Application Of New Optical Material Diffuse Reflector In Space Remote Sensor

The spaceborne diffuser is mainly used in the radiation calibration system of space remote sensors,and the on-orbit calibration scheme based on the "sun + diffuser" is widely used because it can achieve high-precision on-orbit radiation calibration with full aperture and all optical paths.As the key component of this on-satellite calibration scheme,the optical characteristics and space irradiation characteristics of the diffuser greatly affect the accuracy of on-orbit radiation calibration.In order to meet the needs of high-precision on-orbit radiation calibration of Fengyun-3 ultraviolet hyperspectral ozone detector,a new type of ultraviolet band alternative material diffuser-high-purity opaque fused silica material diffuser(HOD diffuser)is proposed on the basis of investigation and analysis of the characteristics of commonly used spaceborne solar diffuser.The results show that the key characteristics of the new material HOD diffuser are better than those of traditional aluminum diffuser,which can effectively improve the long-term accuracy of on-orbit radiation calibration of space ultraviolet remote sensing instruments.This paper focuses on the following three parts:(1)Carry out the Lambert property research of the HOD diffuser of the new optical material.On the basis of the theoretical derivation of the Lambertian optical property distribution function,a high-precision measurement device for Lambert properties of UV-visible continuous band diffuser was constructed,and the comparative measurement of diffuse reflection Lambertian optical characteristics of the new optical material HOD diffuser and the traditional aluminum diffuser was completed.The cosine deviation of the Lambert property at 290 nm is less than 10%,which is greatly improved compared with the 40% deviation of the traditional aluminum diffuser,which can reduce the influence of the change of the incidence angle of the sun in orbit on radiation calibration.(2)Carry out research on the spatial irradiation characteristics of the new optical material HOD diffuser.Aiming at the harsh working environment of the ultraviolet hyperspectral ozone detector in orbit,the influence principle and irradiation amount of space vacuum ultraviolet irradiation,atomic oxygen irradiation and total dose irradiation on the characteristics of spaceborne diffuser were analyzed and calculated in detail,and the research on space vacuum ultraviolet irradiation characteristics was carried out,and the space vacuum ultraviolet irradiation simulation environment test was carried out on the new optical material HOD diffuser and the traditional aluminum diffuser,and the results showed that the new optical material HOD had better space vacuum ultraviolet irradiation characteristics.Long-term stability of on-orbit radiation calibration is guaranteed.(3)Carry out high-precision calibration of the bidirectional reflection distribution function of the whole machine level HOD diffuser and research on the in-orbit pollution attenuation model.According to the characteristics of ultraviolet hyperspectral ozone profile detector,the calibration optical path of the bidirectional reflection distribution function of the diffuser is designed,and the calibration device and optimization processing algorithm are established to ensure that the calibration accuracy of the bidirectional reflection distribution function of the whole machine level HOD diffuser is better than 3%,which meets the requirements of on-orbit radiation calibration.On this basis,the diffuser Mueller matrix containing pollutant film is established,and the diffuser on-orbit pollution attenuation model based on the Mueller matrix model at different times can be used for its subsequent on-orbit radiation attenuation correction to ensure the long-term high-precision on-orbit radiation calibration of space remote sensors.