Study On Laser Uderwater Target Detection

Laser underwater target detection technology is a new kind of advanced detection technology. It included many technologies such as laser, communication, signal processing and object identification, electronic technique and so on. Researching and exploiting in this field have important value.The author mainly researched into the effects of underwater channel and object shapes on laser underwater target detection; compared with some imaging technologies which commonly used in underwater detection. Taking range gated selection for example, the author researched and analyzed modulation transfer function and signal noise ratio. All the researches are important problems under water laser detection, and offer the base of theory to improve the capability of laser detection. This paper mainly include the following content:1) Discussed the change rule of laser light intensity and spot of underwater laser transmission, gotten the conclusion: with increasing water parameters, laser light will be weaken and laser spot will be increased.2) Educed an equation of fore-scattered. And also educed an equation of echo signal power, which considered the differences of optical paths. Taking plane object for example, analyzed and researched the influences of an angle of incidence, object shapes, etc on signal power.3) In the use of range-gated technique situation, obtained the connection of the gate opening time and the signal noise ratio. The author also discussed imaging distance and modulation transfer fuction.