Of significance was the multi-altitude test per
formed across the Ajo-Catalina line* Data was acquired
on two different days approximately three weeks apart.
Twenty-eight (28) separate lines were flown at altitudes
varying from 36,34-9 feet to below the line of sight
(4,745*)• The internal consistency of this data was
0.0006 nautical mile probable error or 3.6 feet. Refer
to Table 5 on page 20 for detailed results.
The controlled photography test was performed on two
separate days over the 36 mile by 30 mile area located in
the vicinity of Phoenix, Arizona. Each mission consisted
of seven north and south flight lines and three east and
west flight lines. Over one hundred (100) photographs
were obtained for each mission. Analysis of this test
indicates a capability of determining nadir points to a
circular probable error of 3.37 meters. The precision of
Shiran was further depicted during the controlled photo
graphy tests by the use of the redundant data obtained
from the four station ranging capability. Mean northing
and easting coordinates were computed for each nadir point
from the four station combinations. The deviations of the
individual northings and eastings were determined from the
mean values and plotted. Figure 7 depicts the plotting of
these points for the first photo mapping mission. The
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