Revolutionary AUTOFOCUS for High-Resolution Coherent Radar Imaging Systems

"Vexcel Corporation proposes the implementation of a recently invented AUTOFOCUS technique as a revolutionary new way to correct defocus and remove blurring from coherent two-dimensional (2D) radar imagery and as an enabling technology for emerging coherentthree-dimensional (3D) imaging systems.High-resolution 2D coherent radar imaging is a critical component in existing ballistic and theater missile defense systems and provides data for advanced detection, tracking, and discrimination processing. Unavoidable aperture synthesis errors (e.g.inaccuracies in target location estimates, ionospheric propagation dynamics, etc.) lead to phase errors that cause defocusing in radar imagery. As these effects change during the aperture time, they cause a fully-coupled 2D phase error that cannot becorrected using conventional algorithms. Potential operation in a nuclear environment holds the possibility of very significant exaggeration of these types of effects.A recent Vexcel study to extend the established Phase Gradient Autofocus algorithm to 2D revealed theoretic limitations and lead to the discovery/invention of the proposed autofocus technique. Preliminary results show this technique to be a much morerobust method for removing severe fully-coupled 2D errors from data, vastly improving image quality in many cases where the 2D PGA technique showed practically no improvement. Vexcel expects to realize commercial benefits directly and indirectly