s le domaine de laquelle 
•eneurs travaillent avec 
aux: 
1948 une activité bien 
îment nouveaux ont été 
)grafo Simplex mod. III 
: solaire et le calculateur 
a été aussi bien sensible, 
otogrammétrie aérienne, 
ur une surface totale de 
1/4000. 
entreprises privées. L’er 
re a celle des levés topo- 
létrique ne doit surpasse 
dressement de la carte 
et 1952 la surface totale 
étriqué est de ± 1.50 m 
tolerable. 
îcutés par les entreprises 
'ur projets de barrages et 
études au sujet de l’aero- 
du point nadiral sur les 
e poursuivie par l’EIRA 
tudier avec beaucoup de 
à les importantes conclu- 
conduites par M. Nistri, 
yroscopes employés et la 
rrait attendre. 
(77) 
NATIONAL REPORT ON THE NETHERLANDS 
by 
B. Scherpbier. 
It is a great honour to me to be given the opportunity to say a few words at 
this meeting as President of the Netherlands Society of Photogrammetry. It 
also is a great pleasure to me personally to speak again in Washington. I had an 
opportunity to do so for our hosts of this Congress for the first time in 1936 
and later in 1946 and 1948. I dare to claim to be a member of long standing of 
the American Society of Photogrammetry since I joined already in 1936, so I 
may say I feel quite at home in these surroundings. 
The report on activities in photogrammetry in the Netherlands since 1948 
has been written by Prof. Dr. W. Schermerhorn, following an old tradition, as 
all previous reports have been written by him. 
From these reports it appears that not many changes in methods have 
occurred since the sixth Congress. 
The Netherlands Topographical Survey, uses photogrammetry for making 
new map series and for keeping the maps up to date. Work has commenced on 
a new map series in scale 1 : 10.000. Photo interpretation has already been 
applied for many years by the Director Mr. Yon Freytag Drabbe. 
The Photogrammetric section of the Surveying department of Public Works 
applies photogrammetry for maps for engineering and other purposes for public 
works and also for cadastral and especially for reallotment work. This agency 
also carries out the photogrammetric part of the preparation of maps from air- 
photographs for the B.P.M. (Royal Dutch/Shell Group). The methods of trian 
gulation applied vary from slotted template triangulation to aero triangulation 
in the A5 or the stereoplanigraph. Aero levelling is also carried out in the A6. 
For mapping a wide range of methods and instruments is applied, depending 
on whether paper prints, diapositives, or films are used and on the scale of 
photographs and ultimate maps as well as on the kind of terrain to be mapped. 
The Geodetic Institute of the Technical University at Delft does research 
work especially on objectives of air cameras and also carries out photogram 
metric work for special purposes, such as the solution of hydraulic problems, 
checking the flatness of ships plating etc. 
The Photogrammetric and Cartographic Bureau of K.L.M. (Royal Dutch 
Airlines) carries out all the photographing for the Government and other 
agencies in the Netherlands and also does airphotography and photogrammetry 
in mapping in contract in various parts of the world. 
Soil studies by interpretation of aerial photographs are made by the Geo 
logical and Agricultural Government agencies. 
The International Training Centre has now started to work, and students 
from many countries are being trained, or follow refresher courses. 
In 1950 the Netherlands Society of Photogrammetry has organized a sym 
posium on photo-interpretation in which most of the aspects of interpretation 
were presented by competent experts. The auditorium amounted to about five 
times as many as normally attend the meetings of the Society. This illustrates