Dimdex 2014

FAM

UNDERWATER MULTI-INFLUENCE MEASUREMENTS

Terrestrial Reconnaissance and Exploration System

IKONOS PRESS

SAES

SERT

SPECIAL

Nº 133 AÑO XI 2013 6,00 €

www.FUERZASMILITARES.com

World NAVAL

FORCES AVANTE

opv,s for the Middle East

special issue of fam fuerzas militares magazine

NEW WEB

naval solutions for the Middle east

AVANTE OPV

The Spanish shipbuilder Navantia is showcasing its AVANTE family of offshore patrol vessels (OPV) at DIMDEX. These ships will be able to carry out a wide variety of missions such as coastal surveillance and protection, protection of maritime traffic, health assistance to other ships, external firefighting, the fight and control of marine pollution, transport of personnel and provisions, search and rescue operations, rapid intervention, frogmen support, surface defence and passive electronic warfare.

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avantia has developed a new family of OPV’s, the “AVANTE class”, that includes a variety of options. It is a new concept of ships where they will share same hull lines, same compartment division, same arrangement of common spaces and maximum commonality of propulsion and auxiliary systems. What makes them different is the mission they will accomplish: combatant, patrol, support, research.

The ship and systems of the AVANTE family are specially designed to operate in the environmental conditions of the Arabian Gulf, where air temperature reaches 50º C and the seawater temperature could reach 37ºC. n this sense, the capacity of the HVAC system is designed to such environmental conditions.

Furthermore, the hull materials, the building process and the ships’ design itself are defined in

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such a way that the AVANTE family ships can operate under heavy dust/sand storms.

The pieces of equipment design and material are able operate under high humidity up to nearly 100% in conjunction to somewhat lower ambient temperatures than 50ºC. The materials used and protection are defined considering that the ships will be able to operate in aggressive seawater with the presence of industrial pollutants and a higher than usual salt content.

Navantia says the AVANTE family of vessels are adaptable to perform the typical missions of the Arabian Gulf as: • Patrolling • Maritime safety • Securing economical waters and islands.

FAM Report

in service AVANTE 1400 The "Guaicamacuto" class patrol vessels (Avante 1400) is a class of offshore patrol vessels or BVL (Spanish: Buque de Vigilancia de Litoral) in Venezuelan Navy service for patrol duty in economic exclusive zone. The contract for the BVL and POVZEE was signed together on the November 25, 2005. The last vessel "Tamanaco", would be constructed locally at Venezuelan Dams Astilleros Nacionales (DYANCA) in Puerto Cabello, Venezuela.

• • • •

Guaicamacuto GC-21 Yaviré GC-22 Naiguatá GC-23 Tamanaco GC-24

Avante 2200 The Guaiquerí class patrol vessels (Avante 2200 Combatant) are a class of ocean patrol vessels or POVZEE (Spanish: Patrullero Oceánico de Vigilancia de la Zona Económica Exclusiva) in Venezuelan Navy service.

The POVZEE vessels feature stealth technology with reduced radar and infrared signatures as well as special design to minimize the propulsion system's noise emissions and vibrations.

• Guaiquerí PC-21 • Warao PC-22 • Yekuana PC-23 • Kariña PC-24

Avante 3000 The BAM (Maritime Action Ship - Buque de Accion Marítima) (AVANTE 3000) is a modular type of vessel, adapted to different purposes on a common basis, being manufactured by Navantia for the Spanish Armada (Meteoro class). Four units has been built and five more has been commanded in three different configurations.

• • • •

Meteoro (P-41) Rayo (P-42) Relámpago (P-43) Tornado (P-44)

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AVANTE OPV

• • • •

Securing gas and oil rigs Securing coastal boundaries.

Search and Rescue Law enforcement

The ship and systems are specially designed to operate in environmental conditions of high air and seawater temperatures and humidity nearing 100%.

The combatant version has been designed for naval operations in crisis time (command, antiair, anti-surface, electronic and mine warfare) for protection of the exclusive economic zone control The patrol version has been designed for protection and surveillance of national waters, allowing a fast intervention or escorting convoys and warships

Above, two Avante 2200 and one AVANTE 1400 fron the Venezuelan Navy. Left, Command brigde of the

The support version has been designed for emergency situation assistance (fire, pollution, sanitary), divers support or transport of loads and personnel

"Guaicamacuto" GC-21. In the other side, inside cabins of AVANTE 1400, and infographics of AVANTE 1800.

Page 4, GC 21 "Guaicamacuto" (AVANTE 1400).

The research version has been designed for hydrographic and oceanographic survey and Remote Operated Vehicle (ROV) operations

Navantia has recently built four of the ships for the Spanish Navy (AVANTE 3000) and four units of each class for the Venezuelan Navy (AVANTE 2200 and AVANTE 1400).

Furthermore, the mission combined with a determined size of the ship (specified in tones) provides a wider catalogue of products: Avante 300, Avante 700, Avante 1400, Avante 1800, Avante 2200 and Avante 3000.

The AVANTE 3000 has a length of 93.90m, a displacement of over 2,900t and a maximum speed of 21 knots. Her main missions are the protection and escort of other ships, the control of maritime traffic, terrorist actions, piracy, fishing legislation

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FAM Report and environmental legislation, operations against drug and persons trafficking, and crisis situation support and humanitarian assistance.

The AVANTE 2200 has a length of 98.90m, a displacement of 2,200t and a maximum speed of 25 knots. It is able to perform a variety of missions such as surveillance and protection of the exclusive economic zone, protection of maritime traffic, defence of strategic interests, search and rescue operations, support for other units and humanitarian actions, control of marine pollution, the fight against smuggling, drug trafficking and illegal immigration, surveillance and gathering of operational and environmental intelligence, surface defence and passive electronic warfare.

The AVANTE 1400 has a length overall of 79.90m and the capacity to displace 1,500t and reach a maximum speed of 22 knots. FAM

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AVANTE OPV

AVANTE OPV FAMILY Model

AVANTE 1400

AVANTE 1800

AVANTE 2200

Length/Beam/Depth

79.9 x 11.8 x 7.0 m

89.80 x 13.2 x 7.2 m

98.9 x 13.6 x 7.2 m

Full load displacement (aprox.)

1.500 t

1.900 t

2.500 m

Design draught

3.7 m

3.8 m

4.1 m

Acommodation

35 + 29

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92

Maximum/Cruising speed

+ 22 kt / 16 kt

28 kt /15 kt

Range at cruising speed

+ 4.000 nm

+ 5.000 nm

Provision endurance

35 days

Propulsion plant

CODAD 2 diesel x 5,920 kW 2 shaft lines, 2 CP propellers

CODOE 4 diesels x 4,440 kW, 1 x Electric 450 kw, 2 shaft lines

CODAD, 4 Diesels x 5,920 kW, 2 shaft lines, 2 CP propellers

Helicopters & RHIBs operation

Flight deck for medium size helicopter (AB-212, AB-412, AS-565) 1 x 5.7 m RHIB (stern ramp) 2 x 5.5 m RHIB (crane)

·Helicopter medium size ·Flight deck 16.1 long, 12.7 m wide ·Hangar Retractable type ·Helicopter in-flight refueling capacity. ·Landing and securing aids.

Flight deck & hangar for 10 t class helicopter (AB-212, AB-412, AS-565, NH-90) 2 x 5.5 m RHIB (with crane recovery & deployment)

Command & Control

- Integrated Combat System - 1xCMS 6 x MFC, 1 x LSD, 3 Tactical s, Vid- 3xMultifunction consoles - 1xTactieo distribution system, Redundant cal LAN tactical LAN and Tactical Data Link - 1xTactical data link

Integrated Combat System: - CMS - 5 x Multifunction tactical consoles - 2 x LSD 1 x Video distribution system - Tactical processors - Tactical LAN - Tactical link system

Sensors

1 x 2D Air/Surface surveillance radar.

- 1 x IFF (Interrogation & transponder). - 1 x LPI Surface/Navigation radar.

- 1 x Navigation radar - 1 x Radar-EO fire control system director. - 1 x EO fire control system director. - 1 x ESM system Radar band. - 1 x ESM system Communications band.

Air Surveillance Radar 1 x 3D Air/ Surface Surveillance radar ·Surface/ Navigation Radar 1 x S Band 1 x X Band ·IFF 1 x Interrogator & Trasponder ·OPTRONIC 1 x IRST ·Electronic Warfare 1 x Radar ESM/ ECM 1 x Communication ESM/ ECM ·Underwater sensors 1 x Hull Mounted Sonar 1 x CAPTAS (W&S reserve) 1 x Bathythermograph

1x Air surveillance 3D radar - 1x IFF (Interrogator and Transponder) - 1x Surface and Navigation LPI radar - 1x Navigation radar - 1x EO surveillance and tracking system - 1x EO fire control system director - 1x ESM system in radar band - 1x ESM system in communications band - 1x TAS system

1 x 76/62 mm Gun - 1 x 35 mm CIWS - 2 x 12.7 mm machine guns (manual operation)

Guns:1 x 76 mm 1 x 25 - 35 mm 2 x 12.7 mm ·Fire Control System 1 x Radar-EO Pedestal 1 x EO Pedestal ·Vertical Launcher System . 8 x cells SAM system ·Surface to Surface Missile 8 x SSM (two quadruple launchers) ·Torpedoes 2 x Triple 324 mm torpedo launchers ·Decoys 2 x Multipurpose Decoy launchers

Guns: 1x76mm, 1x35 mm, 2x12.7 mm - Fire Control System: 1x Radar-EO, 1x EO - SAM system: 1x VLS 8 cells SSM system: 2x quad launchers - ASW torpedoes: 2x triple launcher - RF & IR Decoys: 2x launchers (12 tubes each)

Weapons

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21 days

Terrestrial Reconnaissance and Exploration System (SERT) The characteristics of the battlefield of the future make it vital to have effective terrestrial surveillance systems which provide timely information about the terrain and the enemy, allowing Spanish Army units to execute their plans and offer an effective challenge.

This means that the Armed Forces (mainly the Army) need access to resources which meet their existing needs both at technical and operational levels. Among other measures, this demands that reconnaissance units be equipped with the resources allowing them to perform their surveillance and reconnaissance missions. The objectives of the SERT project are: • Development and manufacture of a technological demonstra-

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tor for a navigation, detection, identification and target location system using electro-optical and radar-based sensors and self-protection for Intelligence, Armoured, Field Artillery and Marines vehicles.

• Development of algorithms for the integration of cutting-edge radarbased and electro-optical sensors with advanced target identification and location functions.

• Full integration across the vehicle's technical systems (observation sensors) and tactical systems (command and control).

• Development of an integrated night vision and navigation system for vehicles.

• Development of a remote control system for small-calibre weapons.

• Presentation of the demonstrator's results on national and international forums. FAM

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World Navies

General Dynamics Bath Iron Works Awarded $21 Million Contract for Coast Guard Offshore Patrol Cutter Program The U.S. Coast Guard has awarded General Dynamics Bath Iron Works a $21.4 million contract for the Offshore Patrol Cutter (OPC) program. Bath Iron Works is one of three shipyards chosen from a field of eight competitors to proceed to Phase I design work on this next-generation cutter program.

The Bath Iron Works team includes L-3 Communications (New York, N.Y.) and Navantia, S.A. (Spain), a shipbuilder that Bath Iron Works has collaborated with for more than 30 years.

Bath Iron Works president Fred Harris said the Coast Guard design contract was an important development as the shipyard seeks to expand its customer base and maintain its design and manufacturing workload.

"Our experienced engineering and design team will now focus on developing a preliminary OPC design that meets or exceeds our customer's requirements," said Harris. "We will also continue our yard-wide actions to ensure we can build these ships affordably, safely and on -- or ahead of -- schedule."

At the end of the 18-month Phase I period, the Coast Guard will select one team to develop Phase II detail design and build the first nine to 11 ships of a planned 25-ship class.

The OPC is a next-generation ship which will replace the Coast Guard's aging fleet of Medium Endurance Cutters, complementing the current and future fleet and extending the service's operational capabilities. The OPC will feature increased range and endurance, more powerful weapons, a larger flight deck and improved command, control, communications, computers, intelligence, surveillance and reconnaissance equipment. FAM

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LOADING OF THE ALHD “ADELAIDE” ON BOARD THE BLUE MARLIN FOR TRANSPORTING TO AUSTRALIA The ALHD “Adelaide” has been transported to BAE Systems Australia, where the ship will be finished The ALHD “Adelaide” was loaded on board the “Blue Marlin”, owned by the Dutch Company Dockwise, on 10th December 2013 in Northern Spain.

The operation began with the approaching and positioning maneuvers of the ALHD “Adelaide” on the supporting bed installed on the “Blue Marlin”. The operation finished once the mentioned vessel was refloated being the “Adelaide” on the deck of the “Blue Marlin”.

AS well as it was done with the ALHD “Canberra”, the ALHD “Adelaide” has been transported to BAE Systems Shipyard at Williamstown in Australia. Once there, the works on the ship continue and finally it will be delivered to the Commonwealth of Australia.

The contract to build two units of the ALHD based on the LHD “Juan Carlos I” owned by the Spanish Navy, was signed in 2007 and it supposed the introduction of Navantia in the military Australian market. The delivery of this ship, in advanced from scheduled date, means the consolidation of Navantia as technological partner in Australia and its positioning for future contracts with the Australian

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Navy. At present, Navantia is building 12 Fast Landing Craft and is participating, with the design and transference of technology, in the building of 3 destroyers.

Navantia wishes to highlight the excellent relationships and communications between the parties involved in this programme: Commonwealth of Australia, BAES and Navantia.

Main Characteristics: - Length overall: 230,8 m - Beam moulded: 32,0 m - Depth to flight deck: 27,50 m - Maximum speed: more than 20 kt - Range at 15 kt: more than 6000 nm - Crew: 243 - Total Accommodation Capacity: more than 1400 The ALHD is a multipurpose vessel with different capacities depending on the mission: -Air: Platform for helicopters and VSTOL (up to 20 planes) -Amphibious: Platform for marines, vehicles, landing crafts(4xLCM-1E) and support elements.

-Transport and expeditionary: capability for troops, tanks and helicopters.

- Humanitarian and rescue: capable to transport goods and provide assistance and medical support (aid containers + full medical facilities). FAM

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NAVANTIA and local partner selected by Turkey for construction of one LHD based on the “Juan Carlos I” 27th. December 2013.- The SSM of the Government of Turkey has announced today that the partnership formed by Navantia and SEDEF, the Turkish shipyard, has been selected in first place for the design and construction of one LHD and four LCM landing crafts for the Turkish Navy.

Navantia will provide the design, transfer of technology, equipments and technical assistance to SEDEF for local construction. Besides the design, based on the LHD “Juan Carlos I” for the Spanish Navy, Navantia will also provide several components and systems, as the engines, the turbine and the IPMS (Integrated Platform Management System).

Navantia’s design has been selected due to the fact that it is a built and proven design in the case of LHD “Juan Carlos I, and a very advanced Construction in the case of LHD “Canberra” and LHD “Adelaide” for the Royal Australian Navy.

Last, this contract means the entrance of Navantia in the Turkish market, where is presenting also the F-100 frigates, as well as the consolidation of Navantia as a reference in the LHD market. FAM

NAVANTIA and the U.S. Navy sign service contract of 4 destroyers Navantia has signed with the US Navy a service contract of four destroyers who will be deployed during 2014 and 2015 in the Naval Base of Rota, as part of the BMDl, according to the agreement reached between both governments in 2011 and signed in 2012. The contract includes the maintenance of these units in the periods of immobilization in Rota, and has a duration of 1 years more 6 optional years.

Navantia's experience in the design, construction and maintenance of the ships, similar to the Spanish Navy in its systems, as well as its excellent infrastructure and workforce skill capacity, have been decisive for the adjudication of this contract.

Likewise, the attainment of this contract with the US Navy, with the highest level of requirements, supposes for Navantia a great international prestige, guaranteeing his leading world position in the naval military construction. FAM

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AOR CANTABRIA INTEGRATED IN ROYAL AUSTRALIAN NAVY (RAN)

The ship is candidate to be the best option for the RAN The Spanish Navy AOR “Cantabria”, built by Navantia and commissioned in 2010 was deployed in Australia in 2013, as part of the agreement signed between the Spanish Navy and the Royal Australian Navy. The target of this mission is offer the RAN the possibility of evaluating the capabilities of the ship and giving the crew the necessary training on the operational aspects of the ship.

Since her arrival, the ship has participated in a great number of sea exercises, providing logistic support to several ships, totally integrated in the RAN: As expressed by RAN the deployment has been totally successful and the capabilities of the ship have been highly evaluated.

day and night - NBC Protection: Classification of space as citadel and sub-citadel, detection systems, “wash-down” and decontaminations units - Integrated Platform Management System.

- Integrated Commanding Bridge and Auxiliary Bridge - Reduced crew - High availability and autonomy.

Main characteristics - Length overall: 173.9 m - Length between perpendiculars: 162.0 m - Beam: 23.0 m - Design draught: 8.0 m - Depth: 11.8 m Weight: 9,800 t - Displacement: 19,500 t - Propulsion: 2 x 10.890 kW 1 CPP - Electric plant: DG 4 x 1,270 kw - Maximum speed: 20 kn - Crew: 122 people FAM

About the ship The AOR “Cantabria” is capable of providing underway replenishment during long periods at sea, minimising the time it spends in port. On its way back to Spain, the ship visited the post of Goa where the Indian Navy had the opportunity to be on board and be briefed about the ship and capabilities.

Provision of efficient replenishment at sea to war ships all around the world can be the key to the success of the missions. Navantia has designed, built and delivered a unique ship capable of supplying fluids (FAS) and solids (RAS), that incorporates the most demanding requirements: - Double hull in loading tanks area (MARPOL + OPA 90) - Outstanding platform stability for RAS/FAS opera-tions during

NAVANTIA’S NEW GENERATION OF SHIP MANAGEMENT SYSTEMS

During the last decade, Western Navies assumed a challenge to improve warships operative capacity by integrating and automating their primary and domestic functions. At the same time, the need for large crews was remarkably reduced by implementing commercial-off-the shelf equipment and the most updated technologies available within the industrial field.

Navantia Systems has developed a new integrated systems for platform control and management (IPMS), provided with an open architecture for the integration of all types of additional subsystems and their specific software so that all of them can operate under the same operative system. The results are new functionalities, meaning great saving for installation, purchasing, and maintenance costs.

Navantia Systems has a wide experience in the integration of IPMS that can be installed in any type of platform, from patrol vessels to aircraft carriers. The IPMS consist of the following components: • Operator Console: It is intended to provide surveillance, alarms warning and commands generation.

• Local Substations (LSS): Information gathering, execution of control algorithms and sending commands to the machinery actuators.

• Data Transmission Network (DTN): for interconnection of data between consoles and substations, ensuring the information integrity • The consoles, LSS and DTN can be configured with any COTS available in the market. They can be suited to the ship´s characteristics.

With the purpose of guaranteeing the system survivability, the IPMS configuration implies a redundant and distributed architecture (not centralised) with identical functionality for all operator consoles. The IPMS architecture allows assigning the platform control to any combination of operator consoles.

The main target in the development of the IPMS is to make the platform status information available from any turned on console.

The control of one subsystem is assigned to only one console, and just those users with Supervisor category are allowed to modify that assignment. The IPMS provides a high automation level, allowing reduced crews safely sail the ship. COMPLEX organizes and presents the information in the optimal way to help operators get the knowledge of the platform’s state (propulsion, power plant, auxiliaries and damage control) and make the best decisions.

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The main functions are: • Monitoring and Warning functions: Analog and digital information display, communications and sensors diagnosis, alarm warnings and trend charts.

• Automatic functions: IPMS can operate under different levels of automation: manual, semiautomatic and automatic.

• Security functions: These functions are used to provide machinery and equipment automatic Emergency Stop, without the operator´s assistance, under risk operating conditions.

• Damage Control functions: Including management of incidences related whit fire, flooding, smoke, NBQ alarms, stress and stability calculations, on line Personnel location, Kill cards, etc.

Other IPMS services: • Navigation data, e-mail, videoconference, video surveillance, on line help, On Board Training System (OBTS).

• Predefined Configurations: Set of commands issued with a single action. E.g. Firemain valves, Tightness conditions. Individual and Summary status is shown.

• Data Logging functions: IPMS has Data Store Units (DSU) which collects and store continuously Events, Alarms, Analog values, operator actions, etc.

• Playback: projects historical data on the mimics, 3D scenes and Data Viewers. FAM

UNDERWATER MULTI-INFLUENCE MEASUREMENTS

AS A MEAN TO CHARACTERIZE THE OVERALL VESSEL SIGNATURE AND PROTECT THE MARINE ENVIRONMENT All the vessels, independently of their shape and size, emit to the sea a set of radiations that make up the so-called vessel signature. This signature characterizes and identifies univocally the vessel in the same way that the fingerprint identifies the human being.

The importance of this signature is well-known since early the past century, mainly in the defense field and specially centered on the so-called acoustic and magnetic signatures. As an example, detection of vessels based on their acoustic signatures had a great importance in the naval field during the Second World War.

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Autor SAES

I

NTRODUCTION In parallel with technological improvements during the 20th century, and especially in the defense field, specific techniques have been developed to get smaller the level of the radiations emitted to the sea by vessels. At the beginning, reduction techniques were limited to the acoustic radiation. Next, the magnetic radiation was also taking into consideration and more recently the electric-field, pressure and seismic radiations have also been considered of interest. The group of five radiations referred to above make up the so-called multiinfluence signature of a vessel. In Figure 1 an example of the simulated electric signature radiated by a sweep gear is shown.

ence of threats in harbours/ports, critical infrastructures or cultural assets located on the sea floor, making it possible to implement specific actions to neutralize these threats.

Figure 1. Simulation of the electric

2. CHARACTERISTICS OF THE MULTI-INFLUENCE SIGNATURE OF A VESSEL As previously stated, the multi-influence signature of a vessel comprises five types of radiation: acoustic, magnetic, electric, pressure and seismic. Each of them incorporates specific characteristics. Next, a brief description of their main characteristics is presented.

field radiated by a sweep gear

The monitoring of the multi-influence signature has a great importance in the defense field and in the case of vessels such as submarines becomes a matter of survival. Also, it is becoming increasingly important in the civilian field related to the marine environment preservation, especially in the case of the marine fauna living in this environment, due to the influence of these radiations on their behaviour. Finally, it is worth to outcome that the detection of this signature permits us to determine the pres-

This paper comprises four sections in addition to this introduction section: in the first section the main characteristics of the radiations that make up the multi-influence signature are described. In the next two sections, the importance of this signature in the defense and civilian fields is analyzed. In the next section, a system especially adapted to measure multiinfluence signatures is described.

Finally, the paper is completed with the conclusion of the study.

Acoustic radiation The sound generated by a vibrating source is propagated as a wave in an elastic medium such as the sea, originating pressure changes that are susceptible of being measured.

The underwater sound propagation characterises by its high performance, being in fact the way of radiation today known that best propagates through this medium [1], being able to reach long distances in the case of low frequencies.

Vessels emit two types of generic signals: broadband and narrowband. The former characterises by covering a wide spectrum of frequencies, meanwhile the latter is limited to a narrow spectrum.

There are different sound sources in vessels. The three main are: machinery noise, propeller noise, and hydrodynamic noise. In Figure 2 a scheme of sound underwater propagation obtained from an underwater acoustic propagation model is shown.

Figure 2. Sound underwater propagation paths obtained from an acoustic propagation model

Magnetic radiation The ship magnetic influence is composed by two components: the static component (SM) and the alternating one (AM). The static component is generated by the permanent and induced magnetic fields.

The permanent magnetic field of the ship is due to the magnetization of its construction magnetic materials by the Earth’s magnetic field. Besides, the Earth’s mag-

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UNDERWATER MULTI-INFLUENCE MEASUREMENTS

netic field, as an extern magnetic field, always contributes to the ship magnetic signature. This component depends on the ship course and localization of the area.

In addition to permanent and induced magnetic fields, CRM (Corrosion Related Magnetic) field also contributes to the static magnetic component of the signature.

This field is due to the existence of corrosion currents through the sea water, which have an associated magnetic field.

The alternating component of magnetic signature is generated by: • The currents in the rotating coils of ship turbines. These coils perform as magnetic dipoles, which generate AC magnetic signature.

• Sea water Foucault currents induced by the magnetic dipoles. These currents are time varying and are associated also with alternating electric fields.

• Electric currents flowing through ship hull due to electric equipment failures or inadequate design.

• Inherent magnetic field radiated by any rotating electric machinery in the ship.

Besides, power supply ripple generates alternating currents through the water. In Figure 3 an example of simulation of the magnetic field generated by a vessel is shown.

Figure 3. Simulation of magnetic field generated by a vessel

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Electric-field radiation The ship electric signature is composed by two components: the static component UEP (Underwater Electric Potential) and the alternating component ELFE (Extremely Low Frequency Electric).

The static component UEP represents the near field influence and its temporal variation depends on speed and size of the ship. The static electric signature of a ship is due to the electric currents generated by the galvanic corrosion process. In order to avoid this corrosion, cathodic protection systems are used. There exist two types of cathodic protection systems: passive and active or ICCP (Impressed Current Cathodic Protection). The passive systems use sacrifice anodes, whereas active systems use impressed current anodes and reference electrodes. Quite often, cathodic protection systems contribute drastically to electric signature and constitute the main generator for this influence.

The alternating component ELFE covers a bandwidth of approximately 3 kHz and represents the near and far field influence. ELFE component is due to the following factors: 1. Modulation of the corrosion current: galvanic current is modulated due to the spin of blades and propellers.

2. Ripple in machinery power supply of the ship. It appears a tone of frequency corresponding to the power supply frequency.

3. Ripple in degaussing systems ICCP, corresponding to the modulation suffered by the ICCP system current due to variations in the resistance between the shaft and hull of the ship.

In Figure 4 is shown an example of simulation of the electric signature radiated by a vessel.

Figure 4. Example of simulation of the electric signature radiated by a vessel (longitudinal, transverse and vertical components).

Pressure radiation Hydrostatic pressure due to water depth varies slowly with atmospheric pressure changes and tide rising and falling. Besides, it can vary fast with waves and train of waves, or with a ship.

Pressure variation due to a ship movement is usually very small. This small variation constitutes the ship pressure signature and it is produced

by Bernoulli Effect of the water flowing from bow to stern. This flow originates a pressure increase at bow and stern of the ship and a decrement in the central zone (suction), which peak is directly proportional to ship speed and its underwater shape. Figure 3, shows this pattern in a simulation of the pressure signature of a ship.

Therefore, induced pressure fluctuations by the ship superpose with the nominal static pressure of the bot-

Figure 5. Ship Pressure Signature Simulation

FAM Special

tom and natural disturbances caused by tide, waves and swells.

Seismic radiation Seismic influence is generated by the same sources as for the acoustic influence. When an acoustic wave reaches a surface, the majority of the energy is reflected but a percentage is absorbed by the new medium.

Thus, acoustic signals of very low frequency (below 10Hz) propagate up to the sea floor and transmit through it as a seismic perturbance. This type of perturbance travels much faster through sea floor than through sea water.

From this seismic point of view it is obvious that the acoustic energy penetrating into the sea floor may sometimes contribute considerably to medium-range and long-range acoustic transmission. One clear example that shows seismic influences behavior is the existence of a critical frequency. For all frequencies below this limit absorption phenomena in incident waves appears, and this phenomena depends on characteristics of the materials and layers of the see floor.

Figure 6. Ship seismic signature physic phenomena

3. THE MULTI-INFLUENCE SIGNATURE IN THE DEFENSE FIELD The intelligence databases have become an element of great importance for the navies of the different countries. These databases contain as distinctive data the signatures of the vessels. At the beginning they contained acoustic data and sometimes magnetic data. Currently, they seek to incorporate also data corresponding to the rest of influences.

These databases permit us to discriminate not only the type and class of the vessel but also the specific unit of the class, providing a considerable tactical advantage.

rate detection of the threats coming from the marine environment, such as: divers moving autonomously, manned and unmanned underwater vehicles (SDV, ROV, UUV), minisubmarines, etc.

Figure 7. Multi-influence Signature

Currently, the trend of the last decades relative to the reduction of the vessels signature is being accentuated. This trend is particularly intense in the case of submarines. They seek to increase their level of protection becoming every time more stealth vessels as a mean to counteract the development of increasingly intelligent weapons such as last generation torpedoes.

In parallel with that stated above, every time more sophisticated systems incorporating a wide range of sensors are being developed nowadays. The use of these multi-influence systems permits vessels to increase significantly their detection capacities from the combination of the data provided by their suite of sensors, making it possible a considerable reduction in the number of false alarms.

By other hand, in the defense facilities protection field the use of these multi-influence sensors is permitting to increase their security in a significant way. This fact is based on the early and more accu-

measurement by MIRS

4. THE MULTI-INFLUENCE SIGNATURE IN THE CIVILIAN FIELD During the last years, a growing awareness has emerged worldwide on the necessity of protecting the marine environment, especially from the human activities such as: fishing, sailing, harbour works or seismic oil and gas explorations that convey significant increases in the level of a range of pollutants such as acoustic noise and other sources or energy including the electric and magnetic ones.

This growing awareness has entailed the development of a range of national and international regulations focus to get an effective preservation of the marine environment. Among these regulations is the Marine Strategy Framework Directive, promulgated by the European Union in the year 2008, which introduces a set of qualitative descriptors to determine the good environmental status. One of these descriptors states that: “The introduction of energy, includ-

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UNDERWATER MULTI-INFLUENCE MEASUREMENTS

ing underwater noise, is at levels that no adversely affect the marine environment”. The effective application of this Directive, and of other regulations related with the marine environment protection, implies both the measurement of the level of the energy radiations emitted to the sea [2] and the detection of the marine fauna presence in specific areas on which high energy levels are detected, with the aim of protecting this fauna from the potential harmful effects of the radiated energy. This detection is mainly based on acoustic sensors, although other alternative detection means are currently being analyzed, such as the detection of the marine fauna based on the alteration of the underwater electric or magnetic fields originated by its presence. In Figure 8 two kinds of cetacean species: bottlenose dolphin and sperm whale are shown.

Both are endangered species.

Just like in the defense field, the use of multi-influence sensor systems provides an effective protection of harbours and critical infrastructures, such as oil refineries and thermal power stations, against hostile intruders. This pro-

Figure 8. Species of cetaceans: bottlenose dolphin (left) and sperm whale (right)

tection can also be extended to other fields of remarkable interests as is the case of marine reserves, ship wrecks or underwater archaeological remains.

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5.MULTI-INFLUENCE SIGNATURE MEASUREMENTS With regards to multi-influence measurements, the trend in the civilian field is to advance towards a standardisation process in the procedures and parameters of the measurements. These standards already exist since time ago in the defense field. The precursor of this process is again the acoustic influence for which a standard has recently (2009) been developed by the Acoustical Society or America (ASA): “Quantities and Procedures for Description and Measurement of Underwater Sound from Ships”. Additionally, in the European Union scope there exist specific programs focused to the definition of a European standard. Measurements are usually normalised to common references in order to be able to compare these coming from different systems, as is the case of the 1-meter from the source reference for acoustic measurements or a common reference point for all the vessels in the case of electric and magnetic fields measurements.

The fact that multi-influence sensors provide different detection ranges permits us to establish different detection layers as a function of the sensor range, Detection ranges depend on both the specific characteristics of the marine environment and these ones of the vessel under test and the used sensors. In a first approach, it can be stated that both acoustic and seismic sensors provide detection distances in the range of kilometers, being the seismic sensor especially dependent on the characteristics previously referred to, electric-field and magnetic sensors in the range of hundreds of meters and pres-

sure sensors in the range of tens of meters.

The wide range of operational environments in which multi-influence measurements are susceptible to be taken makes highly advisable to have at our disposal modular and portable systems with small dimensions and weights. These kinds of systems permit us their deployment and recovery in different marine areas within a reduced time interval and without requiring complex means. Other aspects to be stressed are: the capacity of data transmission to base centers (located on shore or onboard vessels) with an adequate bandwidth to cover the characteristics of the signatures under test and the capacity of storing and processing the measured influences, focused to provide accurate and useful information to the system operator.

MIRS system developed by SAES, (outlined in the next section) is an example of a system that complies with the characteristics previously described.

6. INDUSTRY SOLUTIONS The use of advanced multi-influence processing techniques allow the development of last generation systems in the segments of activity in which SAES operates.

MIRS - Multi-influence Range portable System for surface ships and submarines The SAES Multi Influence Range System (MIRS) for surface vessels and submarines provides real influence measures (magnetic, electric, pressure, acoustic, and seismic) in a

FAM Special

real and controlled scenario, to successfully counter related threats.

MIRS is among the best systems in the world in its class and compared to fixed stations, a decisive advantage of the MIRS system is that, due to its portability, low weight, power consumption and high performance can obtain all signatures of the ship in different geographical locations .

MIRS is also a tool for testing and calibration of: • Systems developed to reduce those influences as degaussing systems, ASG, etc.

• Systems developed for MCM as the mine sweeping systems.

Figure 10. Set of measurement of the

MIRS has been primarily designed using Commercial Off The Self (COTS) equipment for maximum reliability at minimum cost.

NAVAL MINES Based on the experience in Underwater sensors, SAES has developed a complete set of Multi-influence Naval Mines, at the forefront of the market, that use a variety of sensors to detect different physical influences.

Figure 9. Underwater units of the multi-influence measurement system MIRS developed by SAES

MIRS has two installations modes: can be located at a fixed station or, using the portable capability, can be located in the desired location, since it is easily deployable by two people from a rigid-hulled inflatable boat (RHIB).

The MIRS system has been tested in operational environments showing its versatility ease of use and accuracy taken as reference-calibrated systems. In Figure 10 graphic outputs of the multi-influence signature of a merchant vessel are shown.

acoustic (upper left), seismic (upper middle), magnetic (upper right),

edge of this intelligence is essential to programming the fire algorithm of the Combat units.

electric (lower left) and pressure (lower right) influences of a merchant vessel taken by the MIRS system developed by SAES

MINEA The family of MINEA products comprises three kind of naval mines: cylindrical bottom mine, conical shape shallow water mine and moored mine. MINEA includes the following sensors: • Triaxial magnetic sensor.

• Triaxial electric sensor, UEP and ELFE. • Acoustic sensor.

• Triaxial seismic sensor (except moored mine).

• Pressure sensor.

In addition, Exercise MINEA version is available to be used for MCM training and to gathering intelligence information by measurement and recording of ships influence signatures. The knowl-

Figure 11. MINEA multi-influence NAVAL mines.

MILA MILA-6C is a smart computer controlled time-fuzzed underwater limpet mine. It can be fixed by frogmen onto the hull of the ships or be used as demolition charge as well. It has a conical shape and low weight in water. MILA is available in Exercise (reusable & inert) and Combat versions.

Figure 12. MILA. Limpet Naval Mine.

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 UNDERWATER MULTI-INFLUENCE MEASUREMENTS

SIMOAC. Acoustic Monitoring System.

Environmental protection configures nowadays as one of the areas of highest interest worldwide. The acoustic monitoring system SIMOAC has been designed on the basis of providing a reliable measurement system based on calibrated acoustic sensors, that permit to measure and analyze the underwater acoustic environment and to detect the presence of marine mammals in a specific area, besides their localization. SIMOAC configures as a versatile system, completely respectful with the environment and powered by renewable energy, based on marine nodes with capability of: including additional sensors, unwired communication with a base center on shore, automatic processing of the signals captured by the sensors and sending of selected data via internet to specific surveillance centers.

SIDIS configures itself as a net of nodes that can operate in a stand-alone way or making part of an integrated surveillance system.

These nodes characterize as multiinfluence sensors (acoustics and non-acoustics), modular, versatile and high-performance systems.

The SIDIS design, based on a layer protection concept, increase its degree of effectiveness, its adaptability to be integrated with other sensors and surveillance systems to configure wider control systems.

Furthermore, its highly efficient communication system and the inclusion of reaction capabilities become it in a complete security system.

Figure 14. SIDIS configuration for harbor protection.

Figure 13. SIMOAC Communication Buoy.

SIDIS The SIDIS system for marine environment surveillance and protection characterizes by the wide range of tasks that is able to undertake: environmental monitoring, marine mammals detection, protection of ship wrecks or archaeological remains or protection of vessels and critical infrastructures in the marine environment.

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7. CONCLUSION All vessels when sailing through the sea radiate a set of influences (acoustic, magnetic, electric, pressure and seismic) that make up their multiinfluence signature. Some of these influences (acoustic and magnetic) have being measured since decades ago to characterise the vessels in the defense field and to monitor the acoustic pollution in the civilian field.

Recently the interest in the international community on having at our disposal the overall signature of the

vessels has emerged, with the aim of evaluating globally its impact on the marine environment.

In the defense field, from the point of view of the own fleet to have at our disposal multi-influence data from vessels permits us to perform specific tasks and studies focused to reduce the own signature in order to decrease the probability of being detected. By other hand, from the point of view of the threats this data permits us to characterise the vessels signature with the aim of increasing our capacity to detect them.

In the civilian field, the interest is centered on the marine environment preservation, especially of its marine fauna. In the dual defensecivilian field, protection systems based on multi-influence sensors constitute a highly efficient mean to detect hostile intruders.

Due to the variety of operational areas in the marine environment it is highly advisable to have at our disposal modular systems with contrasted capacities of data transmission, recording of the measurements and processing focused to provide relevant information to the system operator. The MIRS system developed by SAES configures as a verified and in-service system than complies with the requirements established for the multiinfluence measurement of all kind of platforms or naval devices in the whole spectrum of operational environments. FAM