Stray radiation research in CSRS

Cryogenic space remote sensor(CSRS), working on the Sun-synchronous orbit, is used to make observation of deep space and implement scientific research tasks. To observe small targets in deep space, CSRS should have quite low noise. Stray light is a major part of noise that affects the imaging quality, therefore, stray light control is a critical part of CSRS. CSRS is cooled to 10K, and works on the orbit which is never directly illuminated by the Sun and far away from other radiation sources such as the Earth and the Moon, so stray light from these objects can be neglected. This paper focuses on stray light from self thermal emissions of CSRS components, which plays a more important role in acquiring qualified image. Based on the theory of radiation energy transfer in the optical system, a method is proposed to calculate self thermal emission. After analysis of self thermal emission, measures suppressing stray light are put forward. Also in the paper, a few simulations to testify the scheme mentioned above are presented. Component emittance and paint absorbance are measured at various wavelengths as inputs for simulations. The results show that peak value of irradiance is well restricted to meet the system's requirement.