Non-line-of-sight super-resolution imaging with quasi-constant-delay circular pattern

Non-line-of-sight (NLOS) high-resolution imaging remains a significant challenge under constrained system time resolution on the order of hundreds of picoseconds. The imaging fidelity of existing NLOS research mostly depends on the time resolution of NLOS system. To overcome this limitation, we propose a novel acquisition strategy that can obtain multiple groups of time-delay signals within a single acquisition and improve the acquisition efficiency. The core of our method involves generating quasi-constant-delay circular (QCDC) acquisition pattern and applying a corresponding quasi-constant-delay super-resolution (QSR) algorithm. The highest time resolution can be improved from 200 to 20 ps. Moreover, a reconstruction result of 256 × 256 can be successfully reconstructed from the signals collected by a 15 × 64 QCDC pattern. Experimental results confirm that the signals processed by the QCDC–QSR method are available for typical NLOS algorithms. By breaking the system hardware limits, our method has significant application potential in NLOS systems with low time resolution.