Unmanned Aerial Vehicle (UAV) is defined as a powered, aerial vehicle that does not carry a human operator, uses aerodynamic forces to provide vehicle lift, can fly autonomously or be piloted remotely, can be expendable or recoverable, and can carry a lethal or nonlethal payload. Unmanned aerial vehicles (UAVs) are quickly becoming ubiquitous in military command and control operations. With reduced radar signatures, increased endurance, and the removal of humans from
immediate threat, unmanned (also known as uninhabited) aerial vehicles have become indispensable assets to militarized forces around the world, as proven by the extensive use of the Shadow and Predator in recent conflicts. UAVs have become indispensable to modern military for large number and variety of missions; intelligence & reconnaissance missions like signal intelligence, image intelligence; communications mission like radio relay; electronic warfare missions like electronic attack and electronic protection, and Nuclear, Biological and Chemical (NBC) missions.
A typical unmanned aircraft is made of light composite materials to reduce weight and increase maneuverability. This composite material strength allows military drones to cruise at extremely high altitudes. Typical tactical UAV like SEARCHER consists of many functional systems, including Command Datalink system , payloads Optical and COMINT, Flight control and Navigation systems. UAVs also differ on the level of autonomy programmed in it. Most UAVs however have both remote controlled and autonomous modes. Despite the absence of a crew onboard any of these UAVs, human operators are still needed for supervisory control.
The requirement for UAVs is growing exponentially. At the same time, their capabilities need to increase in terms of data rates, area coverage and operation in a hostile environment. The traditional command and control links in UAVs were line of sight microwave links which connect it to ground Control systems. However these data links are limited to hundreds of kilometers depending on UAV height.
One critical need is to provide data connectivity for control and non-payload communication (CNPC), also known as command and control (C2) communication. The non-payload communication link is dedicated to secure and reliable communications between the remote pilot ground control station and the aircraft to ensure safe and effective UAV flight operation. This link can be either a line of sight (LOS) air-ground (AG) link between the two entities or a beyond-line-of-sight (BLOS) link using another platform such as a satellite or high altitude platform (HAP). Data rates for such links are expected to be modest (e.g., a maximum of 300 kbps for compressed video, which would not be used continuously). In contrast, the payload communication link is usually used for data applications, and often requires high throughput.
The disruption of payload links—albeit inconvenient—is not critical, whereas CNPC link disruption can be critical. The functions of CNPC can be related to different types of information such as telecommand messages, non-payload telemetry data, support for navigation aids, air traffic control (ATC) voice relay, air traffic services data relay, target track data, airborne weather radar downlink data, non-payload video downlink data, etc
High-altitude long-endurance (HALE) AISR aircraft can fly 60,000 feet or higher, for up to 32 hours over vast stretches of oceans and terrain. Other variants of unmanned systems cover a wide range of mission profiles and geographies. These variances and complexities of missions reflect modern military operations, all of which depend upon the “anytime/anywhere” transmission of reliable and secure video and data.These sophisticated drones use satellite command and control links which can extend the range of command and control links to thousands of kilometers. Additionally both methods of communications are used during a single mission. For example, a direct line-of-sight communication is used during take off and landing; then, during flight the drone is switched over to satellite communication so the drone can be controlled remotely from halfway across the globe.
Another advantage of the the tandem approach is the avoidance of the infamous one-second delay that is present during the satellite portion of the drone’s flight. When flying in the open expanse of the skies, the one-second delay does not cause that much of an issue. However, it does pose a threat to delicate maneuvers that are required during landing and take off. However, with line-of-sight communication, the drone can be controlled in real-time without a delay. Allowing the crew at the Ground Control Station (GCS ) to control the drone and it respond immediately lessening the threat of the drone crashing during these portions of the mission.
The disparate links (LOS and BLOS) mean different channel conditions and frequencies of operation, with different latency and range, and this increases challenges for the very high reliability required of CNPC links. In addition to existing cellular frequency bands (600 MHz to 6 GHz), the 5th generation (5G) cellular community is also considering the use of spectrum in the millimeter wave (mmWave) bands (24–86 GHz). In these bands, large free-space and tropospheric attenuations limit the link range, thus if the mmWave link is the only LOS link, when beyond the LOS mmWave range, BLOS capability will be needed. Such BLOS links are also of course required when in remote areas, out of range of any ground station (GS). Although satellites are an obvious choice for BLOS communications, the choice of satellite orbit, i.e., low-earth orbiting (LEO) or geosynchronous earth orbiting (GEO), distinctly affects the latency, link budget parameters, Doppler, and handoffs/handovers.
Military surveillance drones typically communicate via satellites that have wide beam coverage so the aircraft always stays in the same footprint. Newer satellites have multiple high-powered spot beams, each covering narrow geographic areas. The challenge for the unmanned airplane was to switch beams in flight at about the 600 mile-point.
UAVs require human guidance to varying degrees and often through several operators, which is what essentially defines a UAS (Unmanned Aerial System). For example, the Predator and Shadow each require a crew of two to be fully operational. However, with current military focus on streamlining operations and reducingmanning, there has been an increasing effort to design systems such that the current many-to-one ratio of operators to vehicles can be inverted.
Satellite Beam switching by UAV
An unmanned aircraft in a test in August switched between two spot beams on an Intelsat high-throughout satellite. A MQ-9 Reaper (also known as Predator B) switched between two spot beams on an Intelsat EpicNG high-throughput satellite. Military surveillance drones typically communicate via satellites that have wide beam coverage so the aircraft always stays in the same footprint. Newer satellites have multiple high-powered spot beams, each covering narrow geographic areas. The challenge for the unmanned airplane was to switch beams in flight at about the 600 mile-point.
Intelsat and other satellite operators see unmanned aircraft as a critical target market for their new high-capacity spacecraft that push more data at faster speeds than the legacy wide beam kind. Vast amounts of bandwidth are available for live high-definition video streaming but the issue is how to get it into military UAVs that have older antennas and terminals. Nicole Robinson, corporate vice president of SES Networks, said the company demonstrated that an Air Force MQ-9 Reaper drone that typically can pipe data at 5 to 10 megabits per second over commercial Ku band could increase the data rate to 30 megabits when connected to the company’s O3B satellite network. That system uses Ka band, as do Inmarsat’s high-capacity satellites.
Rebecca Cowen-Hirsch, senior vice president of Inmarsat U.S. Government Business, has been pushing the case that the military should use commercial Ka band for manned and unmanned airborne missions. “A unique advantage of Ka-band over Ku-band is that it is the only frequency where the commercial and military bands are immediately adjacent to each other,” so commercial services can more seamlessly complement military satellite capacity. The U.S. government-owned Wideband Global SATCOM constellation uses the military Ka band.
Satellite communications providers for some time have been trying to show the military the potential advantages of multiple spot beam satellite designs. Bigger and faster data pipes are one selling point. Another is enhanced security. Signals in spot beams are more difficult to jam and interference can be worked around more easily, Butler said. Whether it’s intentional jamming or accidental interference, he noted, the satellite’s digital payload can disconnect the uplink from the downlink and assign new frequencies and a new link to the UAV to reestablish the connection. Intelsat is talking to military users about how they would fly drones with multi-spot satellites, he said. “Increased data rates and interference mitigation are both of great interest.”
Multi-Domain Multi-Platform Drone Control System
Kongsberg Geospatial announced in 2019 that the company is introducing a new multi-domain control system for coordinating the use of drones and robotic systems in the battlespace. Over the past four years, the company has developed an airspace awareness system for operating unmanned aerial systems (UAS) beyond visual line-of-sight (BVLOS), called IRIS UxS. The IRIS system was first developed to help commercial drone operators safely operate beyond visual line-of-sight. The system integrated real-time data from a variety of sensors and other sources to create a very accurate picture of the airspace around a drone. This presented users with an integrated display with a 3D map showing exactly where their drone is, and all of the terrain, navigation hazards and other aircraft and drones in the vicinity.
Since then, IRIS has been developed into a full-fledged multi-platform control system integrated with a variety of autopilot systems, allowing a single operator to actively control multiple drones from a single station. Now, Kongsberg Geospatial has announced a new, military-focused version of the IRIS system based on its participation in the NATO STANAG 4817 standard for multi-domain control stations. The new system collects and fuses data from a wide range of sensors: allowing operators to control multiple autonomous vehicles in a truly multi-domain mission theatre. This control system integrates different kinds of geospatial data and sensor input to create a composite operating picture which includes the airspace, 3D terrain, bathyscapy (undersea terrain visualization), and features from S-57 nautical charts. The system leverages a real-time DDS bus architecture and sensor fusion technology that allows operators to simultaneously track and operate UAVs as well as USVs (unmanned surface vehicles) and UUVs (unmanned underwater vehicles).
“Multi-domain C2 systems present a variety of unique technical challenges”, explained Paige Cutland, IRIS program director at Kongsberg Geospatial. “With the development of IRIS UxS, we’ve addressed many of these challenges in the airspace. Then we worked out how to coordinate with real-time tracking of ground-based assets. Now we’ve added the capability to work simultaneously in the maritime domain as well, allowing a single operator to control drones in the air, on the water, and underwater at the same time.”
The company hopes that their work relating to coordinating unmanned platforms with larger manned vehicles can help evolve new ways of visualizing multi-domain mission spaces for other command and control purposes. “We’ve successfully proven we can coordinate manned, unmanned, aerial, and ground assets in the civilian emergency mission space,” said Ranald McGillis, president of Kongsberg Geospatial. “Now we’ve implemented the STANAG standard in a way that can make it easy to integrate unmanned systems in the military mission space.”
Lockheed Martin has just launched VCSi, – commercial software that enables operators to simultaneously control dozens of unmanned vehicles and conduct information, surveillance and reconnaissance missions.
“VCSi is a safe and reliable software platform that can be adapted to any vehicle – from one you can hold in your hand, to a 50,000-pound machine; from a vehicle that flies for a few minutes, to a vehicle that flies for months at a time,” said John Molberg, business development manager, Lockheed Martin CDL Systems. “The user can integrate as many vehicles as required to complete their missions, including boats, quadcopters, fixed-wing aircraft or even high-altitude pseudo satellites. Across commercial or military missions, VCSi is adaptable to the challenge and further extends the power of the human-machine team.”
VCSi’s major enhancements include:
Multi-Vehicle: Control interfaces to allow for true 1:n control of dissimilar vehicles anywhere on earth
Intuitive: Lockheed Martin further advanced its fly-by-mouse interface to enable easier training and reduce operator/analyst task loads
Affordable: Priced competitively with all unmanned systems in mind, customers can buy essential modules for their mission set
Modular: Offers a robust plug-in architecture, which allows for custom content to be added by the user or selected from pre-existing modules
International: Commercial software, made in Canada and free of export restrictions.
VCSi is designed around the NATO Standardization Agreement known as STANAG 4586, which supports unmanned vehicle interoperability. Customers can build attachments or plug-ins beyond 4586 to customize the VCSi software, which also supports multiple languages and non-Latin scripts. VCSi provides advanced 3D visualization of vehicles and airspace, and it is at the forefront of integration into unmanned traffic management systems.
TAI delivers first satellite-controlled ANKA-S system to Turkey
The Turkish Aerospace Industries (TAI) has delivered the first ANKA-S system with satellite control capability to the Armed Forces of the country. The package delivered to the Turkish Armed Forces includes two unmanned aerial vehicles (UAVs) and relevant systems. The delivery has been carried out following the successful completion of an acceptance test for the ANKA-S system, which is capable of performing on both day and night autonomous aircraft.
The satellite-controlled ANKA-S system will be used by the Turkish Armed Forces to strengthen the strategic power of the Air Forces Command. The Air Forces Command will be capable of simultaneously controlling six aerial autonomous vehicles through the use of the satellite. The UAV is capable of individual emergency landing due to completely simulated missions. In the case of link loss, the vehicle can carry out full autonomous landing in defined places.
It is fitted with fully autonomous flight mission and camera-guided features that allow it to provide task-oriented flight. The advanced electro-optic / infra-red (EO / IR) camera diagnosis follow-up and designation tasks help provide combat search-and-rescue missions, air-to-ground / ground-to-ground communication support through radio relay. Technical and flight training provided for the Air Forces Command, which commenced in October last year, has been successfully completed.