Fig. 1. Map A - 1:8000 (reduced 2/3) - compiled by geodetic and 
photogrammetric methods in the field. 
The main problems to be studied are the following ones. How de- 
pend the fullnes of detail and the accuracy of the mapping out by pho- 
togrammetric methods on the different negative scales in comparison 
to the corresponding values of mapping out by geodetic methods in the 
field? What variables are the most suitable for studying those pro- 
blems ? 
2.3. The primary material. The area experimented on is situated in 
Dalecarlia. It consists of about 530 hectares of forested land, 130 hec- 
tares of swamp and 40 hectares of watercourses, together about 700 
hectares. It is divided in two parts, a and b, each of which is studied 
separately. 
The area was interpreted and mapped four times at a scale of 1:8 000. 
A. By geodetic and photogrammetric methods in the field. 
B. By photogrammetric methods from aerial photographs at a scale of 
1:18 000. 
C. By photogrammetric methods from aerial photographs at a scale of 
1:13 000. 
D. By photogrammetric methods from aerial photographs at a scale of 
1:8 000. 
The map A was compiled partly in the stereoplotter Wild A 6 from 
aerial photographs at a scale of 1:17 000 and partly by geodetic me- 
thods in the field. All planimetry was controlled in the field. It was