The applications of remote sensing technologies to precision agriculture were reviewed. The different uses of conventional satellites and unmanned aerial vehicles (UAVs) for data collection were also examined. The ways in which the collected data have been used in terms of precision agriculture are laid out in further detail. Modern UAVs provide a range of advantages over conventional satellites in data collection and analysis. In addition, precision agriculture itself is a wide topic; and practitioners, researchers, and policy planners need to account for a complex value chain with diverse stakeholders. Thus, in order to further the discussion in a meaningful manner, the later sections of this article provide additional analysis on topics deemed crucial for the development of precision agriculture: a discussion on key technological limitations for scaling, a corresponding list of suggestions for the development of solutions, and a brief overview on the current social-economical landscape of the agriculture industry.

This paper develops a method of calculating the three-dimensional (3-D) coordinates of a target with image information taken from an unmanned aerial vehicle (UAV). Unlike the usual approaches to target geolocation that rely heavily on georeferenced terrain database or accurate attitude sensors, the contribution of the proposed method is to offset the constraints and also perform 3-D geolocation of the target based on the relative altitude between the aircraft and the target calculated using the stereo vision technique. Considering the poor performance of the yaw-angle measurement provided by the low-quality attitude sensors in the UAV, a novel vision-based 3-D geolocation method is designed. The proposed method is proven to be valid and practical via simulation results and actual flight experiments.

In this work, we report our solutions to the problems given in the 2014 International Micro Aerial Vehicle Competition, held in Delft, the Netherlands, August 2014, which involves using micro air vehicles in urban post-disaster search and rescue missions. Solutions to all key mission elements of the competition, including real-time map stitching, indoor navigation and roof-top perching, are documented and highlighted in this manuscript. The proposed solutions are successfully demonstrated in the competition and help us win the championship.

The recent development of small yet sophisticated sensors has led to the development of smaller unmanned aerial vehicles, especially in the form of quadrotor. When it is limited by the availability of the reverse propellers, the conventional quadrotor will no longer be realizable, and thus introducing the 4-standard-propeller (4SP) quadrotor design. This paper presents a comprehensive nonlinear modeling of a 4SP quadrotor, and the guidelines to design it. The advantages of constructing such aircraft and its detailed working principle are first highlighted. A nonlinear mathematical model is then derived based on the first-principles approach. The model parameters are finally identified and verified through actual flight tests.

This paper presents a comprehensive control and navigation scheme for an indoor UAV system. In addition to the inertial measurement unit commonly used onboard of most UAVs, the testbed quadrotor platform is also equipped with a mono-camera looking downwards and a laser range finder capable of scanning a level plane. With this setup, the UAV is able to estimate its own velocity and position robustly, while flying along the internal walls of a room without collision. The whole system does not require any remote sensory information or off-line computational power. All algorithms are self-sustained and running onboard in real time. Complete flight tests have been carried out to verify the solution.