Modern airborne radars are highly versatile and can be used for a number of missions that require extremely accurate surveillance information. This includes real-time detection, target tracking and providing detailed ground imagery. HENSOLDT is now at the forefront of a new generation of powerful, yet compact, airborne radars.
Radar is a powerful asset for an aircraft tasked with ISR (Intelligence, Surveillance and Reconnaissance), as it can provide target detection, tracking, and classification, as well as high-resolution synthetic aperture radar (SAR) imagery over large distances. This is even the case in poor weather conditions where electro-optic imagery could be degraded.
In the past, airborne surveillance radars were large and usually required a significant amount of modification to the aircraft in order to attach an array (or arrays) and cuts in the aircraft hull, as well as large internal space for all the equipment needed to operate them. This meant the real powerful ISR radars were often limited to larger aircraft and not all countries could afford such bespoke and expensive platforms.
HENSOLDT has been at forefront of this radar innovation for several decades and the company has an impressive heritage when it comes to the development of next-generation sensor technology. One of the latest products that leverages this decades-long experience is PrecISR, a new generation airborne multi-mission radar that will set a new baseline for what is possible with airborne sensors.
PrecISR gives customers cutting-edge airborne radar capabilities in a system that weighs below 58kg. That means the radar can be integrated onto a large range of aircraft, including special mission aircraft, helicopters, and even unmanned systems.
What is PrecISR Capable Of?
PrecISR has a number of software-defined radar modes depending on the mission it is required to carry out – it can track over a thousand targets in the air, on land and at sea at the same time.
For air monitoring missions, the radar can provide airborne moving target indication (A-)MTI with speed and direction data, especially for low-flying targets that may be trying to evade detection. The data from the radar can then be cross-referenced with other sensors and data, including ADS-B and EO/IR imagery.
In the maritime domain, PrecISR can carry out maritime (M-)MTI to build a situational picture of the water below. Using the Inverse Synthetic Aperture Radar (ISAR) and Range Profiling (RP) modes, the radar provides an image of a vessel as well as information on its length – even if the aircraft is a hundred kilometres away. This information can be cross-referenced with additional data from tracking systems such as Automatic Identification Systems (AIS).
PrecISR can also provide ground (G-)MTI, relaying data about multiple moving objects over a large area. The radar can also be used for high-resolution (0.3m) SAR imagery for reconnaissance missions in both a strip and spot mode. “You get an extremely detailed picture where you can even detect smallest objects,” according to Carsten Maier, Product Manager Airborne ISR Radars at HENSOLDT.
Maier also explained that the radar data are capable for coherent change detection, an AI-driven process that compares images and alerts an operator if the scenery has changed. This could provide vital strategic intelligence for an area that is being monitored, for example if a mine or IED has been dug into the ground, or if a formation of vehicles has moved.
“This is not done by flying over the area, but can be done from 35km away – you will not see the aircraft, helicopter or UAV.”
Product Manager Airborne ISR Radars
The Difference – Tile-Array Architecture
One of the biggest innovations for PrecISR is on the “front-end” antenna, which is an evolution of traditional active electronically scanned array (AESA) radar technology. HENSOLDT’s PrecISR antenna uses what is known as a tile-array architecture, which sees high-density transmit/receive (T/R) elements mounted directly onto a printed circuit board (PCB).
The PCB incorporates all the radiofrequency (RF) microwave components, and unlike legacy AESA radars, does not require the addition of bulky cabling and equipment. “The tiles make it so compact, yet so powerful,” explained Maier.
The PrecISR also utilises Gallium Nitride (GaN) semi-conductor technology, instead of Gallium Arsenide (GaAs), which results in double power output for the radar but in a much smaller footprint than was possible before. This results in increased performance and precision, as well as far greater distances that the radar can cover.
But the innovation doesn’t stop there. Unlike previous generations of radar where the “back end” processing units had to be separate from the radar and were normally inside the aircraft, the PrecISR incorporates all the radar electronics and processing on the radar itself without separate LRUs. This includes the latest generation GPUs as well as 5G technology, and all that is required to relay radar data to an operator station is an ethernet connection and mil-spec connectors.
This significantly eases integration and maintenance, especially as there is no need to connect separate LRUs within the cabin to the radar itself, which would often require a hole being cut in the fuselage and additional high-speed connections and wiring inside the aircraft.
“This costs a lot for the integrator and requires a new certification, but with PrecISR we do not penetrate the aircraft and you only mount it on the outside of the aircraft.”
Product Manager Airborne ISR Radars
Standard interfaces also mean that the radar can be easily integrated into a customer’s preferred mission system, and HENSOLDT can also offer various human-machine interface solutions such as the Radar Control & Display (RCD) that allows operators to be trained in just a few hours.
Plans – Scalable Radar for Future Growth
HENSOLDT’s PrecISR successfully passed its Factory Acceptance Test in March 2021 and has already been delivered to its first customer QinetiQ, a provider of airborne special mission operations and technical solutions. Demonstrations are ongoing with other potential customers in various configurations.
The PrecISR’s flexible and modular architecture means that the radar can be scaled to meet a customer’s specific requirement, both in fixed panel or gimbal mounted configurations.
The “front end” tile architecture described above means that the radar can be scaled up or scaled down – and HENSOLDT plans new variants of the PrecISR in the future with development already underway. The back end processing element also has significant growth potential, according to Maier. “If the customer wants to have more capabilities, it can be easily done,” he explained.
“We are far away from the limit of what the radar is capable of. Within the realms of physics, we can do it.”