Sense and avoid technology in unmanned aerial vehicles: A review

The term unmanned Aerial Vehicle (UAV) has become a quiet a bit popular over the last 10 years because of its humongous growth in both military and commercial applications. Every UAV must possess S&A capability so that it can be allowed by National Airspace System (NAS) to fly in space. This paper gives a brief overview on the recent trends and advancements in sense and avoids technology. This paper gives a brief outline about the existing challenges and threats that can encountered while operating an UAV, which is followed by the discussion on sensing mechanisms, obstacle-tracking, collision detection, and collision avoidance in sequence. Different approaches and potential solutions regarding the above-mentioned four aspects have been highlighted throughout the paper.