acquired for this survey by NASA with an Itek KA80A panoramic camera.
Evaluation of photography acquired for this mission and other panoramic
photography acquired a year later in central Oregon with color IR film (SO-
131) indicated that high-altitude photography with high-resolution camera
systems such as the KA80A may be a viable tool for stratification of infes-
tations into intensity classes, and perhaps for detailed photo interpretation,
thus combining two stages of sampling in one stage of photography. This
premise was further strengthened by Heller (1971) who reported that multi-
tree infestations of mountain pine beetle have been detected at photo scales
as small as 1:32,000.
In order to determine feasibility of interfacing this technology into the
survey system we developed in 1977, we conducted a preliminary evaluation
during the spring and early summer of 1978. A bark beetle outbreak in low-
elevation ponderosa pine stands on the west slopes of California's Sierra
Nevada range, resulting from two years of drought, provided an opportunity to
conduct this evaluation.
Complete photo coverage was acquired of a 40 x 110-mile (24.8 x 68.3 Km) test
site during April 1978, by the NASA Ames Laboratory, Moffett Field, Cali-
fornia. Two camera systems, the KA80A optical bar 4.5 x 50.26-inch (1.77 x
19.8 cm) format panoramic and an HR732 9 x 18-inch (3.54 x 7.09 cm) frame
camera were compared. High-resolution color IR film (SO 131) was used in
the KA80A camera, and 3 films, color IR, color, and an extended red sensitivity
panchromatic film (3400) with an A-25 (red) filter were exposed with the
HR732 frame camera. These films will be used later for a comparison of films
for detection of bark beetle damage from high altitudes.
The color IR photography is currently being interpreted using an equal-area
map registered grid developed by R.L. Liston of the USFS Engineering staff,
Washington, D.C. These are produced on mylar with a Calcomp flatbed plotter
and reproduced on clear acetate for use as overlays (Fig. 2). Grids for the
KA80A panoramic photography are corrected for scale variation across the film
plane which ranges from 1:30,000 at nadir to 1:60,000 at 60° using standard
photogrammetric resection techniques. In addition, changes in terrain eleva-
tion are compensated for in the grid generation process through interface
with Defense Mapping Agency digital terrain data.
Classification of bark beetle damage by intensity classes is by grid cell as
opposed to classification of polygons in aerial sketch mapping. A microfiche
viewer with 13x magnification is used for the classification (Fig. 3).
Sample cells within each stratum are then selected for detailed counts.
These data will be compared to counts of discolored crowns on corresponding
conventional 1:6,000 scale color IR film and ground truth acquired on a
number of 40-acre cells. Preliminary results appear promising, and if success-
ful will provide the basis for substituting aerial sketch mapping with small-
scale, high-resolution photography.
