含钾消焰剂的使用, 大大降低了火箭尾焰的二次燃烧及辐射量, 提高了对其探测与追踪的难度。基于空间外差光谱技术微弱光谱信号精细探测的优势特性, 采用自行设计的近红外波段仪器, 以室外天空为背景, 用酒精喷灯火焰模拟火箭尾焰, 实验研究了其中钾盐信号的探测, 并以现代谱估计方法中的自回归AR算法和MUSIC算法对测量信号进行提取研究。结果表明, 两种算法均能实现对钾特征信号的提取及对噪声的抑制, 使特征信号的峰宽变得更窄, 其中AR算法对钾766.49 nm特征峰的半峰宽减小率为21%, 噪声减小率为42%; MUSIC算法对钾特征峰的半峰宽减小率为50%, 噪声减小率为47%, 两相比较可见MUSIC算法的效果更好, 说明将空间外差技术应用于火箭等喷射式飞行器的识别具有可行性。

The secondary combustion radiation of rocket plume can be significantly reduced by using potassium flame agent, which leads to unprecedented improvement of missile invisibility. With the advantage of spatial heterodyne spectroscopy on weak spectrum signal detailed detection, potassium signal detection experiment in missile plume spectrum was performed by a near infrared spectrum instrument. Alcohol burner flame was used to simulate the missile plume, while the outside sky was regarded as background. Two of the modern spectral estimation methods, Autoregressive AR algorithm and MUSIC algorithm, were used to extract the potassium signal. Both algorithms can suppress noise, extract potassium signal and narrow the width of its characteristic peaks. For AR algorithm, the characteristic peak of 766.49 nm reduce 21% respectively, and noise reduce 42%. While for MUSIC algorithm, those characteristic peak reduce 50% and noise reduce 47%. The results illustrate that MUSIC algorithm has a better performance, and the application that using spatial heterodyne technology to identify the jet aircraft such as missiles is feasible.