Research On Polarization Imaging Technology Of Space Target

Optical imaging is an important application for the space target surveillance.As a new technology in the field of optical imaging,polarization imaging boasts incomparable advantages in suppressing background noise,highlighting the outline information of the target,enhancing image details,distinguishing material and identifying camouflage compared with traditional optical imaging.The use of polarization imaging in the space target surveillance will help to effectively improve the detection distance and the contrast of detected target.As a result,the in-depth study of polarization imaging of space target is of great significance.After analyzing the mechanism and technical indicators of polarization imaging of space target,in combination with the domestic and foreign trial applications of polarization imaging of space target,an exploratory study on the realization of space target polarization imaging in the technical engineering is carried out,and a space target polarization imaging system suitable for functional small satellite monitoring platform is built.The system mainly consists of optical detection unit and polarized image processing unit,and active imaging mode is adopted for the design.The polarization camera Genie Nano-M2450 is adopted for the processing of polarization image.Simultaneous polarization image is used to acquire the data source of polarization images.With Xilinx Zynq series P-SoC as the control chip of the system,an integrated dual-core architecture ARM Cortex-A9 and FPGA of XC7Z020 is adopted to finish the hardware and software collaboration design of space target polarization imaging system,and the automatic acquisition,transmission,pre-processing,storage and display are realized on the polarization imaging system on chip.Furthermore,the system's functions are verified in the laboratory environment.Besides,the on-board information recovery technologies at home and abroad are explored,and the method of recovering polarization imaging data on the space target polarization imaging system is presented.The solid-state disk with USB interface is used to store polarization image data,which are then uploaded to PC through USB interface.PC can be used to achieve the acquisition of polarization sequence images and polarization characteristic images.Moreover,the discrete multi-wavelet transform-based image fusion algorithm is used for the fusion of polarization degree image and polarization angle image,further verifying the feasibility of space target polarization imaging.The experimental results show that the polarization imaging system presented here can be used to effectively suppress the background noise and improve the target identification,providing accurate information for the analysis and cataloguing of space targets,and laying a foundation for the realization and engineering of space target polarization imaging while achieving miniaturized space target surveillance platform.