自校准型光谱辐亮度标准光源

针对高精度空间光学定量遥感的需求,研制了一种采用数字微镜器件的自校准型光谱辐亮度标准光源。该光源具有两种工作模式:在窄带工作模式下,由Gershun管辐射计和CAS光谱辐射计自校准;在宽带工作模式下,作为光谱辐亮度标准光源用于地面或空间遥感仪器的光谱辐亮度响应度定标。以光谱辐照度标准光源和Spectralon标准漫反射板组成光谱辐亮度标准光源为CAS光谱辐射计定标,测得自校准光源的光谱辐亮度。又以标准探测器定标的Gershun管辐射计测量自校准光源,采用迭代法得到自校准光源的光谱辐亮度。窄带模式下两种不同定标方法对自校准光源的光谱辐亮度测量结果在测量不确定度允许范围内一致。不确定度分析显示:基于标准光源和基于标准探测器的自校准光源光谱辐亮度测量不确定度分别为1.41%~2.09%和1.28%~1.61%。实验及不确定度分析结果表明,该光源可以满足高精度空间光学定量遥感的使用要求。

Self-calibrated spectral radiance standard source

Aiming at the demand of high-precision space-based optical quantitative remote sensing, a self-calibrated spectral radiance standard source which employs Digital Micromirror Device (DMD) was developed.The light source has two working modes.In narrow-band mode, it is calibrated by CAS spectroradiometer and Gershun radiometer.In broad-band mode, it is used for calibration of the spectral radiance responsivity of ground-based or space-based remote sensing instruments.An spectral radiance standard source comprised by spectral irradiance standard lamp and Spectralon standard plaques was adopted to calibrate CAS spectroradiometer, which was used to measure the spectral radiance of the self-calibrated source.Meanwhile a Gershun radiometer calibrated by a standard detector was used to measure the self-calibrated source, thus the spectral radiance of the source was achieved by iteration.The measurement results of the two calibration methods are coincident within the measurement uncertainty range.The uncertainty analysis shows that the uncertainties of the spectral radiance based on standard source calibration and based on standard detector calibration are 1.41%~2.09% and 1.28%~1.61% respectively.The results of the experiments and the uncertainty analysis indicate that the self-calibrated spectral radiance standard source can meet the requirement of the space-based optical quantitative remote sensing.