aa mid system requirements...

Name Designation Affiliation Date Signature

A.W.Gunst

A.Faulkner

AAdomainspecialist

Systemengineer

SPDO

AAVP

20111115

20111115

ApprovedforreleaseaspartofSKAAAdCoDRdocuments:

K.Cloete ProjectManager SPDO 20111115

AAMIDSYSTEMREQUIREMENTSSPECIFICATION

Documentnumber.................................................................WP2015.020.010SRS001Revision...........................................................................................................................DAuthor...............................................................................................................SeebelowDate.................................................................................................................20111114Status........................................................................................................................FINAL

brinkStamp

BrinkAndreG

WP2010.020.020SRS001 Revision:D

20111114 Page2of52

DOCUMENTHISTORY

Revision DateOfIssue EngineeringChangeNumber

Comments

A 20111003 Firstdraftreleaseforinternalreview

B 20111021 CommentsIlseincluded

C 20111109 Commentsincludedaftertelecondiscussion

D 20111114 Release

DOCUMENTSOFTWARE

Package Version Filename

Wordprocessor MsWord Word2007 02WP2015.020.010SRS001D_AAMidReq.docx

ORGANISATIONDETAILS

Name SKAApertureArrayVerificationProgrammePhysical/Postal

AddressASTRONOudeHoogeveensedijk4P.O.Box27990AADwingelooTheNetherlands

Fax. +31(0)521595144Website www.skatelescope.org

WP2010.020.020SRS001 Revision:D

20111114 Page3of52

LISTOFABBREVIATIONS

AA-Mid ....... Aperture Array for mid-frequencies

AC .............. Alternating Current

ADC ........... Analogue to Digital Converter

ADD ........... Architectural Design Document

CI ............... Configuration Item

CMS ........... Configuration Management System

COAR ......... Consolidated Observation Action

Register

CoDR ......... Concept Design Review

dB ............... Decibel

deg ............. degree

DRM ........... Design Reference Mission

DC .............. Direct Current

EM .............. Electro Magnetic

EMC ........... Electromagnetic Compatibility

EMI ............. Electromagnetic Interference

FAT ............ Factory Acceptance Test

FCA ............ Functional Configuration Audit

FMECA ...... Failure Modes, Effects and Critically

Analysis

FOV ............ Field of View in squared degrees

GHz ............ Giga Hertz

Hz ............... Hertz

HFE ............ Human Factors Engineering

HPBW ........ Half Power Beam Width

HPC ........... High Performance Computing

IEC ............. International Electrotechnical

Commission

IEEE ........... Institute of Electrical and Electronics

Engineers

ITU ............. International Telecommunications Union

ICD ............. Interface Control Document

INCOSE ..... International Council on Systems

Engineering

ISO ............. International Standards Organisation

Jy ............... Jansky

K ................. Kelvin

Kg ............... kilogram

km .............. kilometre

LEMP ......... Logistic Engineering Management Plan

LO .............. Local Oscillator

LOFAR ....... Low Frequency Array

m ................ metre

M&C ........... Monitoring and Control

MHz ........... Mega Hertz

MIL-STD .... Military Standard

MTBF ......... Mean Time Between Failures

MTTR ......... Mean Time To Repair

OAR ........... Observation Action Register

OEM ........... Original Equipment Manufacturer

OICD .......... Operator Interface Control Document

PAF ............ Phased Array Feed

PCA ........... Physical Configuration Audit

PDR ........... Preliminary Design Review

PEMP ......... Power Engineering Management Plan

PITF ........... Power Investigation Task Force

PPR ........... Pre-production Review

PrepSKA .... Preparatory phase for the SKA

RAM ........... Reliability, Availability and

Maintainability

RAS ........... Radio Astronomy Service

RFI ............. Radio Frequency Interference

RMS ........... Root Mean Square

RQZ ........... Radio Quiet Zones

SAT ............ Site Acceptance Test

SEMP ......... System Engineering Management Plan

SI ............... Systme International d'units

SKA ............ Square Kilometre Array

SKADS ....... SKA Design Studies

SPDO ......... SKA Program Development Office

SRR ........... (Sub)System Requirements Review

SRS ........... System Requirements Specification

SS .............. Survey Speed

SSEC ......... SKA Science and Engineering

Committee

STaN .......... Signal Transport and Networks

TBC ............ To Be Confirmed

TBD. ........... To Be Determined

TBV ............ To Be Verified

TRR ........... Test Readiness Review

V ................ Volt

WBS ........... Work Breakdown Structure

WP ............. PrepSKA Work package

1 IntroductionThisdocumentcovers theSystem requirements for themid frequencyApertureArray for theSKAPhase2,SKA2.ItispartofthesystemsengineeringdocumentsetforthedeltaconceptdesignreviewforSKAAAmid.

TherequirementsourcesarefromtheSKA2DRM[5]andthetechnicalevaluationstakingplace.

Notes:

1. Commentsareinreditalics

2. TBDsetcarejustinred

3. IhavecreatedtheneedforaTechnicalRequirementsdocumentthatderivesdetailsofthesystemrequirementsforAAsgiventheparametersfromthescienceandotherrequirementsdocs....

4. ThereneedstoanOperationsdocumenttoreference.

5. SomeoftherequirementswillneedtobefedbackuptotheSystemSRS

6. Thereisverylittleuseofstandardsintherequirementsthisneedstobefixed

7. ReallythisshouldbeoperatingunderISO9001qualitystandards

8. ThereferencesarenowusingWordsstructureforthem.

WP2015.020.010SRS001Revision:D

20111114 Page5of52

2 References

[1] Cloete,K.,et.al.,SKASystemRequirementsSpecification,Rev.E,WP2005.030.000SRS001,20100212.

[2] Stevenson, T. et. al., SKA Phase 1 System Requirements Specification, Rev. A, WP2005.030.000SRS002,20110214.

[3] SKA ScienceWorking Group, The Square Kilometre ArrayDesign ReferenceMission: SKAPhase1,report,v.1.3,January2011.

[4] Dewdney, P.E. et. al., SKA1:High Level SystemDescription,Rev.A.,WP2005.030.010TD002,20110214.

[5] SKAScienceWorkingGroup,TheSquareKilometreArrayDesignreferenceMission:SKAmidandSKAlo,report,v.1.0.


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3 FunctionalandperformancerequirementsTheserequirementscoverAAmidforSKAPhase2.TheserequirementsarespecifictoAAmidandflowdownfromthesciencecasesintheSKADRM1.0[5].

3.1 Functionaloverview

The top level context diagram for the AAmid Reception is shown in

Figure1,thesearethesameforallAAsintheSKA.ThisispartofthesecondleveloftheSKAcontextdiagramaspresented in [2].From this figure it isclear that theAAmid requirementsaredirectlyinfluencedbythefollowingexternalaspects(bluearrows):

RFSignal:thesignalofinterestreceivedbytheAA

RFInterference:anyhumanmadedisturbingsignalwhichisalsoreceivedbytheAAandforwhichthesystemshouldbemaderobust

Maintenance:thedesignoftheAAreceptionsystemshouldtake intoaccounttheaffect ithas onmaintenance since the total amount of electronics in the fieldwill be significant.Hencemaintenanceshouldbeminimizedandanyextrainvestmenttoachievethatmustbebalancedagainstthereductioninmaintenancecost.

Environment: the environment of the AA poses extra requirements on primarily themechanicaldesignoftheantennaelementandreceiversystems, installationofcablesandbunkers necessary for the AA system. Examples of environmental influences are dust,


20111114 Page7of52

temperature (and its variation), humidity and soil composition. The soil composition hasmechanicalimplicationsandastronginfluenceontheelectricalgroundingoftheantennas.

Recycling:sincetheSKAhasalimitedlifetimetheusageofmaterialswhichcanberecycledmaybeofrelevance.

Weather: the AA reception systems should be designed to withstand rain, lightning,earthquakes,hail,snowetc.dependentontheweatherprofileofthesite.

In

Figure 1 the internal SKA interfaces are shown in black. These interfaces are required for AAreceptiontoworkproperly.Thefollowinginternalinterfacesaredefined:

Networking:viathis interfacethedatafromtheAAreceptionsystem istransportedtothecentralsystemstobefurtherprocessed.

Monitor&Control: via this interfacemonitor information like status reports from all thesubsystems in the AA reception system are communicated in one direction, while thecontrol of the AA reception system is done in the other direction. Control of the AAreception system isnecessary since therearemany settings:beam steering, selecting thefrequencybands,etc.

Sync&Timing:via this interface thesynchronization, timingandeventuallyLOsignalsareretrievedfromacentralsystem.Forradioastronomicalsystemsoneofthemostimportantaspects istosynchronizeallAAreceptionsystemswitheachothersincethephaserelation


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betweentheAAstations isaprimaryparameterwhichshouldberetrieved.TypicalsignalsrequiredbytheAAreceptionsystemare:clocksignaltosampletheanaloguesignalandasynchronisationsignale.g.apulsepersecondsignaltoalignallAAreceptionsystems.

AAReceptorCooling:coolingisnecessaryprimarilybecausetheamountofsignalprocessingrequired in theAA reception systems is significant and the environmental conditions arelikelytobehot.

AAReceptorPower:ThisinterfaceisdefinedtopoweralltheelectronicsintheAAReceptionsystem.

Figure1ContextdiagramoftheAAReceptionsystem(level2)


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Considering in more detail the AAmid Reception context diagram of

Figure1resultsinthethirdlevelcontextdiagrampresentedinFigure2.


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AA Monitor &Control

EM WavesReception

Beamforming&

Filtering

Beamforming&

Correlation

AA ReceptionCooling

AA ReceptionPower

Generation

DigitizingAmplification

AA Calibration

RF Signal

To All

Monitor&

Control

Sync&

Timing

Networking

RF Interference

Level 2 interfaces not drawn has an interface to

all functionalities

Figure2ContextdiagramoftheAAReceptionsystematlevel3

AsshowninFigure2theprimaryfunctionsoftheSKA1AAmidreceptionsystemare:

1) EMwavesreception:theelectromagneticradiationisconvertedintotheelectricaldomain.

2) Amplification: thisboosts the signal fordigitisationand reduces thenoisecontributionoflaterstages.

3) Beamforming & Filtering: adds optionally multiple antenna elements with an analogbeamformer and filters out the frequencies outside the AAmid specification. In practicemultipleamplifierandfilteringstageswillbeimplemented.

4) Digitizing:theanaloguesignalissampledandquantized.

5) Beamforming&Correlation:inthebeamformingphasethesignalsofmultiplereceptorsarecombinedinordertomakebeamsonthesky.Acorrelationfunctionisrequiredtocalibrateall the individual receiver chains with each other to compensate for gain and phasevariationsbetweenthemasafunctionoftime.

6) AACalibration:calculatesthegainandphasedifferencesbetweenreceiverchainsandusestheoutputofthecorrelationfunctionalityasaninput.

7) AA Monitor & Control: translates high level system control information to specificcommandsfortheAAhardwareandsoftware.Themonitor informationfromthesoftwareandhardwareistransmittedtotheSKAMonitor&Controlsystem.ThissystemalsoenableslocalcontroloftheAAstationformaintenanceandtroubleshootingactivities.

8) AAReceptionPowerGeneration:powerisgeneratedorretrievedfromacentralnode.


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9) AAReceptionCooling:maintainsthetemperatureofallpartsoftheAAmidstationwithinspecificationlimits.

3.2 AAmidspectralcharacteristics

ThespectrumtobeobservedwithSKA1AAmidisspecified.

3.2.1 OperatingFrequency

Identification Requirement Applicability Parent Verification

AAM_REQ_1110 Electromagneticfrequencyrange.

AAmidshallbeabletomeasureelectromagneticradiationinafrequencyrangefrom:

Essential Test

400MHzto1450MHz LowerboundaryfromSection16.4.2and17.4in[5].ThehigherboundaryisfromSection12.4.1[5],1450MHzistakensinceneutralhydrogenisat1421MHz.

3.2.2 InstantaneousBandwidth


AAM_REQ_1120 Instantaneousbandwidth.AAmidshallhaveaminimuminstantaneousbandwidthof:

Essential Test

1000MHz

[5]Section1.4,fractionalbandwidth~1

3.2.3 SpectralFlatness

Identification Requirement Applicability Parent Verification/Comments

AAM_REQ_1130 Spectralripple.Thepassbandrippleovertheband,aftercalibration:

Essential Test

Maximum+/1%(TBD).

Notethatthisisnottheanaloguesystem,butafterdigitisationandprocessing.Theonlycharacteristics

[2]SYS_REQ_1190 Theparentisnotveryspecific.


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theanaloguechainrequiresistodeliverasignalwithinboundstotheADC,stabilityandbecapableofmeasurementforcalibration.

3.2.4 SpectralPassbandSlope

Identification Requirement Applicability Parent Verification/Comments

AAM_REQ_1135 Spectralpassbandslope.Thepassbandslopeoverthebandshouldbe:

Essential Test

MaximumxdB(TBD).

Notethatthisistheanaloguesystem,priortodigitisation.ThiscanbecalibratedoutbutdecreasestheSignaltoNoiseRatio.

3.2.5 SpectralResolution

The following requirementsare for theAAmidstationonly.This iswhenusing frequencydomainbeamformingandisnecessarytomeetthesizeandspacingoftheelements.Thespectralfiltermustalsotransmitthedatasuchthatthecorrelatormayfurthersubdividethedata intomuchnarrowerbands required for correlation.The final required SKA spectral resolution shouldbemadeby thecentralsystems.


AAM_REQ_1140 Spectralresolution.

TheAAmidstationshallhaveaminimalspectralresolutionoverthefullinstantaneousbandwidth(TBV):

Essential Test

1MHz(TBD)

[5]Table12.2requiresresolutionbeforecorrelationof3kHz

3.2.6 SpectralDynamicRange


AAM_REQ_1150 Spectraldynamicrange.

SKAshallhaveaminimumspectraldynamicrangeattheoutputofthecorrelatorof:

Essential Test

62dB [1] Paragraph3.3.5,changed1400to


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1450MHztoenablesurveysofneutralhydrogenat1421MHz.

3.2.7 Clipping

Thedynamicrangeoftheelement(orTile)uptodigitisationispartlysetbytheeffectivenumberofbits, ENOB, of the digitiser. This is ameasure of the ability to copewith interference and largeastronomicalsignals;itisnotameasureofthedynamicrangeofthearrayitselfortheimagesthatgetproducedafterprocessing.

It is not practical to expect to precisely digitise every possible interference signal, however,statisticallytheamountofobservingtimelostduetoclippingcanbedetermined.


AAM_REQ_1160 Clipping. Essential Test

ThedynamicrangeoftheADCsshallbesuchthatnoclippingwilloccurfor95%(TBC)ofthetime.

[2]SYS_REQ_5430

Theparentrequirementneedssomechangessinceitspecifiesnoclipping

AAM_REQ_1165 Clippingdatashouldbemarkedinthedatastream

Essential [2]SYS_REQ_5430

3.3 AAsensitivity,FOVandsurveyspeed

3.3.1 Sensitivity


AAM_REQ_1210 Sensitivity(Aeff/Tsys).

TheAAreceptorsystemshallhaveaminimumsensitivityforscananglesofmaximal45degrees(TBD)of:

Essential Test

10,000m2/KexpressedinStokesI.

This is equivalent with the sensitivity which is required for one polarisation.

[5]Section18,Table18.2(DRMChapters6, 7, 8, 15 and 17)


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3.3.2 InstantaneousFieldofView


AAM_REQ_1220 Instantaneousfieldofview.

TheSKAshallachieveaminimumtotalFOV(thatcanbesynthesizedfrommultiplebeams)of:

Essential Test

100squaredegrees

Thefieldofviewisderivedfromthesurveyspeedandsensitivity.

3.3.3 SurveySpeed


AAM_REQ_1230 Surveyspeed.

AAmidshallhaveasurveyspeed(m4K2deg2):

Essential Test

1010m4K2deg2 [5]Section12.4.2

3.4 SpatialCharacteristics

3.4.1 BaselineRequirements


AAM_REQ_1310 Baseline.

Themaximumbaselineis:

Essential Test

180km(TBD) [4]

3.4.2 SkyCoverage


AAM_REQ_1320 Skycoverage. Desirable Test

6000deg2(TBD)

3.4.3 ScanAngle

Thisrequirementisderivedfromtheskycoverage.


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AAM_REQ_1330 Scanangle.

Thescanangleisdefinedfromzenith.ThemaximumscanangleforSKAshallbeatleast:

Test

45degrees(TBD) Desirable

3.4.4 Corefillingfactor


AAM_REQ_1340 Corefillingfactor.

Thefillingfactorofthecoreshouldbeatleast:

Essential Analysis

?%

3.4.5 StationSideLobes


AAM_REQ_1350 Stationsidelobes.

Theintegralofallstationsidelobesshouldbesmallerthan

Essential Analysis

?dBcomparedwiththemainlobe.

3.5 SystematicErrors

3.5.1 CoherenceLoss

Anycoherencelossinthesystemintroducedshouldbebelowthevaluespecifiedbelow.Anexampleofacoherence losseffect is thebeamsquintwhich iscausedbyabeamformerusingphaseshift.Sinceonlyonephaseshiftsettingpersubbandorchannelcanbesetanerrorarisesattheedgesofthesubbandorchannel.Theerrorcausescoherencelossinthebeamformerandshouldstaybelowthespecifiedvalue.


AAM_REQ_1410 Coherenceloss. Essential Test


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ThecoherencelossofeachsubsystemintheSKAshouldbelowerthan:

1%(TBD) Shouldbederivedfromtheimagingrequirementifpossible.

3.5.2 PositioningError


AAM_REQ_1420 Positionerror.

Thepositionerroroftheallantennaelementsfromthespecifiedpositionshouldbesmallerthan:

Essential Test

TBD

Notethatthiswilldependonthearrayconfigurationusede.g.randommaybeverytolerantoferrorscalibrateout.

LOFARuses/40

3.5.3 OrientationError

Theorientationof the elements is consideredwithinone array.Array to arrayorientation is thesubject of the System SRS (2). It is necessary to orientate the elements for consistency ofpolarisation,however,itmaybeeasiertocalibrateoutdetailederrors.


AAM_REQ_1430 Orientationerror.

Theorientationerroroftheantennaelementsfromthespecifiedorientationshouldbesmallerthan:

Essential Test

TBD

Thiswilldependontheabilitytocalibrateindividualelements

LOFARuses1degree

3.6 TemporalCharacteristics

The stability of the analogue systems directly impacts the calibration requirements and theirregularity.Theyneedtobetradedofftogether.


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3.6.1 GainStability


AAM_REQ_1510 Gainstability.

ThegainstabilityofeachSKAreceiverchainwhichisdigitizedshouldbesmallerthan:

Essential Shouldbederivedfromacalibrationrequirementifpossible.

Test

StabilityperC: 0.5%(TBD)

over24hours: 0.5%(TBD)RMS

ataconstanttemperature

3.6.2 PhaseStability


AAM_REQ_1520 Phasestability.

ThephasestabilityofeachSKAreceiverchainwhichisdigitizedshouldbesmallerthan:


Test

DegreeperC: 0.5deg(TBD)

over24hours: 0.5deg(TBD)RMS

ataconstanttemperature

3.6.3 BeamStability


AAM_REQ_1530 Beamstability.

TheSKAshallhaveamaximalRMSstabilityintheHPBWof:


Test

over24hours: TBD%RMS

withazenithpointingdirection

TBD%RMS(TBD)withazenithpointingdirectionifonereceiverchainisfailinginthefullbandforSKA


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3.6.4 Smoothness


AAM_REQ_1530 Smoothness.

AnyvariationintheSKAsystemshallbesmootherthan:


Test

0.01%persecond(TBD)

0.1%/Hz(TBD)overtheinstantaneousbandwidth

Thisneedsmuchmorethought......

3.6.5 TrackingAccuracy


AAM_REQ_1540 Trackingaccuracy.

Thebeampointingaccuracyshouldbesuchthat:

Essential (2)SYS_REQ_1980 Test

ApointsourceremainswithinTBD%oftheHPBWofthebeam.

Presumablythisrequirementisduetothefrequencydependantnature.Evenso,itmaywellbethatafigureindegreesfortheAAmidisbetter.

3.6.6 BeamSwitchingAgility


AAM_REQ_1550 Beamswitchingagility.

Thebeamswitchingtimeincludesthedistributionofthecommandfromthecontrolcentre.

Abeamshouldberepointedtoapredefinedpositionin:

Essential TBD Test

TBDsecs.


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3.6.7 MaximalObservationPeriod


AAM_REQ_1560 MaximalObservationPeriod.

TheAAsubsystemshallbedesignedsothatadeepfieldobserved.Therequirementismaintainnoiselimitedsensitivity.


Capableof1000hrintegrationtime

3.6.8 TemporalResolution


AAM_REQ_1560 Temporalresolution.

TheAAsubsystemshallhaveanattainabletimeresolutionofatleast:

Essential Test

50s [5]Paragraph16.4.4

3.7 PolarisationCharacteristics

3.7.1 BeamPolarizationStability


AAM_REQ_1610 Beampolarizationstability.

Thepolarisationpropertiesofthebeamsshallbestableenoughtoenabletheircalibrationto:



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AAM_REQ_1640 Beampolarizationpurity.

Theisolationbetweenbothpolarisationsshallbeatleast:

Essential Test

40dB(TBD)

See[5]Paragraph17.4.5

3.8 ImagingCharacteristics

3.8.1 UVCoverage

Ident Requirement Applicability Parent Verification

AAM_REQ_1710 UVcoverage.SKAshallhavea:

Essential UV coverage isnotdefinedgoodatthemoment

Analysis

3.8.2 ImagingDynamicRange

STATIONDYNAMICRANGEThishastobetranslatedintoAAstationrequirements.Theimagingisasystemwide requirement dominated by the post processing the tech requirements of the AAstationisdeterminedhere.


AAM_REQ_1720 Imaging dynamic range.SKA shallbeable toprovidean imaging dynamic rangefor continuum imaging(thermal noise imaging toclassical (micro Jansky (Jy))confusionlimits)ofatleast:

Essential Test

74dB [5]Paragraph6.4.5

3.9 MonitoringandControl

MonitoringandControl isacentral system responsible foracquiringandmonitoringdataand forcontroloftheSKAsystems.TherequirementsinthissectionreflecttheconsequentrequirementsfortheAAreceptionsubsystems.


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3.9.1 M&CMonitoringData


AAM_REQ_2110 M&Cmonitoringdata.

AAsubsystemsshallprovidemonitoringdatatothemonitoringandcontrolfunction(forperformancemonitoringandclosedloopcontrolfunctions)

Thiswillneedsubstantialexpansion.

Essential (2)SYS_REQ_2220 Demo

3.9.2 M&CCalibrationInformation


AAM_REQ_2120 M&Ccalibrationinformation.

IndividualAAsubsystemcalibrationinformationshallbeavailabletothemeasurementfunction.

Thiswillneedsubstantialexpansion.


3.9.3 SubsystemM&CAction


AAM_REQ_2130 SubsystemM&Caction.

AAsshallreportcompletionofactionstoM&C


3.9.4 AutonomousControl

Thisistoprovidemaintenanceandtroubleshootingcapabilities.Allthefunctionsavailablecentrallywillbeavailableatalocalstationinterfacee.g.powerupanddown,parametersettingandreportingandotherdiagnostictools.


AAM_REQ_2140 AutonomousControl.

TheAAstationshallbecapableofcomingunderlocalcontrolandnotinteractingwiththeoverallSKA.

(2)SYS_REQ_3620 Demo


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3.9.5 Calibration

ThecalibrationoftheAAsisimportanttotheiroperation.Thedetailsoftheschemeusedneedstobedefined: theycouldbecalibratedusingexternalsources;astronomicallywhilenotobservingorduringobservationsusingaseparatebeam.


AAM_REQ_1620 Calibrationupdaterate.

ExternalCalibrationmeasurementsshallbenecessaryatarateof:

Essential (2)SYS_REQ_1720

Thisdependsontherequiredprecisionandtherategainandphasearechangingasafunctionoftime.

Test


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AAM_REQ_2220 Aggregatemode.

SKAshallprovideanaggregatemodeinwhichbandwidthisexchangedforspatialcoverage.


AAM_REQ_2225 Selectablenumberofbitspersample.

Thenumberofbitspersampleusedshouldbeselectablewithintheconstraintsofaconstanttotaloutputdatarate.

Thisneedsascientificreasonforprovidingite.g.pulsarobservations

Desirable TBD Demo

3.11 DataProducts

3.11.1 Totaloutputdatarate

The output data rate, station to correlator, defines the survey capabilities of the array. It alsodetermines therequirementsof thecorrelatorandpostprocessor.Theaggregatedatarate foralltheAAmidstationsisconstantforagivensensitivityandsurveyspeed,howevermanystationsareused.


AAM_REQ_2305 Datarate.

TheaggregatedatarateofallAAmidstationsshouldbe:

Essential TBD Demo

Totaldatarate:TBD

Thisisafunctionofsensitivityandsurveyspeed

3.11.2 BeamProducts


AAM_REQ_2310 Beamproducts.

AAmidshallbecapableofcommunicatingthebeamproductsasavoltagetimeseriesovertheobservedFoV.

Essential (4)Paragraph5.4.6 Demo

3.11.3 DataProductTypes



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AAM_REQ_2320 Dataproducttypes.

TheAAshallproducerecordableintermediatedataproducts.

forexamplepulsarvoltagetimeseriesandRFIstatistics.

Whatisthis?ThisisnotreallyanythingnewaboutAAsthisisallderivedfromthebeams.RFIdataisnotanintermediatedataproduct.

Perhapsclippingdata,calibrationcorrection,beamformerweights.


4 Operationalrequirements4.1 General

4.1.1 Uptime


AAM_REQ_2410 Uptime.

AAmidshallbedesignedtobeoperatedcontinuously,otherthanforregularmaintenance.

Thisneedsqualificationwhataboutmaintenance?


4.1.2 ReconfigurationTime


AAM_REQ_2420 Reconfigurationtime.

ReconfigurationtimeforAAmidfromoneobservationalmodetoanother:



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AAM_REQ_2430 Startupsequence.

ThestartupofAAmidfunctionsshallfollowapredefinedsequencetakingnotlongerthan:


Hotstart: 10minutes

Thisisarestart

Coldstart: 24hours

Acoldstartisdefinedasrequiring.....

4.2.2 ShutdownSequence


AAM_REQ_2430 Shutdownsequence.

TheAAstationswilluseacontrolledshutdownprocess.


4.2.3 AAmidAutonomousShutdown


AAM_REQ_2440 AAautonomousshutdown.

AnAAmidstationshallbecapableofautonomouslydetectingconditionsrequiringstationshutdowne.g.poweranomalies,overtemperature,coolingfailureetcandthenshuttingdownandreportingtheconditiontothecentralM&Csystems.

ThisimpliesaseparatelypoweredM&Csystemthatiskeptalivewhatifthatneedspoweringdown?

(2)SYS_REQ_3190 Test

4.2.4 StartupandShutdownIndividualAntennaSystems


AAM_REQ_2440 StartupandshutdownindividualAAmidstations.

ItshallbepossibletostartuporshutdownindividualAAmidstationsandcommunicatestatustotheM&Csystems.



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4.2.5 StartupandShutdownDependencies


AAM_REQ_2450 Startupandshutdowndependencies.

Anydependenciesinthestartupandshutdownsequencesshallbeautomaticallyverified(sotheydonotdependonoperatorintervention).

Essential (2)SYS_REQ_3220 Inspection

4.2.6 SubsystemShutdown


AAM_REQ_2460 Startupandshutdowndependencies.

TheshutdownofpredefinedpartsofAAmidstationsshallhaveno(TBC)impactonSKA1operationsafterappropriaterecalibrationperformedautomatically.

Thiscannotbecompletelytruee.g.sensitivitywillbelostorgainedjustqualifywithsignificantly?


4.2.7 InitialCheckout


AAM_REQ_2470 Initialcheckout.

AAmidshallbedesignedtoenableanoperationalreadinesscheck,includingredundancies,priortocommencementofanySKA1operations(initialcheckout).


4.2.8 OperationalReadinessCheck


AAM_REQ_2480 Operationalreadinesscheck.

TheAAmidoperationalreadinesscheckshalltake:


>5minutes.


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4.3 FailureManagement

4.3.1 General


AAM_REQ_3310 Personnelsafety.

Asfaraspossible,nosinglefailureinAAmidshallleadtopersonnelsafetyhazards.

Thisseemsverymildsurelyitshouldcopewithsomelevelofanticipatedfurtherfailuremodes.Suggestion:takesingleoutandchangeto:asfarasreasonable,nofailures...

(2)SYS_REQ_3310


AAM_REQ_3320 Failurepropagation.

FailuresintheAAmidsubsystemsshallnotleadtofailuresinotherAAsubsystemsorotherSKAsystems.

(2)SYS_REQ_3320


AAM_REQ_3330 Operatorcommandsafety.

NosingleoperatorcommandforAAmidshallcausecatastrophic,serious,ormajorconsequences.

(2)SYS_REQ_3330


AAM_REQ_3340 Voltagetransientconsequences.

Novoltagetransientsor"cutoff"ofelectricalpowershallleadtocatastrophicorseriousconsequencesinAAmid.Thisincludesvoltagetransientsappliedtotheinputofthereceivers.

(2)SYS_REQ_3340


AAM_REQ_3350 Operatorcommandabsence.

Theabsenceofoperatorcommandsshallnotcausecatastrophicor

(2)SYS_REQ_3350


20111114 Page28of52

seriousconsequences.


AAM_REQ_3360 Singlepointfailures.

SinglepointfailuresintheAAmidshallbelistedinthedesignandoperationaldocumentation.

(2)SYS_REQ_3360


AAM_REQ_3370 Singlepointfailurejustification.

EachsinglepointfailurelistedfortheAAmidshallbejustified,andassessedagainstalternativedesign(s)wherethissinglepointfailurewouldnotoccur,ifpossible.

(2)SYS_REQ_3370

4.3.2 DetectionandReporting


AAM_REQ_3520 Statusreportavailabilitytime.

TheavailabilityofastatusreportofthefunctioningofAAmidshallbein:

(2)SYS_REQ_3520

5seconds

Thisistoogenericarequest,howmuchstatus,inwhatdetailetc?


AAM_REQ_3530 Statusreportrequest.

Thestatusreportofasubsystemshallshowthefunctioningofthesubsystematoraftertheoperatorrequesthasbeensubmittedtothesystem.

(2)SYS_REQ_3530


AAM_REQ_3540 Statusreportscope.

Thestatusreportshalldisplaythestatusofasubsystem,togetherwiththesystemtimethestatuswasdetermined.

(2)SYS_REQ_3540


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4.3.3 DiagnosisandRecovery


AAM_REQ_3610 Systeminterrogationreply.

EachAAmidstationshallhavethecapabilitytoansweranoperatorinterrogation.

Isthiswhatismeantorisitsubsystem?

(2)SYS_REQ_3610


AAM_REQ_3670 Autonomousrecovery.

AAmidshallbeabletorecoverautonomouslyincaseoffailuresthatareclassifiedasminorornegligible.

Wheretheclassificationoffailuresandwhatismeantbyrecovery?

(2)SYS_REQ_3670


AAM_REQ_3680 Effectofdisabledunits.

TheAAmiddesignshallensurethatdisabledunitsdonotcorrupttheobservationaldataintheremainingsystem.

(2)SYS_REQ_3680

4.3.4 Lifetime


AAM_REQ_3710 Continuousoperationperiod.

AAmidshallbedesignedforacontinuousoperationalperiodsof:

(2)SYS_REQ_3710

6months

Afterthistimemaintenancemaybenecessary,e.g.exchange/cleaningofairconditioningfilters.


AAM_REQ_3720 Minimumlifetime.

TheAAsubsystemshallbedesigned

(2)SYS_REQ_3720


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foraminimumlifetime(includinginitialinstallation,testingandcommissioningperiod)of:

TBDyears


AAM_REQ_3725 Supportequipmentlifetime.

AAmidsupportequipmentshallbedesignedtomaintainSKA1for:

(2)SYS_REQ_7960

12(TBC)years.


AAM_REQ_3730 Availability.

TheaverageavailabilityofallAAmidsubsystemsduringtheoperationalperiodshallbe:

(2)SYS_REQ_3730

>90%(TBC).

Availabilityisdefinedhereasbeingavailableforscheduledobservationsinatleastoneofthesupportedoperationalmodes.

Thisisfartooloose.Whatlevelofsubsystem?Boardthearraywouldneverbeinuse.Thestation?Thiswouldtakeintoaccountredundancyofelements


AAM_REQ_3740 Upgradeability

AAmidshallbeupgradable.

Thisisagainfartoovague.Anythingisupgradeabletoatrivialextent.Thisshouldbedefined...

(2)SYS_REQ_3740


AAM_REQ_3750 Lifetimeextension.

Largescalemaintenanceand/oranupgradeshallgivethepossibilitytoreachalifetimeof:

(2)SYS_REQ_3750

50years(TBC).

Thelevelofmaintenanceneedstobe


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specified,couldeextremeinthisspec.


AAM_REQ_3760 Reusability.

ReusabilityofAAmidequipmentshallbeensuredthroughdesignandcanbebyrefurbishmentandmaintenancewherethishasbeendemonstratedasbeingcosteffective.

(2)SYS_REQ_7940


AAM_REQ_3770 Spareparts.

AAmidsparepartsshallhaveastoragelifeconsistentwithavailabilityanduseduringthefulloperationallifetimeoftheSKA2equipmenttowhichitapplies.

ThisshouldbeSKAoverall

(2)SYS_REQ_7950

4.3.5 Reliability


AAM_REQ_7420 Fieldreturnrate.

Thefieldreturnrateofequipment,duringinstallationandthefirstyearfullusage,shallbe:

(2)SYS_REQ_7420

99.4%(TBC).

Thisisaveryconfusingspecification.Doesitmean1000years)?Orisittheoverall


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stationbeingkeptuptoperformancethroughmaintenance?

4.4 Maintenance


AAM_REQ_3840 Datalossduetopoweroutage

ThisspecdoesnotapplytoAAmiditisasystemparameter,thereisnosignificantdatastoredlocally.

TheAAsubsystemshallnotlosemorethan4hoursofacquiredorprocessedmeasurementdata(notyetpermanentlystored)asaresultofanoutageintheexternalpowersupply.

(2)SYS_REQ_3840

ThisrequirementsneedstoberewritteninordertobefeasiblefortheAAsubsystems


AAM_REQ_3850 Autonomousrestartafterpoweroutage.

AAmidshallhavethecapabilitytorestartautonomouslyandwithoutfailures,afteranoutageinexternalpowersupply.

HowdoesthisvaryfromAAM_REQ_3670?

(2)SYS_REQ_3850


AAM_REQ_3860 Systemavailabilityafterrestart.

AAmidshallbeavailablewithin5minutes(TBC)afterrestart.

HowdoesthisvaryfromAAM_REQ_2480?

(2)SYS_REQ_3860


AAM_REQ_3870 Software/firmwarereinstallation.

Allsoftware/firmwareinAAmidshallbecapableofbeingreinstalled

(2)SYS_REQ_3870


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AAM_REQ_3880 Software/firmwareupgrades.

Itshallbepossibletoreplaceallsoftware/firmwareconfigurationitemsinAAmidthroughsoftwareupgrades.

(2)SYS_REQ_3880


AAM_REQ_3890 Softwarecodeidentification.

Softwareconfigurationitemsshallprovideunambiguousidentificationtoallowthemaintenanceofaconfigurationmanagementdatabase.

(2)SYS_REQ_3890


AAM_REQ_3910 Softwarecodeidentificationresponsetime.

Thesoftwareidentificationrequestsshallbeavailabletotheoperatorwithin:

(2)SYS_REQ_3910

10seconds(TBC)

Whytheurgency?


AAM_REQ_3920 AAmaintenancefunctions.

TheAAmidshallincludefunctionsthatallowmaintenanceofhardwareandsoftware.

Thisisfartoowholly!Whatmaintenanceetc.

(2)SYS_REQ_3920


AAM_REQ_7820 Toolsandtestequipment.

TheAAmiddesignshallrequireandspecifyaminimumnumberofspecialtoolsandtestequipmenttoperformassembly,integrationandrepairandmaintenanceactivities.

(2)SYS_REQ_7820

(2)SYS_REQ_9110


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AAM_REQ_7830 Inaccessiblehardwaremaintenance.

Inaccessiblehardwareorstructuresshallrequirenomaintenanceduringoperationandshouldhavebuiltintestcapabilitywhenapplicable.

(2)SYS_REQ_7830


AAM_REQ_7840 Testandrepairinstructions.

TestandrepairinstructionsshallbewrittenforfaultdetectionandmaintenanceoftheAAmidequipment.

(2)SYS_REQ_7840


AAM_REQ_7850 Maintenanceteamsize.

Itshouldbepossibletoexecuteregularmaintenancejobswithnotmorethantwo(2)peopleperjob.

(2)SYS_REQ_7850

4.5 DisposalPhase


AAM_REQ_4110 Environmentalrulecompliancy.

TheAAmiddesignshallbefullycomplianttoallenvironmentalrulesapplicabletotheSKAsite.

Thisrequirementshouldbemuchmorespecific

(2)SYS_REQ_4110


AAM_REQ_4120 Lastingenvironmentaleffects.

AAmidshallbedesignedtohavenolastingadverseenvironmentaleffectsonthefacilityandsite.

Thisrequirementshouldbemuchmorespecific

(2)SYS_REQ_4120


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5 EngineeringDesignConstraintsThischapterspecifiesthedesignconstrainingrequirementsforengineering.

5.1 MaterialsandProcesses


AAM_REQ_7110 Materials,PartsandProcesseslists.

EachsubsystemsupplierofAAmidshallestablish,collect,reviewanddelivermaterials,partsandprocesseslistsincludingalltheMaterials,PartsandProcessesintendedforuseintheSKAbyhissuppliersandhimself.Theyshallreflectthecurrentdesignatthetimeofissue.

Thisallreadsverymuddledshouldbepartofaqualitysystem

(2)SYS_REQ_7110


AAM_REQ_7130 Partsavailability.

Theestimatedavailabilityofthepartsandproductsobtainedfrommaterialsandprocessesusedshallbecompatiblewiththefinalsystemslifecycle(tests,storage,mission).

(2)SYS_REQ_7130


AAM_REQ_7140 Productmanufacturing.

Productsshouldbemanufacturedasmuchaspossibleinafactory.


AAM_REQ_7150 Productassembly.

Productswhichneedstobeassembledatthesiteshouldbeconstructedassimpleaspossibletominimizetheconstructiontime.


AAM_REQ_7160 Producttesting.

Productsshouldbetestedasmuchas


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possiblyinthefactoryinsteadoftestingatsite.


AAM_REQ_7170 Productsealing.

Productsexposeddirectlytotheenvironment(likeantennaelements)shouldbefullysealedbeforeshippingtothesite.

5.2 Marking


AAM_REQ_7210 Partidentification.

Eachpart,materialorproductshallbeidentifiedwithauniqueandpermanentpartortypenumber.

Needstobemorespecifichowfardownthehierarchytheidentificationisnecessary(boardlevel,cables,connectors,...)

(2)SYS_REQ_7210


AAM_REQ_7220 Markingmethod.

Methodofmarkingshallbecompatiblewiththenatureoftheitemanditsuse.

(2)SYS_REQ_7220


AAM_REQ_7230 Documentationmarking.

Identificationnumbersshallbemarkedondocumentationand,wherepossible,onallitems.

(2)SYS_REQ_7230

5.3 Powerandotherutilities


AAM_REQ_7330 Limitingexcessivecurrents.

AAmidequipmentcircuitryshallbeprotectedagainstexcessivecurrentsbyacurrentlimitingdevice,which

(2)SYS_REQ_8160


20111114 Page37of52

shallnotitselfproduceexcessivecurrents.

Whatisthis?Isthisontheinterfacesagainstlightningorotherproblemsifso,sayso.


AAM_REQ_7340 Powersurgeprotection.

AAmidsubsystemsshallbeprotectedagainstpowertransientsandsurges.

(2)SYS_REQ_8170


AAM_REQ_7350 Polaritymisconnectionprotection.

AAmidequipmentcircuitryshallbeprotectedagainsttheeffectsofinadvertentwrongpolarityconnections.(TBC)

Thisneedstobespecifiedatwhatlevelandifitreallyneedstobedone.Thiscouldusesubstantiallymorepowerduetodiodedropsetc.

(2)SYS_REQ_8180

5.4 Accessibilityandtestability


AAM_REQ_7880 Selftestcapability.

TheAAmidsubsystemdesignforbothhardwareandsoftwareshallprovideselftestcapabilities.

(2)SYS_REQ_7880


AAM_REQ_7890 Servicingpointmaking.

AllservicingandtestpointsshallbeclearlymarkedusingTBDlabellingstandards.

(2)SYS_REQ_7890

5.5 Transportabilityandstorage



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AAM_REQ_7910 Handlingheavyequipment.

AAmidparts,testequipmentorsupportingequipmentwithamassexceeding25kgshallbeprovidedwithprovisionsforhandlingandtransportation.

Warnings?

(2)SYS_REQ_7910


AAM_REQ_7920 Disassemblyfortransport.

ItshallbepossibletodisassembleAAmidequipmentfortransportationorstorageasnecessary.

(2)SYS_REQ_7920


AAM_REQ_7930 Longtermstorage.

ItshallbepossibletostoreAAmidequipment(spareparts)for10yearswithoutanydegradationofitsfunctionorperformance.

(2)SYS_REQ_7930


AAM_REQ_7935 Specialstorage.

Ifspecialstoragefacilitiesareneededtheyshallbesuppliedaspartofthesparesprocurement.

(2)SYS_REQ_7935


AAM_REQ_7940 Packingdensity.

Packingdensityfortransportationshouldbedesignedasanoptimisedcost/performancerequirement.

TBD


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AAM_REQ_7950 Packingmethod.

Allproductsshouldbepackedpriortotransportationsuchthatitcanwithstand(1)rigourstransportation,(2)transportvibrationand(3)movement.

PerhapsthisshouldbespecifiedmorequantativeinGsforexample.

TBD


AAM_REQ_7960 Largeequipmentsize.

Thevolumeoflargeequipmentwhichcannotbedisassembledshouldbedrivenbystandardshippingcontainerguidelines.

TBD

5.6 ArrayDeployment


AAM_REQ_8000 Antennaelementdeploymenttime.

Thetimetoassembleanddeploytheantennaelementsshouldbeminimizedto?minutesperantennaelement.

TBD


AAM_REQ_8010 Antennaelementdeployment.

TheAAarraydesignanddeploymentshouldbeableforinstallationonasitewithalocalflatnesstoleranceof?cmover?m.

TBD


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AAM_REQ_8020 Antennapositions.

Eachindividualantennapositionshouldbemeasuredandknownwithin?mminthreedimensionsintheITRFcoordinatesystem.

TBD


AAM_REQ_8030 Antennaorientation.

Antennaelementsshouldbedesignedsuchthattheycanberotatedquickandsimple.

TBD


AAM_REQ_8040 Antennafixation.

Antennaelementsshouldbedesignedsuchthattheycanbesimpleandeffectivelyfixedtotheground.

TBD


AAM_REQ_8050 Housingheights.

Anyhousingneartheantennafieldshouldnotbeinthelineofsightof=xdegreesabovehorizon.Thefollowingrelationshouldhold:h


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5.7 ElectronicDesignRequirements


AAM_REQ_8100 Devicejunctiontemperature.

ThedevicejunctiontemperatureofthemaindevicesshouldbekeptbelowxdegreesCelsiustoincreaselifetime.

ShouldfollowfromtheRAMSanalysis.Dontknowifyoushouldputthisasarequirement.

TBD


AAM_REQ_8110 Designforupgradability.

TheAAlowdesignshouldbemadesuchthatfutureupgradesareabletoprocessthefullbandwidthofeachantennaelement,assumingthecostimpactissmall.

TBD

6 ExternalInterfaceRequirementsExternalInterfacesaredefinedasinteractionsorcommunicationswiththeworldoutsideanAAmidstation.Thesearerepresentedasbluearrowsin


20111114 Page42of52

Figure1.

6.1 RFSignal


AAM_REQ_8300 RFsignal.

TheinputsignalofeachAAmidstationhasthefollowingcharacteristicsintheband70450MHz:

Theinputforthisrequirementisthespectrummeasuredattheselectedsite.

TBDdBm:24hoursaveragepower

TBDdBm:Peakpower

6.2 RFInterference


AAM_REQ_8400 Damaginginterferencelevels.

TheAAmidsubsystemshallnotbedamagedbyRFIsignalsoflessthan:

(2)SYS_REQ_5410

TBDV/m


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6.3 Maintenance

Therequirementsformaintenancearelistedintheoperationalrequirementssection(Section4.4).

6.4 ReCycling

Currentlynorecyclingrequirementsareformulated.

6.5 Environment

6.5.1 General


AAM_REQ_5120 Compliancywithlocalenvironment.

ThedesignoftheAAmidshallbeappropriate(TBD)foroperationinthenaturalenvironmentforthegeographicaldeploymentlocationoftheSKA.

Thisrequirementshouldbemademorespecific

(2)SYS_REQ_5120


AAM_REQ_5130 Transportationconditions.

AAmidequipmentshallbedesignedforthethemodeoftransportbeingused(road,air,sea,etc.)betweenplaceofmanufacturingandfinalinstallationontheSKAsite(includingpackagingrequirements).

Thisrequirementshouldbemademorespecifice.g.useproperstandardsetc

(2)SYS_REQ_5130

6.5.2 Siteandinfrastructurerequirements


AAM_REQ_5220 Facilitiesandequipmentintrusion.

ThisisasystemwiderequirementandnotspecificallyAAmid:deleteit

(2)SYS_REQ_5220


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AAmidequipmentandoperatingfacilitiesshallbeadequatelyprotectedagainstintrusionbyunauthorizedpersonsorbylargerwanderinganimals.


6.5.3 Contaminationandprecipitation


AAM_REQ_5230 Precipitation.

AAmidshallbeabletooperatewithmaximal1%(TBD)degradationoftheperformanceduringanytypeofprecipitation(TBD).

Theoriginalrequirementistoostringent.Precipitationlikesnowwillalwayshavesomeinfluence.Needtodeterminereasonableacceptabledegradationanddefineit.

Shouldntthisbewith6.6Weather?

(2)SYS_REQ_5230


AAM_REQ_5240 Pollutionandcontaminationprotection.

AAmidshallbeadequatelyprotectedagainstperformancedegradationcausedbycontaminatingparticles(dust,sandetc),pollutedairoranyprecipitation.


(2)SYS_REQ_5240

6.5.4 ElectroMagneticCompatibility


AAM_REQ_5420 EMimmunity.

AAmidshallnotbesusceptibletoRFIsignals,inbandoroutband,otherthanviathereceptors.(Whatdoesthismean??)

Thisrequirementshouldbemademorespecificwithnumericalvalues

(2)SYS_REQ_5420


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otherwisethisleadtoanoverdesignbyputtingallequipmentinaFaradaycage.


AAM_REQ_5610 EMCsafetymargin.

TheEMCsafetymargin,whichisdefinedastheratiobetweensusceptibilitythresholdandtheinterferenceatanypointwithinthesystem,shallbegreaterthanTBDdB.

(2)SYS_REQ_5610


AAM_REQ_5620 EMCcompatibilitymarking.

All"offtheshelf"equipmentappliedwithintheAAmidsubsystemshallpossesasaminimumthehostcountryEMCmarking,includingelectricalandelectronicsupportingandinfrastructuralequipment.

Needstobemorespecificwhenthesiteisselected.

(2)SYS_REQ_5620


AAM_REQ_5630 Groundingconcept.

AhybridgroundingconceptasshowninfiguresTBDshallbeusedforEMCpurposes.GroundloopsinvolvingDC,andlowfrequencyAC,currentsshallbeavoidedinsidethesystem.Intentionalcurrentsthroughstructurearenotpermitted.(tobeelaborated)

(2)SYS_REQ_5630


AAM_REQ_5640 EMCdesignefforts.

Maximumeffort(tobedetailed)shallbeputintodesigningsignalinterfacestowithstandnoisyenvironmentsandtominimizethegenerationofexcessivenoise.

Thisneedstobeproperlyfleshedout.

(2)SYS_REQ_5640


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6.5.5 SelfgeneratedRFIenvironment


AAM_REQ_2910 SelfgeneratedRFIsusceptibility.

InterferenceduetoselfgeneratedRFIshallnotdegradetheperformanceoftheinstrumentbygreaterthan1%byanymeasure(TBC).

Thisisawildguess....

(2)SYS_REQ_2910

6.5.6 Grounding


AAM_REQ_5810 Safetyground.

Electricalsafetygroundshallbedesignedaccordingtotheregulationsimposedbythelocalgovernment.

Thisshouldbemademorespecificassoonthesiteisselected.

(2)SYS_REQ_5810

6.5.7 Corrosion


AAM_REQ_5820 Corrosionprotection.

AAmidequipmentandbuildingsshallbeprotectedagainstcorrosion.

Specifythestandard...

(2)SYS_REQ_5820


AAM_REQ_5830 Corrosionprotectioninairflows.

AAmidelectronicsandconnectorsinareaswithahigherairflow(forcooling)oroutdoorenvironmentshallbeadditionallyprotectedagainstcorrosion.

Specifythestandard...

(2)SYS_REQ_5830


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6.6 Weather

6.6.1 ClimaticRequirements


AAM_REQ_5310 Humidity.

AAmidequipmentshallbeabletowithstandmoistureandhumiditylevelsupto:

(2)SYS_REQ_5310

100%RH.

Forhowlong?Operating?


AAM_REQ_5320 Allowableairtemperaturerange.

AAmidequipmentshallbeabletowithstand(nonoperatingifnecessary)anoutsideairtemperaturewithintherangeof:

(2)SYS_REQ_5320

15C(TBC)to+60C(TBC).

Forhowlong...?


AAM_REQ_5330 Airtemperatureoperationrange.

AAmidequipmentshallbeabletooperatewithinspecificationiftheoutsideairtemperatureiswithintherangeof

(2)SYS_REQ_5330

5C(TBC)to+50C(TBC).


AAM_REQ_5340 Windvelocities.

AAmidshallbeabletoleratewindvelocitiesupto:

(2)SYS_REQ_5340

Survival: 160km/hr(TBC)

Normaloperation:40km/hr(TBC).


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6.6.2 Lightning


AAM_REQ_5710 Lightningdischargesusceptibility.

AAmidshallbeabletowithstandtheelectromagneticfieldimpactdefinedinTBDduringoperationorinanyothermodewithoutanydamageorcharacteristicsdegradationbecauseofalightningdischarge.

Thisneedsconsiderablestudy,theremaybeelementsofthearraydestroyedandstillcarryon.

(2)SYS_REQ_5710


AAM_REQ_5720 Lightningprotection.

AAmiddedicatedbuildingsandequipmentlocatedonsitesshallbeprotectedtominimizetheeffectsofadirectlightningstrikeusingcertifiedmethods(e.g.asdescribedinNEN1014).

(2)SYS_REQ_5720

6.6.3 Seismicity


AAM_REQ_5910 Earthquakes.

AAmidequipmentandbuildingsshallbeprotectedagainstearthquakeswithamagnitudeupto:

(2)SYS_REQ_5910

Richter3.8(TBC).

7 InternalInterfaceRequirementsInternal interfacesaredefinedas interactionsorcommunicationswiththeSKAsystemoutsidetheAAmid subsystems. These are represented as black arrows in


20111114 Page49of52

Figure1.

7.1 AAReceptorPower


AAM_REQ_8110 Supplypower.

ThepowersuppliedtoAAmidshallhavethefollowingcharacteristics(TBC):

(2)SYS_REQ_8110

Voltage: 380V+/10%

Phases: Three

Frequency: 50Hz+/1Hz


AAM_REQ_7320 Powerconsumption.

ThepowerconsumptionofallequipmentatanAAmidstationshallbe:

(2)SYS_REQ_7320


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7.2 SyncandTiming


AAM_REQ_8140 Subsystemtimestandard.

EachAAmidstationshallmaintainaninternaltimestandardwithanaccuracyof:

(2)SYS_REQ_8140

TBDnanoseconds.

Needstodiscussstandaloneanddriftrateetc.


AAM_REQ_8150 Centraltimestandard.

AllAAmidstationsshallsynchronizetheirinternaltimestandardstothecentraltimingstandardwithanaccuracyof

(2)SYS_REQ_8150

TBDnanoseconds.


AAM_REQ_8160 Synchronisationsignal.

Asynchronisationsignal(tickorpulse)isdistributedtoeachAAstationandhasthefollowingcharacteristics:

ThiswillbederivedfromtheSignalTransportandNetworksdomain.

Voltage: TBDV

Thisisrubbish,itwillbeanopticalsignaloverfibre.

Risetime: TBDps

Itwillprobablynotbedonethisway

TBDspulsewithawidthofTBDs


AAM_REQ_8170 Clocksignal.

Thislookswrongsurelyitwillbealocallygeneratedsignalthatissynchronisedwiththeabove

ThecentralclockisdistributedtoeachAAmidstationandhasthe

ThiswillbederivedfromtheSignalTransportandNetworksdomain.


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followingcharacteristics:

VoltageofTBDV

FrequencyofTBDMHz

JitterofTBDns

LongtermstabilityofTBD

7.3 Network


AAM_REQ_8200 Data timetagging. Allaperture arrays shall timetag received and processeddata with the accuracy oftheirinternaltimestandard.

[1]SYS_REQ_8210


AAM_REQ_8210 Datapacketizing.

AllAAmidobservationdatashallbepacketizedaccordingtotheSKAstandardwrittenin[TBD].

TBD


AAM_REQ_8220 Datainterface.

ThedatainterfaceofAAmidtothecentralprocessinghasthefollowingcharacteristics:

ThiswillfollowfromtheSignalTransportandNetworkdomain.

TBD

7.4 MonitorandControl


AAM_REQ_8500 M&Cprotocol.

TheM&CprotocolusedtointerfacewiththeAAmidisTBD

ThisisdrivenbytheM&Cdomain.


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AAM_REQ_8510 M&Cinterface.

TheelectricalcharacteristicsoftheM&CprotocolfortheAAmidstationare:

ThisisdrivenbytheM&Cdomain.

TBD

TBD

7.5 AAReceptorCooling


AAM_REQ_8600 Coolingcapacity.

TherequiredcoolingcapacityforeachAAmidstationrequires:

TBDkW

TBD

TBD

aa mid system requirements...

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