Raytheon

United States Air Force

Weather Data Architecture Capability (WDAC)

Fortran to J2SE/Java

History: The US Air Force is replacing its legacy weather systems with a single integrated capability and implementing the "To Be" architecture for the Air Force Weather Weapon System (AFWWS). The Weather Data Architecture Capability (WDAC) system provides architecture for the assimilation of advanced weather models. Radar and satellite data are fused into a single user interface for timely production, analysis, and delivery of fine-scale weather products to operational commanders. WDAC supports worldwide combat operations of the US Air Force and US Army as well as other government agencies. AFWWS employs evolutionary acquisition concepts for rapid acquisition of mature technology. As prime contractor for this modernization, Raytheon contracted with TSRI for a fixed-price modernization of WDAC from Fortran into J2SE/Java.

Challenge: WDAC is a unique high-quality information system, originally written in Fortran for performance reasons. The US Air Force required a scalable platform independent Java version of WDAC. Raytheon contracted with TSRI to use their automated solutions in transforming WDAC from Fortran into J2SE/Java. With the advancement in hardware and web-based technologies, modernization of WDAC into platform-neutral J2SE/Java would provide the Air Force with a highly advanced weather data capability. WDAC was originally designed to run as a batch process on a UNIX machine. It needed to retain the ability to invoke functions and procedures procedurally, as they had been on the original system. TSRI's automated processes normally convert functions and procedures into methods or classes. WDAC programs were transformed into classes, but to accommodate these special requirements the Fortran subroutines and functions were transformed into static functions to permit invocation without the run-time overhead of class instantiation.

WDAC originally made extensive use of data overlays (e.g. Fortran Common Blocks and Equivalences). This required TSRI to develop a specialized Java data model to support these Fortran data overlays. WDAC also employed complex data initializations by using Fortran data/read assignments from flat-files. This required TSRI to construct an API for interpreting Fortran formatted I/O and to construct a Java Flat File manipulation API. Flat-file I/O statements were transformed into SQL allowing for a future interface with a relational database. WDAC contained hundreds of GOTO statements, a construct not allowed in Java. TSRI's automated re-factoring process removed the GOTO statements and smoothed control-flow logic.

Results: TSRI transformed WDAC into J2SE/Java with 100% automation as a fixed-priced deliverable. The perfect precision and accuracy of the highly maintainable J2SE/Java deliverable allowed Raytheon to carry out testing and integration without requiring further assistance from TSRI. This Java modernization of WDAC facilitated user access via web-browsers and distribution of WDAC data via secure internet protocols.