6 
The sample plots are studied in Ihe field and described. Necessary 
forest measurements of them are also performed. 
So the ground is prepared for photography and it is time for starting 
the geodetic field work. 
Photography usually is performed at the time with the best possibi- 
lity of looking into the ground, that 1s after the thawing of the snow and 
before the bursting into leaf. 
Contact prints, enlarged photographs and photomosaics are delivered 
short time after photography. All signalized points and areas are 1den- 
tified in the photographs and put numbers on. The contact prints are 
used especially for identifying the control-points and as an aid for 
orientation in the photogrammetric instruments. The enlarged photo- 
graphs are studied stereoscopically especially for identifying the signa- 
lized boundary marks, for inventory and for photointerpretation. The 
photomosaic 1s used as a preliminary substitute for the map to give the 
landsurveyor and the landowners a general survey of the district to be 
reallotted and also as a basis for planning the,work and as an index. 
> 
3.3. Photointerpretation and plotting in photogrammetric instru- 
ments. Photointerpretation 1s opened with a preliminary study of the 
photographs in order to get a general survey of the ground. The move- 
ment of the field parties are planned by studying the enlarged photo- 
graphs in mirror stereoscope. Cruise lines are located especially over 
the high producing forested areas as narrow winding zones spaced 1—2 
km from each other. In these zones sample plots are arranged and mea- 
sured in respect of forest elements. All areas in the zones arc also esti 
mated visually as to soil, moisture, tree species, forest site etc. The 
collected informations are noted on the photographs or separately. So 
the photointerpretor will be furnished with good means for correlating 
the informations on the ground with the corresponding informations in 
the photographs. 
At the following indoor photointerpretation all areas in between the 
zones are interpreted. Then the pieces of ground in these areas are de- 
lineated on the photographs, determined as to soil, moisture, tree spe- 
cies, forest site, land appraisal, landowner etc. The informations are 
noted on the photographs by some classification system. 
The roads and drainages are also planned preliminary by photointer- 
pretation. 
In that way practically all the necessary informations are collected 
and noted on the photographs. However some small scattered areas 
must be studied further in the field. This work advantageously will be 
executed from helicopter. 
In some cases a preliminary and partly planning of the landed estate 
system 1s performed especially of basic boundaries on. water-partings 
and along the more important roads. Already in this step of the proce- 
dure it 1s possible to stake out in the field some of the basic boundaries. 
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