星载同步监测大气校正仪(SMAC)用于获取遥感图像中时间同步、空间匹配的多光谱偏振大气信息,为高分辨率遥感图像的大气校正提供了气溶胶、水汽等微物理参数。为满足SMAC环境试验过程中现场光学性能标定的需要,设计了一种便携式多通道辐射参考光源(PMRLS)。PMRLS采用与SMAC一致的多通道光学设计,且各通道均为独立发光组件。发光组件采用发光体配合扩散板形成均匀照明,在可见近红外波段、短波红外波段分别选用LED和小功率卤钨灯作为发光体以降低整体功耗,采用低噪声稳定电流源驱动光源,结合散热片和风扇的散热设计以保证光源温度稳定性,并通过结构限位固定结构位置关系以提高光源测试的重复性。通过PMRLS应用对象,即SMAC,将积分球光源的辐亮度直接等效传递至PMRLS,并进行了非稳定度、非重复度评价。性能测量结果显示,SMAC地面检测光源各通道输出能量与SMAC动态范围典型辐亮度值的偏差在7%之内,非稳定度优于0.76%,非重复度优于1.3%,测量结果表明研制的PMRLS能够满足SMAC性能快速监测的需求。

The space-borne synchronous monitoring atmospheric corrector (SMAC) is a sensor that can obtain real-time spatial multispectral polarization information of the atmosphere. In this way, aerosol and water vapor parameters that are then used for the atmospheric correction of high-spatial-resolution images can be provided. A portable multichannel reference light source (PMRLS) was designed to evaluate the optical performance of the SMAC during environmental testing. The multichannel design of this source was consistent with that of the SMAC and had independent luminous components corresponding to each channel. A luminous element was equipped with a semitransparent diffuser plate, thus, enabling the luminous components to produce uniform illumination. To reduce the power consumption, a light-emitting diode and halogen tungsten lamp were chosen as the luminous elements at the visible and near-infrared band and the short-wave infrared band, respectively. The luminous element was driven by a low-noise stable current and cooled by an electric fan and cooling fin so as to improve the temperature stability of the PMRLS. In addition, the position of the PMRLS was limited by design to improve its repeatability. The radiance adjustment and performance testing for the PMRLS were performed using the SMAC. The maximal deviation in the radiance found during the PMRLS's radiance adjustment was within 7%, and the instability and non-repeatability values were less than 0.76% and 1.3%, respectively. Overall, therefore, the performance of the PMRLS meets the requirements for a quick evaluation of the SMAC.