Signals intelligence collection, submarine-based
- 1 Australia: Submarine Platforms
- 2 Canada: Submarine Platforms
- 3 Chile: Submarine Platforms
- 4 China: Submarine Platforms
- 5 Denmark: Submarine Platforms
- 6 Egypt: Submarine Platforms
- 7 France: Submarine Platforms
- 8 Germany: Submarine Platforms
- 9 Greece: Submarine Platforms
- 10 Italy: Submarine Platforms
- 11 Israel: Submarine Platforms
- 12 Netherlands: Submarine Platforms
- 13 Russia: Submarine Platforms
- 14 South Africa: Submarine Platforms
- 15 South Korea: Submarine Platforms
- 16 Spain: Submarine Platforms
- 17 Sweden: Submarine Platforms
- 18 Taiwan: Submarine Platforms
- 19 United Kingdom: Submarine Platforms
- 20 United States: Submarine Platforms
- 21 References
Since submarines are the original stealth platforms, they are natural platforms for bringing signals intelligence SIGINT antennas close to targets. When no more than a mast breaks the surface, they immediately become radar targets, so virtually all modern submarines will have the minimum ELINT of a radar warning receiver. Far beyond that, however, many submarines will penetrate hostile areas, raise SIGINT receiver masts, usually with some type of radar-observant covering, and listen. Especially sophisticated SIGINT submarines may tap undersea cables.
The minimum radar-warning receiver is usually a set of spiral antennas, backed with resonant cavities, whose amplitude can be compared to determine the direction of greatest signal strength. To go to the next level of sophistication, phase is considered as well as amplitude, and interferometry adds further information.. He reports that the ArgoSystems/Condor AR-740 was installed on submarines of Australia, Chile, Egypt, Greece, the Netherlands and Sweden.
Australia: Submarine Platforms
Australia's Collins class has a SIGINT mission, emphasized when the vessels' combat system was replaced with an open-architecture surveillance system. reported to be upgraded, on two vessels, to the Condor CS3701. 
Canada: Submarine Platforms
Canada's acquisition of reconditioned British diesel-electric submarines (ex-Upholder class, now Victoria-class submarine) raised eyebrows of many analysts, wondering how these could have a strategic effect given the strength of Canada's southern neighbour's undersea strength. Writing in the Canadian Military Journal, an officer of Canada's maritime forces gave some subtle insights, of which submarine intelligence capabilities play a significant role . "However, submarines also have a contribution to make in deterring and countering the asymmetric threats that now preoccupy Canadian/US (CANUS) planners. This is centered upon Intelligence-gathering, Surveillance, and Reconnaissance (ISR) activities...possession of submarines admits Canada to that exclusive group of states participating in regulated and highly classified submarine waterspace management and intelligence-sharing schemes. The intention to re-establish a Pacific submarine presence led to the immediate cooperation of the United States in development of a west coast Waterspace Management Agreement with Canada, whereas none existed previously. Likewise, Arctic transits and deployments by allied submarines are generally first signalled when Canada’s Atlantic Submarine Operating Authority is advised of foreign submarine movement across 70 degrees North latitude. Taken together, these various factors result in a capability of strategic importance in so much as it exponentially expands the range of coercive options available to decision-makers."
Chile: Submarine Platforms
An ARGOsystems/Condor AR-900 is aboard the French-built Chilean Scorpene-class submarines.
China: Submarine Platforms
Denmark: Submarine Platforms
Egypt: Submarine Platforms
Egyptian submarines use ArgoSystems/Condor AR-700 series SIGINT for targeting their Harpoon missiles.
France: Submarine Platforms
Older French export submarines came with the Thales/Thompson-CSF X-band radar warning system, which is a manual analog system. The digital replacement, in French service, is the ARUR-13. It is reasonable to expect continuing upgrades from the EADS consortium.
Germany: Submarine Platforms
German submarines use multiple SIGINT systems. Most basic is the DR3000U, although the Type 206 submarines replaced it with the Ginny. The newer Type 212 submarines use FL 1800U units made by the German-French EADS consortium. These units use four spiral antennas and a radar warning receiver under a common dome, with the ELINT function covering 0.5-18 GHz in five bands. This can achieve 5-degree direction finding.
EADS (formerly DASA) also equips German submarines with the Telegon 12 HF interception and DF suite.
Greece: Submarine Platforms
As with Egypt, Greece uses the use ArgoSystems/Condor AR-700 series SIGINT for targeting their Harpoon missiles.
Italy: Submarine Platforms
Older submarines use an Elettronica BLD-727 DF, but the newer Type 212s will use German SIGINT.
Israel: Submarine Platforms
German-built Dolphin submarines in Israeli service have several missions, SIGINT being one of them. Domestic Elbit makes the TIMNEX 4 CH ELINT/targeting set, which covers 2-18 GHz, provides radar warning, and 1.4 to 5 degree DF (depending on frequency).
Netherlands: Submarine Platforms
For Harpoon targeting, the Netherlands uses the ArgoSystems/Condor AR-700 series SIGINT.
Russia: Submarine Platforms
Akula and Oscar attack submarine have Rim Hat (NATO designation) Nakat-M SIGINT, which is integrated with a Snoop Pair search radar.
Kilo export diesel-electric submarines have the NATO Squid Head/MRM-25 ESM, which includes IFF.
South Africa: Submarine Platforms
The domestic Avitronics firm installs the Shrike ESM system, covering 2-18 GHz, as does the Israeli Elbit TIMNEX 4 CH ELINT/targeting set, which provides radar warning, and 1.4 to 5 degree DF (depending on frequency). The CelsiusTech-Grintek Ewation partnership probably will provide systems as well.
South Korea: Submarine Platforms
These have GTE/Israeli SIGINT.
Spain: Submarine Platforms
Spanish boats have the domestically produced Indra BLQ-355, which may have been exported. With its participation in the EADS consortium, Spain obtains access to new technologies. Spain appears to be developing a coordinated SIGINT approach using submarine, ship, and aircraft platforms.
Sweden: Submarine Platforms
For Harpoon targeting, Sweden uses the ArgoSystems/Condor AR-700 series SIGINT.
Taiwan: Submarine Platforms
Israeli Elbit provides the TIMNEX 4 CH ELINT/targeting set, which covers 2-18 GHz, provides radar warning, and 1.4 to 5 degree DF (depending on frequency).
United Kingdom: Submarine Platforms
EADS (formerly DASA) also equips British submarines with the CXA(2) HF interception and DF suite. Racal/Thales makes the UAP precision DF system.
Several submarines have a COMINT system made by US Southwest Research, under the US code name CLUSTER SENTINEL, probably a joint US-UK effort. Beyond NATO interoperability including JTIDS Link 16, it can reasonably be assumed that the UKUSA partners closely coordinate submarine SIGINT, except, of course, with New Zealand, which does not operate submarines.
Britain's new Astute class parallels the US Virginia class of next-generation submarines. Both are avoiding hull penetrations for periscopes and antennas, preferring controlled buoys or separate masts, both with optical fiber for information transfer. ESM gear for this series is UK-designed and US-built.
United States: Submarine Platforms
Under the code names HOLYSTONE, PINNACLE, BOLLARD, and BARNACLE, began in 1959, US submarines infiltrated Soviet harbors to tap communications cables and gather SIGINT. They also had a MASINT mission against Soviet submarines and missiles. The program, which went through several generations, ended when compromised, by Ronald Pelton, in 1981.
US submarines infiltrated the territorial waters of potential opponents to raise low-observability antennas and collect radio SIGINT US. submarines made extensive clandestine patrols to measure the signatures of Soviet submarines and surface vessels.  Various submarines, including the USS Parche and USS Halibut, from the early seventies onwards, reportedly tapped Soviet copper and optical undersea cables, using divers, probes from the main vessel, or remotely operated vehicles. 
While the Sturgeon-classs have been retired, as with any class of submarines, their design had tradeoffs. Sturgeons were more optimized for reconnaissance than the subsequent Los Angeles class, which have greater speed, but less internal space, and optimized for blue water, principally antisubmarine, missions. They used the AN/WLQ-4 "Sea Nymph" SIGINT system, which may have been too large to fit the Los Angeles class. The Sturgeon class submarine USS Parche (SSN-683) received an addition 100 Feet (30.48 metres) hull extension containing "research and development equipment" that brought her total length to 401 Feet (122.22 metres). Of the three-vessel Seawolf class, the USS Jimmy Carter also is of extended length, presumably for intelligence systems and special operations. Seawolf and Los Angeles classes were directed at a Soviet threat, so the newer Virginia class has additional capabilities for the littoral environment.
Los Angeles class submarines have modernized and smaller ELINT, the AN/WLR-18 "Classic Salmon" for lower frequencies and the AN/WSQ-5 "Cluster Spectator" for higher frequencies. The latter is in a series of code names suggesting it is for tactical use, while the former name is more associated with strategic systems, especially for intelligence. Newer submarines have an AN/WLR-8 radar signal analyzer and an AN/WLR-10 (or AN/BLR-15) radar warning receiver. There are variants, among the classes, of a radar antenna, interferometric direction finder, COMINT receiver.
All US submarines, as new construction on the Virginia class submarines and retrofitted to the Improved Los Angeles class submarines and possibly Seawolfs, will receive an upgraded Electronic Support suite, designed as a minimally manned, passive receiving system capable of detection, acquisition, identification, and localization of a variety of signals of interest . ES contains the AN/BLQ-10 SIGINT system, which gives detection, emitter location and MASINT identification, direction finding, and strategic intelligence support. It was first implemented in 2000 and should be in all US submarines by 2012 .
ES is not limited to the AN/BLQ-10 alone, but a major improvement in receiving, with an expected 200% improvement in performance with the Type 18I periscope and Integrated Electronics Mast (IEM), especially in the littorals. Completing the current ES concept is the AN/ULR-21 CLASSIC TROLL system that increases the probability of SIGINT intercept by 500%, supporting tactical and national requirements.
- Friedman, Norman, Up Periscope, Up Antenna: Hunter-Killer Submarines increasingly are Hunter-Gatherers of Intelligence, Harpoon Waypoint
- Derek Woolner (4 February 2009), From Sea 1114 to Sea 1000: the Collins submarine project and the next RAN submarine, Centre of Defence and Strategic Studies (Canberra)
- Mike Holmes, Electronic Warfare in Australia, Association of Old Crows, Australia Chapter
- Craven, Michael (Winter 2006-2007), "A Rational Choice Revisited -- Submarine Capability in a Transformational Era", Canadian Military Journal: 21-32
- Fisher, Richard Jr. (November 22nd, 2005), Growing Asymmetries in the China-Japan Naval Balance, International Strategy & Assessment Center. Retrieved on 2007-10-08
- Richelson, Jeffrey T. (1989), Chapter 8: Signals Intelligence, The U.S. Intelligence Community, Ballinger
- Sontag, Sherry; Christopher Drew, Annette Lawrence Drew (1999). Blind Man's Bluff: The Untold Story of American Submarine Espionage. Harper Torch. ISBN 006103004X.
- Submarine cable interception, Talinn University
- Fages, Malcolm I (23 March 2000), Statement to Senate Armed Services Committee Seapower Subcommittee on Submarine Warfare Systems for the 21st century
- "Navy ISR", Sea Power, January 2006