Range resolution improvement by a reversed m-sequence phase coded lidar system

Abstract

The traditional phase coded lidar systems require the collection of every returned laser pulse and are restricted in range resolution by sampling frequency and subpulse width. This paper proposes a reversed m-sequence acquisition method for signal detection. The detector accumulates N − 1 bits of the emitted laser sequence to deduce the Nth bit of the sequence. The indoor experiment achieved 2 μs resolution with the sampling period of 28 μs by employing a 15-bit m-sequence. This method achieves the acquisition of an m-sequence with narrow subpulse width whereas the sampling frequency is kept low. This paper also presents the phase coded imaging lidar simulation, which achieved 1.5 m range resolution with a 50 kHz sampling frequency by employing a 2047-bit m-sequence. The simulation showed an approach to implement phase coded imaging lidar in practical application.