6 
The stability tests in the manual mode consisted of measuring a five- 
point pattern on grid plate and repeating the measurements continuously 
over a period of one hour. The accuracy tests in the manual mode 
consisted of measuring a symmetrical 25-point pattern on a grid 
plate. The standard deviation of the errors in both x and y have 
been determined. The marking test consisted of aligning the reticle 
on a grid line intersection actuating the marking unit, and observing 
and measuring the deviation of the mark with the grid line inter 
section. The grid plate used for the accuracy test was a Wild pre 
cision grid plate with 20-micron line width. Measurements were taken 
over 200 x 200 mm area. The system resolution was tested by placing 
a high contrast resolution target in the diapositive plane and reading 
the least resolvable image on the monitor scope. By this method 
it was determined that the system resolution of approximately 90 
lines/mm had been obtained. 
The results in microns obtained (except where malfunction 
occurred) are tabulated below for the manual mode: 
AVERAGE ERROR 
Operator 
Stability 
x y 
Accuracy 
Sx Sy 
Marking 
Sx Sy 
1 
2 2 
2 2 
2.3 1 
2.7 1 
2 
- 
- 
2.7 
1.8 
3.0 2.0 
3 
1 
2 
2.4 2 
3.8 2 
1 Average of three sets of measurement taken at different times. 
2 Average of two sets of measurements taken at different times. 
The tests performed in the automatic mode were made using both 
diapositives, containing photographic imagery, and photo copy grid 
plates (25-micron line width). To test the correlation capability, 
one table was held fixed and designated as the "master" while the 
other was displaced a distance of 200 microns in the x and y direction, 
and designated the "slave." The correlators were then allowed to 
drive the "slave" table to a zero or stationary position. This test 
was performed on a variety of imagery with a repeatability accuracy 
of one micron. To test the accuracy of marking by using the correlators,