High Precise Estimation of Propagation Time and Reflection Phase Shift Based on Time-Frequency Analysis on Microwave Radar

On a nondestructive inspection using the microwave radar, there are so many researches aiming metallic buried objects. On the other hand, those aiming nonmetallic ones such as a resin are very few. In this research, we propose two kind of high precise estimation methods for microwave propagation time based on the time-frequency analysis focusing on a phase shift when microwaves are reflected on surface of buried objects. In addition, we analyze observed microwaves by using proposed methods and evaluate the effectiveness of them on a propagation time estimation process. As a result, we have achieved high precise propagation time estimation results in both cases of metallic and nonmetallic buried objects. However, we have confirmed that an advanced consideration on noise reduction is necessary for higher precision of a propagation time estimation.