Characterization ofZero-Doppler Clutter Removal Techniques forISARApplications

Inverse Synthetic Aperture Radar(ISAR) process- shift. However, mainbeam andsidelobe energy also illuminate ingisusedtogenerate high-resolution images. Thisworkconsid-surrounding terrain andother objects havingminimalorzero ersanoutdoor test range whereby theISARprocessing inducesvelocity. Thesestationary objects induce noDoppler shift zero-Hz Doppler clutter (ZDC)effects whichadversely impact imagequality byeither 1)masking actual target responses, or andproducetheso-called zero-HzDoppler clutter (ZDC) 2)inducing responses notdirectly attributable totarget features. response. Thecoherent summation ofthesezeroDoppler Techniques forremoving adverse ZDCeffects havebeendevel-returns cannegatively impact ISARimagequality byeither opedandaregenerally userdependant and/or target specific. 1)maskingactual target responses, or2)inducing responses Thisworkaimstoidentify keyZDC reduction mechanisms notdirectly attributable totarget features. TheZDC response andcharacterization metrics tobeexploited formoregenericisdistinguishable asastrong retur, referred toasthe"clutter applications. Twocharacterization techniques areconsidered: ridgelocateat acronge while o as downt pixel-average percentage difference andimagecross-correlation ridge," located atzerocross-range whileoccupying alldown- ofpre-ZDC andpost-ZDC processed data. Theimpact ofdatarange locations. windowing isalso investigated using various windowwidths and Therearesomeobvious compensation techniques forcon- types.