Leica HDS4400 is a 3D laser scanner from the company Leica Geosystems and operates using the time-of-flight measurement method. The scanner is primarily applied for monitoring in mining industry. Leica HDS4400 is suited for high ranges up to 700 m (27559 in) – 600 m (23622 in) to rock (40% albedo) and 150m (5905 in) to coal (5% albedo). At full range, a discrepancy of 50mm (2 in) is possible; at a range of 50m (1968 in), a discrepancy of 20mm is possible. The system for High Definition Surveying has a measuring speed of max.