**5. Conclusions**

This study has reviewed the most recent techniques for UAV/drone and its controller detection, classification, and localization. Cost-effectiveness, precision, accuracy, reliability, and real-time processing are among the factors considered while developing UAV detection systems. After discussing the high-level architecture of UAVs and security concerns, a comprehensive review of radio frequency, radar, acoustic, electro-optic, and hybrid systems for UAV detection is presented. The UAV detection systems employ different algorithms and techniques depending on the applications for detecting, classifying, locating, tracking, and alerting. To address the challenges, meet market needs, and improve reliability, employing a hybrid fusion of multiple cues, such as radio frequency, radar, acoustic, and visual sensors, can enhance detection performance.

**Author Contributions:** Conceptualization, J.Y. and M.G.; methodology, J.Y., M.A. (Marah Alhalabi), M.Y., T.B., E.A.S. and M.G.; validation, J.Y., H.Z., M.A. (Marah Alhalabi), M.Y., T.B., E.A.S., A.G. and M.G.; formal analysis, J.Y., H.Z., M.A. (Marah Alhalabi), M.Y., T.B., E.A.S., A.G. and M.G.; investigation, J.Y., H.Z., M.A. (Marah Alhalabi), M.Y., T.B., E.A.S., A.G. and M.G.; resources, J.Y., H.Z., E.A.S., M.A. (Mohammad Alkhedher) and M.G.; data curation, J.Y., H.Z., M.A. (Marah Alhalabi), M.Y., T.B., E.A.S., A.G. and M.G.; writing—original draft preparation, J.Y., E.A.S. and M.G.; writing—review and editing, J.Y., H.Z., M.A. (Marah Alhalabi), M.Y., T.B., E.A.S., A.G, M.A. (Mohammad Alkhedher) and M.G.; visualization, J.Y., M.A. (Marah Alhalabi), M.Y., T.B., E.A.S. and A.G.; supervision, J.Y., M.A. (Mohammad Alkhedher) and M.G., project administration, J.Y. and M.G.; funding acquisition, J.Y., M.A. (Mohammad Alkhedher) and M.G. All authors have read and agreed to the published version of the manuscript.

**Funding:** This paper is part of a research project funded by the Office of Research and Sponsored Programs (ORSP) at Abu Dhabi University through a research fund (Grant number 19300564).

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** Not applicable.

**Conflicts of Interest:** The authors declare no conflict of interest.
