A Hybrid Bistatic–Monostatic Radar Technique for Calibration-Free Estimation of Lossy Wall Parameters

Estimation of wall parameters is important for proper imaging and wall compensation and mitigation in through-the-wall radar imaging. In this letter, a hybrid technique based on a bistatic time-delay-only estimation and a monostatic-based measurement of wall reflections is presented and shown to be able to robustly estimate the constitutive parameters of the homogeneous wall under test. This hybrid method does not require a calibrated reference signal, thus making it useful for real-world applications. The formulation of the proposed method is discussed along with its application to simulated and measured results.