PRC, Inc., founded over 40 years ago, is a major developer and integrator of science and technology based systems for government and industry. PRC has approximately 6,800 employees working in more than 200 offices in the United States and abroad. It is a subsidiary of the Black and Decker Corporation.
Project 2851, also known as the Standard Simulator Digital Data Base/Common Transformation Program, was a Tri Service effort managed by the Air Force Aeronautical Systems Center. The AFASC served as Executive Agent for the three services. Project 2851 was instituted in March 1987 as a Research and Development effort to design and implement standard data bases and software to support DoD training simulators. The original objectives of the program included:
The Ada Application
- Reduction in duplicative and costly simulator data base preparation and maintenance,
- Reduction in duplicative and costly simulator data base transformation software development and maintenance,
- Improvement in the scene correlation among different sensor displays (e.g., radar, out the window visuals, infra red, night vision goggles) within a simulator, and
- Creation of a data base library and production capability which will address the Services' need for high resolution terrain and culture data to support realistic mission training.
The client specified the use of Ada to keep from being platform-dependent. The use of Ada with this architecture led to a loosely-coupled system that was easily and quickly developed, tested and integrated.
The Standard Simulator Database
Project 2851 is a major Ada software development effort. At the end of 1993, over 1,100,000 lines of source code had been written for the project, 95% of them in Ada. The program was developed in accordance with MIL STD 2167. The large system was to be incrementally developed and consisted of the following major elements:
- The Standard Simulator Data Base (SSDB), a large highly structured database of cartographic and raster data, supported by common database access routines.
- Many stand-alone main subprograms that perform standard functions on the database.
- A system executive that controls the scheduling and execution of these stand-alone programs.
- Several large system or subsystem common type declaration packages that ensure that all data objects in the system are consistent.
- A user interface that allows multi user access to the system through the system executive.
Subsequent enhancements were tested and added to the system with minimal impact. The staff of programmer/analysts averaged ten, over the period of the contract. With an average of over 1,200 lines of source code per month to test, integrate and document, it would have been virtually impossible for such a small staff to develop the system in seven years with any other language. Ada is most definitely the language of choice for developing large systems!
Project 2851 generates Standard Simulator Databases (SSDB) by starting with existing digital cartographic data sources, such as Digital Feature Analysis Data (DFAD) and Digital Terrain Elevation Data (DTED), from the Defense Mapping Agency. The data is enhanced by digitizing non digital source materials, including maps, charts and photos, to achieve the higher resolution detail required to simulate visual and sensor displays in advanced air, ground, and naval weapon systems.
Additional Project Objectives
Synthetic data may be generated or photo texture applied where required for scene realism. The enhanced data is integrated with two- and three-dimensional graphic models. These may be developed internally through the use of constructive solid geometry techniques or input from other simulation databases that had been or will be developed for DoD simulation programs.
When requests are received for digital databases developed under Project 2851, data is selected based on the parameters selected by the requester and is extracted from the SSDB; a Generic Transformed Data Base (GTDB) is produced. This GTDB is optimized for use on a specific image generator to support a particular weapon system training requirement. GTDBs can be produced for image generators that simulate visual, radar, infrared or night vision goggle scenes. The GTDBs that are furnished to the requester will be closely correlated, providing consistency between the various sensor displays for a common geographical area.
Project 2851 was given an additional objective to develop and implement a Standard Simulator Data Base Interchange Format (SIF). The SIF would serve as an input/output vehicle for sharing externally created simulator data bases via the Project 2851 library function. The SIF has been approved as a formal Military Standard (1821). Data bases developed using this standard were used to support Interoperabiity Demonstrations in November 1992 and December 1993 at the Interservice/Industry Training Systems Conference (ITSEC). In these demonstrations the heterogeneous equipment of over 50 government and industry members of the training and simulation community participated in mock battles over the standard terrain data base provided by PRC.
Other enhancements to the system during this phase included:
- Increasing system utility by augmentation of system functionality;
- Increasing throughput by system tuning;
- Further de coupling the system by restructuring the system executive;
- Enhancing the configuration control portion of the system by converting selected database functions to Sybase;
- Increasing user control by adding a linked multi job submission capability (pipelining); and
- Replacing the forms based user interface of the prototype was replaced with a Graphic User Interface (GUI). MOTIF and DEC's VUIT were used in developing the interface.
Project 2851 development and production activities were accomplished at the PRC facility in McLean, Virginia until July 1994. At that time, the system was deployed to Kirtland AFB, NM and the acceptance demonstration was completed.
Project 2851 can claim several important accomplishments resulting from its development:
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- Development of two military standards, Mil Std 1820 GTDBs and Mil Std 1821 SIF, which have been adopted by the government.
- Successful management of the Industry Service Working Group (ISWG), involving over 300 government, industry, and academic representatives over a six year period.
- System development in Ada with over 1,040,000 lines of Ada code.
- Development of an implementation approach based on the concept of screen as the primary object in a MOTIF GUI interface.
Subcontractors on this project include Martin Marietta, Autometric, LNK, Hughes, McDonnell Douglas, TRIFID.
Based on an article by Paul Botting and Eugene Clayton, PRC, Inc.
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