Voxtel Blog

Laser Ranging—Technical Notes Released

December 18, 2018

Voxtel has released a series of technical notes on laser ranging:

  • LRF Effective Range: The effective range of a laser rangefinder (LRF) depends on the sensitivity of its photoreceiver and the strength of optical signal returns as a function of target range. Parameters affecting signal-return strength are reviewed in this technical note, including laser pulse energy, atmospheric conditions, and the size, orientation, and surface properties of the target.
  • Relationship Between False-Alarm Rate and Probability of False Alarm: Discussed is the relationship between the probability of false alarm, as calculated from the false alarm rate (FAR), and the probability of detection as it relates to measuring target distance using a laser rangefinder.
  • Range-Walk Correction Using Time Over Threshold: This paper shows that a lookup table or polynomial correction based on time-over-threshold measurements can be used to reduce the range walk of an avalanche photodiode-based laser rangefinder to within ±0.2 m, at all ranges, over a pulse-return dynamic range of greater than 90 dB.
  • Limitations of NEP as a Lidar APD Photoreceiver Performance Metric: This paper shows that noise equivalent power (NEP) alone is not a good measure of the sensitivity of a laser-rangefinder receiver that employs an avalanche photodiode (APD). The optical signal required to achieve a specified detection probability for a detection threshold that achieves a specified false-alarm rate is shown to be a more reliable characterization of APD photoreceiver performance for laser-ranging applications.