AUTOMATIC PHOTOGRAMMETRIC INSTRUMENTS 
7 
Fig. 4. CRT assemblv on the B8-Stereomat. 
have been obtained in approximately \\ to 2 
hours, while the average time for an auto 
matic relative orientation is from 3^ to 4^ 
minutes. 
Analytical Plotters 
The concepts of the analytical plotter were 
presented at the Ninth Congress. There are 
now three models in this group, the AP-1, the 
AP-2, and the AP-C (not including the proto 
type AP-1C), all built by OMI and the Ben- 
dix Corporation. The first two were con 
structed to U. S. Air Force specifications; the 
latter was developed to provide the ad 
vantages of the analytical principle to users 
of the more common commercial types of 
aerial photography. The design character 
istics of the family of analytical plotters were 
thoroughly discussed during the Second In 
ternational Photogrammetric Conference in 
Ottawa, Canada, in 1963. 
The major components of an analytical plot 
ter are the stereometer, the computer, and 
the coordinatograph. An operator views a 
stereopair through the binoculars of the 
stereometer and controls the location of a 
floating mark in the stereomodel by means 
of two handwheels and a footwheel. The com 
puter receives data from the handwheels and 
footwheel defining the coordinates of the ref 
erence mark and transmits servo commands 
to the photo carriage in the stereometer so as 
to position both photographs continuously 
in their proper position. The computer also 
controls the operation of the coordinato 
graph. 
In a recent paper, “Operational Result 
Using the AP-C Instrument,” U. K. Helava, 
National Research Council, Canada, re 
ported on limited tests conducted on that in 
strument. These tests showed that the AP-C 
Plotter is accurate and capable of producing 
results of the highest quality; that complete 
and precise orientation can be performed in 
30 minutes or less; and that human factors 
have been adequately covered. 
A second paper related to this instrument 
has been presented by V. C. Kamm and 
A. E. Whiteside of the Bendix Corporation, 
“General Mapping and Surveying Applica 
tions of the AP-C Computer.” This paper 
describes the general characteristics of the 
computer and operations which the AP-C 
either has or can be programmed to perform. 
The computer is several times faster than 
most medium-scale computers in current use 
and has the same computational capabilities, 
memory size, and variety of operations of 
computers in its class. 
The standard AP-C programs include 
those supplied to permit operation of the 
system. In addition there are other programs 
provided which can be used for other pur