Robert Dennis Windhorst

US Patent:

60826665, Jul 4, 2000

Filed:

Dec 3, 1997

Appl. No.:

8/984238

Inventors:

Robert D. Windhorst - Oro Valley AZ
Stephen V. Sosinski - Tucson AZ

Assignee:

Raytheon Company - Lexington MA

International Classification:

F41G 700

US Classification:

244 315

Abstract:

A system (30) for determining a missile kinematic property. The inventive system includes a radar system (36) for obtaining radar range measurements (34). An inertial reference unit (40) tracks changes in missile acceleration without the use of the radar range measurements and provides a signal (38, 42) in response thereto. An altitude Kalman filter (32) and a subtractor circuit (48) are used to combine the signal (38, 42) and the radar range measurements (34) to provide an accurate estimate (50) of the property. In a specific embodiment, the kinematic property includes missile vertical velocity and missile altitude. A radar system (36) supplies radar range information (34) to the Kalman filter (32). A loop (52) from the Kalman filter (32) to the radar system (36) facilitates estimating the radar range measurements (34) when invalid radar range measurements are provided by the radar system (36). The Kalman filter (34) is a two state filter, one state corresponding to missile altitude, and the other state corresponding to missile vertical velocity bias error in the inertial reference unit's (40) velocity measurements (42).