT OF COMMISSION II: PLOTTING, THEORY AND INSTRUMENTS 
9 
sists of the Wild A8, Poivilliers D4, Morin 
instruments, the Wild RC8 (115, 152, and 210 
mm. focal lengths) and the Zeiss 30X30, 
(750 mm. focal length) cameras; as well as 
auxiliary equipment for numerical photo- 
grammetry operations and coordinate re 
corders. Both black and white and color 
photography are used. 
APA was organized in 1957 with eight 
personnel to carry out cadastral and topo 
graphic mapping at scales of 1 :500 to 1:20,000. 
Equipment consists of three Photo-Carto- 
graph SFOM-Nistri, Type 6. 
Personnel 
Photogrammetric Department of IGN : 
10 geographical engineers (chief geogra 
phers) 
35 engineers of geographical works of the 
state 
65 technical assistants 
300 workers (compilers, photographers, illus 
trators) 
A group of photographic aircraft is attached 
to the Photogrammetric Department which 
has important resources in personnel and ma 
terial (10 teams and maintenance personnel, 
12 four-engine planes, 8 twin- engine planes 
(Type H.D. 34)). 
Aerial Triangulation and Plotting 
Instruments Employed 
The Photogrammetric Department (IGN) 
has the following equipment available which 
is assigned to large and medium scale work; 
the scale of the negatives on plates varies 
from 1:3,000 to 1:30,000. 
AEROTRI ANGULATION 
1 Nistri T.A. 3 
3 SOM Stereocomparators 
3 Type B Poivilliers equipped with co 
ordinate recorders 
51 Type B Poivilliers—1st class equipment 
with coordinatographs 
2 Operators (1 compiler and 1 draftsman) 
11 Poivilliers Type C (Requirements no 
longer needed). 
COMPILATION 
The scale of the image is intermediate be 
tween the viewing scale and the “restoration” 
scale. For example: 
[negative 1:3,000 
Scale] image 1:2,000 
Idrawing 1:1,000 
1:13,000 1:30,000 
1:10,000 1:20,000 
1:5,000 1:20,000 or 
1:10,000 
equipment assigned to medium scale and 
small scale work (1:50,000 to 1:200,000): 
57 Poivilliers D (2nd order instruments). 
(This type of equipment makes it possible to 
make an anamorphic restitution and permits 
the use of film made with the Wild RC 9 
camera). 
5 Stereoflex; simplified equipment assigned 
to small scale work in regions with very few 
hills (low relief). 
A few units of Poivilliers Type B instru 
ments are used for work on terrestrial photo- 
grammetry (architecture, comparison of re 
duced and actual models, determination of 
position of clouds released by rockets, etc.). 
Note also the Poivilliers Type B are out 
fitted with recorders of coordinates for the 
determination of points, recorded on tapes 
and punch cards with a view toward the se 
lections of the best highways (programming 
toward computation on electronic computer 
under study at the Flighway Department). 
Aerial Data Recording 
cameras 
At IGN all the photographic coverage that 
will be made use of by aerotriangulation or 
by restitution are made on glass plates with 
automatic Poivilliers SOM plate cameras. 
The format of the plate is 19X19 cm. The 
focal lengths are: 125 mm. Aquilor lens; 210 
mm. Orthor lens and 300 mm. The IGN also 
has cameras for SOM film (Aquilor lens, 125 
mm., 19X22 cm.) used for infrared coverage; 
the Wild cameras, etc. 
The scale of original negatives varies from 
1:3,000 to 1:65,000 for coverage made with 
automatic Poivilliers SOM plate cameras. 
For 1:65,000 cover (focal length 125 mm.) 
the photographic height is 9,000 to 10,000 
meters. Finally, the RC 9 camera enables 
IGN to get cover at a scale of about 1:100,000. 
RECORDING MEDIA 
The infrared and color films at IGN are not 
used for cartographic purposes but solely for 
interpretation. It is easy and cheap to obtain 
simultaneous panchromatic and infrared 
coverage. The simultaneous study of the two 
coverages is priceless for interpreting. 
The infrared and color films are requested 
by Water and Forestry Department and other 
Departments. 
APR profiles made in the recovery zones of 
photographic strips give, after internal and 
external adjustment, the required reading for 
small scale restitution. In open and low