Drones are also known as unmanned aerial vehicle. They are the class of aircrafts that can fly without the onboard presence of pilots. Unmanned aerial vehicles are employed in various real life applications such as payload delivery,traffic monitoring and surveillance. The use of UAVs in any of these applications necessitates the planning of feasible and optimal trajectories for the motion of the vehicles. UAVs were originally developed through the twentieth century for military missions and by the twenty first century they had became an inevitable assets to human. Due to the improved control technologies and cost fell,their use expanded to non-military purposes. These include aerial photography,precision agriculture,forest fire monitoring,river monitoring,environmental monitoring,policing and surveillance,infrastructure inspections,smuggling,product deliveries,entertainment and predominantly in agriculture and allied sectors. The term Unmanned Aircraft System(UAS) was adopted by the United States Department of Defense and the United States Federal Aviation Administration in 2005 .An agricultural drone is an unmanned aerial vehicle used in agriculture operations,mostly in yield optimization and in monitoring crop growth and crop production. Agricultural drones provide information on crop growth stages,crop health and soil variations. For efficient field planning,agricultural drones can be used for soil and field analysis. They can be used to mount sensors to evaluate moisture content in the soil,terrain conditions,soil conditions,soil erosion,nutrients content and fertility of the soil. Light weight unmanned aerial vehicles will revolutionize spatial ecology according to Anderson and Gaston in the year 2013.In fact,since last few years farmers are realizing the benefit of drones in agriculture. Drones carrying special sensors can be used to measure pasture growth. Monitoring the livestock population is an essential step in farm management and it can be done easily with the help of drones.