Robust Channel Registration and Clutter Suppression for Airborne Terahertz Multichannel SAR-GMTI

Airborne terahertz (THz) synthetic aperture radar (SAR) demonstrates significant potential for real-time ground moving target indication (GMTI) due to its high frame rate and superior resolution. The performance of the system is driven by its high pulse repetition frequency (PRF) and short wavelength, which introduce two key characteristics: enhanced Doppler sensitivity and a broad non-clutter region. First, the Doppler sensitivity amplifies group phase shift error between channels caused by non-ideal platform motion, leading to reduced interchannel data correlation. To achieve precise phase correction, an adaptive iterative phase spectrum compensation method is proposed. Then, due to the broad non-clutter region in the THz band, conventional methods are only effective in the clutterdominated region, which elevates the noise floor in the non-clutter region. To ensure the high signal-to-clutter-noise ratio (SCNR) of the moving target, a weighted displaced phase center antenna (DPCA) method based on wavelet decomposition is proposed. Finally, the moving target is detected and preliminarily imaged. Real-measured THz-SAR data processing results are presented to validate the effectiveness and feasibility of the proposed methods