Imaging Method Based on Time Reversal Channel Compensation: Scientific Approach

The conventional time reversal imaging (TRI) method builds imaging function by using the maximal
value of signal amplitude. In this circumstance, some remote targets are missed (near-far problem) or
low resolution is obtained in lossy and/or dispersive media, and too many transceivers are employed
to locate targets, which increases the complexity and cost of system. To solve these problems, a novel
TRI algorithm is presented in this chapter. In order to achieve a high resolution, the signal amplitude
corresponding to focal time observed at target position is used to reconstruct the target image.
For disposing near-far problem and suppressing spurious images, combining with cross-correlation
property and amplitude compensation, channel compensation function (CCF) is introduced. Moreover,
the complexity and cost of system are reduced by employing only five transceivers to detect four
targets whose number is close to that of transceivers. For the sake of demonstrating the practicability
of the proposed analytical framework, the numerical experiments are actualized both in nondispersive-
lossless (NDL) media and dispersive-conductive (DPC) media. Results show that the performance of
the proposed method is superior to that of conventional TRI algorithm even under few echo signals.