Effect of Trajectory Shaping on Observability of NTW Interceptor In-Flight Alignment Errors
Abstract
Navigation system and in-flight alignment requirements for a Navy Theater Wide (NTW) tactical ballistic missile interceptor are discussed. The missile navigation system is externally aided with both GPS and radar data for dynamic alignment and calibration of the missile's navigation system during flight. System alignment errors arise from missile incanister initialization, ship navigation errors, and ship radar face misalignments. Reduction of these errors during flight is critical so that the rather small field-of-view of the Kinetic Warhead (KW) seeker can acquire and divert successfully to the target. The extent to which attitude errors are removed depends on the accuracy of the measurements, the kinematic activity in the trajectory, and the degree of observability associated with the state error dynamics. An observability metric is developed and used to quantify a measure of error state observability and evaluate the potential benefits afforded by intentional trajectory shaping. Several trajectory shaping techniques including nominal and aggressive launch azimuth biases, vertical plane shaping, and sinusoidal lateral plane maneuvers are investigated. Handover alignment accuracy is determined throughout the tactical engagement envelope and compared to NTW system requirements. The study also quantifies the value added of combining GPS and radar aiding data for in-flight alignment versus the use of radar alone.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1999
- Accession Number
- ADA381219
Entities
People
- David B. Hanger
- Ernest J. Ohlmeyer
- Thomas R. Pepitone
Organizations
- Naval Surface Warfare Center