Open AccessResolving range ambiguity in a photon counting depth imager operating at kilometer distances
Author(s) -
Nils J. Krichel,
Aongus McCarthy,
Gerald S. Buller
Publication year - 2010
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.18.009192
Subject(s) - optics , photon counting , ranging , physics , lidar , laser , photon , pulse repetition frequency , range (aeronautics) , pulse (music) , remote sensing , computer science , materials science , detector , telecommunications , geology , radar , composite material
Time-correlated single-photon counting techniques have recently been used in ranging and depth imaging systems that are based on time-of-flight measurements. These systems transmit low average power pulsed laser signals and measure the scattered return photons. The use of periodic laser pulses means that absolute ranges can only be measured unambiguously at low repetition rates (typically <100 kHz for > 1 km) to ensure that only one pulse is in transit at any instant. We demonstrate the application of a pseudo-random pattern matching technique to a scanning rangefinder system using GHz base clock rates, permitting the acquisition of unambiguous, three-dimensional images at average pulse rates equivalent to >10 MHz. Depth images with centimeter distance uncertainty at ranges between 50 m and 4.4 km are presented.