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BUREAU OF LAND MANAGEMENT
Wallace A. Crisco
The BLM has developed a new system for analytical aerotriangu-
lation simultaneous adjustment of aerial photography (Ball 1973).
Tests of the system have demonstrated high degrees of accuracy and
reliability in rugged terrain, and that it is an excellent means of
establishing control points for all scales of mapping and of per-
forming independent checks of conventional cadastral surveys.
(Fieber and Strand 1973) The system has been utilized for mapping
Indian reservation and National Park boundaries, and topographic
mapping projects for road design and timber resource management.
From 1969 through 1973 the Montana Office of the Bureau was
engaged in a cooperative research project with Dr. Meryl Meyer of
the University of Minnesota to develop a system for interpretation of
resource data from color and color infrared photography. Upon
completion of the research, the Bureau contracted for photo interpre-
tation of a 2,842 square mile project. Color infrared photography
at a scale of 1:80,000 was utilized. The following interpretative
classifications were required: 13 basic vegetation types; 13 types
of wild life habitats; 5 categories of erosion conditions; 9 types
of hydrological features; 7 categories of land use and classes of
range. Field checks demonstrated approximately 85% accuracy in the
interpretation by the contractor of the erosion conditions and
hydrological features, and approximately 95% accuracy of the other
classifications. :
During the last two years (FY 74 and 75), over 180,000 square
miles of color photography (1/3 of total) and color infrared
photography (2/3 of total) was flown for interpretive use by BLM
resource management personnel.
Ball, W.E. 1973, A Tensor Approach to Block Triangulation, Photogrammetric
Engineering, Vol. 39, No. 1
Fieber, A. L. and Strand, LA 1973. Development and Testing of the
BLM Analytical Aerotriangulation System. Branch of Cartographic
Services, Portland, Oregon
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