An investigation into the precision of determining 
property boundaries without demarcation points 
Bv: Ola Einevoll, Leader of Research, Department 
of Agricultural Department and lecturer Jon 
Holsen, The technical highschool of Norway, 
Trondheim. 
The object of the investigation. 
Photogrammetric plotting of signal points on boundaries which are seen on the 
pictures, do not presents more problems than the plotting of other clear details, 
and can be done quite as accurately. In many countries, attempts have been made 
to find out how accurate plotting can be. 
A complete marking with signals of the property boundary would be most expen 
sive, and often difficult to carry out. This is especially true in closely wooded 
areas, where risk is also greatest that the signal points would not be seen on the 
photos. 
The question therefore arises wether, if one omits the signal points on boundaries, 
partially or entirely, the map will fullfil the demand for accuracy, which is required 
of it. This was investigated on an experimental area in the Idd district started 
in 1960. The area used was about 100 sq.km, and can be regarded as a good 
example of coniferous wooded area in our country. The investigation was planned 
to give a direct comparison of the accuracy achieved when recording boundary 
points not signalled with the same points after signalling. The investigation was 
otherwise planned as described in the following sections. 
Photographing. 
The photographing of the area for the experiment was carried out on May 14th, 
1960, before signalling with one series of photos in each of the following scales: 
1:10.000 Aviogon, 15 cm 23x23 cm 
1:15.000 Aviogon, 15 cm 23x23 cm 
1:20.000 Aviogon, 15 cm 23x23 cm 
1:15.000 Aviotar, 21 cm 18x18 cm 
On August 22nd, 1960, signal points were marked, with one series in the scale 
of 1:17.500 Aviogon, 15 cm, 23 x 23 cm. This was the control series, and was much