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Military Microwaves Supplement
Recent Advances in Radar Technology
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Egyptian service provider Egypt Telecom, Cairo, Egypt, has contracted with a consortium comprising Thomson-CSF Systems Canada and Mackay Radio Systems Inc., Youngsville, NC, to provide the shore-based communications infrastructure for Egypt's national Global Maritime Distress and Safety System (GMDSS) as well as its public maritime correspondence network. The programme will establish a digital communications system to serve Egyptian coastal waters along the country's Mediterranean and Red Sea coasts together with the Suez Canal. The network will comprise three communications control centres and 22 radio sites that will provide coverage along 2450 km of coastline. The service provided will operate in the VHF (30 to 300 MHz) band and extend out from the coastline to a range of approximately 56 km from the coast. The network will incorporate digital selective calling to facilitate automated radio watch keeping on the maritime distress and calling channels together with automatic direct dial public telephone connectivity between ships at sea and Egypt Telecom's terrestrial telephone network. The network's GMDSS function is designed to provide automatic warning of emergencies at sea using digital communications technology. The approach has been adopted by the United Nations' International Maritime Organisation as a worldwide standard and the organisation's member states have agreed to install GMDSS equipment with their merchant fleets as an article of the International Convention for the Safety of Life at Sea. Funding for the maintenance of the network's GMDSS capability is to be partly derived from the revenue raised by the system's public access ship-to-shore/shore-to-ship communications element.
UK contractor Racal Defence Electronics has issued the first open source description of its Triton noncooperative, passive bistatic radar system, which apparently is related to an application Racal may be supplying to the UK's Royal Navy (RN) for use within its submarine fleet. Triton is a passive enhancement to an existing electronic support (ES) capability, which generates a radar-type picture of a vessel's surroundings (including other ships and coastline features) that is updated in real time. As such, the system exploits noncooperative donor radar to calculate the range and angle of a target via comparison of the direct transmissions from the donor radar and reflections from the target.
Functionally, Triton makes use of an automatic search algorithm that identifies an optimum donor radar. An integral recall feature allows use of optimum gain, range, automatic gain control and fade settings for any scenario. The system offers both real-time and snapshot operating modes. The real-time option provides a traditional plan position indicator display that plots each successive sweep of the donor radar's antenna with a fade control adjusting clutter levels and contact intensities. In snapshot mode, Triton allows its operator to record a selectable time-slice of the donor radar. Once recorded, the data can be plotted immediately or stored for subsequent analysis.
The system comprises an antenna assembly, receiver unit, processor and optional local controller. The antenna assembly can be either the omnidirectional array of the host ES equipment or a dedicated omni unit. The receiver is high sensitivity, low noise, ruggedised, commercial-off-the-shelf (COTS) superheterodyne equipment that is designed for installation in standard 19-inch (48 cm) racking. Similarly, the equipment's processor is a COTS device that incorporates digital signal processing cards and integral DVD random access memory discs. The processor also includes an interface for an optional differential Global Positioning System receiver. The display generated by Triton can be overlaid on the host ES system's display or presented on the optional local controller, which takes the form of a ruggedised laptop computer. Racal notes that the Triton system can make use of most commonly used radar bands and has a minimum and maximum range of 0.19 km and 74+ km, respectively. The equipment's range resolution is 25 m (typ), with an azimuth resolution value of 0.1° (typ).
Information received by 'International Report' has started to flesh out the bones of the British Army's proposed Mobile Artillery Monitoring Battlefield (MAMBA) radar programme. Designed to support the evolving Joint Rapid Reaction Force, the MAMBA requirement will provide a highly mobile mortar and in-flight munition detecting radar that is capable of round-the-clock operation in all weather conditions. Key user requirements include a minimum range of 15 km, air transportability, a 75 m circular error of probability against a 155 mm shell at a range of 15 km and an elevation of 25°, a 50 percent probability of detection, an operational availability figure of at least 95 percent over a 30-day in-action period and interoperability with indirect fire systems via digital links. As currently scheduled, a preferred MAMBA bidder is expected to be selected by the end of this year, with a procurement contract being signed by the end of March 2001. The envisaged initial operating capability for the first five MAMBA systems is set at 2002/3, with a second tranche of four radars having a target in-service date of 2008/9. The British Army already evaluated the Swedish Arthur and American Firefinder radars in the MAMBA context in 1999. It is not known whether this evaluation was intended to define the MAMBA requirement or examine systems capable of fulfilling the programme specification.
Northrop Grumman's UK-based subsidiary, Park Air Electronics, Lincolnshire, England, is supplying the UK's RN with a new VHF-band radio system to facilitate communications between its surface ships and civilian aircraft. According to Park Air, the requirement for such a capability has been focused by the need to coordinate communications in areas where its operations are likely to impinge on civilian airspace users. The urgency of the requirement was also driven by the recent introduction of 8.33 kHz channel spacing in the VHF air mobile band and a continuing desire on the service's part to comply with the latest relevant International Civil Aviation Organisation (ICAO) standards. Park Air's T6M base station is at the heart of the new capability and features a compact design that is suitable for installation aboard ships of varying sizes. T6M makes use of digital signal processing technology that enables it to support the recently introduced 8.33 and 25 kHz channel spacings laid out in the latest ICAO standards. Each installed base station will be equipped with four parallel remote control interfaces that will allow it to be operated from key communications positions around its host vessel. In addition, T6M is able to automatically monitor the 121.5 MHz international distress frequency using its integral scanning facility. Park Air is also under contract to install the system and run the necessary trials prior to the equipment's introduction into service.
Russia's Bryansk Electromechanical Plant is reportedly marketing the new SPR-2 proximity fuze jamming system. Installed aboard an eight-wheeled BTR-70 armoured personnel carrier, the 500 kg SPR-2 system operates in the 100 to 500 MHz frequency band and is designed to protect high value targets (such as artillery batteries) from attack by proximity fuzed munitions. SPR-2 provides area coverage of between 200,000 and 600,000 m2 and can detonate incoming shells at an altitude of approximately 400 m. The system is operable while the carrier vehicle is moving or stationary, and is believed to have been in service with the Russian Army since the late 1990s.
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