Research On The Effect Of Space Contamination For Optical System Imaging

In recent years,with the development of space technology,the world aerospace industry has made a series of breakthroughs.But for the space station projects,there are still a lot of unresolved issues.The station exposure to the space in long-term caused the space contamination.This will make severely affect to the space optics system.In the last century1970s and 1980s,the United States has a total of 20 satellites that carried out operational failure because of space contamination.Until now,the U.S.was the main country and the other countries aerospace designers began to make extensive experimental study on space contamination in order to effectively control and protect the normal operation of the spacecraft.This article is based on the above background,research the effects of optical contamination caused by optical shielding on the optical imaging system and use the method of simulation to explore the impact of optical scattering contamination.Finally,the analysis of space contamination on optical imaging system is finished.The main contents are:Discuss the space contaminated material sources and classification,according to the effects of contaminated product,the optical contamination includes the shielding contamination and the scattering contamination.Generally considered contaminants deposited on the optical surface,the optical transmittance and reflectance of the system is reduced.But the contamination which is very little does not affect the transmittance and reflectance of the optical system,and an optical scattering effect is produced.This paper studies two aspects of space contamination will affect the mechanism of the optical imaging system:When a large amount of contamination,so that the optical system of the optical transmittance and reflectance is reduced,this shielding contamination caused by the change in optical properties;and little amount in contaminated,not yet attracted the optical transmittance and reflectance changes significantly.The optical surface properties change is caused by scattering of micro particulate contamination.For the shielding contamination problem,establish surface imaging optical system based on optical spectral irradiance variations of the optical system for the contamination damage model.Screening the carbon powder,vacuum paint and silicone,which are the space of three common contaminants,a large number of optical damage effects on optical imaging system were studied experimentally.Were investigated based optical shielding contamination on visible and infrared light imaging studies the relationship between image quality and the degree of contamination.Thereby,we can obtain a large amount of contamination of the optical system imaging effect mechanism.By studying the results obtained when the thickness is greater than the quality of the carbon powder contamination with 3×10^-6g/mm²,the transmittance of the entire system of the optical element is less than 50%,and when the thickness of the carbon powder contamination mass 16×10^-6g/mm²,the optical transmission system will drop to almost zero.The black paint contaminated comparison,in the system of the optical transmittance decreased to 70%and 50%,the carbon powder contamination on the optical transmittance is more obvious,and when the transmittance drops to 30%,the paint contamination affects the transmission rate of the optical system more obvious than the carbon powder.Molecular film contamination effects on optical imaging do not affect obviously,but it will produce thin-film interference phenomenon affecting optical imaging.For the scattering contamination problem,establish the lattice model of contaminated surface on the optical imaging system to analyze and study the effect of space contamination on the optical imaging system caused by light diffraction.The class of scattering contamination is researched and analyzed by Fraunhofer diffraction theory.The visible and infrared bands scattering type optical contamination was simulated respectively.The results as follow:The smaller particle diameter,the smaller particle spacing and the longer wavelength was the greater impact on the class of optical scattering contamination on the space optical imaging.