Simulation of satellite, airborne and terrestrial LiDAR with DART (II): ALS and TLS multi-pulse acquisitions, photon counting, and solar noise

•LiDAR single-pulse waveform simulation is extended to multi-pulse system.•ALS and TLS configurations and output data can be converted to SPD format.•A new approach to simulate photon counting LiDAR data with atmosphere.•A new approach to simulate solar noise by 2-source-1-sensor simulation.•CAO, ILRIS, MABEL and ATLAS are simulated.

Light Detection and Ranging (LiDAR) devices are increasingly used to provide data on Earth's landscapes structures and atmosphere constituents. Their developments, especially with scanning and multi-beam systems require accurate modeling tools to analyze existing data and to design future systems. A few radiative transfer models (RTMs) can simulate LiDAR waveform of one pulse. Based on that, this paper presents an efficient, flexible and user-friendly approach that extends the existing single-pulse simulation to a device-specific multi-pulse tool in the Discrete Anisotropic Radiative Transfer (DART) model. The realistic acquisition configurations (platform positions and orientations dataset) can be imported and the simulated waveforms can be converted into industrial data formats and processed by industrial software. Multi-pulse simulations of several airborne and terrestrial devices are presented. DART was also extended to simulate photon counting devices, by combining the physical principles of the single-photon detector with the waveforms. In addition, it computes solar noise contribution in LiDAR signal for any atmospheric configuration through combined simulation of waveforms and passive radiance images with any sun-sensor geometry. With these improvements, DART has become a comprehensive tool for satellite, airborne and terrestrial multi-pulse systems. Several studies are illustrated with configurations of existing and future devices, including CAO, ILRIS, MABEL, and ATLAS.