The US Army’s MQ-1C Grey Eagle unmanned aerial vehicles are destined to receive important signals intelligence enhancements which will enhance army and joint force air defence suppression capabilities.

The US Army is contemplating updating its General Atomics MQ-1C Grey Eagle medium-altitude, long-endurance unmanned aerial vehicles with new signals intelligence systems.

The move follows its publication of a Request For Information (RFI) on 27 December. The RFI calls for information regarding “Multi-Domain Operations Support Equipment (MDOSE)”. Principally, the army is concerned with ensuring that aircraft can operate in contested airspace to gather Electronic Intelligence (ELINT) concerning hostile early warning, ground-based air surveillance and fire control/ground-controlled interception radars supporting integrated air defence systems and deployed ground-based air defence systems.

Given that the MQ-1C has a maximum altitude of 29,000 feet (8,839.2 metres), the aircraft could gather ELINT on radars at ranges of up to 209 nautical miles (387 kilometres) from the aircraft. From the army’s perspective such a capability could be invaluable to ensuring that the location, identity and characteristics/parameters of hostile radars are apparent at the operational and tactical levels. This intelligence will aid the force not only in air defence suppression efforts, but also in ensuring that its aircraft can be safely routed to and from targets to avoid these radars as much as possible.

In addition the RFI states that the MDOSE must be able to collect communications intelligence on hostile air defences. This will be imperative to understanding the nature of hostile radar threats writ large, and for ensuring that the communications links ground-based air defences rely on, particularly when networked, are identified. This will allow key nodes to be disrupted and/or destroyed in support of air defence suppression. Equipment suggested to meet these requirements, the RFI continues, must be at a minimum of the US Department of Defence’s Technology Readiness Level (TRL-6). TRL-6 specifies that a system or subsystem prototype can be tested in a relevant environment.

Specifically, the RFI has called for information regarding a Radar Warning Receiver (RWR) and Electronic Support Measure (ESM) to equip the MQ-1C. This will enable the collection of radar signals and the analysis of their characteristics. The document continues that the RWR/ESM ensemble must offer two gigahertz/GHz of instantaneous bandwidth and cover a 500 megahertz/MHz to 40GHz frequency spread. Crucially, the equipment must detect radars employing low probability of interception/detection waveforms. The RFI makes no mention of the COMINT gathering requirements, however given the ELINT bandwidths stipulated for the RWR/ESM it is reasonable to assume that these will encompass frequencies of at least 500MHz to three gigahertz.


The MDOSE initiative could be worth up to $468 million to potential suppliers, assuming that the full complement of circa 150 MQ-1Cs is equipped with these subsystems. According to Armada Analysis’ figures the expected expenditure on the RWR and ESM for each aircraft could be worth up to $3.1 million. Presuming that these procurements eventually materialise they will promise quantitative and qualitative improvements for the US Army, and the US forces, writ large, in their combined air defence suppression capabilities. This will be particularly relevant in supporting the air-land battle where the aircraft can be used to gather reconnaissance in highly contested airspace without placing aircrew at risk.

by Dr. Thomas Withington