Drone technology is the set of aircraft, software and radios that let a drone do a planned job, such as surveying a pipeline, filming a wedding or watching a border. A drone is an aircraft with no pilot on board. An operator flies it from the ground, or it flies itself.
Say a pipeline company in Gujarat has to inspect 40 km of pipe for rust and leaks. A team on foot would need several days, and some stretches are hard to reach. A fixed-wing drone flying at 50 km/h covers the 40 km in under an hour, and its camera records every stretch. The journey in the diagram follows such a flight, from the plan to the report.
A drone system has four parts. The first is the drone itself: its frame, motors, battery, a small flight computer and a payload. The payload is what the drone carries to do its job, such as a camera, a sensor or a parcel. The second is the ground control station, the screen and controls from which an operator plans and watches the flight. The third is the data link, the radio connection between the drone and the ground. The fourth is the software that flies the drone and recognises what its camera sees.
How much the operator does depends on the level of autonomy. At the lowest level, a person flies each drone by remote control. At the next level, the drone follows a route planned on the screen, using GPS to know where it is. Further up, drone autonomy software lets the drone find its way with no GPS and no link to the operator. At the highest level, a group of drones, called a swarm, coordinates by itself. Swarms and army units often exchange messages over a mesh network, in which each radio passes messages on for the others, so no mobile network is needed.
Some drones sit in a box on site and need nobody to launch them (drone in a box). Other systems exist to stop a hostile drone (counter-drone systems). The same ideas also move boats and ground vehicles (unmanned systems). Two common civilian jobs are drone surveying and robotic inspection.
In India, a drone flight also has to follow the Drone Rules, 2021. Most drones must be registered, and the airspace is divided into green, yellow and red zones. The ground control station software checks a route against these zones before the flight. Most buyers of military and police drones are government bodies, and they usually buy through a public tender.