Active Laser Imaging Detection Of Underwater Targets Based On The Polarization Information

In this dissertation, according to the background of polarized light detection and identification of targets, a research on polarized laser imaging detection to targets is carried out. When the polarized laser reflection on the material surface, it will produce different de-polarization effect depending on the material composition and structure of different substances. And based on the mechanism we start a research which using a polarized laser imaging to probe underwater target.Firstly, this article comprehensive overview of domestic and international solutions of de-polarization and polarization imaging studies. Then several methods about describing linearly polarized light are introduced, and the measurement method of polarization is analyzed and discussed in detail. The next, studies on depolarization at home and abroad are also described and summarized. The dissertation not only uses depolarization as the key breakthrough but also designs a set of polarization measurements way that can be used to retire for the degree of depolarization, this provide basis for the subsequent study area. Then analyze the scattering phenomena of the water and conduct small experiments about water scattering. According to the simple comparison of the scattering imaging which is collected from calm water and wave water surface, do a research on scattering phenomena which is occurring in water reflection and think about the cause of it. And put forward the idea that using laser active lighting to conduct imaging detection. In order to carrying out the study of the depolarization happening in scattering further, measure the degree of line polarization of laser sources with the way of measuring the degree of polarization and get a better result by this way. It has provided support for the subsequent study of the depolarization of scattering. Finally, carry out polarization imaging detection experiments to the design target respectively in a non-water environment and in an environment with water. And compare the experimental images with each other. A conclusion is found that the image contrast can be improved to some extent by polarization detection. In order to further enhance the image recognition capabilities, carry out analysis on the obtained experiment images, and with MATLAB programming to process the underwater image of an angle of 90 degrees of the polarization. What is more, it obtains a good recognition results.