Tracking unresolved targets in theater ballistic missile defense

Fire control requirements for designating an interceptor against a warhead impose stressing tracking requirements. The article introduces these issues and defines resolution and data association performance measures in the context of theater ballistic missile defense (TBMD). The emphasis of the paper is on definition of underlying concepts and use of analytical expressions to estimate resulting radar requirements, as these issues are often neglected in even high fidelity simulation efforts. Resolution and measurement-to-track data association requirements in a dense multiple object environment are parameterized using an analytical model for exoatmospheric rocket body fragmentation. This model is then used to illustrate the tradeoff between range resolution (waveform bandwidth) and track degradation imposed by a fragmentation event. Some associated waveform design issues are briefly addressed. TBMD may mandate precision track such that a significantly higher degree of track filter smoothing is demanded than that normally associated with fire control against airbreathing targets. Proposed tracking algorithms that improve track maintenance under stressing conditions do not necessarily lend themselves to achieving the high degree of track filter smoothing demanded by TBMD.