SPIE Proceedings, International Symposium on Optics, Imaging, and Instrumentation: Infrared Technology XX, Session: IR in Canada part 2, July 24-29, 1994., San Diego, California, USA
range imaging; infrared; tracking; time-of-flight; synchronized scanning; position detectors; infrarouge; poursuite; temps de vol; balayage synchronisé; détecteurs de position
This paper presents work performed at the National Research Council of Canada in infrared range imaging, i.e., from 1.5 µm to 1.8 µm. This region of the spectrum is chosen for eye-safety reasons. Basic concepts explaining the triangulation principle used in NRC prototypes are presented. The requirements for laser source and optics are described in some detail. Laser spot position detection is reviewed in the context of infrared range imaging with actual design examples and detailed calculations of signal-to-noise ratios. These calculations are useful in the early stage of a design. Experimental results show range images taken with the first prototype built at the Institute for Information Technology. A discussion on current developments concentrates on another prototype range camera intended for space applications. The current version of that prototype operates at 0.82 µm and can perform tasks in tracking mode at a refresh rate of 130 Hz (60 targets per second) or in imaging mode at a data rate of 18000 registered 3-D and intensity points per second. The useful range is about 0.5m to 10m. For distances greater than 10m, a time-of-flight unit along with a pulsed-laser source operating at 1.54 µm will be included. The change of operating wavelength will provide a system that is eye-safe and increase the signal to background light rejection for space applications.