I. Introduction
With the maturity of industrial technology, unmanned aerial vehicles (UAV) have gradually become mainstream. They are widely used in logistics [1], transportation [2], monitoring [3], and other fields because of their small size, low price, and simple operation [4]. Although UAVs provide convenience, they cause a series of problems. Either public safety or personal safety and privacy are easily violated. Therefore, the detection and tracking of illegally or unintentionally invading UAVs are crucial. However, no complete and reliable anti-UAV detection and tracking system is available at present. Most of the existing detection and early warning technologies are based on radar [5], radio frequency (RF) [6], and acoustic sensors [7], which often have limitations, such as high cost and susceptibility to noise. These limitations lead to unreliable results. Therefore, these existing algorithms cannot be used extensively. Their application range is limited to airports and other public places.