大气同步校正仪（Synchronous Monitoring Atmospheric Corrector, SMAC）是高分辨率多模综合成像卫星的业务载荷之一，为卫星主相机提供时空一致的大气观测数据，实现基于辐射传输模型的高分辨率遥感图像大气校正。SMAC设置了专用于卷云识别的水汽强吸收波段，该波段特点使其稳定性测试极易受到实验室水汽波动影响，难以真实反映该波段性能。采用水汽波动控制、探测器同步监测等措施抑制水汽波动对测试数据的影响，结果显示采取措施后SMAC的稳定性误差由4.08%降低至0.23%，表明SMAC卷云识别波段稳定性测试方法合理有效，能够体现产品自身稳定性能，对后续同类产品的稳定性测试具有重要的参考价值。

Synchronous Monitoring Atmospheric Corrector (SMAC), a support for the main camera, was one of the mayor facilities of high resolution and multi-mode imaging satellite. SMAC was designed to achieve atmospheric correction for high spatial resolution images based on radiative transfer model by getting synchronous parameters of aerosols and water vapor. SMAC had a special channel, where the radiance could be mostly absorbed by water vapor, for remote sensing of cirrus cloud. This channel was sensitive to the fluctuation of water vapor in the lab while stability measurement, thus the real performance of this channel could be covered up. The influence of water vapor fluctuation on stability test data was suppressed by controlling water vapor and setting synchronous monitoring detector. The results show that the stability error of SMAC’s channel for cirrus cloud detection decreased from 4.08% to 0.23%. It indicates that the stability measurement method of cirrus cloud diagnosing band for SMAC is reasonable and effective, which could reflect the stability performance of the product, and has important guidance significance for stability measurement of similar instruments.