438 
In the figure, a data base (consisting of various stages of 
parameter estimation) contains all the. information that. is 
required for using digital methods in the various operations. 
For instance, existing geodetic control.for.an.area along with 
à fictitious data generator and adjustment programs can be used 
in "planning" to compute optimum airstation positions and 
additional field control requirements, along with predictions 
of the statistical estimates of. the aerotriangulation results. 
These data can, in turn, be used in the adircraft for navigation 
and exposure control, whereby the actual measured coordinates 
of the airstation during the acquisition can be returned to the 
data base for use as approximations in the adjustments of the 
aerotriangulation data. Using standard analytical methods, the 
triangulation process computes precise dirstation data for the 
photography and thereafter, this data is used directly in the 
compilation instrument for data extraction, negating the 
repeated orientation process and the necessity for any type of 
pre-plotted worksheet. The data base, therefore, becomes the 
controlling factor for the entire process and; ‘as such, must be 
well designed and general. More inportantiy, the definitions 
of the data in storage must be consistenc, unambiguous, and 
require a minimum of post- or pre-processing. Likewise, the 
algorithms used in the various stages of data manipulation must 
be concise, rigorous, and consistent. 
A good example of the need for consistency was revealed in a 
recent inquiry memorandum mailed to members of Commission II, 
WG 11/1, by S. Wu. In the memo, Dr. Wu requested information 
on "parameters necessary for the evaluation of an analytical 
plotter." His request was prompted by a discussion in Ottawa 
whereby the Subworking Group on Software Development decided 
that they should focus their attention on "trving to define 
those parameters to be used to evaluate an analytical plotter.” 
Parameters, in this case was meant to be the numerical descrip- 
tors associated with a pair of' pnotographs. The accompanying 
questionnaire requested opinions on three basic sets of para- 
meters--those associated with the camera, the photography, and 
the model. (Of special interest was the list of items associa- 
ted with "model paremeters and ground control." On reading it, 
one comes to the conclusion that there exists as many "methods" 
Of forming a stereomodel as there are analytical systems on the 
market. Obviously, with the present variations in hardware and 
operating systems, one cannot expect to establish a universal 
Software. However, it is reasonable to suggest that a standard 
be established for the definition-of parameters and, in some 
cases,.the algorithms for computations. If this were done, 
data could be easily exchanged and tests of equipment could 
thereby pe standardized. °“Early'in the ‘study at the National 
Ocean Service, NOAA, it was recognized that any organization 
must "standardize in order “fo realize the full ‘potential of an 
analytical system. 
3 
Fh 
us look at à graphic description 'o 
st an analyti- 
tter in figure 3. 
Tosamplify, 1 
cal stereopio