Passive detection of unmanned aerial vehicle (UAV) is an important part of surveillance. Satellite has the potential to play a key role in many applications of space-air-ground integrated networks (SAGIN). In this paper, we propose a novel passive detection method for UAV based on Rao detection. Two hypotheses of UAV detection features are proposed when constructing the signal model. Under this condition, the Rao detection method is extended to weak echo signal detection in a multi-satellite scene. When the noise variance is unknown, two different Rao detectors are designed according to the existence of an interfering target. Moreover, the two detectors’ detection thresholds are obtained given the false alarm probability, respectively. Then, the detection performance of the two detectors is analyzed. Finally, we evaluate the Rao detection performance in different situations with extensive simulations.

无人飞行器（UAV）的被动检测是监视的重要组成部分。卫星有潜力在天地一体化网络（SAGIN）的许多应用中发挥关键作用。在本文中，我们提出了一种基于饶检测的无人机被动检测方法。在构建信号模型时提出了无人机检测特征的两个假设。在这种情况下，Rao检测方法被扩展到多卫星场景下的弱回波信号检测。当噪声方差未知时，根据干扰目标的存在设计两种不同的Rao检测器。此外，分别给定虚警概率，得到两个检测器的检测阈值。然后，分析了两种检测器的检测性能。最后，