RIEGL VZ-400 are high-performance 3D LiDAR scanners designed to provide high-accuracy measurements. They are time-of-flight, multiple-return, waveform instruments operating in the near-infrared. Typically, the RIEGL VZ series laser scanners are operated with an angular resolution between sequentially fired pulses of 0.04° in dense forests, resulting in approximately 22.4 million emitted pulses per scan (i.e., 5.42 billion per ha). Up to four targets can be resolved per pulse, with a nominal ranging accuracy of 5 mm. The laser itself is characterised by a beam divergence of 0.35 mrad, and the diameter of the beam at emission is 7 mm (e.g., the diameter of the beam at a range of 50 m, would be 21 mm). The pulse repetition rate can be set between 300 and 1200 kHz, with the trade-off being lower power but more rapid scanning with increased repetition rate, 300 kHz was used for ForestScan data collection. Each scan took approximately 3 minutes to complete at this rate.