Modulated laser range finder and method

摘要

A laser range finder including a laser configured to project a laser beam onto a target object thereby causing a target beam to be reflected from the target object, wherein the laser beam has a frequency, and wherein the frequency is modulated at a known rate, a first beam splitter positioned to split a reference beam from the laser beam, a second beam splitter positioned to receive the target beam and the reference beam, wherein the target beam and the reference beam are coherently combined, the coherently combined beams establishing a difference frequency, and a detector configured to measure the difference frequency.

主权项

1. A laser range finder comprising:
a laser configured to project a laser beam onto a plurality of target objects thereby causing a plurality of target beams to be reflected from said plurality of target objects, wherein said laser beam has a frequency, and wherein said frequency is modulated at a known linear modulation rate; a first beam splitter positioned to split a reference beam from said laser beam; a second beam splitter positioned to receive said plurality of target beams and said reference beam, wherein said plurality of target beams and said reference beam are coherently combined to form coherently combined beams, wherein said coherently combined beams simultaneously establish difference frequencies based from a difference between a frequency of said reference beam and frequencies of said plurality of target beams at a given time, and wherein said difference frequencies are directly proportional to time delays between said reference beam and said plurality of target beams; and a detector configured to simultaneously measure distances to said plurality of target objects based from said difference frequencies.