TM 5-1260-206-34
Theory Of Operation - The OMS assemblies are:
b.
optics
1.
2.
Base plate
Photo-carriage
3.
The circled numbers are keyed to F0-2.
O p t i c s - The optics allow the operator to view the left photo plate with
h i s left eye and the right photo plate with his right eye. A measuring
mark dot within each field of view provides a measurement reference point.
When a set of photographs is mounted on the photo plate, the optics trans-
form them into a three-dimensional image.
Base plate - The base plate contains the data grid, an X-Y array of con-
d u c t o r s that interact with the electromagnetic signal generated by the
c u r s o r coil. The orientation of the data grid to-the base plate is
a l i g n e d during manufacture.
P h o t o - c a r r i a g e - T h e photo-carriage consists of:
Two photo plates
Cursor coil
X-axis encoder
The operator moves the photo-carriage in the X-Y directions to locate the
p h o t o g r a p h i c feature. This causes the cursor coil attached to the photo-
c a r r i a g e to move relative to the data grid. This movement is converted
into an amplitude-modulated analog signal. T h i s signal provides position
d a t a for the Calculator. The right photo plate can be moved in the X
d i r e c t i o n using the X-axis parallax adjust, and the Y direction using the
Y - a x i s parallax adjust. The X-axis movement is coupled to the shaft angle
encoder. T h e operator moves the right photo plate relative to the left
photo plate in the X-axis direction to superimpose the measuring mark dots.
This movement is converted into SAE rotation pulses. These pulses provide
e l e v a t i o n data for the Calculator.
1-13. TID PRINCIPLES OF OPERATION - T h e TID provides back-lighting of the
photography placed on the OMS photo plates. T h e light intensity is controlled
i n d i v i d u a l l y for the left and right photo plates.
1-14. DIC PRINCIPLES OF OPERATION - The DIC controls the transfer of data
from the DAC to the Calculator. T h e operator-controlled pushbuttons select
RECORD 1, 2, 3, 4, and CLEAR signals. The footswitch selects RECORD 1 signals
f r e e i n g the operator's hands for photo-carriage control. The sonalert provides
audible indications when the Calculator receives a command or when an alarm
condition is present.
NOTE
Throughout this manual DIC pushbuttons are indicated by
1-14