天空背景亮度测量系统的研制

为了实时测量天空背景亮度,满足目标探测、跟踪、成像和大气探测等方面的应用需求,研制了一台具有全天空扫描与给定方向测量400~1000 nm波段范围积分辐亮度的仪器（DTL-1）。从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,给出了仪器研制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/m^2.sr,均方根误差为0.463W/m^2.sr,与MODTRAN软件模拟结果比较相对误差在20%以内。能够满足科研与实际应用对测量可靠性和精度的要求

Development of measuring instrument for sky background brightness

Sky background brightness is a significant physical quantity. The sky background brightness should be measured in real time to satisfy the requirement in the application areas of target detecting, tracking, imaging and sounding of atmosphere. An instrument entitled Sky Brightness Meter (abbreviated to DTL-1) was developed which measures the integral radiance of wavelength range of 400 to1000nm in two modes of all-sky scanning and given direction sounding. First, the design scheme is introduced in detail by the functional-block diagrams of system structure and the flowchart of signal acquisition about DTL-1, and the main technical parameters which are demanded in designing the instrument were also presented. Second, the measurement of absolute integral radiance in the spectral range of 400 to 1000 nm is realized using the method of wide wave range absolute calibration to calibrate DTL-1. Third, the test under the condition that the value of brightness is constant was analyzed to verify the stability of the instrument. At last, the results measured by DTL-1 were compared to simulation of MODTRAN5. The results show that, (1): The instrument works steadily and the Root-Mean-Square Error is 0.463W/m^2.sr. (2): The variance between measurements of DTL-1 and simulations of MODTRAN is under 20%. (3): DTL-1 could satisfy the requirement of scientific research and the actual application because of its high accuracy and portable design.