SPACE-TIME PHOTOGRAMMETRIC DETERMINATIONS 
FOR OPTIMIZING THE RIVER NAVIGATION 
Ovidiu Andrei 
and 
Eugen Cotovanu 
Romanian Committee of Photogrammetry 
ABSTRACT 
The photogrammetrical space - time 
measurements, with synchronized taking of 
photograms, spread on large spaces, find 
themselves a direct application in the 
technical field, namely in the optimizing 
study of the river navigation. It refers 
to the photogrammetrical measurements con- 
cerning a naval convoy in moving state, 
while inscribing in a curve of the Danube 
navigation channel, at the hydroelectrical 
complex of the Iron Gates With the pur- 
pose of making at the same time a study of 
the achieved precision in such space - time 
measurements, simultaneous telemetrical 
measurements were made. They were synchro- 
nized with the taking of photograms, so 
that finally a comparison of the results 
achieved by two methods, be possible. 
The photogrammetry, as a discipline 
dealing with a phenomenon or object ren- 
dering and sizing, on the basis of photo- 
grams, in order to determine their shape 
and position in space, and time, has been 
concentrated mainly on the space measuring 
of objects. 
Either in the case of air photogram- 
metry or the ground one, having in view 
57 
both the design activity and the laborato- 
ry researches, the object which is to be 
measured has often a fixed position against 
a, three-dimensional reference system, or 
its movement is so slowly that it may be 
considered motionless taking into account 
the time of taking photograms. o 
This characteristic of the photo- 
grammetry was considered as & limit be- 
cause it excluded the phenomena with ra- 
pid movement out of the field of photo- 
grammetric measurements. 
To extend the photogrammetric mea- 
surements in the space-time range is an 
important problem and it complies with 
the ever growing technical necessity of 
an accurate measuring of the moving phe- 
nomena as far as the respective movement 
is faster and more complicated. 
We can give exemples such as the 
problem of wave behaviour necessary to 
the ship design and the location of har- 
bours or sea platforms for oil extractiors 
or the problem of controlling the ship 
launchings from the docks, or to study on 
models the way of the moving boat etc. 
In most cases the measurements of 
phenomena in motion i8 limited to the use 
of some mechanical,eleetromagnetical or 
electronic devices placed in different 
points in order to record the phenomenon 
development in these points. 
No matter how much fine and rigorous 
such an operation would be, the final re- 
sults is a measurement of isolated points 
which only by interpolation could give the 
phenomenon interpretation on the whole of 
his movement. 
An interpolation implies an approxi- 
mation which is the less accurate the smal- 
ler the number of points used at interpo- 
lation is. 
Using the photogrammetry in the 
space - time range eliminates this short- 
coming. The advantages of this system con- 
sists of & general recording which enables 
us to obtain very important information. 
From stereophotogrammetric point of 
view the problem of a space-time measure- 
ment has two different aspects. 
One of them refers to the determination 
of the moving object shape and position at