The relationship/TWAA and BMD

The military missions of tactical warning attack assessment (TWAA) and ballistic missile defense (BMD), researched under the strategic defense initiative (SDI), have many similar requirements for missile launch detection and tracking. While overall BMD requirements are generally established, the assignment of requirements to each system element is not final. The authors discuss the requirements for both missions, alternatives for satisfying these requirements, and the plan for developing a single ballistic-missile-launch detection system to satisfy both sets of requirements