2, PROFESSIONAL AND TECHNICAL ACTIVITY, RESEARCH, 
The large variety of works done by Czechoslovak photogrammetrists during 
the 1968 - 1972 period is reported in the sequence of the fields of inte- 
rest of the seven technical commissions of the ISP. T 
1. Aerial photography is carried out by the only agency in Czechoslovakia, 
which is looking after production and research as well. The research of 
several years had been accomplished when automatized processing of aerial 
negatives and diapositives was introduced into production during the repor- 
ted period, The Research Institute of Geodesy in Prague contributed in 
this field, too, carrying out some tests and investigation on application 
of color photography/28/ : tests with color photographs for large scale 
mapping, particularly in built-up areas, led to conclusion that there was 
no advantage of using color photographs when field inspection prevailed to 
photointerpretation. Therefore black-and-white photography is excludingly 
used for large scale mapping in our country. 
2. There are no photogrammetric instruments manufactured in Czechoslovakia. 
However, photogrammetry is the main method for large scale surveying and 
mapping, therefore investigation of photogrammetric procedures is in the fo- 
cus of our professionals. The active membership of Czechoslovak photogram- E 
metrists in the Working Group Standard Tests of Commission II from the ve- o o 
ry beginning in the period 1964 - 68, and again in the next period 1968 - 
712, therefore is not surprising at all. Two testing methods of photogram- 
metric stereoplotters were developed in Czechoslovakia, one at the Research 
Institute of Geodesy in Prague, another one at the Technical University in 
Prague; both of them were based on the measurement of a three dimensional 
grid model. In this field of interest is worth to mention the tests of small 
stereocomparators suggested by the Technical University in Prague; the same 
place implied an interesting way of the numerical relative orientation /40/. 
3. Two methods of the analytical aerial triangulation, one of them develo- 
ped at the Research Institute of Geodesy in Prague /33/,/42/, another one 
in Brno /2/, were largely used in practice during the period 1968 - 1972. 
Strip aerial triangulation by means of stereoplotters is applied when maps 
for highway or railway projects are plotted. A method of aerial triangula- 
tion from independent models was defined at the Research Institute of Geo- 
desy in Prague in the year 1970. The analytical bloc triangulation with 60% 
end and side overlaps of photographs has been investigated at the Research 
Institute of Geodesy in Prague /16/, /18/, /20/; two theoretical contribu- 
tions were published and briefly reported at the London Symposium of Com - 
mission III. 
4. The topographic maps at the scales 1:25000 and 1:10000 of the whole ter- @ © 
ritory of Czechoslovakia were published in 1957 and 1969 respectively; at