Sidelobe minimization in MTI processing

摘要

Moving target indication (MTI) algorithms often operate within a relatively narrow frequency band relying on Doppler processing to detect moving targets at long standoff ranges. At these standoff ranges, received wavefronts impinging on a linear array can be considered planar, enabling implementation of a variety of phase-based beam-forming techniques. At near ranges, however, the plane-wave assumption no longer holds. We describe enhancements to an impulse-based, low-frequency, ultra-wideband, moving-target imaging system for near-range, through-the-wall MTI. All MTI image processing is performed in the time domain using a change detection (CD) paradigm. We discuss how MTI image quality can be increased through the introduction of randomized linear arrays. After describing the process in detail, we present results obtained using data collected by an impulse-based, low frequency, ultra-wideband system.