Lockheed Martin Corporation

Jonathan Alan Boardman

Jeffrey Bruce Boka

Naresh Raman Patel

Jack Gray

Purusottam Mookerjee

Jerzy W Luk-Paszyc

There may be situations in which a ship at sea is lost and GPS is not available due to jamming, and neither a position fix nor GPS is available. A system and method allow estimation of ship position (SPOS) using only single radar range measurements and satellite ephemeris data. The same radar can determine ship velocity using radar range rate information.

Ship position and velocity using satellite ephemerides and radar range measurement of satellite

A system and method for performing correlation processing for identifying an object of interest in a cloud of remote objects of different types comprises receiving RF and IR measurement data including rotational, translational bias and noise errors and determining and removing biases by minimizing a weighted distance metric. Correlation pairing metrics are then determined according to a maximum likelihood criteria. This method produces a correlation solution that minimizes the effects of biases and random noise while accounting for the statistical properties of the parameters being estimated.

Correlation/estimation reporting engagement system and method

A system and method for determining a 3-dimensional target position and velocity using 2-dimensional IR sensor angular measurements for objects travelling in a ballistic manner within an IR sensor's field of view (FOV). Resulting 3-dimensional states may be used to generate updated inputs for correlation and object selection to drive missile guidance and intercept operations.

Passive range estimating engagement system and method

There may be situations in which a ship at sea is lost and GPS is not available due to jamming, and neither a position fix nor GPS is available, or the heading and attitude sensors are degraded. A system and method allow estimating a ship's heading and pitch using radar range measurements, multiple antennas and satellite ephemeris data.

Ship heading and pitch using satellite ephemerides and radar range measurement of satellite

A system for engaging hostile air or space threats with a defensive missile, where the defensive missile comprises an antenna for receiving global positioning system (GPS) signals. A global positioning system receiver is coupled to said antenna, for receiving global positioning system signals directly from global positioning system satellites and global positioning system signals reflected from the threat. A processing arrangement processes the direct and reflected global positioning system signals for determining the position and velocity of the threat. Vectoring controls are coupled to the processing arrangement, and are responsive to the location of the threat for directing the defensive missile toward the threat. In a particular embodiment, the antenna of the defensive missile is directionally controllable, and the defensive missile includes an antenna direction controller responsive to the processor for directing at least a beam of the antenna toward the threat.

Missile tracking by GPS reflections

A method determines the atmospheric refraction of a radar beam by utilizing a stabilized optical telescope directed toward a star near the radar target location. This allows measuring the target refraction as observed from ships at sea without a-priori knowledge of the local refraction index or weather conditions in the target area. The telescope may employ an infra-red (IR) sensor and is capable of imaging stars. The atmospheric refraction of the star light is determined by pointing the telescope based on star ephemeris data, and measuring the star image deviation from the center of the telescope's field-of-view (FOV). The corresponding refraction of the radar beam can be determined by employing a conversion factor relating the IR-to-RF atmospheric propagation characteristics. This conversion factor can be obtained by dedicated tracking measurements.

Correction of radar beam refraction using electro-optical measurements

Current targeting approaches involve guiding to a spatially derived guidepoint of a group of objects likely to be the preferred object. This method may not allow the intercepting missile to contain the preferred, or other probable object(s), within its divert capability. The guidepoint is shifted closer to the preferred object using specific energy and angular momentum, constants of orbital motion, which describe properties of an object's trajectory. Guiding to the specific energy derived guidepoint does not offer significant benefit over guiding to the spatially derived guidance point. However, computing the spatial rate of change of specific energy within the plane formed by the guidance objects establishes a vector pointing close to the preferred object. This is the direction to shift the guidepoint in order to contain the preferred object within the interceptor's divert capability.

Method for targeting a preferred object within a group of decoys

A method of selecting a sub-set of a plurality of available sensors to guide an interceptor to a target is described. The method includes characterizing a quality of position estimate received from each of the plurality of available sensors, projecting the positioning errors of the sensors onto a plane normal to a line-of-sight of the interceptor, and selecting the sub-set of the plurality of available sensors based on the projection of positioning errors.

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Mount Laurel, NJ, United States of America

Jonathan Alan Boardman