Raytheon’s ADAS could significantly enhance the MQ-9 REAPER’s ability to locate signals of interest
Raytheon Deutschland’s announcement in early February of the successful demonstration of the firm’s Advanced Radar Detection System (ARDS) is the culmination of work originally announced in 2017.
The podded ARDS was demonstrated onboard a General Atomics Aeronautical Systems, Inc. (GA-ASI) MQ-9B REAPER Unmanned Aerial Vehicle (UAV). The test flights took place from the Grey Butte Field airport in California, a GA-ASI press release stated. The publication continued that the ARDS was flown against ground-based radar targets. No further information was given on these targets. It is highly probable that the aircraft performed its flights at the US Navy’s Electronic Combat Range. This is located to the northeast of Palmdale, California, just to the east of which is Grey Butte Field. The range is known to house several representative ground-based air surveillance and Fire Control/Ground Controlled Interception (FC/GCI) radar threats, along with simulated threats.
The ADAS was developed from the Raytheon Emitter Location System (ELS). This equips the Panavia TORNADO-ECR SEAD (Suppression of Enemy Air Defence) aircraft flown by the Luftwaffe (German Air Force), and the Aeronautica Militaire (Italian Air Force). The ELS provides target detection and fire control for the Raytheon AGM-88 HARM (High Speed Anti-Radiation Missile) air-to-surface series weapons carried by these aircraft. The ELS is thought to be closely based upon Raytheon’s AN/ASQ-213(V) HTS (HARM Targeting System). The company developed this for the US Air Force’s General Dynamics/Lockheed Martin F-16CJ VIPER WEASEL SEAD aircraft. The AN/ASQ-213(V) plays a similar role to the ELS.
The ELS performs two functions: It can act as an Electronic Intelligence (ELINT) gathering system detecting RF (Radio Frequency) emissions from radars, identifying these radars and noting their location. Similarly, the ELS’ ability to detect and locate radars with enviable accuracy allows the TORNADO-ECR to engage these threats with the AGM-88. One useful element of the ELS is that it can reportedly detect radar sidelobes. This allows it to determine the position of a radar without necessarily being in the radar’s line-of-sight. This could enable the AGM-88 to be fired ‘off boresight’ using sidelobe RF transmissions to maintain a radar target lock. This has the added advantage of reducing the possibility that the targeted radar will detect the incoming AGM-88. Sources in the TORNADO-ECR community have shared that they expect the ELS be upgraded this year to provide the system with a digital architecture.
Routine Surveillance
Work commenced on the ARDS in 2016, with a press release from GA-ASI announcing that the product was being realised as an ELINT capability for the MQ-8B. It was envisioned that this would assist users in mapping the electronic order-of-battle regarding hostile ground-based air surveillance and FC/CGI radars. The ARDS architecture takes the form of a pod which can be mounted onto an MQ-9B’s centreline hardpoint. Doctrinally, the ARDS could be deployed as a stand-off ELINT system. This could potentially gather intelligence relating to emitters at a stand-off range of 270 nautical miles (500km) from the aircraft. It’s use on the battlefield is less certain.
The service ceiling of the MQ-9B, typically around 49,212 feet (15,000 metres), could place the aircraft within the engagement envelope of some short-range/medium-altitude surface-to-air missiles. Nevertheless, the aircraft could be used to fly relatively close to the airspace of countries of interest, and still be able to gather ELINT on radars several hundred nautical miles within that airspace without needing to violate it. This capability could be particularly relevant for routine ‘pattern of life’ ELINT gathering flights where airborne SIGINT assets regularly fly close to an area of interest to ascertain the normal electromagnetic activity at any given time. This helps to spot signals-of-interest which maybe out of the ordinary.
Such missions currently tend to be performed by inhabited assets such as the US Air Force’s Boeing RC-135V/W RIVET JOINT SIGINT-gathering aircraft. Nevertheless, it is possible that the routine aspects of such missions could eventually be handed over to UAVs. The development of the ARDS could mark an important step in this direction.
