TM 5-6675-324-14
(7) Determine length constant, CL (multiplier), using the following formula:
= Length of constant
CL
CL
= Length of known object
D
R=
Counts generated by measuring length of known
object
On aerial photograph of unknown scale or magnification where a telephone
Example:
line is visible, use the known distance between two telephone poles, 105.
feet, for D in formula.
(1) With linear measuring probe, measure the known distance (between
two telephone poles) to obtain R.
(2) The value shown on the auto-scaler LED display (5692) can be used
for R in the formula
(3) compute
(4) Result is 0.02. Press
to display six decimal places,
0.018477 = CL.
(5)
press
to
activate
PRINT
command.
(8) Key in C value (computed with known length of object in photograph being
L
measured). P r e s s
Do not release until ready to begin measurement.
(9) Press foot switch.
(10) Position linear measuring probe so that pricking pin is at beginning of
length to be measured. Release foot switch.
(11) Make measurement by tracing length of line with linear measuring probe.
(12) Press
to activate PRINT command and freeze count.
Area measurements on aerial photographs of unknown scale or magnification.
To make area measurements of aerial photographs, there must be a known length of an
object. This known factor must be used to compute constants needed for
measurements.
(1) Assemble QPS with planimeter.
(2) Activate QPS:
(a) Plug foot switch into ACCU input jack on back panel of auto-scaler.
(b) Plug planimeter into E2 encoder socket on back panel of auto-scaler.
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