things were discussed as map scale and contour interval, accuracy, mea- 
suring method, flying altitude, the kind of film, control points, photo 
signalisation, the material of the maps, as well as the drawing and repro- 
duction procedure. 
Map scale and contour interval 
According to tradition in Sweden, maps for cadastral purposes and for 
new building within the towns are prepared in the scales 1:400 or 
1: 1000. 
A change-over from map scale 1: 400 to 1: 500 has been discussed and 
has also been the subject of an investigation. Considering that the City 
of Stockholm employs the scale 1: 400 and that there is a joint coordina- 
te system and system of map sheets for Stockholm and communities 
bordering upon Stockholm, there was not sufficient reason for the Com- 
munity of Huddinge to change over from the scale 1:400 to the more 
practical scale 1: 500. A decision was consequently made to use the scale 
1: 400. The intervals between contour lines were established at 1 metre 
and 0.5 metre normally on fairly level ground. 
Accuracy 
In large scale mapping, the demands for accuracy are often defined as 
standard errors in position and elevation which must not be exceeded. 
The maximum standard error in sharply defined planimetric details is 
usually set at 0.25 mm in the scale of the map, and in contour lines at 
a third of the interval between the contour lines. For mapping in the 
scale 1:400 with 0.5 metre contour lines this implies 0.10 and 0.17 
metres respectively. : 
In maps of this kind, spot heights of, for instance, streets and roads are 
often desired. The standard error of such points should not exceed 0.10 
metres. 
Keeping in view the use of the maps, these demands regarding accuracy 
were considered sufficient and the decision was made that the following 
standard errors should not be exceeded: 
Standard error in sharp planimetric details ........ 0.10 metres 
Standard. error in. contour lines ........... 2... es 0.20 metres 
Standard. error in. spot heights ............ v 0.10 metres 
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