Near-Infrared Laser Range Finder, using kHz Repetition Rate

摘要

The paper deals with laser range finding (LRF) technology for tracking fast-moving objects with kHz laser repetition rates. The LRF is based on time-of-flight measurement, where a short emitting laser pulse is transmitted and its time-of-flight is accurately measured by the electronics with respect to the received impulse from a non-cooperative target. The emitted laser energy is in the near infrared wavelength region. The detector is based on a single-photon detection principle of a silicon Avalanche photodiode, operated in so-called Geiger mode. A solution was devised to utilise single photon detection even at strong daylight conditions. The LRF has been integrated in a robust and compact technology demonstrator, and has successfully ranged to rapidly-moving and accelerating small targets. A detailed mathematical model was developed to predict the ranging performance of the LRF for evolution of application-specific designs. The current technology allows ranging up to a maximum range of 1.5 km with +-0.5 m accuracy against large stationary targets, as well as tracking of small targets of 75 mm diameter moving up to a range of 300 m with a speed resolution of +-5 m/s. The LRF device uses a standard serial protocol for device communication and control, and operates at a temperature range from 0 deg C - 55 deg C.