Telerobotic control issues for NLOS, NOE rotary wing target drones

The author explains why a certain degree of vehicle autonomy will be necessary for affordable, yet realistic teleoperator control of rotary wing target drones engaging in NOE (nap-of-the-earth) flight regimes during NLOS (non-line-of-sight) conditions. It is noted that a rotary wing target drone operating in NLOS, NOE modes should implement both primary and backup command and telemetry links. Frequency hopping/spread spectrum techniques, information coding, and redundant transmissions should be used to achieve some degree of processing margin. A transponder for tracking should be incorporated into the drone command and telemetry links to reduce cost; however, care must be taken to assure that transponder activity does not adversely increase the latency of the command and control system. A relay must be used to allow NLOS operation while maintaining acceptable overall link margin. Relay specifications are discussed. The various automatic flight control modes that should be designed into the flight control system are: heading hold, altitude hold, position hold, lost link, auto take-off, auto landing, and auto-maneuver.<>