Sweden 7 
The preparation of the Photo-Map of Sweden from air photographs 
was already described in the Swedish national report of 1948. 
The methods used in preparing maps to order are adapted to the re 
quirements as to accuracy etc. in each individual case. In this connec 
tion the method of triangulation by precision instruments, model tri 
angulation described by Ekelund [4] and [48], is being ever increas 
ingly used. 
The Land Survey Organization 
The Purposes to which Photogrammetry is applied. In the Land 
Survey Organization photogrammetry is used primarily for map draw 
ing and secondarily for preparing various technical projects and plans, 
and for ground appraisals. 
The maps are in the first place drawn in connection with the plan 
ning and legal branches of the Land Survey Organization. Thus maps 
have been produced 
for totvn planning on the scales of 1:800, 1:1 000 and 1:2 000, as a 
rule with contours (at 1 m intervals), 
for re-allotment, determination of boundaries, exchang of allotments, 
and expropriation, on the scales of 1:2 000, 1:4 000 and 1:8 000, pre 
viously as a rule without but now increasingly with contours, and 
for the planning of roads, sewages, factories, mines, etc. on the sca 
les of 1:800, 1:2 000 and 1:4 000, usually with contours. 
Several air triangulations have been done in conjunction with the map 
production. These triangulations were done on short strips, 3—7 mo 
dels. 
Photogrammetry is also used by the Land Survey Organization for 
staking allotment boundaries and determining the coordinates of bound 
ary marks. Photo-interpretation has come into use in recent years for 
projecting roads and sewages, land developments, forestry, towns, in 
dustries, etc. and also for inventories and appraisals of the ground, spe 
cially when wooded. 
The Extent of the Land Survey Organization’s Photogrammetric 
Activities. This is shown in Tables 8 and 9. By ’’equivalent hectare” 
(equiv. ha.) in these Tables is meant an area of 1 hectare (ha.) in a 
town planning map on a scale of 1:2 000 with contours at 1 m intervals. 
The following relations between hectare and equivalent hectare have 
been used for contoured maps produced by stereo-methods. 
1 
ha. on the scale of 
1 
:800 corresponds 
to 2,50 equiv. ha. 
1 
>> )) yy yy yy 
1: 
: 1 000 
„ 2,20 „ „ 
1 
yy yy yy yy yy 
1: 
:2 000 
„ 1,00 „ „ 
1 
yy yy yy yy yy 
1: 
:4 000 
„ 0,25 „ „ 
1 
yy yy yy yy yy 
1: 
:8 000 
„0,12 „ „