Study Of Polarized Laser Beam Range Profile

The target laser scattering characteristics has been a key issue in laser detection and identification, which describes physical phenomena between laser and target, revealing the inherent nature of the interaction between target and laser. Based on the light scattering theory of rough surface, the intensity, polarization and phase space distribution and time distribution of the scattering light are studied. It is of great academic value and extensive application background on the national defense, military aerospace and many civil fields. Theoretical study of target laser range profile is based on the laser scattering characteristics, which is a new target detection and recognition method developing with the laser and optoelectronic detect technology. The radar based on polarized beam has a longer detection distance and a stronger recognition capability for target than general beam.Based on microfacet theory and polarized bidirectional reflectance distribution function (pBRDF), the Stokes vectors of scattering-light and the Muller matrix of rough target are derived. The polarization characteristics of rough surface are discussed in detail through the Stokes vectors on which elliptically polarized light incidence and natural light incidence are both considered. The effects of incident angle, azimuth angle and refractive index on polarization characteristics of rough surface are numerically calculated. The research shows that the incident angle, the refractive index and the azimuth angle are of great influence on the ellipiticity angle and the degree of polarization (DOP). The change trend of the curves with different incident angle or refractive index have a high similarity, but the change trend of the curves with different azimuth angle have a large difference and the two curves that azimuth angle complementary are symmetric about scattering angle θr=O.The minimum value of the degree of polarization is obtained in the backscattering direction. Each element of the Muller matrix is analysed and the first element M00shows the changes of the incident light intensity in scattering occurred before and after. Thus, the first element of the polarized bidirectional reflectance distribution function f00can be calculated. The laser one-dimensional range profile simulations are done for some typical targets such as the spherical bait, inclined plate, ball and circular cone based on scalar laser radar cross section calculation formula and laser radar equation. The research shows that the laser one-dimensional range profile reflects the distribution structure of the object surface. The one-dimensional range profile of inclined plate, ball and circular cone reflects side shape, radius and side profile respectively.