Abstract
There is currently considerable in developing underwater target detection, the underwater imaging
system can be divided into active imaging system and passive system. The main feature of the active
imaging system is that they use light sources to illuminate the targets and collect the reflection from
targets. The advantages of active imaging system over passive imaging systems are high contrast and
without the affection of environment sources. In this article, a range-gated underwater laser imaging
system is built, which consists of laser illumination system, photoelectric imaging system and control
system. The laser illumination system includes a light-pumped solid state doubled ND-YAG
laser(532nm) which laser power and frequency can be adjusted and an optics expanding system of
variable ratio. The photoelectric imaging system includes a gated Intensified CCD(ICCD) cameras
which ICCD scheduling, gate width, delay time and gain can be adjusted and a optics received system
of variable ratio. In order to acquire effectual target image using range-gated underwater laser imaging
system, appropriate control parameters that include laser power and frequency, ICCD scheduling, gate
width, delay time and gain, optics expanding system ratio and optics received system ratio must be given accurately. A control system which used C8051F320 and C8051F040 (MCU) as the core is designed, the control system can effectively control seven parameters that given above. The construction of software and hardware of the control system is introduced. And target image of underwater distance 25 m and 40m is given, Experimental results showed that the control system has high control precision, safe and stable operation and good speed adjusting performance can be achieved. It can be satisfied to apply to underwater target detection.
