A Gaussian-based distance energy envelope method for enhanced ranging accuracy in laser gated imaging

Laser gated imaging is a pivotal technique for active three-dimensional(3D) reconstruction in challenging environments. The traditional triangular distance energy correlation algorithm, widely used in such systems, suffers from practical laser pulse and camera shutter waveforms, which are typically Gaussian. To address this limitation, this paper proposes a novel ranging method based on a Gaussian distance energy envelope. Firstly, we accurately model the temporal distribution of the pulsed laser output and the response of the intensifier camera’s gating shutter using Gaussian functions. The convolution of these two functions results in a Gaussian-shaped energy envelope, which more faithfully represents the actual energy distribution received by the system. Subsequently, a new ranging algorithm is derived. This algorithm intelligently utilizes the monotonic segments of two transient gated images captured with a precise delay, effectively isolating valid signal regions and inherently suppressing outliers and noise that do not conform to the Gaussian model, thereby enhancing computational accuracy. The performance of the proposed method was validated through rigorous experiments. In a multi-plate target experiment, the results demonstrated that the Gaussian method achieved distance measurement errors of 1.81 cm and 2.18 cm for different intervals, which is a 75% reduction in error compared to the conventional triangular algorithm. Furthermore, a 3D reconstruction experiment on a projectile target confirmed the method's robustness, with absolute ranging errors consistently below 1 cm at various points. The experimental outcomes conclusively show that the proposed Gaussian-based approach significantly outperforms the traditional method in terms of ranging precision and stability. This method provides a more accurate and reliable solution for high-precision 3D reconstruction in laser gated imaging systems, showing great potential for applications in precision measurement and target recognition.