Range extended SP-iToF LiDAR with time-gated and spatially fused imaging

Light detection and ranging (LiDAR) systems based on indirect time-of-flight (iToF) sensors have garnered considerable interest due to their all-solid-state design, high resolution, high reliability, and cost-effective nature. However, the challenge of extending the operational range of iToF LiDAR systems without compromising the range precision is a significant barrier to their broader application. This paper introduces what we believe to be a novel method to overcome these hurdles, which involves pre-setting the delay between the light pulse emission and the sensor's transfer gates to extend the operational range and utilizing spatial overlap fusion techniques to enhance the range precision. In hardware, a pulsed current driver for the light source with adjustable peak power has been developed to accommodate the varying power budget demands across a longer range. Experimental results demonstrate that, under the same signal-to-noise (SNR), the proposed method exhibits enhanced performance in range error and range precision compared to the conventional method. Furthermore, the designed LiDAR achieves 3D imaging at a distance of up to 120 meters with centimeter-level precision.