Experimental Moving Target Imaging in a Nonanechoic Environment With Linear Sampling Method

Abstract

In this letter, imaging of moving targets with qualitative microwave imaging methods (Q-MWMs) is addressed. The problematic side of Q-MWM is the requirement of background measurement. To eliminate this necessity, the total electric field measured at different time instants (say $E^{\mathrm{ tot}}_{n}$ and $E^{\mathrm{ tot}}_{l}$ are the total electric fields measured at the $n$ th and $l$ th time instants, respectively) is applied to Q-MWM. For these input data, the output of Q-MWM can be assumed to be the summation of the indicators at these time instants (i.e., $E^{\mathrm{ tot}}_{n}-E^{\mathrm{ tot}}_{l}$ produces the differential indicator $I_{nl}=I_{n}+I_{l}$ , where $I_{n}$ and $I_{l}$ are the indicators at the $n$ th and $l$ th time instants, respectively). Using this information for all possible time pairs, an equation system is set for indicator values at different time instants. Solving this equation system, the indicator of Q-MWM for each measurement time is obtained, without taking any background measurement. The performance of the proposed algorithm is verified for the linear sampling method (LSM), which is an example of Q-MWM, with the 3-D and 2-D [both transverse magnetic (TM) and transverse electric (TE)] experimental measurements performed in a nonanechoic environment.