Unmanned Systems Technology 008 | Alti Transition UAS | Ground control systems | Xponential 2016 report | Insitu Orbital N20 | UAVs | Solar power | Oceanology International 2016 report

39 processor of the GCS to coordinate the activities of UAVs in the air and systems on the ground, all delivering consistent sensor data back to the operator. When this is coupled with a connection to the cloud, the operator can be coordinating the swarm of craft from anywhere in the world. Military systems All of this is for commercial operators. For large government and military systems the GCS can have quite different comms requirements, and this in turn leads to very different implementations. Like commercial GCS designs, these systems use a PC motherboard, although they are high-reliability boards with a long lifetime – up to 15 years – and so do not use the latest processors. Many of the systems are mounted in vehicles or in a fixed location where power delivery is not an issue, as it is provided by the site or a vehicle’s battery, which can be 24 or 48 V depending on the age of the vehicle. The comms systems are clearly defined and fixed so there is no need for a flexible interface; however, there is still a need for custom boards. For example, the F-35 fighter jet can be controlled remotely while on the ground to collect data from systems on the aircraft, and this is handled over a dedicated 1553 board in a PC form factor that has been added to the GCS. The boards for the GCS are mounted in a standard 19 in rack and communicate over a passive backplane. No wireless For security reasons, none of these systems use wireless links such as wi-fi, and USB ports are disabled to prevent memory sticks from introducing malware or unauthorised copying of data. This is leading to a new way of interfacing with the GCS via a tethered tablet which acts as a ‘zero client’. Essentially it is just a screen; all the data is stored in the GCS and the operator logs on via the tablet. It is connected by an Ethernet cable for some portability, and to power the tablet using Power-over-Ethernet technology. That means the tablet’s power consumption has to be less than 15 W. While it has USB ports for a keyboard and mouse, nothing can be stored on the unit or copied from it. Data deluge High-end unmanned military systems such as Reaper and Predator use cameras that generate vast amounts of data. In the case of the latest Gorgon Stare and Argus IS cameras for example, this runs into terabytes, which has to be captured by the GCS and delivered for analysis. The Gorgon Stare is a wide-area airborne surveillance two-pod camera system: one pod has five optical cameras each generating 16 megapixels/frame, while the other has four infrared cameras. The data from these is combined and sent back to the ground station. The successor to the Gorgon Stare, the Argus IS, consists of 358 separate cellphone cameras, each with 5 megapixels, creating an array of 1.8 billion pixels. Streams from groups of the sensors can track up to 65 targets selected by the ground station, but all the data collected is stored in the aircraft for later analysis. The solution to handling the large amounts of data generated by the cameras has been to develop a transit case that can store up to 65 Tbytes of data. It comes with its own PC board and fibre-optic comms power conditioning power supply to handle up to 600 Gbyte/s of data securely without having to move the data into the cloud. Conclusion Ground control systems cover a wide range of applications but have many common elements. Rugged, long-lifetime PC systems are at their heart, and mostly use Windows 7 to provide a common platform for Unmanned Systems Technology | June/July 2016 Ground control systems | Focus Handling 65 Tbytes of data securely from a ground station requires a dedicated transit case (Courtesy of Chassis Plan)