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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
