323 
IDPF TECHNOLOGICAL COMPONENTS 
IDPF is a software package that controls a highly automated 
environment for performing all photogrammetric office processing in a 
typical mapping and charting organization. It integrates computer 
graphics and data base management technologies in a network 
environment that supports a cluster of photogrammetric work stations 
(PWS's). Operationally, IDPF is a software package operating on a 
selected hardware platform in which production efficiency is 
optimized through automated error checks, superimposition, image 
point mensuration controls, and minimal operator data input. 
Operator input is minimized after creation of a project-wide data 
base. IDPF is currently implemented on Digital Equipment 
Corporation's VAX/VMS operating system. The package utilizes 
Graphical Kernel System and Standard Tektronix Interface as interface 
standards to graphical hardware. IDPF is designed to accommodate any 
type of photogrammetric stereoviewing hardware (past, current or 
future). This capability is secured through the formalization of 
rules for communications between IDPF and the PWS. These rules are 
encapsulated in a standard protocol that defines the rules for 
communications between the PWS control computer and the physical 
photogrammetric stereoviewer. 
IDPF SYSTEM ARCHITECTURE 
IDPF is a general photogrammetric processing system which operates on 
a group of general purpose computers connected into an integrated 
network. (See fig. 1.) Some of the computers in the network serve 
as controllers to attached PWS's. The PWS itself is a collection of 
several devices which are viewed collectively as a single node in the 
computer network. A PWS consists of four components. 
1. A standard computer terminal serving as a computer control 
console. 
2. A graphics display stage which can be any one of the many 
available computer graphics terminals. A line plotter 
could be also used for this display station. 
3. One or two injection graphics stages which are computer 
graphics terminals. A PWS can function without this 
component if superimposition is not a requirement for the 
system. 
4. A Photogrammetric stereoviewer which contains provisions 
for two image transports and a variety of controls 
necessary for performing typical photogrammetric 
operations. 
A number of data bases reside on the same computer network. One of 
these data bases contains complete history of camera calibrations for 
the mapping institution. The other data bases contain individual 
project data. Both the camera calibration data base and project data 
bases are shared among all PWS's. The coordination of data base 
sharing is one of the primary functions performed by IDPF. 
IDPF COMPUTING STYLE 
The control computer for a PWS drives and coordinates its four 
components. The interfaces that provide communication between the 
control computer and the first three components of the PWS (mentioned