Ground Surveillance With An Active LLLTV
Dennis S. Cleverly · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1973
Passive low-light level television has been used extensively for years in both mili-tary and civilian surveillance applications. The widespread usage of LLLTV comes from its capability of allowing the monitoring of areas which are necessarily dark by direct visual observation. Thus, the television surveillance system extends the observer's keenest decision-making sense -- sight. However, just as the human eye becomes limited at night, the passive LLLTV becomes limited on moonless, overcast nights and in poor visibility weather. To overcome this limitation and to increase the average usable range, an artificial covert illuminator is added to the television system. The illuminator not only alleviates the dependency of performance on naturally occurring nocturnal sources, but increases the system's capability to perform under poor visibility conditions.