SOUTHSOUTH AFRICA’SAFRICA’S MMeerKATeerKAT More than 20 MeerKAT antennas have been installed on the SKA SA Losberg site outside Carnarvon in the Northern Cape. RADIORADIO TELESCOPE MARCH 2014

TECHNICAL FACT SHEET

TheThe SouthSouth AfricanAfrican MeerKATMeerKAT radioradio telescope,telescope, currentlycurrently beingbeing LOCALWHO IS PARTICIPATION MANUFACTURING IN THE builtbuilt somesome 90 90 kmkm from north-west Carnarvon of the in thesmall Northern Northern Cape, Cape is atown CONSTRUCTIONTHE MeerKAT ANTENNAS? OF MeerKAT precursorof Carnarvon, to the is Squarea precursor Kilometre to the Array Square (SKA) Kilometre telescope Array and will StratosatStratosat Datacom (Pty)(Pty) Ltd, thethe contractorprimary industry for the partner design, manufacturingon the be(SKA) integrated telescope into and the will mid-frequency be integrated component into the mid-frequency of SKA Phase andmanufacturing acceptance of thethe MeerKAT Antennaantennas, Positioner, leads a technology leads a technology 1.component The SKA Project of SKA isPhase an international 1. The SKA Projectenterprise is an to international build the consortiumconsortium including including international international partners partners General General Dynamics Dynamics Satcom largestenterprise and tomost build sensitive the largest radio and telescope most sensitive in the world, radio and telescope will be (GDSatcom,Satcom (GDSatcom, USA) and USA) Vertex and Antennentechnik Vertex Antennentechnik (Germany). (Germany). locatedin the world, in Africa and and will Australia. be located in Africa and Australia. At least 75% of the components making up the MeerKAT dish will be Atmanufactured least 75% of inthe South contract Africa value by will several be spent sub-contractors. in South Africa Keyresulting local in most TIMELINE FOR MeerKAT CONSTRUCTION ofsuppliers the MeerKAT include antenna Effi cient components Engineering being (pedestals manufactured and in yokes); South Africa. Titanus March 2014: First antenna installed Slew Rings (azimuth bearings) and Tricom Structures (back-up March 2014: First antenna installed Mid 2014: First antenna qualifi ed and critical design review Keystructure), local suppliers all based include in Gauteng. Efficient In someEngineering cases foreign(pedestals companies and yokes); Titanus Slew Rings (azimuth bearing), Tricom Structures and Namaqua June 2016: completed16 antenna array ready will manufacture components for the fi rst antenna – such as the fi rst End 2014: Four MeerKAT receptors will be fully assembled, Engineeringset of refl ector (back-up panels, structure), fi rst receiver Westarcor indexer Engineering and fi rst sub-refl and General ector Profiling (receiver indexer); and Stratosat (reflectors). End 2017: integrated64 antenna and verifi array ed ready – but the rest will be made locally. Suppliers from abroad include End 2015: Array to ofdo 16 science antennas commissioned and ready to the National Research Council of Canada, through the Herzberg, Due to schedule pressure some of the components (such as the reflector do science Programs in Astronomy and Astrophysics (low-noise amplifi ers and panels, sub-reflector and receiver indexer) for the first two antennas End 2016: All 64 antenna positioners will be in place. fi rst sub-refl ector); Oxford Cryogenics in the UK (cryogenic cold- were manufactured internationally. Since then, this function has been Mid 2017: Full array ready to do science. heads) and Vertex Antennentechnik (control systems). successfully transferred to local suppliers. highhigh with with a adeviation deviation from from thethe ideal ideal shape shape being being no no moremore than than 0.6 0.6 mm mm RMS RMS (root(root mean mean square). square). The The mainmain reflector reflector surface surface is is mademade up up of of 40 40 aluminium aluminium panelspanels mounted mounted on on a asteel steel supportsupport framework. framework. Z Z This This framework framework is is mountedmounted on on top top of of a ayoke, yoke, whichwhich is is in in turn turn mounted mounted onon top top of of a apedestal. pedestal. The The combinedcombined height height of of the the pedestalpedestal and and yoke yoke is is just just overover 8 8m. m. The The height height of of the the total total structure structure is is 19.519.5 m, m, and and it it weighs weighs 42 42 tons. tons. Z Z The The pedestal pedestal houses houses the the antenna’s antenna’s pointing pointing control control system. system. Z Z Mounted Mounted at at the the top top of of the the pedestal, pedestal, beneath beneath the the yoke, yoke, are are an an TheThe MeerKAT MeerKAT will will become become part part of of SKA SKA phase phase 1. 1. azimuthazimuth drive drive and and a ageared geared azimuth azimuth bearing, bearing, which which allow allow the the mainmain and and sub-reflectors, sub-reflectors, together together with with the the receiver receiver indexer, indexer, to to MMeereerKAT’SKAT’S MAK MAKE-UPE-UP bebe rotated rotated horizontally. horizontally. The The yoke yoke houses houses the the azimuth azimuth wrap, wrap, which which (see(see annotated annotated diagram diagram on on back back page): page): guidesguides all all the the cables cables when when the the antenna antenna is is rotated, rotated, and and prevents prevents Z Z The The MeerKAT MeerKAT telescope telescope will will be be an an array array of of 64 64 interlinked interlinked themthem from from becoming becoming entangled entangled or or damaged. damaged. The The structure structure receptorsreceptors (a (a receptor receptor is is the the complete complete antenna antenna structure, structure, with with allowsallows an an observation observation elevation elevation range range from from 15 15 to to 88 88 degrees, degrees, thethe main main reflector, reflector, sub-reflector sub-reflector and and all all receivers, receivers, digitisers digitisers and and andand an an azimuth azimuth range range from from -185 -185 degrees degrees to to +275 +275 degrees, degrees, where where otherother electronics electronics installed). installed). northnorth is is at at zero zero degrees. degrees. Z Z The The configuration configuration (placement) (placement) of of the the receptors receptors is is determined determined by by Z Z The The steerable steerable antenna antenna positioner positioner can can point point the the main main reflector reflector thethe science science objectives objectives of of the the telescope. telescope. veryvery accurately, accurately, to to within within 5 5arcseconds arcseconds (1.4 (1.4 thousandths thousandths of of a a Z Z 48 48 of of the the degree)degree) under under low-wind low-wind and and night-time night-time observing observing conditions, conditions, receptorsreceptors are are andand to to within within 25 25 arcseconds arcseconds (7 (7 thousandths thousandths of of a adegree) degree) during during concentratedconcentrated normalnormal operational operational conditions. conditions. inin the the core core areaarea which which is is ABOUABOUTT M MeereerKATKAT – – HOW HOW I TIT WOR WORKKS:S: approximatelyapproximately Antenna foundations in the coreZ ofZ Electromagnetic Electromagnetic the MeerKAT waves waves from from cosmic cosmic radio radio sources sources bounce bounce off off the the 1 1km km in in diameter. diameter. array, as seen in this image from Februarymainmain reflector, reflector, 2014. then then off off the the sub-reflector, sub-reflector, and and are are then then focused focused in in Z Z The The longest longest thethe feed feed horn, horn, which which is is part part of of the the receiver. receiver. distancedistance between between Z Z Each Each receptor receptor can can accommodate accommodate up up to to four four receivers receivers and and anyany two two receptors receptors digitisersdigitisers mounted mounted on on the the receiver receiver indexer. indexer. The The indexer indexer is is a a (the(the so-called so-called rotatingrotating support support structure structure that that allows allows the the appropriate appropriate receiver receiver AntennaAntenna foundations foundations in inin the thethe core corecore of ofof the thethe MeerKAT MeerKATMeerKAT maximummaximum toto be be automatically automatically moved moved into into the the antenna antenna focus focus position, position, array,array, as as seen seenseen when inwhen this flying flyingimage over over from the the February Karoo Karoo site, site,2014. baseline)baseline) dependingdepending on on the the desired desired observation observation frequency. frequency. FebruaryFebruary 2014. 2014. isis 8 8km. km. Z Z The The main main function function of of the the receiver receiver is is to to capture capture the the Z Z Each Each MeerKAT MeerKAT receptor receptor consists consists of of three three main main components: components: electromagneticelectromagnetic radiation radiation and and convert convert it it to to an an voltage voltage signal signal that that 1.1. The The antenna antenna positioner, positioner, which which is is a asteerable steerable dish dish on on a a isis then then amplified amplified by by cryogenic cryogenic receivers receivers that that add add very very little little noise noise pedestal;pedestal; toto the the signal. signal. The The first first two two receivers receivers will will be be the the L-Band L-Band and and UHF- UHF- 2.2. A A set set of of radio radio receivers; receivers; BandBand Receivers. Receivers. 3.3. A Aset set of of associated associated digitisers. digitisers. Z Z Four Four digitisers digitisers will will be be mounted mounted on on the the receiver receiver indexer, indexer, close close to to Z Z The The antenna antenna positioner positioner is is made made up up of of the the 13.5 13.5 m m effective effective thethe associated associated receivers. receivers. The The function function of of the the four four digitisers digitisers is is to to diameterdiameter main main reflector, reflector, and and a a3.8 3.8 m m diameter diameter sub-reflector. sub-reflector. In In convertconvert the the radio radio frequency frequency (RF) (RF) voltage voltage signal signal from from the the receiver receiver thisthis design, design, referred referred to to as as an an ‘Offset ‘Offset Gregorian’ Gregorian’ optical optical layout, layout, intointo digital digital signals. signals. This This conversion conversion is is done done by by using using an an electronic electronic therethere are are no no struts struts in in the the way way to to block block or or interrupt interrupt incoming incoming componentcomponent called called an an analogue analogue to to digital digital converter converter (ADC). (ADC). The The electromagneticelectromagnetic signals. signals. This This ensures ensures excellent excellent optical optical L-bandL-band digitiser digitiser samples samples at at a arate rate of of 1 1712 712 million million samples samples every every performance,performance, sensitivity sensitivity and and imaging imaging quality, quality, as as well well as as good good second.second. (The (The amount amount of of data data that that is is generated generated by by the the digitiser digitiser for for rejectionrejection of of unwanted unwanted radio radio frequency frequency interference interference from from orbiting orbiting a areceiver receiver is is equivalent equivalent to to approximately approximately 73 73 000 000 DVDs DVDs every every day day satellitessatellites and and terrestrial terrestrial radio radio transmitters. transmitters. It It also also enables enables oror almost almost 1 1DVD DVD per per sec.) sec.) thethe installation installation of of multiple multiple receiver receiver systems systems in in the the primary primary Z Z Once Once the the signal signal is is converted converted to to digital digital data, data, the the digitiser digitiser sends sends andand secondary secondary focal focal areas, areas, and and provides provides a anumber number of of other other thisthis data data via via buried buried fibre fibre optic optic cables cables to to the the correlator, correlator, which which is is operationaloperational advantages. advantages. situatedsituated inside inside the the Karoo Karoo Array Array Processor Processor Building Building (KAPB) (KAPB) at at the the Z Z The The combined combined surface surface accuracy accuracy of of the the two two reflectors reflectors is is extremely extremely LosbergLosberg site site complex. complex. 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MeerKAT TECHNICAL SPECIFICATIONS NumberM Meerofeer antennasKATKAT TECHNICAL TECHNICAL SPECIFICATIONS SPECIFICATIONS 64 ConfiMMMeereereer gurationKATKATNumberKATNumber TECHNICAL TECHNICAL TECHNICAL of of antennas antennasMeer SPECIFICATIONS SPECIFICATIONS SPECIFICATIONS KAT TECHNICAL SPECIFICATIONSOffset Gregorian6464 NumberDiameterNumberNumberConfi Confiof of ofof antennas gurationantennas mainantennas guration refl ectorNumber (dish) of antennas 6413.56464 mOffsetOffset Gregorian Gregorian64 ConfiDiameterConfiConfi guration guration DiametergurationDiameter of sub-refl of of main ector mainConfi refl reflguration ector ector (dish) (dish) Offset3.8OffsetOffset m Gregorian 13.5Gregorian Gregorian13.5 m m Offset Gregorian DiameterSurfaceDiameterDiameterDiameter accuracyDiameter of of of main main main of (main reflof refl sub-reflrefl sub-refl ectorDiameterector ector and ector(dish) (dish) sub-refl(dish)ector of main ector refl combined) ector (dish) 13.5 0.613.513.5 mm m m m3.8 RMS3.8 m m (root mean13.5 square) m DiameterPointingDiameterDiameterSurface Surfaceaccuracy of of of sub-refl sub-refl sub-refl accuracy accuracy ectorector Diameterector (main (main and of and sub-refl sub-refl sub-refl ector ector ector combined) combined)3.85”3.8 3.8 under m m m 0.6 0.6optimal mm mm RMS RMS conditions; (root 3.8(root meanm mean 25” square) under square) normal conditions SurfaceWindSurfaceSurface optimalPointing accuracy Pointingaccuracy accuracy (mean/gust) accuracy accuracy(main (main (mainSurface and and and sub-refl sub-refl sub-reflaccuracy ectorector ector (main combined) combined) combined) and sub-refl ector10/15 0.6 0.6 0.6 mm mm mm combined)km/h5” RMS 5”RMS underRMS under (root (root (root optimal optimal mean mean mean 0.6 conditions; square)mm square) conditions;square) RMS (root25” 25” under mean under normal square) normal conditions conditions PointingWindPointingPointing operatingWind Windaccuracy accuracy accuracy optimal optimal (mean/gust) (mean/gust) Pointing(mean/gust) accuracy 5”35/485”5” under under under km/h10/1510/15 optimal optimal optimal km/h km/h conditions; conditions; conditions;5” under 25” 25” 25”optimal under under under conditions;normal normal normal conditions conditions conditions 25” under normal conditions WindWindWind optimalstow optimal WindoptimalWind (gust) operating (mean/gust) operating(mean/gust) (mean/gust) Wind (mean/gust) (mean/gust) optimal (mean/gust) 10/1568.410/1510/15 km/h km/h km/h35/48 km/h35/48 km/h km/h 10/15 km/h WindWindWind operatingsurvival operating WindoperatingWind stow 3stow sec(mean/gust) (mean/gust) (mean/gust)(gust) (gust)gustWind operating (mean/gust) 35/4814435/4835/48 km/h km/h km/h68.4 km/h68.4 km/h km/h 35/48 km/h WindAzimuthWindWind stow stow Windstow Windspeed/range (gust) (gust) survival(gust) survival 3 Windsec3 sec gust stow gust (gust) 68.4268.4 68.4deg/s km/h km/h km/h144 (-185144 km/h km/h to +275 deg)68.4 km/h WindElevationWindWind survival survival AzimuthsurvivalAzimuth speed/range 3 3 3speed/rangesec sec secspeed/range gust gust gustWind survival 3 sec gust 1441144 144deg/s km/h km/h km/h2 (15 deg/s2 deg/s to 88 (-185 (-185deg) to 144to +275 +275 km/h deg) deg) AzimuthLowestAzimuthAzimuthElevation elevation Elevationspeed/range speed/range speed/range speed/range speed/range Azimuth speed/range 2152 2deg/s deg/s degdeg/s1 (-185 deg/s(-1851 (-185 deg/s to to (15to +275 (15+275 +275to to 88 deg) 2 deg) 88deg) deg/sdeg) deg) (-185 to +275 deg) ElevationContinuumElevationElevationLowestLowest speed/range speed/range speed/rangeimaging elevation elevation dynamicElevation range speed/range at 1.4 GHz 1 601 1deg/s deg/s dBdeg/s 15 (15 (1515 (15deg todeg to to 88 88 88 deg) deg) deg)1 deg/s (15 to 88 deg) LowestLine-to-lineLowestLowestContinuum elevation elevationContinuum elevation dynamic imaging imaging rangeLowest dynamic at dynamic elevation 1.4 GHz range range at at 1.4 1.4 GHz GHz 15401515 degdB deg deg 60 60 dB dB 15 deg

ContinuumMosaicingContinuumContinuumLine-to-lineLine-to-line imaging imaging imaging imaging dynamicdynamic dynamic dynamic Continuumdynamic rangerange range range range imaging atat at at 1.414at 1.4 1.4 1.4 GHzGHz GHz dynamicGHz GHz range at27 60 60 601.4 dB dB dB GHz 40 40 dB dB 60 dB 4 receivers, 1 min switchover min 1 receivers, 4 Indexer 4 receivers, 1 min switchover min 1 receivers, 4

Line-to-lineLinearLine-to-lineLine-to-line MosaicingpolarisationMosaicing dynamic dynamic dynamic imaging imagingcross range Line-to-linerange range coupling dynamic at dynamicat at 1.4 1.4 1.4 GHz dynamic GHzacross rangeGHz range at-3 rangeat 14dB 14 GHz beam GHz at 1.4 GHz40 -3040 40 dB dBdB dB 27 27 dB dB 40 dB Indexer 1 deg/s (15 to 88 deg) 88 to (15 deg/s 1

MosaicingSensitivityMosaicingMosaicingLinearLinear UHF-Bandimaging imaging imaging polarisation polarisation dynamic dynamic dynamic Mosaicing(0.58 cross – crossrange range1.015 range couplingimaging coupling at GHz)at at 14 14 14 GHz GHz dynamicacrossGHz across -3 range-3 dB dB beam beamat27220 271427 dB dBGHz m dB 2 -30/K -30 required dB dB (expect27 dB to achieve better) Elevation 2 deg/s (-185 to +275 deg) +275 to (-185 deg/s 2 Azimuth 2 deg/s (-185 to +275 deg) +275 to (-185 deg/s 2

LinearSensitivityLinearLinear Sensitivitypolarisation polarisation Sensitivitypolarisation L-Band UHF-Band (0.9 UHF-Bandcross cross crossLinear – 1.67 coupling coupling coupling (0.58 polarisationGHz) (0.58 – across across 1.015–across 1.015 crossGHz)-3 -3 -3GHz) dB dB dB couplingbeam beam beam across220 -30 -30 -30 dB mdB -3dB2 220/K dB 220 required m beam m2/K2/K required required(300 -30 m (expect2dB/K (expect achievable) to to achieve achieve better) better) Azimuth > 99.5% (main and sub) and (main 99.5%

SensitivitySensitivitySensitivitySensitivitySensitivity X-BandUHF-Band UHF-Band UHF-Band L-Band (8 L-Band – Sensitivity(0.58 (0.5814.5 (0.58 (0.9 – (0.9GHz)– –1.015 –1.015 1.015 1.67– UHF-Band 1.67 GHz) GHz) GHz)GHz) GHz) (0.58 – 1.015 GHz)200220220220 m m m22202/K/K2/K220 required required mrequired m2/K2/K required required(expect (expect (expect220 (300 mto to(300 to2 /Kachieve achieve machieve requiredm2/K2/K achievable) better)achievable)better) better) (expect to achieveciency better)effi ecting refl ector Refl < < 1K contribution noise ector Refl 1K

SensitivityApertureSensitivitySensitivitySensitivitySensitivity phase L-Band L-Band L-Band effi X-Band (0.9 ciencyX-Band(0.9 (0.9Sensitivity – – –1.67 1.67(8 1.67 (8– GHz) 14.5–GHz) GHz)14.5 L-Band GHz) GHz) (0.9 – 1.67 GHz) 2200.91220220 m (atm m22002/K /K214.5/K200 required required mrequired GHz)m2/K2/K required required(300 (300 (300220 m m m2 m2/K/K2/K2 /Kachievable) achievable) achievable) required (300 m2/K achievable) contribution noise ector Refl < 15” RMS 15”

SensitivitySurfaceSensitivitySensitivityAperture accuracyAperture X-Band X-Band X-Band phase phase (8 (8 (8 – –Sensitivity –effi14.5 14.5 14.5effi ciency GHz) ciencyGHz) GHz) X-Band (8 – 14.5 GHz) 2000.6200200 mmm m m20.912/K/K 2RMS/K0.91 required required required(at (at 14.5 14.5 GHz) GHz)200 m2/K required jitter Pointing 5” (optimal conditions, 20 min); 25” (normal conditions, 24 h) 24 conditions, (normal 25” min); 20 conditions, (optimal 5” accuracy Pointing 5” (optimal conditions, 20 min); 25” (normal conditions, 24 h) 24 conditions, (normal 25” min); 20 conditions, (optimal 5”

AperturePointingApertureApertureSurface Surface accuracyphase phase phase accuracy effi effiaccuracy effi ciency ciency ciencyAperture phase effi ciency 0.915”0.910.91 (optimal (at (at (at0.6 14.5 14.50.6 14.5 mm conditions, mmGHz) GHz) GHz) RMS RMS 0.91 20 min); (at 14.5 25” GHz) (normal conditions, 24 h) accuracy Pointing 0.6 mm RMS mm 0.6

SurfacePointingSurfaceSurfacePointing accuracy Pointingjitteraccuracy accuracy accuracy accuracy Surface accuracy 0.6<0.615”0.6 mm mm RMSmm5” RMS 5”RMS (optimalRMS (optimal conditions, conditions,0.6 mm 20RMS 20 min); min); 25” 25” (normal (normal conditions, conditions, 24 24 h) h) accuracy Surface 0.91 (at 14.5 GHz) 14.5 (at 0.91 ciency effi phase Aperture 0.91 (at 14.5 GHz) 14.5 (at 0.91

PointingReflPointingPointing ectorPointing Pointingaccuracy accuracynoise accuracy jittercontribution jitter Pointing accuracy <5”5”1K5” (optimal (optimal (optimal<15”<15” conditions, RMSconditions, conditions,RMS 5” 20 20 (optimal20 min); min); min); 25” 25” 25”conditions, (normal (normal (normal conditions, conditions,20 conditions, min); 25” 24 24 24(normal h) h) ciency h) effi conditions,phase 24Aperture h) 200 m 200 GHz) 14.5 – (8 X-Band Sensitivity /K required /K

PointingReflPointingPointing ectorRefl Refljitter jitterrefl jitterector ectorecting noise noise effiPointing contributionciency contribution jitter <><15”99.5%<15”15” RMS RMS RMS< (main1K<1K and2 sub)<15” RMS /K achievable) achievable) /K /K m m (300 (300 required required /K /K m 220 GHz) 1.67 – (0.9 L-Band Sensitivity 220 m 220 GHz) 1.67 – (0.9 L-Band Sensitivity

2 2 2

ReflAzimuthReflRefl ectorector ectorRefl Refl noise noiseector noise ector contribution contributionrefl contribution refl ecting ectingRefl ector effi effi ciency ciencynoise contribution <2<1K <1Kdeg/s1K > 99.5%(-185>99.5% to (main2 +275(main and deg)< and1K sub) sub) 220 m 220 GHz) 1.015 – (0.58 UHF-Band Sensitivity /K required (expect to achieve better) achieve to (expect required /K

ElevationReflReflRefl ectorector ectorAzimuthAzimuth refl refl refl ectingecting ecting effi effi effiRefl ciency ciency ciency ector refl ecting effi ciency 1>>99.5% >99.5%deg/s99.5%2 (main (15 (maindeg/s 2(main deg/s to and 88and2 (-185 and (-185deg) sub) sub) sub) to >to 99.5%+275 +275 deg) (maindeg) and sub) Linear polarisation cross coupling across -3 dB beam -30 dB dB -30 beam dB -3 across coupling cross polarisation Linear

AzimuthIndexerAzimuthAzimuthElevation Elevation Azimuth 242 2deg/sreceivers, deg/s deg/s1 (-185 deg/s(-1851 (-185 deg/s 1 to min to (15to +275 (15dB +275 +275switchoverto to -30 88 deg) 2 deg) 88deg) deg/sdeg) deg) (-185beam dB to-3 +275 deg)across coupling cross polarisation Linear 27 dB dB 27

ElevationElevationElevationIndexerIndexer Elevation 11 1deg/s deg/s deg/s4 (15 receivers,(154 (15 receivers, to to to 88 88 88 deg) deg) deg)1 min1 1min deg/s switchover switchover (15 to 88 GHz deg) 14 at range dynamic imaging Mosaicing 40 dB dB 40 GHz 1.4 at range dynamic Line-to-line 40 dB dB 40

IndexerIndexerIndexer Indexer 44 4receivers, receivers, receivers, 1 1 1min min min switchover switchover switchover4 receivers, 1 min switchover GHz 1.4 at range dynamic Line-to-line Continuum imaging dynamic range at 1.4 GHz 60 dB dB 60 GHz 1.4 at range dynamic imaging Continuum

15 deg 15 elevation Lowest 15 deg 15 elevation Lowest

1 deg/s (15 to 88 deg) 88 to (15 deg/s 1 speed/range Elevation

2 deg/s (-185 to +275 deg) +275 to (-185 deg/s 2 speed/range Azimuth 2 deg/s (-185 to +275 deg) +275 to (-185 deg/s 2 speed/range Azimuth

144 km/h 144 gust sec 3 survival Wind

68.4 km/h 68.4 (gust) stow Wind 68.4 km/h 68.4 (gust) stow Wind

35/48 km/h 35/48 (mean/gust) operating Wind

10/15 km/h 10/15 (mean/gust) optimal Wind 10/15 km/h 10/15 (mean/gust) optimal Wind

5” under optimal conditions; 25” under normal conditions normal under 25” conditions; optimal under 5” accuracy Pointing

Surface accuracy (main and sub-refl ector combined) 0.6 mm RMS (root mean square) mean (root RMS mm 0.6 combined) ector sub-refl and (main accuracy Surface Surface accuracy (main and sub-refl ector combined) 0.6 mm RMS (root mean square) mean (root RMS mm 0.6 combined) ector sub-refl and (main accuracy Surface

3.8 m 3.8 ector sub-refl of Diameter

13.5 m 13.5 (dish) ector refl main of Diameter 13.5 m 13.5 (dish) ector refl main of Diameter

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KAT TECHNICAL SPECIFICATIONS TECHNICAL KAT eer M

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than 150 000) monitor everything from electronic component component electronic from everything monitor 000) 150 than

operators want it to do. A large number of internal sensors (more (more sensors internal of number large A do. to it want operators

the health of the telescope and for controlling it to do what the the what do to it controlling for and telescope the of health the

region.

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that lives in the Karoo Karoo the in lives that

align the signals from all receptors. all from signals the align

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all synchronised to the same clock. This is important to properly properly to important is This clock. same the to synchronised all

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KAPB with a portion of the science archive data moved off site site off moved data archive science the of portion a with KAPB the team re-named it it re-named team the

science. The science data products are also archived at the the at archived also are products data science The science. building of 64 receptors, receptors, 64 of building

a number of narrow, high sensitivity beams used for pulsar pulsar for used beams sensitivity high narrow, of number a the budget to allow the the allow to budget the

coherently adds the signals from all the receptors to form form to receptors the all from signals the adds coherently

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to which the antennas are pointing – and beam-forming, which which beam-forming, and – pointing are antennas the which to

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from all the receptors to form an image of the area of the sky sky the of area the of image an form to receptors the all from

of 20 receptors. When When receptors. 20 of

processing, such as correlation – which combines all the signals signals the all combines which – correlation as such processing,

(KAT) that would consist consist would that (KAT)

At the KAPB, the signals undergo various stages of digital digital of stages various undergo signals the KAPB, the At Z

Karoo Array Telescope Telescope Array Karoo

for thermal stability. stability. thermal for

originally known as the the as known originally

The fi bre cables run inside conduits buried 1 m below the ground ground the below m 1 buried conduits inside run cables bre fi The Z

The telescope was was telescope The single antenna being 12 km. 12 being antenna single

KAT? KAT? eer M WHY the KAPB, with the maximum length between the KAPB and a a and KAPB the between length maximum the with KAPB, the

A total of 170 km of buried fi bre cables connect the receptors to to receptors the connect cables bre fi buried of km 170 of total A Z MeerKAT ANTENNA TOTAL HEIGHT: 19.5 m; TOTAL STRUCTURE WEIGHT: 42 TONS

The antenna consists of the main reflector (effective diameter The antenna consists of the main refl ector (effective diameter Lightning conductors 13.5 m)m) plus the sub-reflectorsub-refl ector (diameter(diameter 3.83.8 m).m). TheThe mainmain reflectorrefl ector around the refl ectors isis made upup ofof 4040 panels,panels, made made of of aluminium. aluminium. The The sub-reflector sub-refl ector is is protect the structure a single piececomposite composite structure. structure. during lightning strikes.

Steel support framework and The L-Band receiver connecting and the UHF-Band back-up receiver are mounted structure. on the receiver indexer. The indexer can accommodate up to four receivers.

TheThe yoke,yoke and elevation bearingelevation and bearing/ drive motorsactuator allow allows the the reflreflectors ectors to to tilt tilt up up andand down.

The receiver TheThe azimuthazimuth bearing indexer can rotate andbearing/actuator azimuth drive each receiver to motorsallows theallow structure the the desired focal structureto rotate into arotate in position. ahorizontal horizontal plane. plane.

The L-Band digitiser and the UHF-Band The pedestal digitiser are mounted contains the drive on the indexer. control system.

An underground network of fi bre optic The pedestal is cables links each receptor to the Karoo anchored and Array Processor Building (KAPB) on site. bolted to a concrete foundation.

SKA South African Project Offi ce Meerkat Engineering Offi ce SKA Organisation: www.skatelescope.org Contact17 Baker Street, us: Rosebank, 3rd Floor, the Park, Park Road, More information, visuals and media SKAJohannesburg, SA, 3rd FloorSouth Africa Pinelands, South Africa releases at www.ska.ac.za TheTel: +27Park, (0) Park11 442 Street, 2434 Pinelands, 7405 Tel: +27 (0) 21 506 7300 Project updates at Tel: +27 (0) 21 506-7300 www.ska.ac.za www.facebook.com/skasouthafrica