TM 5-1260-206-34
Section III.
TECHNICAL PRINCIPLES OF OPERATION
APPS PRINCIPLES OF OPERATION - F0-1 is a functional block diagram of
1-11.
the APPS. The OMS allows the operator to view the aerial photography through
a stereo-optical system. T o locate the desired terrain feature, the operator
moves the photo-carriage. This movement is converted into electronic pulses
b y the datagrid/cursor coil, providing X and Y analog position data for the
DAC. To measure the height of the feature, t h e operator adjusts the right
photo holder to produce a 3-dimensional image. This movement is converted into
electrical pulses by the shaft angle encoder and provides AX rotation data
for the DAC. The TID provides illumination of the photography on the OMS.
The DAC continuously monitors and computes the X-axis and Y-axis coor-
d i n a t e s of the photo-carriage. T h e s e digital coordinates are indicated to the
o p e r a t o r by the Digital Display. The AX data from the OMS is also counted.
When the operator has measured the terrain feature, he selects this data to be
t r a n s f e r r e d to the Calculator. This is done by the RECORD 1-4 signals from
the DIC or footpedal switches. T h e sonalert sounds to indicate the selection
has been received by the DAC. The Calculator performs as programmed by the
data base and the computed point position data is printed out on paper tape.
The position data may also be stored on the data cartridge.
A dc power supply contained in the DAC provides +5 volts, +15 volts,
and -15 volts required by the APPS circuits.
1-12. OMS PRINCIPLES OF OPERATION - The OMS (F0-2) translates the operator-
controlled motion of the photography as viewed through the magnifying stereo-
o p t i c s into electronic signals. These signals are used to compute the position
data of the observed feature.
F u n c t i o n a l Description - The OMS provides two measurement outputs:
a.
The movement of the cursor coil in the X-Y directions relative
t o the data grid.
The movement of the right photo plate in the X direction (AX)
r e l a t i v e to the left photo plate.
The data grid is secured in the base plate and serves as the base reference
f o r the optical system. The cursor coil is secured under the photo-carriage
and serves as the photography reference. Any movement of the photo-carriage
( c u r s o r coil) relative to the base plate (data grid) is seen through the
stereo optics as a movement of the measuring mark dots relative to the photo-
graphy. The photo-carriage contains two photo plates, each having its
associated optics. Because the movement of both measuring mark dots is
represented by the movement of the cursor coil, both dots must move equal
d i s t a n c e s in the X-Y directions. The parallelogram prevents any rotation
of the measuring mark dots from taking place. T h i s is essential for accurate
measurements to be made.
1-13
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