12 
Sm = 1:100 000 
f = 150 mm 
Forward lap = 60°/o 
10. Bridging Tests 
All bridging tests were made using calibrated grids. The idea 
here was that if precision could be maintained with grids, any further 
degradation in practice would be due to the nature of materials used 
and not rightly attributable to the AP-2. Viewing optics capability 
was not questioned. 
The test performed consisted of making a 6 model cantilever using 
9" x 9" Wild grid plates. Model space coordinates were recorded and 
the strip was adjusted to theoretical grid values by an analytical 
process based upon conformal plane and vertical polynominal equations. 
The unit standard errors after adjustment were as follows: 
7n 
o. 
X 
lOq 
CT, 
z 
Model parameters for this triangulation were 
f = 150 mm 
Z = 150 mm 
Forward lap = 60°/o 
11. Compilation Tests 
Compilation tests were performed using real materials and 
consisted of two parts: 
a. Spot height measuring tests 
b. Contouring evaluation tests 
11.1 Spot Height Measuring Tests 
A pair of overlapping photographs taken over the Arizona Test