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1 April 1991 High-speed short-range laser rangefinder
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Proceedings Volume 1419, Eyesafe Lasers: Components, Systems, and Applications; (1991)
Event: Optics, Electro-Optics, and Laser Applications in Science and Engineering, 1991, Los Angeles, CA, United States
A high precision multi-target, short-range laser range-finder using a semiconductor laser diode is described. The laser diode is intensity modulated with a time-dependent frequency voltage signal. The return bundle is detected by a semiconductor photo diode and mixed with an undelayed fraction of the time-dependent frequency signal. This produces sum and difference frequencies, of which the difference frequencies are filtered out and are analyzed for individual components by a fast fourier transform processor. Each individual frequency component represents a specific distance to a target. The optical transmit and receive bundles are coaxial and can be scanned by a mirror scanner up to 100 Hz in elevation and 10 Hz in azimuth over a 30 degree(s) by 30 degree(s) field of view. The estimated accuracy in distance is 10 cm with a 1 ms 1.5 Ghz chirp and 36 mW of optical power at a wavelength of 1310 nm, over distances ranging from 1 to 50 m. The fast fourier transform processor estimates the up to 512 individual frequency components in less than 1 ms. The non-linear time-dependent frequency behavior of the voltage controlled oscillator is compensated by an optical feedback path. This contributes greatly to the accuracy of measured distances. This study has been carried out in the framework of IEPG activities on autonomous guided vehicles.
© (1991) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Robert M. A. M. Gielen and Ronald P. Slegtenhorst "High-speed short-range laser rangefinder", Proc. SPIE 1419, Eyesafe Lasers: Components, Systems, and Applications, (1 April 1991);

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