Scale invariant coherent change detection to locate micro-motion in single pass SAR images

Micro-Doppler analysis of SAR signals has a broad range of applications including target vibrometry, structural health monitoring, and maritime surveillance. Location of sources of micro-Doppler signals in SAR images is however not straightforward, where typical artifacts such as ‘ghost’ targets may be unnoticeable if, for example, a vibration is of low amplitude and frequency. This issue is exacerbated by background noise and clutter. A method for locating micro-Doppler signals using scale invariant coherent change detection between subaperture images is developed and tested on SAR data of vibrating targets with a ground truth vibrational frequency of 2 Hz and amplitudes of 16.13 mm and 1.08 mm. The results indicate that this method is promising, where micro-motion from both targets was located and the relative insensitivity of the technique to bright stationary targets is also demonstrated.