Lockheed Martin Corporation

Bert L Bradford

Richard A Lodwig

Sandra Lodwig, Legal Representative

Richard Lodwig, Legal Representative

Aspects of the disclosure provide a method and an apparatus for sensor fusion. The method includes receiving, by a processor, track reports of at least a first sensor and a second sensor for sensor fusion, selecting a best track from at least the first sensor and the second sensor to reduce track error, determining a fused track that combines at least the first sensor and the second sensor and selecting one of the fused track and the best track as a system track of sensor fusion to minimize a system error.

Method and apparatus for sensor fusion

The present invention is directed to a system and method for Doppler track correlation for debris tracking in PCL radar applications. The disclosed embodiments describe the systems and methods used in the detection of debris pieces and the association of the Doppler signals from the debris pieces across multiple illumination channels. The present invention also provides computation of debris state vectors and the projection of trajectories to determine debris impact points.

System and method for doppler track correlation for debris tracking

In a system for estimating the launch point of a missile, Doppler shifted signals reflected from the missile as it travels from its launch point are used in a Kalman filter to estimate the missile position, velocity and acceleration, in earth centered fixed coordinates. The coordinate system is rotated to a rotated earth fixed (REF) coordinate system in which the X-axis passes through the estimated missile launch point and the Z-axis is made parallel to the missile azimuth as represented by the missile velocity determined by the Kalman filter. The error in the downrange component of the missile launch point is then reduced to a minimum in the REF coordinate system using a square root information filter. The coordinate system is then rotated to a second rotated earth fixed coordinate system in which the X-axis passes through the updated launch point position and the Z-axis is positioned at 45 degrees from the missile azimuth. The Z-axis component and the Y-axis component of the error in the launch point is then reduced to a minimum in the new REF coordinate system using a square root information filter.

Missile launch point estimation system

In a continuous wave Doppler system in which a fixed transmitter transmits a continuous wave signal to be reflected by moving targets and by fixed structure, an aircraft receives the reflective signals at two spaced apart antennas. The signals reflected from moving targets are distinguished from ground clutter reflected from fixed structure by the phase difference between the Doppler signals receive by the two antennas. The signals reflected from moving targets are distinguished from the ground clutter in response to the phase difference between the Doppler signals received by the two antennas being not equal to a phase difference value determined to be the phase difference for clutter signals. The phase difference value for clutter signals is determined from a function expressing the phase difference value as a linear variation with the Doppler frequency of the signals.

Continuous wave doppler system with suppression of ground clutter

An estimate of the time of the boost engine cut-off of a missile is provided by irradiating the missile after it is launched with continuous wave signals. The reflected continuous wave signals are detected and an inflection in the Doppler measurements of the reflected continuous wave signals provide an initial estimate of the boost engine cut-off time. A Kalman filter is used to provide initial estimates of the position and velocity of the missile at the boost engine cut-off time and a square root information filter responding to the Doppler measurement residuals after boost engine cut-off reduces the error in the initial estimate of the boost engine cut-off time to a minimum.

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Damascus, MD, United States of America

Bert L Bradford