Electronic weapons: The US military equips unmanned aerial vehicles with active electronically scanned radar (AESA)
Raytheon has developed a new lightweight AESA (Active Electronic Scanning Array) fire control radar for aircraft, ships, or ground forces, weighing approximately 48 kilograms (110 pounds). This is the lightest and most compact radar of its kind developed so far. There are several types of AESA radar, among which sea or ground surveillance is the lightest, and fire control type is slightly heavier because they have more functions. The new Thor AESA radar is lightweight enough for large drones and helicopters to be equipped with.
Similar weight AESA radars for maritime surveillance have been in use for over five years, enhancing the capabilities of unmanned aerial vehicles and small aircraft used for maritime surveillance. For example, in 2016, the US Navy selected the Italian Osprey AESA radar for its MQ-8C fire reconnaissance helicopter drone. The Osprey radar is lightweight (50 kilograms/110 pounds) and uses a small flat plate on the side of the aircraft instead of the rotating radar in the dome below the aircraft. Three tablets enable the Osprey radar to cover the water below in 360 degrees. There are lighter and cheaper versions of the Osprey with smaller coverage, but all versions of the Osprey can detect small boats about 160 kilometers away.
AESA technology has existed since the 1960s, first as PESA (Passive Electronic Scanning Array), and evolved into AESA in the 1980s. Since the 1990s, AESA radar has become a standard configuration for most new and old aircraft upgrades. As AESA systems become smaller and lighter, they are increasingly appearing in drones. AESA is more reliable and increasingly less expensive than old mechanical (small disks moving inside the dome) radars. AESA uses less power and is easier and cheaper to maintain. This makes the more expensive AESA radar cheaper than the cheaper (purchased) mechanical scanning radar over its lifespan. AESA radars are more reliable because they do not have rotating mechanical parts, are more compact and consume less power than early non AESA radars.
AESA type radar has been in existence for a long time, mainly because they can simultaneously process a large number of targets and generate more accurate external images. Initially, AESA was much more expensive and less reliable than older radar technologies, but now the situation is gradually changing. Nowadays, AESA has more and more applications, and it has developed into more than just an improved radar. AESA radar consists of thousands of miniature radars that can independently aim in different directions. The AESA radar made it possible for the E-8 JSTARS ground surveillance aircraft in the 1990s, as its AESA radar was able to locate vehicles moving on the ground, similar to the later Osprey radar, but with a heavier and more expensive AESA radar. Larger and more powerful AESA radar can provide images of surface objects and operate 24/7 and at night. This is what the E-8 uses, and subsequent AESA designs also incorporate this, as well as the ability to act as electronic jammers or communication devices. About ten years ago, MP-RTIP AESA radar was developed for the RQ-4 Global Hawk drone. This weight is about twice that of a fish eagle, but it can detect and identify smaller objects on the ground from high altitude. Therefore, RQ-4 drones equipped with AESA allow the Air Force to choose to extend the lifespan of E-8 aircraft or replace them with drones using the new AESA system. The US Air Force has decided to use a larger version of MP-RTIP AESA in the current E-8 aircraft and the original design in the RQ-4.
Source: Grid Space Warfare