4 
number and positions of the necessary photo-control-points. The basic 
geodetic horizontal and vertical control thereafter is planned together 
with the supplementary network, to be determined photogrammetrically, 
and together with the small geodetic local networks, to be tied in to the 
photogrammetrically, determined supplementary network. It must how- 
ever be done, considering the want for fixed points in the field for field 
completion surveys, for staking out the new boundaries and for secur- 
ing their positions for the future. 
The planning also includes a decision concerning the signalizing of 
the control-points, photo-control-points, boundary marks and forest 
sample areas etc. 
The result of this planning is assembled on a simple scetch or map, 
containing the landed estate system, the lines between open and for- 
ested areas, some ways, waters and buildings, the geodetic control, the 
photo-control-points together with informations on the aerial camera, 
negative scale and signal dimensions etc. 
In fig. 1. some of the principal ideas of such a plauning are made 
visual. 
3.2. Signalizing, reconnaissance and. photography. Some important 
details of the ground will not be reproduced in the photographs, because 
they are too small, have too small a contrast to the background, are 
screened or shadowed. So it 1s necessary to make them visible in the 
photographs by means of signals, or in other case, to survey them geo- 
detically. Usually both methods are used, signalizing of boundary marks 
etc. which will be visible, and geodetic measurement of areas, covered 
with dense treecrowns. In order to get a sharp geometric determination 
of photo-control-points and controls, which are to be measured photo- 
grammetrically, they are also signalized. Forest sample areas are supp- 
lied with signals to make them easier visible in the photographs. 
The basic geodetic horizontal and vertical control is studied in the 
field. 
The supplementary network will be tied in to the basic network geo- 
detically or photogrammetrically but also geodetically to photogrammet- 
rically determined points. In this respect there are many ways to go. 
Single points are signalized in such positions, that initial directions to 
dominating triangulation points are visible. Points are signalized in 
pairs so, that they are visible mutually. Points are also laid out as shor- 
ter traverses, every point of which is determined photogrammetrically 
as to position. Then there is a possibility later on to measure geodeti- 
cally only a distance-traverse or a distance-angel-traverse between these 
points. The possibility of simple trigonometric height measurement was 
also investigated to some degree. Vertical angles will be measured with 
theodolite and distance will be measured on old maps or eventually on 
photographs or in any similar way. So it is possible to get acceptable 
height values for our conditions.