PHOTOGRAMMETRIC OPEN SYSTEMS 
Atef A. Elassal 
Nautical Charting Division 
Charting and Geodetic Services 
National Ocean Service, NOAA 
Rockville, MD-USA 20852 
ABSTRACT 
The motivations for exploring the possibility of an open system for 
photogrammetric processing are both numerous and strong. A 
photogramme trie processing environment that can survive the 
unavoidable and continual change in instrumentation design and 
capabilities would be a very welcomed development indeed. The 
economic and administrative advantages of such a system are 
obvious. 
An effort to develop an open photogrammetric system was started at 
the Department of Commerce, National Oceanic and Atmospheric 
Administration (NOAA) in 1985. The objective of this development was 
to significantly reduce the strong interdependency between hardware 
and software. The result of this effort has been the creation of the 
Integrated Digital Photogrammetric Facility (IDPF) which has been in 
production operation for more than 1 year. 
KEY WORDS: Open System Architecture, Hardware Independent, IDPF, 
Integrated, Interface, Photogrammetric, Stereoviewer, 
Superimposition 
BACKGROUND 
The need for an integrated approach to photogrammetric processing was 
recognized by the Nautical Charting Division (NCD) in 1985. This 
need was driven by three motivating factors. First and foremost was 
the emerging need to interchange photogrammetric data within NOAA and 
with other federal agencies and organizations that are implementing 
digital cartographic systems. Second, IDPF was needed to replace an 
aging NOAA photogrammetric infrastructure (based on obsolete analog 
technology) with a flexible, integrated and automated photogrammetric 
environment. This environment would accept any format photography, 
and handle diverse jobs including airport mapping, photobathymetry, 
topographic mapping, and close-range photogrammetry. In compilation, 
the environment would utilize an accurate stereomodel re-creation 
capability and superimposition. It would also achieve a high level 
of efficiency coupled with facilities for strict quality control and 
audit trails. Third, a data source to supply the Automated Nautical 
Charting System II (ANCS II) with digital photogrammetric data was 
required. The ANCS II, which is being develpped by NCD for 
automating chart compilation and production operations, will include 
NCD's primary nautical information data base. IDPF was developed by 
the Photogrammetric Technology Programs of the Nautical Charting 
Research and Development Laboratory (NCRDL) in response to these 
needs. It was decided, at an early stage of the development, to 
achieve maximum hardware independence. Therefore, open system 
principles were the guiding principles throughout IDPF's development 
cycle. IDPF will be used in this paper to illustrate and describe 
the applicability of these principles to photogrammetric systems.