GVII-26
PHOTOGRAMMETRIC ENGINEERING
to develop means of photo interpretation of Arctic terrain in terms of the signifi
cance of plants and land forms in the determination of ground conditions. A
summary of the results to date is presented in Professional Paper 264F of the
U. S. Geological Survey, by David M. Hopkins, Thor N. V. Karlstrom, and
others, entitled “Permafrost and Ground Water in Alaska.”
In connection with a program of geologic mapping in the islands of the
western North Pacific, carried out by the U. S. Geological Survey in cooperation
with the Corps of Engineers, U. S. Army, photo interpretation was used in
preparing a large scale map of Pagan, a small volcanic island in the northern
Marianas Group, prior to the beginning of field mapping of the island. The use
of photogrammetric techniques in delineating lava flows of different ages greatly
expedited field work, and proved to be of satisfactory accuracy.
RESEARCH IN GEOLOGIC PHOTOGRAPHIC INTERPRETATION CONTINUES
In Sweden, at the geographical department of Lund University, air photos
have, with regard to photo interpretation, chiefly been used for tectonic-
morphological and glacial-morphological investigations.
In the tectonic-morphological work, air photos have been processed to de
tect and identify tectonic lines in the landscape. It has thus been possible to
obtain a far more complete picture of the structural conditions of the bedrock
than the map material in common use can offer. Consequently, there is also
the possibility to obtain a more exact interpretation of tectonic influence on the
genesis of land forms. The investigations include the hogbacks of Skane, the
littoral of Blekinge and the Fjelds of northern Norway.
In glacial-morphological investigations, air photo material has chiefly been
used to identify terminal moraine lines, drumline and “flybio-glacial” hogback
formations. In this connection vegetation and cultivation as appearing in the
photo, have often been able to support the interpretation. In the field regions
above the tree limit where the solid layer is often thin or entirely missing, for
mations from the glacial period as noted above (with the exception of drumlins)
appear clearly through their contrasting color. In the study of nunataks which
are mostly very difficult to climb, air photos are an invaluable aid. The investi
gations yielding the above experience were carried out in south Smaland and on
the west coast of north Norway.
The geographical department of Lund University has also been working on
terrestrial photos from the Andes, taken with a Leica in conjunction with a theo
dolite. The experience and a discussion of the method have been published in
B times sung und Luftbildwesen number 4, 1954.
An intensive research study in the geomorphology and photo-interpretation
of sand dunes has been carried on for the past few years by Dr. H. T. U. Smith
of the University of Kansas, under a research contract with the U. S. Office of
Naval Research. This has involved field studies in southwestern U. S., Peru, and
the coastal areas of northwestern Europe, and of course, correlation of field data
with photographic expression. These studies are still in progress and should lead
to perhaps the most comprehensive study ever prepared of the photo interpre
tation of one single type of landform. This in itself is one unit in a long-range
program which, if circumstances are favorable, may be extended to other types
of landforms.
Projects of a research nature have also been undertaken by the U. S. Geo
logical Survey during the reporting period. These include a diversity of studies
such as: (1) an evaluation of color aerial photography of certain small selected
areas in western United States; (2) experimentation and development of an in-