Improvement of Target Estimation Accuracy of Terahertz Reflection Time-Domain Spectroscopy with MUSIC Using Virtual Arrays

In reflective THz-TDS imaging using virtual arrays (VAs) in the synthetic aperture array (SAA) algorithm, the location of VAs would affect the target position estimation accuracy. This abstract first shows the influence of the distance between the VA and target. Then, to improve the accuracy without increasing the SAA elements, a method using multiple frequency images is investigated, which is suitable for this measurement system because THz-TDS uses pulse signals. The effectiveness is confirmed by simulation and measurement.