为了跟踪和识别飞行的火箭，利用空间外差光谱仪对火箭尾焰辐射中钾光谱的766.490 nm和769.896 nm两条谱线进行研究。考虑大气分子吸收和大气散射对钾光谱在大气中传输的影响，采用逐线积分法、瑞利散射公式及散射系数与气象视程的关系分别计算763～773 nm波段内的氧气的吸收系数、大气分子及粒子散射系数，使用比尔-朗伯定律计算透过率。通过分析该波段内太阳辐射光谱和大气透过率可知，钾特征谱线处于太阳辐射强度弱、大气传输效率高的位置，从理论上验证了钾光谱探测的可行性。然后使用空间外差光谱仪对在火焰上燃烧的K2SO4进行探测，获得了与理论数据相符的实验数据，为火箭尾焰的空间外差光谱探测方法提供依据。

For tracking and recognizing a flying rocket, potassium 766.490 nm and 769.896 nm in rocket plume radiation spectrum were studied by the spatial heterodyne spectroscopy. The atmospheric molecular absorption and atmospheric scattering were considered in the atmospheric transmission model. In 763-773 nm, oxygen absorption coefficient was calculated by using line-by-line method, and atmospheric scattering coefficient was calculated by Rayleigh scattering formula and the relationship between scattering coefficient and meteorological visibility. Transmittance was calculated based on Lambert-Beer law. The analyses of solar radiation spectrum and atmospheric transmittance show that these two characteristics of potassium lines in the location which solar radiation intensity is weak and high transmission efficiency, and theoretically verify the feasibility of detection of potassium spectrum. Then, the spatial heterodyne spectrometer was used to detect potassium spectrum that K2SO4 was burned in flames. The experimental datum are accordant with the theoretical results, which demonstrate that the potassium line detection scheme is feasibleusing spatial heterodyne spectrometer.