大口径宽温区真空黑体辐射源的研制

Development of a Vacuum Blackbody Radiation Source with Large Aperture and Wide Temperature Range

真空黑体辐射源是红外遥感载荷地面实验室辐射定标的重要仪器。为满足红外遥感载荷向着大口径、宽温区范围、高定量化发展趋势,研制了300 mm口径、160~380 K温度范围、发射率为0.9975的大口径真空黑体辐射源。介绍了大口径宽温区真空黑体辐射源的工作原理及结构设计,开展了黑体的发射率计算和热学仿真模拟。测试了黑体在真空低温工况下160~380 K温度范围的底部温度均匀度和波动度,结果表明底部温度均匀度优于0.120 K,控温温度波动度优于0.031 K/30 min;基于控制环境辐射的发射率测量方法测量了黑体空腔发射率,并利用真空低背景红外亮温标准装置测量了黑体的光谱辐射亮温,在10μm波长辐射亮温合成标准不确定度为0.04 K@160 K,0.099 K@280 K,0.095 K@380 K,0.122 K@380 K。大口径宽温区真空黑体辐射源能够满足红外遥感载荷地面实验室辐射定标需求,支撑我国红外遥感定量化水平的提升。

Vacuum blackbody radiation sources are crucial instruments for the radiometric calibration of infrared remote sensing payloads in ground laboratories.To meet the trend of infrared remote sensing payloads towards larger apertures,wider temperature ranges,and higher quantification,a vacuum blackbody radiation source with a 300 mm aperture,a temperature range of 160–380 K,and an emissivity of 0.9975 was developed.This paper introduces the working principle and structural design of the large aperture and wide temperature range vacuum blackbody radiation source.It includes the calculation of emissivity and thermal simulation of the blackbody.The uniformity and stability of the bottom temperature of the blackbody within the 160–380 K range under vacuum low-temperature conditions were tested.The results show that the bottom temperature uniformity is better than 0.120 K and the temperature control stability is better than 0.031 K/30 min.The blackbody cavity emissivity was measured using a method based on controlling environmental radiation,and the spectral radiance temperature was measured using a vacuum low-background infrared radiance temperature standard device.The combined standard uncertainties of the radiance temperature at 10μm were 0.044 K@160 K,0.099 K@280 K,0.095 K@380 K,0.122 K@380 K.The developed vacuum blackbody radiation source with a large aperture and wide temperature range can meet the radiometric calibration requirements of infrared remote sensing payloads in ground laboratories,supporting the enhancement of China's quantitative level of infrared remote sensing.