研制了一台用于实时测量天空背景辐亮度的大气辐射测量设备(DTL-1),该设备具有全天空扫描与给定方向测量两种测量模式,可完成400-1000nm波段积分辐亮度的测量。基于DTL-1系统组成结构原理图,详细说明了各功能部件的研制方案,给出了仪器的各项主要技术指标。对仪器进行了光谱辐亮度定标与恒定亮度下测量稳定性的测试实验;选取不同地区的天空辐亮度实测数据与MODTRAN5理论计算值进行了对比分析。结果表明:DTL-1稳定性测试的平均辐亮度示值为36.496w/m2·sr,均方根误差为0.463w/m2·sr,与MODTRAN软件模拟结果比较其相对误差在20%以内,能够满足科研与实际应用对天空背景辐亮度测量可靠性和精度的要求。
An atmospheric radiation measuring instrument (DTL-1) was developed to research the sky brightness radiance in real time, which could measure the integral radiance at wavelength of 400 to 1 000 nm in two working modes of all-sky scanning and given direction sounding. The design scheme was introduced in detail by the functional-block diagrams of system structure and the flowchart of sig- nal acquisition about DTL-1 and the main technical parameters of instrument were also presented. Then, the absolute integral radiance of the DTL-1 was calibrated in the spectral range of 400 to 1 000 nm by using a wide wave range absolute calibration method, and measuring stability under a constant brightness was tested. At last, the results measured by DTL-1 for practical data from different re- gions were compared to simulation of MODTRAN5. The results show that the average radiance of work stable test and the root-mean-square error are 36. 496 W/m2 · sr,and 0. 463 W/m2 · sr, respec- tively, and the variance between measurements of DTL-1 and simulations of MODTRAN is under 20 %. It demonstrates that DTL-1 can satisfy the requirement of scientific research and actual application.