Laser Rangefinder is a device which uses a laser beam to determine the distance to an object. The most common form of laser rangefinder operates on the time of flight principle by sending a laser pulse in a narrow beam towards the object and measuring the time taken by the pulse to be reflected off the target and returned to the sender. Due to the high speed of light, this technique is not appropriate for high precision sub-millimeter measurements, where triangulation and other techniques are often used.

Laser pulse may be coded to reduce the chance that the rangefinder can be jammed. It is possible to use Doppler effect techniques to judge whether the object is moving towards or away from the rangefinder, and if so how fast. The precision of the instrument is determined by the rise or fall time of the laser pulse and the speed of the receiver. One that uses very sharp laser pulses and has a very fast detector can range an object to within a few millimeters.

Laser Distance Measurement Technologies

  • Time of Flight Laser Measurement – this measures the time taken for a light pulse to travel to the target and back. With the speed of light known, and an accurate measurement of the time taken, the distance can be calculated. Many pulses are fired sequentially and the average response is most commonly used. This technique requires very accurate sub-nanosecond timing circuitry.
  • Multiple Frequency Phase-Shift Laser Measurement – this measures the phase shift of multiple frequencies on reflection then solves some simultaneous equations to give a final measure.
  • Interferometry Laser Measurement – the most accurate and most useful technique for measuring changes in distance rather than absolute distances.

Laser Rangefinder Applications

  • Military Laser Rangefinders provide an exact distance to targets located beyond the distance of point-blank shooting to snipers and artillery. They can also be used for military reconciliation and engineering.
  • 3D Laser Rangefinders are used extensively in 3-D object recognition, 3-D object modelling, and a wide variety of computer vision-related fields. This technology constitutes the heart of the so-called time-of-flight 3D scanners.
  • Forest Laser Rangefinder – Anti-Leaf Filter Laser Rangefinders are used in forestry. These devices have anti-leaf filters and work with reflectors. Laser beam reflects only from this reflector and so exact distance measurement is guaranteed.
  • Sports Laser Rangefinders may be effectively used in various sports that require precision distance measurement, such as golf, hunting, and archery.
  • Industrial Laser Rangefinder technology is used in the automation of stock management systems and production processes.
  • Laser Measurement Tools – Laser Rangefinders are also used in several industries like construction, renovation and real estate as an alternative to a tape measure.