GLOBAL ARCHITECTURE

Flexible architecture Redundant data transmission modes Datatransmissionreconfigurationon

line failureUpmost electronicsintegration ASICStechnology

24bit,Sigma/Delta IndividualA/DconverterperchannelActivestreamerssectionswithdistributedelectronicsMulti-boatscapabilityFullyintegratedacquisitionsystemHighredundancy

Seal 428

Ahead of the CurveSM

SpecificationsGeneral

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General

Figure A-1. The Seal428 system

Global architecture

Flexible architecture Redundant data transmission modes. Data transmission reconfiguration on line failure.

Upmost electronics integration

ASICS technology.24 bit, Sigma /Delta.Individual A/D converter per channel

Active streamers sections with distributed electronics.Reduced weight/diameter/drag/power/bulk.Multi-boats capability.Fully integrated acquisition system.High redundancy

Seal 428 Server

Tape drive

NAS or FTP server

Seal 428 local Client

Seismic Gateway

Seal 428 remote Client

Navigation system

eSQC-Pro local Client

eSQC-Pro Server

Replay link

SEGD File Server

LCI-428

GPS time receiver Plotter

DCXU-428

Streamer sections and electronics

In-sea equipment

Shipboard equipment

Gun controller

Deck equipment

GENERAL

SHIPBOARD EQUIPMENT

SERVER

Rackablex86serverrunningLinuxOperatingSystem.Itma-nagestheflowofacquireddatafromthestreamersandauxiliarychannels.Italsomanagesprocessingofthedataandexporttovariousperipherals(FC-ALandSCSItapedrives,FTPserver,NFSdisks,plotters,QCtools).CommunicationsandsynchronizationwiththenavigationsystemandguncontrollersareensuredviaEthernetlinksoraT0signal.CommunicationswithDCXU-428sareensuredviaEthernetlinkstoo,thereforetheservercanmanageavirtuallyunlimitednumberofDCXU-428s(streamers).

SYSTEM SOFTWARE PACKAGE

-ServersoftwareforLinuxserver.-Clientsoftware(Java)forLinux/Windowsclients.-EmbeddedsoftwareforSercelelectronicsmodules.

GRAPHIC USER INTERFACE (GUI)

RackableclientPC(LinuxorWindows)runningintuitivegraphicalJavaenvironmentsforsettingup,controllingandtroubleshootingthesystem.DuetotheSercelClient/Servertechnology,theGUIPCcanbelocatedanywheresolongasanEthernetconnectionisavailable.

GPS TIME SERVER

Rackable19off-the-shelfequipment,usedforsystemsynchronization.

DCXU-428

Shipboardinterfacewithastreamercable.Itsbuilt-inhigh-voltagepowersupplyallowsupdatedcontrolofthestreamer.DCXU-428s(andthereforestreamers)aretightlysynchronizedviaGPS,ensuringprecisesynchronizationofseismicacquisition.

LCI-428

InterfacebetweenthenavigationsystemandtheSeal428,allowsinputofaphysicalT0andmanagesauxiliarytraces.

AUXILIARY CHANNELS UNIT (AXCU)

Rack-mountedorinstallednearthesources,theAXCUisusedtodigitizeanalogauxiliarychannels,usingFDUelectronics(typically12channels,extensionsavailableupto60channels).

SEG-D FILE SERVER

High-capacitystorageforseismicdata,witharchiveoptionandopenEthernetconnectionallowingreal-timeorpostponedQCofseismicdata.

IN-SEA EQUIPMENT

LEAD-IN

Armouredelectro-opticalcableusedfortowingthestreamer.

SHORT HEAD SECTION (SHS), HEAD ELASTIC SECTION ADAPTOR (HESA)

Dedicatedsectionsallowingmechanicalattachmentattheheadofthestreamer.

HEAD AUXILIARY UNIT AND HEAD AUXILIARY POWER UNIT (HAU-428 AND HAPU-428)

TheHAU-428assuresthefollowingfunctions:-TLFOIpowersupply.-PowersupplytothefirstAcquisitionLineSections.-Measurementofthetensilestress.-Telemetryleakagemeasurement.-HVandtelemetryswitchingforeasytroubleshooting.TheHAPU-428performsthesamefunctions,plus28-Vor50-V,30-Wpowersupplyfortheheadbuoy,andconsumptionmonitoring.

HESE, RADIAL STRETCH, TAIL ELASTIC SECTION (TES), RVIM

Elasticsectionsusedtomechanicallyuncoupletheactivestreamerfromthetowingvesselorthetailbuoyacousticvibrations.

SENTINEL SOLID ACQUISITION SECTION (SSAS), OR ACQUISITION LINE SECTION (ALS-FLUID)

Withalengthof150m,anSSASorALSacquiresdatafrom12channelswitha12.5-mtypicalspacing.ThetypicalchannelarrangementinanSSASfeaturesoneoverlappinghydrophone.

LINE ACQUISITION UNIT MARINE (LAUM)

LAUMsprovidedatacompression,datarouting,andpowersupply.Inastandardconfiguration,eachLAUMhandlesthesefunctionsfor60seismicchannels.Thismeansthatinatypical12.5-mgroupintervalconfiguration,oneLAUMisrequiredforeveryfive150-mSSASorALSsections.Forexample,a960-channelstreamerismadeupof16x5SSASorALSsec-tionsand16LAUMs

SpecificationsGeneral

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In-sea equipment

Figure A-2.

Lead-inArmoured electro-optical cable used for towing the streamer.

Short Head Section (SHS), Head Elastic Section Adaptor (HESA)Dedicated sections allowing mechanical attachment at the head of the streamer.

Head Auxiliary Unit and Head Auxiliary Power Unit (HAU-428 AND HAPU-428)The HAU-428 assures the following functions:- TLFOI power supply.- Power supply to the first Acquisition Line Sections.- Measurement of the tensile stress.- Telemetry leakage measurement.- HV and telemetry switching for easy troubleshooting.The HAPU-428 performs the same functions, plus 28-V or 50-V, 30-W power supply for the head buoy, and consumption monitoring.

HESE, Radial Stretch, Tail Elastic Section (TES), RVIMElastic sections used to mechanically uncouple the active streamer from the towing vessel or the tail buoy acoustic vibrations.

Sentinel Solid Acquisition Section (SSAS), or Acquisition Line Section (ALS-Fluid)With a length of 150 m, an SSAS or ALS acquires data from 12 channels with a 12.5-m typical spacing.The typical channel arrangement in an SSAS features one overlapping hydrophone.

TAPUHAPU HESE HESASHSOptical link ALS LAUMALS ALS ALS TES STIC TBJ

Head Buoy

with Tail Swivel

Lead-in

or HAU-428

Tail Buoy

FDU2MTrace1 Trace2 Trace3 FDU2M Trace4 Trace12ALS

Trace1 Trace2 Trace3FDU2F Trace4 Trace12SSAS FDU2F

ALS

HLFOI TLFOI

428

TAIL AUXILIARY AND POWER UNIT (TAPU)

TheTAPUassuresthefollowingfunctions:-completionofthetransmissionlines(incaseoftelemetryredundancy)-40-V,30-Wpowersupplyforthetailbuoyandconsumptionmonitoring.

STREAMER-TO-TAIL INTERFACE CABLE (STIC)

TheSTICisa25-mlongsectionequippedwithabreakablelink,orfuse,tointerfacethestreamerwiththetailbuoy.

TAIL BUOY JUMPER (TBJ)

A24-mnon-pulling,non-elastic,small-diametercablefromtheSTICtotheelectronicsonboardthetailbuoy.

MAINTENANCE EQUIPMENT

SST

Standalonetesterforalltypesofactiveacquisitionsections.Testsinclude:-Instrument-Sensor-Telemetry-Insulation-Continuity-Polarity-EEPROMcoherencycheck

SHIPBOARD EQUIPMENT

RECORDING (BASIC CONFIGURATION)

Format: 4byte,SEG-DRev.1.0or2.1 demultiplexed,32bitIEEE,code8058

Tapemedia: Upto6drives,simultaneousand alternated modes Drivemodel:3590modelB,E,H,DLT, LTOIBM3580,3592

Ethernetmedia: FTPorNFSprotocol

Simultaneousmultiple streamers: Unlimited(dependingonserverperformance)Maximum number ofseismicchannels: NotlimitedbySercelshipboardhardware

Maximumrecordingcapacityperstreamerwithtelemetryredundancy: 960channels@12.5m,2ms (Typical@2ms,dependingonsignal typeandcompressionratio)

Maximum recordlength: -47s@2msinnavigation-triggered acquisitionmode -Unlimitedincontinuousacquisition mode(dependingonserverhardware configuration)

Samplingrate: 1/4ms,1/2ms,1ms,2ms,4ms

Maximum number ofauxiliarychannels: 60analog.Gundigitalauxiliary channels unlimited

DCXU-428

- Ethernetconnectiontotheserver- Built-inhigh-voltageconverter(powersupplytostreamer)- Remote or local operations- ConnectiontoDecksafetydevices(Emergencystop,warninglights)

- ConnectiontotheStreamerthrougha2-mDeckcableAdaptorprovidedintheDCXU-428accessorykit

- PropagationoftheGPSreferencetime- Auxiliarypairconnection(bird,acoustic,modem,)- NAUTILUSspecificconnectoravailableOutputvoltage: from100VDCto600VDC (limitedto365VDCbytheSeal428software)OutputCurrent: Max.2.5ASafetyfeatures: Currentlimitation,HighVoltageleakage measurementWidth: 19(482.6mm)Height: 2U(89mm)Length: 580mm(withouttherearpanelconnectors)Weight: 18kg

LCI-428

- Ethernetconnectiontotheserver- Receivingnavigationmessage(ifusingserialcommunications)- ReceivingaphysicalT0(pulse)- LowLineportforconnectinganauxiliaryline(AXCU)- SynchronizedwithGPStimeserverconnectedtoXDEV2connector.

Width: 19(482.6mm)Height: 2U(89mm)Length: 420mmWeight: 4.1kg

GPS TIME SERVER

- Acquisitionsynchronizationbetweenstreamers.- Synchronizationofacquisitionandnavigationsystemsincontinuousacquisitionmode

Width: 19(482.6mm)Height: 1U(44.5mm)Length: 320mm

DECK CABLES

Length: Upto100m.

STORAGE AND OPERATING TEMPERATURES (SHIPBOARD)

Storage: 15Cto+55C(5to131F)Operating: +5Cto+40C(41to104F)

Specifications

IN-SEA EQUIPMENT

STANDARD LEAD-IN CABLE

Opticaldatatransmission

CableBreakingstrength 3options:300kN;470kN;570kNMaximumlength 1500m

HAU-428

- 50VDC(+/-25VDC)powersupplyforactivechannelsforthetwolines.

- Tensileloadmeasurement(0to70kN)- HighVoltageLinesandtelemetryswitches- HighVoltageLinesmix.Connectors: standardSealdia.70mmOutsidediameter: 81mmLength: 277.5mm

HAPU-428

- 50VDC(+/-25VDC)powersupplyforactivechannelsforthetwolines.

- Tensileloadmeasurement(0to70kN).- HighVoltageLinesandtelemetryswitches.- HighVoltageLinesmix.- Factory-configurableHeadBuoyConnectorpin-outHeadBuoypowersupply: 50VDC/32Wor28V/32Woutputpower Currentmeasurement ON/OFFbyremoteoperations

LINE ACQUISITION UNIT MARINE (LAUM)

Functions: -Datapre-processing -Datarouting -PowerdistributionPhysicalspecifications:-Mass/weightinseawater:1kg(2.2lbs) - Maxspacingalongthecable:750m@12.5m@2ms -Outsidediameter:53mm -Length:350mm

FDU2F/FDU2M

Functions: -DatatransmissionwithCRCcontrol 24bitsA/Dconversion -D/Aconversionwithprogrammablebit streamFullScaleInputLevels: @G1600:1.6VRMS @G400:400mVRMSOffset: 0(digitallyzeroed)LowCutFilter: Analog3Hz (@20C,1barmatching5%) 2-HzoptionavailableforSSASsectionsHighCutFilter: 0.8FN(linearorminimumphase)StopBandAttenuation: >120dB(aboveNyquist)SampleRates: 4,2,1,0.5,0.25msWordSize: 24bits.TimeStandard: Truesynchronoussystem

PERFORMANCE*

Noise(3-200Hz): @G1600:700nVRMS @G400:200nVRMSInstantDynamicRange: 124dBSystemDynamicRange: 136dBDistortion: -105dBGainAccuracy: 170kN >170kNTerminatedUTS >115kN >115kNOperatingtension upto58kN upto58kNStreamerlength@5knots upto15.75km upto15.75kmBallastfluidcapacity N/A N/ADragofa12kmStreamer 39kN@5knots 36kN@5knotsMaximumRetrievalTension 100kNOperatingtension upto30kN upto30kNStreamerlength@5knots upto12km upto12kmBallastfluidcapacity 200l 200lDragofa12kmStreamer 30kN@5knots 30kN@5knotsMaximumRetrievaltension