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REPORT FROM SWEDEN
Various parts of the report from Sweden have been included in the Working
Group reports for Commission VII. The paragraphs printed here represent only
& small part of the excellent report prepared by Messers Axelsson, Moller,
and Jensen.
General Introduction.
At the begin of 1960 about 91 % of the area of Sweden had been photographe.
from the air. The annual capacity of the Swedish government civil airphoto-
graphy is at present 20 % of the area of the country. During the period
1956 - 1960 many new photogrammetric organizations were established in
Sweden both governmentally and privately. They procured photogrammetric
plotters and other equipment. The many consumers of aerial photographs pro-
cured mirror stereoscopes, stereometers and other minor photogrammetric
equipment. So the possibilities for photographie Interpretation (PI) became
rather good.
Education and training in PI were i_proved and widened. It is however not
yet satisfaetory. Most organizations and people occupied with the study and
planning of the Swedish landscape are now conscious of the great availabi-
lity and value of PI. Much however remains to do.
Since manyysars FI mw sused at topographic mapping in small and medium scales
but also at large scale mapping for cadastral and town planning purposes.
During the last four years Fi also was used for governumt planning of hydro-
electric power stations and of roads. Hereby the geologic PI was especially
successfull.
The work done by the Committe of Forest Photogrammetry gave especially success-
full results during the last four years in the form of a rather general and
broad use of PI in forestry.
Some research concerning PI is going on especially for forestry purposes.
As & whole & considerable progress during the last four years can be noted,
especially as to the PI of surface configuration, drainage, soils, geology
and of vegetation.
1. Photography and Photo Coverage.
Most serial photographs for government civil purposes have been taken with
modern wide angle cameras as Wild Aviogon Ro5a at a scale of 1:25 000 but
now-a-days generally at 1:30 000. During the last four years an area of about
400.000 km^ has been photographed at the expense of the state (The land area
of Sweden is about 440.000 kn“). Several photographs were taken at very large
Scales as 1:8000, 1:10 000 and 1:15 000. Sweden was also photographed with the
camera Eagle MK II, Ross 6, by military organizations inter alia at & scale
of 1:65 000. These photographs are available also for civil consumers. Riks-
antikvarieümbetet (Central Office of National Antiquities) photegraphed from
14 m (45 feet) high steel-towers with Rolleicord, Rolleiflex and Yashikamat.
Picture size 6 x 6 cm.
The general opinion seems to be that the best negative scales for general
PI of the landscape will be 1:15 000 - 1:15 000, provided they were taken
with very good aerial cameras. The smallest negative scale, at which & satis-
fying p1 could be done, might be 1:20 000. For detailed PI it will be neces-
Sary to use photographs at 1:6000 - 1:10 O00.
The extent of geologic PI 8t the State Power Board of Sweden is illustrated
At the enclosed map.
2, Photo-Interpretation Equipment and Taghriques.
Usual equipment as pocket- and mirror stereoscopes, Zeiss Stereopret, Stereo-
top and scetchmasters were used for ordinary PI. Some interpretation for road
planning was made in Balplex plotters. Interpretation for reallotment of
forests was performed at tho land Survey in the Wild A8. The following minor
equipment was used for PI. Special glass plates of the Steroometer furnished
with a serie of different small points and circles with exactly known dimen-
sions. Interpretation-scales, engraved on plastic sheets, consisting of mm-
scales in right angles, parallax wedge, micrometer wedge and a serie of small
circles with different but known dimensions.
-44-
Measuring microscope with two parallell precision-scales, the one for summing
up the crown-diameters of trees and the other for summing up the interspaces
between the crowns.
In order to facilitate the daily use of aerial photographs in forestry and
above all to facilitate the stereovision of the photos some suitable means
and methods was developed. À simple picture holder, for field use was con-
structed. It sonsists of & lins stereoscope with legs of' special construction
holded by magnets. Stereonountings of aerial photographs has been widely used
-2-
in the field.
2. Interpretation of urban, rural and industrial structures.
A thorough PI has been used regulary by governnent and private organizations
at photogrammetric mapping for urban planning in 1:1000, 1:2000 and sometimes
1:4000. It was characterized by the high degree of field control before plot-
ting, sometimes also after plottisg. The method has been described in reports
to earlier congresses. Aerial photographs have also been widely used for the
inventory and planning of open-air regions and for the planning of road-sys-
tems in forests.
1. Interpretation for archeological and antiquarian purposes.
Archeologists used photographs in order to preserve piotures of valuable old
things for the future and to be able to demonstrate them in & simple way.
Viking zraves and similar objects were photographed from 14 m (45 feet) high
steeltowers erected near the actual site. The terrain surface must naturally
be clears from vegetation before photography. Rather small indications of ma
made features could be detected in that way, especially at certain condition
of soil moisture. It must however be stated that some soil conditions as
morse fi 11) are rather unfavourable for archeological PI.
Aerial photographs have been usad since 1938 for the inventory of more than
350 000 ancient monuments and relics from the past. They have been classifi.
ced and localized in the field and drawn in the photographs. This work has
been performed in connection with the production of the modern Swedish eco-
nomic map at 1:10 000.
The Land Survey has also by law to map such ancient monuments in connection
with its ordinary work.
Some sunken old ships have recently been detected with the aid of aerial
photographs.
Stockholm, February 1960
( a / fV
E Ms «Ades
Sven G. Möller)
na A
7far{ Heiler»
(Hans Axelsson) (M, Jensen)
