Texas Instruments Corporation

Raytheon Company

Other

Joel K McWilliams

Don R Van Rheeden

Raymond Samaniego

Theagenis John Abatzoglou

Johan E Gonzalez

Mark B Yeary

Enrique A Santiago

A synthetic aperture radar imaging method that combines each radar return pulse with a sinusoid to reduce the radar return pulses to a baseband frequency and deskew each radar return pulse. It includes determining a maximum likelihood estimate (MLE) of residual motion parameters for a dominant scatterer on the ground relative to the airborne radar and correcting for errors in inertial navigation system measurements based on the MLE residual motion parameters. It includes convolving each radar return pulse with its corresponding radar transmission pulse to generate a range compressed image for each radar return pulse and generating a sub-band range profile image for each radar return pulse and its corresponding radar transmission pulse based on the corresponding range compressed image that has been corrected for residual motion. Performing bandwidth extrapolation on each sub-band and subsequently combining the three bands to produce an enhanced resolution image without grating lobes.

Enhanced radar range resolution

System and method for calculating three dimensional residual motion errors of a moving platform with respect to a point of interest by receiving a radar signal from the point of interest (); forming a radar image including a plurality of scatterers (); using an MLE method to obtain range, radial velocity and acceleration of the moving platform for a first peak scatterer in the radar image (); correcting a location of the first peak scatterer with respect to a scene center of the point of interest (); updating the obtained radial acceleration responsive to the corrected location (); and updating the obtained radial velocity of the moving platform responsive to the updated radial acceleration ().

On-board INS quadratic correction method using maximum likelihood motion estimation of ground scatterers from radar data

A method is disclosed for tracking an aimpoint on an elongate target with a set of arbitrarily related subimages in the field of view of the tracker. A dimensional relationship between the subimages and the aimpoint is initially determined and saved for later calculations. Subsequently, at least one of the aimpoints is reacquired. The aimpoint at the subsequent time is then determined using the position of the later acquired subimage, the saved dimensional relationship and indirectly on the position of the subimage in the field of view of the tracker.

Method and apparatus for tracking an aimpoint on an elongate structure

A method for tracking an aimpoint with arbitrary subimages as described. The method comprises the steps of acquiring an aimpoint (50) on a target and a set of subimages (80) arbitrarily associated with the aimpoint by a sensor in a field of view. For a first time, the dimensionality of each subimage (82) and a normalized distance (54) from each subimage to the aimpoint are determined. For a second time, at least one of the subimages is reacquired (56) and the subsequent location of the aimpoint is estimated (58) based on the subsequent location of the subimages, on the normalized distances, and, where a subimage is one-dimensional, on a maximum eigenvector associated with the subimage.

Method and apparatus for tracking an aimpoint with arbitrary subimages

A method is disclosed for tracking an aimpoint with a set of arbitrarily related subimages. A dimensional relationship between the subimages and the aimpoint is initially determined and saved for later calculations. Subsequently, at least one of the subimages is reacquired. The aimpoint at the subsequent time is then determined using the later acquired subimages and the saved dimensional relationship.

A method for rejecting inaccurate subimages is disclosed for subimages used to track an aimpoint. The difference between the actual location of each subimage and the location of the subimage based on an estimated aimpoint is compared to a threshold value. The subimage is discarded if the difference exceeds the threshold value. The aimpoint may then be reestimated using the revised set of subimages.

Growing community of inventors

Highland Village, TX, United States of America

Joel K McWilliams