Non-Imaging Permittivity and Temperature Change Detection by Coherent Microwave Radiometry

A non-imaging change (anomaly) detection technique using coherent microwave radiometry is reported. The technique is based on the partial coherence, that exists in thermal electromagnetic fields radiated by lossy dielectric objects. The underlying physics permits detection of change in both temperature and permittivity of the object. The statistical approach uses partial coherence measurements of the thermal radiation to derive a statistic which is subsequently used in a generalized likelihood ratio test to determine the presence of change. Monte-Carlo simulations show that the proposed technique can be effective in detection of small anomalies that are challenging to be resolved by other microwave imaging techniques. Detection performance largely depends on the sensitivity and the signal-to-noise ratio of the radiometric system.