Ground stations: ground control stations are part and parcel of a drone system. Their size is almost proportional with the size, and therefore performance, of the aircraft used, while their configuration largely depends on the mission required by the end user.

Whatever the size of the system, a ground control station always includes two basic, essential elements: the control of the aircraft per se, and the data retrieval unit. Their degree of complexity depends, of course, on the complexity of the aircraft used and its mission.

For the lighter and very short-range types, a ground station can boil down to a portable laptop computer and a transmitter/receiver. The mission (flight pattern) is plotted in advance using digital maps and the co-ordinates fed into the aircraft's flight computer via radio on the ground before launch. The computer then merely becomes a display to observe what the drone's miniature camera sees. Of course, modification to mission parameters can always be injected manually while the aircraft is in flight. The step ahead from this configuration is to have another data/ image receiver in a command post equipped with a larger screen. At the very lower end of the spectrum, companies like Elisra are now offering wrist-worn displays called V-Rambo, which might prove invaluable in an urban warfare environment. The company also developed a more substantial receiver, the Starlink, for real-time battlefield intelligence gathering.

This being said, nothing prevents a mini drone operator from using the larger and more sophisticated ground station it employs for more important drones. This compatibility was displayed on the United Arab Emirates Armed Forces Surveillance and Reconnaissance Technologies stand at the Idex exhibition in February 2005. Developed by Ucon from South Korea, the same ground station can be used by both the Ucon RemoEye family of minis and the Schiebel Camcopter S-100. In ground stations of this calibre, one will usually find two control stations: one used by the pilot and the other by the observer. In addition, these stations lend themselves to mission preparation, mission debriefing, mission rehearsal and to training simulation.

The larger drones are not only used to stretch mission range, they are also intended to carry a variety of payloads able to provide a larger amount of information that requires various stages of processing. This means larger computers, data recorders, satellite transmitters and, in turn, a power generator to run all the gear. This explains why we are now stepping into a configuration that will occupy the volume of a transportable container, which will also require an environmental control unit. The size of this container will grow as other systems such as elint and comint are added.

Half-way between this and the laptop-based station mentioned above, however, are clever solutions for missions in which high mobility is at a prime. One example is Elbit's packable system which can be used by all members of the Hermes family.

Another interesting concept was recently unveiled by Denel for its Seeker II. The aircraft itself has a range that far exceeds that of its datalink. This is the reason for which the South African manufacturer had the idea to develop an intermediate cabin that enables a unit in the field to take over control of the aircraft as it reaches the range boundaries of its mother station. Once the mission is accomplished it sends the drone back home.

At the top end of the spectrum, walking in the kingdom of the Global Hawk comparatively is almost like penetrating Nasa's Houston base. Here we have not one but two containers: the two-station launch and recovery element, which, in addition to controlling the flight parameters, also monitors the health of all the systems and subsystems aboard the aircraft, executes mission profile and modifications, monitors en-route traffic and so forth; then there is the even larger four-station mission control element that handles communications, data and sensor processing and information dissemination, as well as aircraft and mission payload control--with a capacity to control three aircraft. To this must be added a large KU-band satcom dish aerial and a Mist common data link, plus all the other sub-elements. But that is not all: given the range and duration of the missions carried out, the elements just described have to be multiplied in case of dramatic weather condition changes necessitating an alternative landing area.

The Northrop Grumman diagram seen in the title of this section alone shows that the Global Hawk is in a league of its own in terms of deployment requirements.