NATO Anti-Air Warfare System (NAAWS)
During the Second World War, anti-aircraft on the ground and fighter planes were placed under the same command in both Germany and the UK. The air defence of the home country against air-borne threats on military targets was paramount. Air defence from the ground could also be used offensively to defend the surrounding airspace.
Until 1950, the standard anti-aircraft cannons fired ballistic ammunition sized 20 mm to 150 mm in diameter. After that date, guided missiles (projectiles) became standard for long-distance defence. Ballistic ammunition against air-borne threats is only used for short-range defence.
Air defence is defined by NATO as “all measures designed to nullify or reduce the effectiveness of a hostile air action.” It includes ground- and air-based weapon systems, associated sensor systems, command and control arrangements, and passive measures (e.g. barrage balloons).
Air defence is used to protect naval, ground, and air forces in any location of the NATO allies. Maritime air defence is an effective weapon against a war with missiles. Missile defence is considered to be an extension of the air defence.
In 1987, NATO drew up a system proposal for integrated air defence, the NATO Anti-Air Warfare System (NAAWS). The joint integrated system should intercept every hostile projectile in flight. The technical requirements for Theater Ballistic Missile Defense (TBMD or TMD) were drawn up for a new NATO air defence frigate under the name NFR-90 (NATO Frigate Replacement for the 90s). The requirements were detailed by the NATO working group UNISAMS. UNISAMS was established for Canada, Germany, the Netherlands, Spain, the United Kingdom and the United States, and consisted of the companies Westinghouse, Hughes Aircraft, LTV, Martin Marietta and McDonnell Douglas for the Missile System; MCR and ORI as system analysts; Vitro, Canadian Marconi, MEL, Oerlikon from Canada, SPAR, AEG, BGT, Contraves, Dornier, Philips ELCOMA, Bazan, Ceselsa, Babcock Power, Ferranti Data Systems, Short Brothers and Thorn-EMI. UNISAMS proposed to design a new missile with a double-functional active and passive seeker and accommodate this one into one single MK-41 vertical launch system. A TNO-FEL employee became the chairman of this working group. The Dutch Royal Navy was also represented at a high level to ensure the defence of our own airspace by the Navy.
To be able to identify the nature of the threat, the working group defined working concepts for a fully integrated, responsive and fully automated air defence system. The NATO system had to be able to dynamically and decisively implement the manually entered battlefield doctrine using a wide variety of multi-national ship configurations. Configuration compatibility would be achieved through one central control system, which would incorporate the main functions of sensor-integrated command, local command and weapon detection with command & control and operational vigilance.
The structure of the NAAWS requirements package:
- Local Area Defense
- High Firepower (rate and capacity)
- Multiple Channels of Fire
- Full Volume Coverage
- High Single Shot Kill Probability
- Short Reaction Time
- Short Launch Interval
- Short Kill Assessment Time
- Full Performance Close to Land
- Provide for Future Growth without Major Redesign
- Maximization of Ship’s Total Local Area Engagement Capability
- Medium Range Surveillance
- Surface Surveillance
- Large Target Handling Capacity
- Resistance to Electronic Counter Measures (ECM)
- High Availability
- Adaptive Doctrine
- Simplified Man-machine Interface
- Control by Negation
- Rapid Response to Environmental Changes
A concept design phase study indicated in broad terms what the course of this study should lead to. A design spiral was used in which, for each step and degree of detail, the objectives to be achieved were set for (1) the total system, (2) the general requirements, (3) the sensors, (4) the management/maintenance, and (5) the armament. Each sub-area of the study depended to a great extent on choices made in the other sub-areas. Hence an iterative design through concept studies was needed.
The American representation withdrew because they did not agree to keep the long-distance radar (3D-Spy1) and the tracking radars separate. They were convinced that these radar systems had to be fully integrated into one instrument column on the ship to prevent radar interferences. At the end of January 1990, this led to a split of the working group. The UK, France and Italy would work together to develop the Horizon class frigates.
On April 26, 1999, the UK withdrew from that collaboration and started to develop its own Type 45 “Daring class” frigate. Germany, the Netherlands and Spain continued working under the heading of ‘Trilateral Frigate Cooperation. In doing so, they developed their own frigates with NAAWS capacities, working together in sub-areas such as sensors. This led to the German Sachsen class, the Dutch De Zeven Provincienklasse LCFs (LuchtCommando-Fregatten), and the Spanish Álvaro-de-Bazán class (F100 class). The characteristic of these frigates is the long-distance radar behind the main structure of the ship.
In 2006, the HNLMS Tromp, one of the Dutch Seven Provinces-class frigates, participated in a test near Hawaii for which the SMART-L radar had undergone a number of software modifications. With these modifications, the radar was able to observe a ballistic missile that was launched more than 400 kilometres away and to follow it during its flight in space, a unique achievement. The SMART-L radar is capable of successfully tracking and tracking missiles 360 degrees around the naval ship, something that other radars (at that time) could not. From 2018 onwards, the detection range of ballistic missiles will be increased to 2000 kilometres by replacing the SMART-L radar with a SMART-L MM/N radar as part of the frigate mid-life upgrade. The APAR has a shorter range, but gives a full 360-degree view around the ship and is able to follow more than 100 air targets simultaneously. The Sirius infrared detection system also provides an aerial image in the case of radar emission silence. Sirius can follow approximately 30 targets simultaneously.