3 
Introduction 
The last few years have seen a very considerable ex- 
tension of photogrammetric practice and a marked 
improvement in its quality, in Czechoslovakia. Photo- 
grammetric methods — that is up-to-date methods 
permitting automated production — are employed as 
a matter of principle in medium-scale mapping, and 
the application of universal plotters is the basic meth 
od of large-scale mapping. Photogrammetry also takes 
a prominent place in single-purpose mapping (for 
road- and railway-construction) and special work of 
other but topographic nature. Recently much interest 
is being taken in the interpretation of aerial photo 
graphs for various fields of science and technology; 
for the time being, this province remains off the main 
track of photogrammetric activities in Czechoslovakia. 
The representation of Czechoslovak photogram 
metry in the International Photogrammetric Society 
has undergone a change, in the period 1964 to 1968. 
Until 1966, the Czechoslovak Socialist Republic was 
represented by the Central Office for Geodesy and 
Cartography, whereas since January 1 st , 1967, the 
Czechoslovak member of the S. I. P. is the Photo 
grammetric Department of the Section for Geodesy 
and Cartography, Czechoslovak Scientific and Tech 
nological Society. All photogrammetric experts in 
Czechoslovakia are members of this organisation, and 
this national report summarizes their main activities 
and results achieved in the years 1964 to 1968. 
1. Aerial Photographs 
Great efforts were made to improve the quality 
of aerial photographs which are the basic working 
stock of photogrammetry. The transition to photo 
grammetric large-scale survey and the utilization of 
aerial photographs for various special purposes ne 
cessitated the adjustment of the techniques of both 
aerial photography and the processing of aerial pho 
tographs in the laboratory. 
11-14 aircraft, especially adjusted for aerial pho 
tography, superseded other types of aircraft which 
were less suited to the purpose. The cameras remain 
ed unaltered, on the whole: The MRB 21/1818 ca 
mera manufactured by Zeiss Jena and RC5 or RC5a 
cameras by Wild (f = 115, 152 and 210 mm) pre 
dominate. 
During the period covered by this report, ex 
tensive investigations into the quality of black-and- 
white aerial photographs were concluded, and new 
methods of taking photographs and processing them 
in the laboratory were introduced. The potentialities 
inherent in the optical systems of the plotting ma 
chines and the demands they make on the semantic 
quality of the picture are fully considered when the 
photograph is being taken and processed. This pro 
cedure has been facilitated by a new set of instru 
ments introduced into industrial practice. Particular 
mention should be made of the new Czechoslovak 
type LF-2 aerial photometer which permits the max 
imum and minimum brightness on the ground to be 
measured from the aircraft. The measured data are 
fed into a new aerial sensitometric computer. The 
optimum variant of the laboratory process for a given 
film is thus determined objectively and the exposure 
values are determined to correspond to the effective 
sensitivity. The negatives are developed in a newly 
designed automatic aerial-film processor (for nega 
tives up to 240mm wide). Electronic printers are 
used to make diapositives of all films. The feedback 
embodied in the sensitometric computation governs 
the entire procedure and integrates the whole set of 
apparatus into a harmonically working system, feed 
ing the plotting machines with diapositives of a con 
stant quality. 
Last year we have started to introduce — on a 
pilot-plant scale — aerial colour photography for 
photogrammetric plotting. A newly developed semi 
automatic colour printer for aerial films makes colour 
photography an economic proposition. A negative 
positive system and Czechoslovak Fomacolor material 
is employed. Film diapositives are used for plotting. 
The first results seem to suggest that colour photo 
graphy will make an essential contribution to photo 
grammetry. 
2. Mapping 
Having completed the photogrammetric oper 
ations involved in topographical mapping on the 
scale of 1:10,000, our surveying service now concen 
trates on the maintenance of those maps, based on 
aerial photographs, as well as on large-scale map 
ping; the scales — 1:1000, 1:2000, 1:5000 — de 
pend upon the economic importance of the surveyed 
territory. In practice, the scale of 1:5000 is used in 
preponderantly agricultural regions, and 1:2000 or 
1:1000 in industrial regions or districts where large- 
scale economic development is intended, as well as 
in towns and large settlements or areas of intended 
urban development. These maps, the “Technical and 
Economic Maps” as they are called, are to meet the 
requirements of all the branches of the national eco 
nomy, and in particular the needs of planning and 
capital investment. Photogrammetry using universal 
plotters is the main surveying method for making 
those maps. 
In order to reduce the cost of surveying, two 
new methods of analytical aerotriangulation — one 
for strip -- and the other for block-triangulation — 
were devised in Czechoslovakia, in recent years. Both 
methods are gaining ground in aerotriangulation for 
mapping on the scales of 1:5000 and 1:2000. 
Photogrammetric plotting is mostly performed 
on data plotters made by Carl Zeiss of Jena, the 
main types being stereometrographs and siereoplani- 
graphs fitted with coordimeter recording devices. Wild 
machines A5, A7 and A8 with EK3 and EK5 regis 
tering devices are also employed. The usual image 
scales are 
1:16,000 for 1:5000 maps, 
1: 9000 for 1:2000 maps, and 
1: 5000 for 1:1000 maps. 
Before the flight, the pass points, some points of 
the geodetic field, points for supplementary survey of 
unplotted spaces, and some detail points are marked 
for more precise definition and higher quality of 
photogrammetric plotting.