PoS(MeerKAT2016)001 http://pos.sissa.it/ b and the MeerKAT Team ab ∗ [email protected] Speaker. This paper is a high-level description of theMeerKAT radio development, telescope implementation and and its initial subsystems. testing of The the rationaleis for presented the design in and the technology choices context oftechnical the overview requirements is of provided the for MeerKAT eachfor Large-scale these of Survey components the Projects. and the major A overall telescope systemification elements, are introduced. tests and The are key results specifications presented of selected to receptorgoals illustrate qual- by that a significant the margin. MeerKAT receptor exceeds the original design ∗ Copyright owned by the author(s) under the terms of the Creative Commons c Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND 4.0). MeerKAT Science: On the Pathway to25-27 the May, SKA, 2016, Stellenbosch, South Africa Justin L. Jonas The MeerKAT Radio Telescope Rhodes University SKA South Africa E-mail: a b PoS(MeerKAT2016)001 Justin L. Jonas . 1 When the DST made the decision to fund the design and construction of a substantial SKA The MeerKAT radio telescope is a precursor for the Square Kilometre Array (SKA) mid- The MeerKAT project resulted from a DST strategy for South Africa to develop appropriate The full MeerKAT array with 64 antennas is scheduled to start early science operations mid precursor instrument in the Karoo, a directivetional was science issued that goals the related instrument to mustinstrument have those should transforma- of be applicable the to SKA, the and eventualwas SKA. that formulated A in the preliminary consultation technologies MeerKAT science with used programme athe to broad SKA implement range science of the scientists case, associated and with this the programme development was of distilled into a set of high level technical require- frequency telescope, located inAfrica. the It arid will be Karoo thebefore region most the of sensitive advent decimetre-wavelength the radio of Northern interferometer SKA1-mid.government array Cape of The in Province South the telescope Africa world in and through its South Department the associated of National infrastructure Science Research and is Technology Foundation fundedhas (DST). (NRF), by been Construction an the the and agency responsibility commissioning of of of theNRF. the the SKA Telescope telescope South operations Africa will Project be Office,Astronomy which the Observatory is (SARAO), responsibility a a of National business Facility unit the administered ofincorporated newly by the into the declared the NRF. MeerKAT South SKA1-mid will be African array towards Radio the end of the construction phasetechnical of and SKA1-mid. scientific capabilities in theticipate academic and fully industrial in sectors the in order internationalundertaken to SKA prior be project. to able embarking to A on par- range the finalnovel of technologies design technology for of use prototyping MeerKAT. These in activities the involved the SKA were and investigationtemperature of MeerKAT, including receiver phased-array clusters, feeds single-piece (PAFs), ambient composite reflectors,port RF-over-fibre and analog signal Stirling-cycle trans- cryogenic coolers.and commissioned as Two part prototype of telescopes theand were the prototyping seven designed, programme: element constructed KAT-7 the interferometer array single inhave 15 the been m Karoo. used XDM for Both dish of productive at these science HartRAO prototype programmes. telescopes 2018. The full deployment will be precededarray, by a and series the of array functionality releases of asramps antennas the are up. added correlator/beamformer, The to science the schedule processor for thisplanned and staged roll-out control implementation is software is to dynamic be - foundhttp://public.ska.ac.za/meerkat/meerkat-schedule the at: current state of actual and 2. The MeerKAT Large (Legacy) Survey Projects MeerKAT 1. Introduction At the time of writingability the to: 16-element (1) Array perform Releasefields deep, 1 and wide-band, (AR1) extended wide-field has sources (mosaic) successfully continuum inOH demonstrated imaging maser the the of sources, Galactic extragalactic (3) plane, produce (2)clusters, neutral (4) perform monitor hydrogen narrow-band pulsar (HI) imaging times data of of cubes arrival, Galactic and for (5) nearby detect galaxies a and pulsar. galaxy PoS(MeerKAT2016)001 ], and 1 Justin L. Jonas 10 kpc. ∼ ]. 2 2 to the low levels observed in the current ≈ 100 HI detections, probing gas dynamics at a 2. This redshift range probes the evolution in z ∼ 2 ≤ z ≤ make detailed maps of the faint gas falling into galaxies and Deep Field South, using both the UHF and L-band receivers to cover ]. A large-scale survey was defined as requiring in excess of 1000 hours 1 1 kpc, and the cosmic web at a resolution of ∼ Chandra A deep HI emission line survey of the Fornax cluster to study the dynamics of neutral gas in In 2009 a call was made to the international science community to self-organize into project An ultra-deep atomic hydrogen (HI) emission survey out to a redshift of 1.4 to investigate the An extra-galactic continuum survey to investigate the evolution of AGN, star-forming galaxies An HI survey to map the distribution and dynamics of neutral hydrogen in a sample of 30 An extremely sensitive survey of HI and OH absorbers that will map the evolution of cold the cluster and its connection to thecluster cosmic in web. These the observations southern of the hemisphere largest should nearby (20 yield Mpc) from their surroundings. 2.4 Fornax teams and propose large-scale surveytelescope projects as (LSPs) defined that in might [ be carried out on the MeerKAT cosmic evolution of HI in galaxiespointing over the within last the 9 Gyr. The observations will be towards one single and galaxy clusters from the epoch offour reionization through fields, to combined the with present extensive day. ancillary Theseof multi-wavelength observations data, cosmic of will magnetism. also probe the evolution 2.3 MHONGOOSE galaxies located within 30 Mpc anduniquely spanning have five the orders capability of to magnitude detect in HI mass. MeerKAT will of observing time, and these surveys wouldfull-scale nominally operations. occupy 75% of This the first solicitationa 5 resulted Time years of Allocation in MeerKAT Committee 20 (TAC). surveyrecommended Eleven for proposals of merger that because the of were proposals the adjudicatedresulting similarity were ten in by approved, LSPs science with objectives approved and for two survey observing definition. of time The are them described very briefly below. 2.1 LADUMA the redshift range. 2.2 MIGHTEE spatial resolution of universe. atomic and molecular gas in galaxies at 0 MeerKAT ments for the MeerKAT telescope.an The early preliminary MeerKAT MeerKAT reference science design case concept is is outlined described in in [ [ 2.5 MALS star-formation rate density from near its peak at PoS(MeerKAT2016)001 Fermi Justin L. Jonas ]. The specifica- 1 transition of 12CO as- ) 0 − 1 ( J 7) galaxies, to investigate the role of molecular 3 ≈ z A program to make image-plane detections of multiple populations of Galactic and extra- The deepest and highest resolution 14 GHz survey of the southern Galactic plane, aiming A survey targeting redshifted emission originating from the Long-term timing of various classes of pulsars for a range of scientific goals, including the Targeted and blind surveys for the detection of fast radio transients and pulsars. The expected The MeerQuittens polarization rotation measure survey to probe the magnetic fields of galax- The science requirements derived from the ten MeerKAT large survey proposals were used tions and reference design concept of the MeerKAT telescope have evolved further since this early Galactic synchrotron transient radio sourcesevents. associated with This high monitoring, energyconcert accretion target-of-opportunity, with and observations and explosive at commensal other wavelengths. program will often be2.7 done MeerGAL in to probe Galactic structure andanomalous dynamics, microwave emission including from the small spinning study dust of grains. hyper-compact HII regions2.8 and MESMER detection of the gravitational wave background,of tests gravity, of probing General binary Relativity evolution, and and alternative constraining theories the structure of nuclear matter. 2.10 TRAPUM discovery of large numbers of Fast Radio Bursts and of pulsars in targets such as unidentified ies, galaxy groups and galaxyinstead the clusters commensal was use not of allocatedservations data observing with obtained MeerKAT time, by was but other not surveys. the consideredrecommended to TAC The that suggested be proposal in VLBI to the conduct observations categoryobservatories. VLBI be of ob- large scheduled surveys, using and the the TAC common practice at other major 3. Concept and Baseline Design to refine the initial telescope specifications provided in the call for proposals [ MeerKAT 2.6 ThunderKAT sociated with molecular gas inhydrogen high-redshift in ( the early universe. 2.9 Pulsar Timing (MeerTime) sources, supernova remnants, and globular clusters,in will extreme contribute environments to and the of understanding Galactic of dynamics. physics 2.11 Proposals approved, but not allocated observing time PoS(MeerKAT2016)001 . 4.2 Justin L. Jonas at 1420 MHz (equivalent 00 ]. This configuration provides 1 ] include: and 80 1 00 8 km. A 60 km “spur” was part of the original 4 ∼ . . 4.3 4.3 (equivalent to a slightly truncated JVLA B configuration), and a gradual 00 Changing the antenna optical configuration from ainal) 12 m 13.5 symmetric m centre-fed offset dish Gregorian to a dish. (nom- The motivation for thisReduction change of is the given in number section ofphysical aperture antennas with from the larger 80 dishes). to 64 (thusLimiting retaining the the maximum original array aggregate baseline to concept, but this was excluded on the basis of costThe and use feasibility of issues. two-stage Gifford-McMahon (G-M)opposed cryogenic to coolers the in the original receiver concept systems, offor as using this single-stage decision Stirling-cycle is systems. given The in motivation section The use of sub-octave band receiver systemsfor in this place decision of wide-band is receivers. given The in motivation section The antenna diameter, optical configuration, cryogenic cooling technology and receiver tech- Formal system design reviews, including a Concept Design Review (CoDR) and a Preliminary Key changes to the early MeerKAT concept described in [ • • • • • a flat sensitivity characteristicto for a angular simultaneous scales hybrid between ofhighest JVLA 8 resolution C of and 6 D configurations), a 50% sensitivity degradation at the The 2009 array configuration was a compromiseserving between pulsars the requirement and of extended, a low-brightness compact sources, coredistribution for and for ob- the medium-resolution, requirement high of dynamic a range scale-free imaging antenna [ nology were determined though aprocess. constrained joint The electromagnetic goal and was mechanicaloperational to optimization costs. maximize A secondary point-source goal sensitivityGiven of under the the difficulty the optimization of was constraints deriving to definitive of system maximizea specifications capital imaging pragmatic from dynamic and strategy a range. dynamic was range adopted requirement, signal where path the were Jones specified matrices to associated betation with stable is all and that components this smooth in will over assist time, the This tractable frequency calibration strategy and algorithms direction. placed to The tight achieve expec- thesidelobe constraints required levels, on dynamic circular range. the symmetry, antenna cross-polarizationand primary at the beam boresight RF characteristics signal and (near path withinreceivers (passband and the and flatness the far primary and physical beam) volume stability). available for Operational receivers, issues, were also such considered as in access theDesign to optimization. Review the (PDR), were convened to obtainpanels guidance were and chosen reassurance to from harness expert the panels.projects, experience of The such individuals as who ALMA, had ATCA, been WRST, involvedpanels eMERLIN in and were similar the large to JVLA. assess Key charges performancepresented. assigned risks, to technology these maturity and costing fidelity of the designs MeerKAT conceptualization. The evolution oftensive the exploration reference of concepts design and wasinstrument, technologies the moderated intended outcome by to the of optimize realities a the of detailed scientific a fixed impact and budget of ex- and the schedule. PoS(MeerKAT2016)001 Justin L. Jonas (equivalent to the proposed JVLA 00 5 (more accurate positions will be published once all baseline calibrations being 1 power and fibre reticulation, power(KAPB). conditioning, The and KAPB the houses Karooemissions a Array from large Processor electrical shielded and Building electronic room equipment providing housed within EMI it. protection against RFI maintenance These facilities include thedish forward assembly sheds, support construction base camps at and the Klerefontein, on-site workshops, road network. strip, electrical power supplyconnections. from the ESKOM national utility grid, and fibre optic data Because of programmatic and financial constraints, the current MeerKAT implementation plan In this section we provide high-level descriptions of the various elements of the MeerKAT MeerKAT infrastructure can be divided into three main categories: 2. On-site infrastructure directly supporting telescope operations, including dish foundations, 3. Infrastructure facilities supporting telescope construction, site maintenance and telescope 1. Bulk infrastructure providing services to the site, including access roads, aircraft landing only allows for two receivers that coverping the bands: frequency range (1) 580 UHF-band: MHz 580 to MHz 1670receivers – MHz 1015 are in MHz, being two and overlap- provided (2) L-band: by 900cover the MHz the Max – 1750 1670 Planck MHz MHz. Institute – S-band for 3500here). Radio MHz The Astronomy frequency implementation of band (MPIfR) the (no that originally specified further will band X-band details 8 receiver, operating of GHz over this the to frequency receiver 14.5 arelength GHz, provided of depends time on that factorsSKA1-mid. MeerKAT that operates Another are as consideration uncertain is an at the independentsystem this implementation that telescope time. plan will prior for operate A over the to the key SKA1-mid being (nominal) factor Band frequency included is 5 range into receiver the 4.6–13.8 GHz. 4. Implementation telescope, together with keysummary specifications of an and extensive engineering design exerciseincluding that considerations. design followed the reviews by principles This expert of panels. systems is engineering, a very abridged 4.1 Infrastructure conducted during commissioning have been completed). Theinto MeerKAT antennas SKA1-mid will towards be the integrated end ofcore the is construction centred phase on of the the MeerKAT array largerfraction core, array. of and The the the SKA1-mid MeerKAT SKA1-mid antennas array aperture will contribute within a the significant core. MeerKAT degradation of sensitivity for extended structures largerE than configuration). 80 In reducingapplied the when number optimizing of the array receptorthe stations positions, reduced from and array the 80 is angular to scale essentially64 64 sensitivity element identical the characteristic array to same of exceeds the criteria that were original.blockage of the of The original the aggregate 80 offset element effective Gregorianare array aperture antennas. listed because of in of The table the the physical reduced positions of of aperture the 64 MeerKAT antennas PoS(MeerKAT2016)001 S, 00 47 0 42 ◦ Justin L. Jonas 54 -57 [m] 674 333 705 998 412 207 106 839 503 -284 -612 -537 -918 -267 -226 -336 -360 -480 -429 -227 2935 3511 2935 1104 1996 -1075 -1614 -2099 -2280 -1614 Y 9 -16 -27 [m] 872 295 461 581 358 386 388 380 213 254 -578 -850 -593 -287 -362 -630 -896 1201 1598 2805 3685 3419 -2805 -3605 -2052 -1440 -3419 -1832 -1467 X M047 M048 M049 M050 M051 M052 M053 M054 M055 M056 M057 M058 M059 M060 M061 M062 M063 M032 M033 M034 M035 M036 M037 M038 M039 M040 M041 M042 M043 M044 M045 M046 Antenna values are positive towards north. 6 Y 16 49 93 27 63 10 32 -11 -51 -66 -93 -19 -49 -61 -52 [m] 123 236 386 462 253 212 148 111 350 330 -169 -302 -137 -279 -118 -135 -160 Y 1 -8 97 41 32 88 84 -99 -51 -89 -32 -66 -18 -90 -93 [m] 171 247 140 237 281 211 288 200 106 171 -296 -322 -373 -351 -182 -124 -102 X M030 M031 M020 M021 M022 M023 M024 M025 M026 M027 M028 M029 M009 M010 M011 M012 M013 M014 M015 M016 M017 M018 M019 M000 M001 M002 M003 M004 M005 M006 M007 M008 Antenna values are positive toward east and X E. Locations of the 64 MeerKAT antennas relative to the fiducial array centre at 30 00 38 0 26 ◦ 21 Table 1: MeerKAT PoS(MeerKAT2016)001 Justin L. Jonas to ensure lightning protec- Ω earthing conductivity specification. Ω 1 < 7 22 C. A smaller shielded room provides an 80 dB EMI shielding envi- ∼ Although primarily providing for the MeerKAT needs, the infrastructure was designed with Infrastructure elements that have direct bearing on the operation and performance of the Two key requirements for the dish foundations were stiffness (to achieve the required dish The KAPB provides three main facilities: electrical power conditioning, electronic equipment Power to the site is provided by three-phase 33 kV overhead lines from an ESKOM national the requirements of SKA1-mid inthe capacity mind. to support In SKA1-mid somecapacity (e.g. cases to the the support power SKA1-mid, currently lines). but installed it Inmid infrastructure is requirements others feasible with has cases to little there disruption extend is (e.g. themid, not existing the capacity site and the data to the installed link meet KAPB has has the sufficient space SKA1- fibres for to more support SKA1- equipment racks andMeerKAT DRUPS). telescope are described below. 4.1.1 Dish Foundations pointing accuracy) and grounding impedance (the specification was 1 racks and staff work areas. Alevel, providing large EMI fraction shielding of for the the buildingimizing electrical volume power EMI is systems buried risks and below and some natural thermal maximizingand ground insulation. construction EMI Min- of shielding the building. were The keybonded reinforcing issues bars and in considered crossing the during points cast the concrete toare walls design implement are galvanically all a bonded galvanically low-frequency to Faraday earthshielded cage, in order and room, to all fabricated prevent metallic using electrostatic fittings and discharge steel computing (ESD) panels, equipment arcing. associated provides A with 100frequency the large dB correlator/beamformer, reference science EMI sub-system, processor, user-provided shielding time equipment, and subsystems for guest (e.g. the instruments electronic the and building othershielded management auxiliary compartment system). at HVAC units keep the air temperature in the power utility substation near Carnarvon (thispower substation requirements). has been Special upgraded careoverhead to lines neet was would the taken not SKA1-mid present during an design EMI risk and due construction to arcing. to All ensure insulators are that over-specified the and a MeerKAT tion and EMI control). Eachpiles dish on foundation a consists of square 8 patternboreholes cast-in-drilled-hole (three are reinforced per drilled concrete to side) varying topped depths,specific with depending site. a on A square the steel geotechnical reinforced ring-cage conditions concretefor prevailing is slab. at the cast the into dish The the pedestal pile foundation flange.icaly slab, providing bonded The a to ring-cage threaded and ensure stud reinforcingbonded robust interface bars to lightning in the current the reinforcing paths. slabThe bars and first Buried in piles foundation radial order are to copper to be galvan- conductorsfor cast achieve the was are the used stiffness also as qualification the test.64 qualification foundations. article, Grounding with impedance a acceptance pull-test tests jig were being conducted used for4.1.2 all KAPB ronment for an on-site laboratory/workshop and telescope control room. 4.1.3 Electrical Power PoS(MeerKAT2016)001 Justin L. Jonas 8 1 redundancy, reducing the risk of down-time due to single points of failure. + N A high aperture efficiency (ranging from 0.71and to hence 0.81 across good the sensitivity. UHF to L-band frequencies), Low far sidelobes, providing some immunityation to of terrestrial strong and cosmic airborne radio RFI, sources and outside the of attenu- the imagingAn field. almost circularly-symmetric main beam andthe inner calibration challenges sidelobe provided pattern, by hence the a primaryvariation beam reduction of rotating in the relative time to the and sky direction (i.e. dependent slow beam pattern JonesElimination matrices). of ground radiation scatteringsystem off temperature of and feed thus legs increasing into the the sensitivity. feed, hence reducing the The data fibre cable from the site is strung on the 33 kV power line poles and terminates in All optical fibre links between the KAPB and the dish foundations are via ducts buried at The selection of a 13.5 metre projected diameter, “feed-down” offset Gregorian optical config- • • • • MeerKAT specialized procedure was employed when installing theof power delivering conductors. just These over lines 5 are capable MVA toare the designed site. for Electrical power conditioning systems within the KAPB All electrical power onrotary the UPS site (DRUPS) is units conditionedand located reliable in and power the protected to KAPB. bydynamic the These three power dishes DRUPS (2+1 factor units and correction. redundancy) provide the diesel cable. extremely central Power stable processing Transformer to substations electronics the distributed in dishes aroundone the is the and provides KAPB, array five via site and provide dishes. a apply 400reduce buried V the 22 Individual power risk kV isolation to of ring-main between transformers equipmentstructures. mounted damage on and down-time the caused foundation by of lightning each strikes dish on4.1.4 or near Optical dish Fibre Carnarvon. Currently this link operates atfibre 10 Gb/s has (constrained a by higher the terminal linkmajor equipment), capacity. national but the data An backbone onward that fibre followsproviding link the access railway from to line the the between SANReN Carnarvon national Cape terminal researchMeerKAT Town and network. data connects Johannesburg, SANReN to archive provides a located connectivity to at the Town. the Centre for High-Performance Computing (CHPC) in Cape a depth of 1.2 m,Waveguide below providing cutoff thermal feed-through stability filters for areroom used the at the for 1 KAPB fibre PPS and penetrations and into into the sample both dish clock the pedestal distribution shielded shielded compartment. fibres. 4.2 Dish Structure uration for the MeerKAT dishes wasof an this outcome of configuration the over system the CoDRthat competing process. results symmetric in: The centre-fed key parabola advantage is the unblocked aperture PoS(MeerKAT2016)001 ): 1 Justin L. Jonas ], to time-varying stresses resulting 3 9 on the sky) reference sources are used to correct for residual pointing offsets due ◦ 7 < An elevation over azimuth mountpre-loaded jack-screw geometry elevation employing drive. a dual-pinion azimuth driveA and cylindrical a pedestal tower with athe conical servo top drive section. electronics, A antenna shielded control compartmentintegral unit, part that receiver control of houses unit the and pedestal. data switches is an The reduction of internal specularmatrix reflections that is and smooth associated over passband frequency). ripples (i.e. aA Jones large volume for locatingindex multiple platform receiver that systems does and not support compromiseof the the services telescope clean on as optical the a path, receiver facility hence instrument. increasing the utility Reduced spill-over from ground radiation, particularly ifsub-reflector, hence an reducing extended skirt the is system fitted temperature below and the improving the sensitivity. Easy and safe access to thetion. receiver Large systems cranes when or the cherry-pickers antenna are not is required stowed for at installation its and lowest maintenance. eleva- The tender process for the dish structure design and construction was run on a “build to specifi- High dynamic range, wide-field continuum imaging requires that the Jones matrix for the The detailed optical configuration for the dish was derived using the joint application of full- • • • • • • . This limit is imposed by the geometry of the optical path and mechanical interference between ◦ to wind and thermal deformations, the pointingconditions accuracy and specification 25" is under 5" “normal” under conditions. “ideal”on These operating various specifications elements placed of tight the design dish constraints structure, including the axis encoders andcation” elevation basis, jack-screw. with the key specificationsreflector being efficiency, the telescope optical pointing configuration, accuracy aperture and phasethresholds. efficiency, repeatability, The and main compliance elements with of strict the EMI successful contractor’s design are (refer to Figure primary beam pattern remains stable overcycle. the This characteristic requirement time-scales of was the a visibilitythat key calibration nearby driver of ( the specifications for the MeerKAT dishes. Assuming from common load cases (e.g. windDeviation loading from and the the elevation-dependence use of gravity of deformation). because pure of conic the sections added complexity for of the the reflectors main (i.e. reflector moulding “shaping”) tools, was and not the associated consider cost. wave electromagnetic simulations andwas mechanical optimized finite to element reduce modelling.leakage the cause sensitivity by The de-collimation of configuration of key the performance reflectors metrics, and feeds such [ as cross-polarization the elevation structure and the pedestal tower. These performance advantages were shown to justifycomplex the structure extra “per relative physical to area” costconfiguration the of has the these the more advantages simpler over the centre-fed “feed-up” design. configuration: Furthermore, the “feed-down” A disadvantage of the feed-down configuration is15 that the minimum elevation limit is constrained to MeerKAT PoS(MeerKAT2016)001 Justin L. Jonas 10 A schematic diagram of the MeerKAT dish structure showing the major elements of the design. A yoke structure fabricated fromimuth steel and plates that the provides elevation physicalmetrology drives. attachments data to for the A the pointing az- two-axis algorithmcompressor tilt-meter within providing helium the is to antenna the mounted control receiver unit. inthe cryogenic yoke. The coolers the closed-circuit is yoke mounted on to the provide exterior of A primary reflector consisting ofporting aluminium a panels. tubular steel Because space-frame the(i.e. primary backup unshaped), reflector structure it is (BUS) is a sup- circularlydish. pure symmetric paraboloid The about of an panels revolution apex are thatin arranged is in a near seven given the concentric ring bottom rings havingpanel edge around the moulds of this to same the fabricate apex, figure all with of (but the everypiecewise not panels. panel linear outline). The because as-built of circumference This the of allowed straight theprojected edges main for diameter of reflector the of is the use 13.965 outer metres, panels. of hence This seven larger results than in the an nominal effective 13.5A metre tubular specification. steel space-frame supportindexer to boom the that BUS. connects the sub-reflector and theA receiver one-piece moulded compositeup Gregorian consists (elliptical) of sub-reflector. kevlar, carbon fibre The and composite aluminium lay- foils. A conical aluminium skirt below • • • • Figure 1: The small rectangular box on the foundation cap is the isolation transformer. MeerKAT PoS(MeerKAT2016)001 1 dB contour Justin L. Jonas − ). 1 from the boresight have a gain of less ◦ ] respectively. 5 ] and [ 4 11 3 dB contour the magnitude of the cross-polarization − 25 dB). − 23 dB below the peak primary beam response, and all further − 20 dB (goal − 30 dB), and within the − the sub-reflector intersects rays fromground the and reflects feed them horn to that the would sky. otherwise pointA towards rotating the receiver indexerthe platform secondary that focus position. positions In oneprovides addition mounting of pads to for the up the receiver digitizers, to a packages, vacuumand the four pump optical-fibre that receiver and receiver services indexer electrical the also systems receiver distribution cryostats, enclosures at (see Figure The UHF-band and L-band feed horns and receiver systems are of very similar design, with The feed horns have a wide flare angle and employ concentric choke rings to control the feed The system-level optimization described earlier showed that the improvement in sensitivity • 26 dB (goal the wavelength dependent scaling of the(OMT) dimensions components of being the the waveguide largest andand difference ortho-mode L-band between receiver transducer them. systems are Detailed to descriptions be of found the in UHF [ A major design challenge was tovery achieve short distances compliance between with the stringent receiver EMI feedswitches horns thresholds, and located driven the in by servo the the drive systems pedestal andhave shielded the digital high-speed drive data compartment clock (SDC). signals These and electronicbulkhead require filters components penetrations are through used the for SDC alldrive, wall. encoder electrical signals), signals High and (e.g. performance waveguide 3-phase below cutoff power penetrations supply, 3-phase are servo used4.3 motor for fibre Receivers optic (including cables. Feed Horns) out sidelobes are below this level. Sidelobes beyond 10 beam pattern. The feedpolarization beam performance patterns across were the optimized operatingconfiguration to . frequency provide range The optimum in main SEFD, theband reason sidelobe context designs for and of was adopting the the sub-octave receiver ability dishprimary systems to optical beam in tune preference performance. horn to andsidelobe wide- Wideband OMT specifications systems parameters are driven to do by obtain not requirementsattenuation optimal for allow of high sensitivity RFI the dynamic cosmic and range sources same away continuum from imaging degreethe the and field of second of sidelobe control. view. For is both more UHF The and than L-band operation MeerKAT than 0 dBi over 99%of of precision the pulsar timing sky. and high The dynamic polarization range specification continuum is imaging. derived Within the from the requirements of the primary beam the magnitude− of the Jones matrix cross-polarization terms must be less than resulting from the use ofLNAs two-stage and Gifford-McMahon lossy (G-M) OMT cryogenic componentsconsumption. refrigerators justified to Secondary the cool costs issues, the associated suchalso contributed with as to the the the complexity decision. use and The ofprovides novel power an cryo-pumping OMT and integrated to cryostat OMT, maintain design balun usedor cryostat and for vacuum calibration vacuum, the break signal receiver package coupler in that theand does waveguide simplified not or assembly require and RF maintenance a signalto procedures. thermal path, the All leading of first to these stage reduced components of losses are thermally the and tied mismatches G-M cooler to reduce noise resulting from resistive losses in the signal terms must be less than PoS(MeerKAT2016)001 Justin L. Jonas 1 m) interconnecting < 90 K for the L-band receivers and ∼ 12 300 K by heater resistors and a closed-loop servo circuit. The ∼ 30 dB, and provides a very good inter-polarization phase match for the calibration signal. RF conditioning unit (RFCU): This component provides analogitoring signal for conditioning a and single mon- polarization RF signalisolated prior RFCUs to digitization per (there digitizer are two package). independent and Amplifiers and programmable attenuators provide The two front-end LNAs (one per linear polarization mode) are thermally tied to the second The calibration noise source and second stage amplifiers are mounted on a temperature-stabilized Two outcomes of the system-level optimization were that the RF signal path should be as The UHF and L-band digitizers are very similar in design, with the only differences being • ∼ − 100 K for the UHF-band receivers. The design of the OMT restricts cross-polarization leakage stage of the cryo-cooler, and are temperaturecontrolled stabilized by at a 20 closed-loop K servo by circuit. heating The resistorsband L-band whose LNAs LNAs current have have is three one InP transistors InP and transistor thenecessary followed UHF- to by achieve two the GaAs gain transistors. stabilityachieve The a specifications thermal high derived stabilization imaging from is dynamic the range. system-leveltemperature The requirement heating and to results an in a almost smallwhere 100% increase the in increase requirement the in for receiver noise Jones the matrixin second-stage stability the heat took design precedence load. process. over raw This point source is sensitivity an example of platform inside the cryostat vacuum jacket.of The the platform cryo-cooler has and a weak is thermal held path at to the first stage short as possible toheterodyne reduce conversion VSWR should related be passbandproducts ripples, implemented (or and to “birdies”). that avoid The direct system resultingthe digitization receiver implementation complexity packages without was on and the to spurious receiver locate indexer the platform, mixer with digitizers a directly pair behind of short ( the frequency-dependent RF components (i.e.generator). the RF The conditioning main circuitry and designhigh the drivers spurious-free sample for dynamic clock range the (SFDR). digitizersappearing SFDR were in is gain a the measure stability, digital of passband outputsignals the flatness of (e.g. strength and the RFI of signals). ADCs spurious The relative signals digitizers to have the six strength functional units, of described strong, briefly narrow-band here: input MeerKAT path. The physical temperature of the∼ crossed-dipole OMT is to noise diode switching is controlled byand the digitizer. does The not receiver apply package any only RF provides signal signal conditioning. gain 4.4 RF Signal Conditioning, Digitization and Digital Signal Path coaxial cables transferring the RFown dedicated signal digitizer, from a the consequence receiver ofcoherent to even the when the requirement the that associated digitizer. receiver the is Each digitizer notof rotated sample receiver the the clocks has digitizers secondary remain focus presented its position. EMI The andprovided location temperature a challenges, successful but implementation. appropriate designshielded The measures necessary enclosures have EMI and shielding fibre isis optic achieved achieved by isolation through using of nested well-defined RFnested thermal compartments and paths to digital heatsinks from on components. the thean outer heat-generating casing environmental Heat shield of components the that management inside digitizer. reflects The direct the digitizers sunlight, are but covered allows by free air-flow over the heatsinks. PoS(MeerKAT2016)001 Justin L. Jonas ). Currently a 2 13 ). The maximum fibre run from a receptor to the KAPB is 4.5 ) in the KAPB and transferred to each individual digitizer via a dedicated 4.6 ) in the KAPB and is transferred to each individual digitizer via a dedicated 4.6 optical fibre. The PPSpassed generator on converts to the the optical ADC via signalple a into data. digital an fibre electrical The link signal to PPStime allow that generator precise delay is has time-stamping calibration of an of voltage optical sam- the(traceable retro-reflector to 1 UTC) that PPS and allows signal the precision digitizers pathrelative round-trip on to between the each the delay receptor centre (with TFR of a subsystem the well-defined at receptor). and the stable offset KAPB Noise diode control: This unit providesis a synchronized programmable with switching the signal 1 to PPS the and receiver that sample clock signals. fibre. The sample clock generator converts theA optical narrow-band clock signal filter to constrains an the electricalspecification. sine-wave. phase The noise sample to clock achieve frequenciesand the for 1712 required the MHz respectively. UHF sample and clock L-band jitter ADCs are 1088 MHz Pulse-per-second (PPS) generator: A precision 1tem PPS (see signal section is generated by the TFR subsys- the correct signal level towhich the is ADC, within and Nyquist a zone bandpass 2is anti-aliasing of the filter the ability ADC to defines employ (A the Nyquist secondary passband down-conversion).path advantage There of because is sub-octave no Walsh receivers phase switching switch is inentire the RF not RF signal implemented signal path on were bandpass MeerKAT. Key flatness design and stability. goals forAnalog the to digital converter (ADC): TheMeerKAT digitizers e2v because AT84AS004 it 10-bit is device a was single-core,SFDR selected non-interleaved performance. ADC for Digitizer that the qualification provides tests excellent have(ENoB) shown that is the effective 7.8, number of which bits isis electrically consistent decoupled with from the all ADCindependent digital circuitry manufacturer’s ADCs, by specification. one digital fibre-optic The forthe links. ADC each digital There polarization. voltage are data two The streamvoltage data ADC to samples. allow encodes single-clock-cycle the precision 1 for PPS time-stamping signal the Packetizer onto (D-engine): The D-engineADCs receives via the the 10-bit digital fibre-optic digital link voltageoptic and transceivers data frames and this from cables data the transfer into these two 10Gbpedestal packets Ethernet shielded to packets. compartment. the Fibre- receptor data switch located in the Sample clock generator: The sample clock(see for section the ADCs originates from the TFR subsystem • • • • • 10 km. ∼ The UHF and L-band digitizersthe on a pedestal given shielded receptor compartment connect via to four the 10GbE receptor multi-mode data switch links located (see in Figure single 40GbE single-mode fibre linkswitch transfers at this the data KAPB from the (see receptor section switch to the CBF core MeerKAT PoS(MeerKAT2016)001 ) extracts 3 CHPC Archive Cape Town

Justin L. Jonas Science Data Processing Data Science Data Terminal and GPS Maser Clocks USE USE TFR SKARAB SKARAB SKARAB SKARAB F−engine F−engine Equipment Equipment X/B−engine X/B−engine Shielded Room Time and Frequency Distribution Karoo Array Processor Building Karoo Array 40GbE

14

Correlator/ Core Switch Beamformer

Optical Fibre Distribution Frame Distribution Fibre Optical

Buried fibre fibre Buried

Switch Switch

Receptor Receptor Fibre Fibre Patch Patch Pedestal Pedestal Antenna Antenna Antenna #1 Digitizer 1 Digitizer 2 Digitizer 3 Digitizer 4 Digitizer 1 Digitizer 2 Digitizer 3 Digitizer 4 Antenna #64 A block diagram showing the overall MeerKAT signal transport and data processing architecture, Receiver Indexer Receiver Indexer Rx4 Rx2 Rx2 Rx4 Rx1 Rx3 Rx1 Rx3 The MeerKAT correlator/beamformer (CBF) subsystem implements an FX/B style central real-time signal processor. Theceptors antenna are voltage split data into streamsbeamforming the for (B) required both by number polarizations processing of from nodesis frequency all done called channels re- by “F-engines” prior a (F to digital asfrequency correlation response polyphase in across (X) filter-bank individual Fourier). channels and/or (PFB) (a that The requirementwhile driven is channelization minimizing by optimized spectral inter-channel line to spectral observations), provide leakagetions). a (a specified requirement uniform The driven by correlation pulsar and timing beamforming observa- operations are performed by processing nodes called voltage and visibility data from theAstronomical CBF Data) switch. is The used SPEAD for protocolthis the (Streaming diagram, transfer Protocol the high-speed for Control data Exchanging and overall Monitoring the of (CAM) Ethernet the subsystem links. components and Although shown. associated not signal shown paths in are embedded into 4.5 Correlator/Beamformer Figure 2: including analogue and digital signal paths, theprocessing digitizers, (SDP) the subsystem, correlator/beamformer and (CBF), the the time sciencethe data and receptor frequency switches reference in (TFR) subsystem. eachcables Signal of carrying transport the from 40 pedestals to Gb/sand the Ethernet. CBF beamforming core functions The switch (F-engines SKARAB ison and via processing the X/B-engines) buried nodes CBF single-mode receive core providing fibre-optic and switch. theto output filter-bank, Ports subscribe data are correlation to available via on various bi-directional the data ports CBF products, switch and that allow the user-provided science equipment data (USE) processing subsystem (see Figure MeerKAT PoS(MeerKAT2016)001 Justin L. Jonas ] that uses com- 6 15 4 096-channel, 4 Stokes visibilities, full digitized bandwidth 32 768-channel, 4 Stokes visibilities, full digitized bandwidth Four 4 096-channel tied-array beams Incoherent sum of antenna data Fly’s-eye mode with 64 independent spectrometers, one per antenna 4 096-channel, 4 Stokes visibilities, for five independentlysub-bands tuneable (TBC) 11.6 MHz or 6.6875 MHz 2 second voltage buffer data for transient capture (TBC) Tied array beam for VLBI The CBF subsystem is based on the CASPER concept and architecture [ The design philosophy for the CBF is to provide a moderate number of modes with limited The core switch will have spare 40GbE ports for the incorporation of user-provided digital • • • • • • • • parameterization (e.g. integration period) thatnumber cover of the very specific required modes, functionality, or rather abased than small on number a prior of experience large highly-configurable from modes. other Thisdevelopment telescopes strategy and and was the commissioning need effort. to maximize Themodes reliability MeerKAT and and CBF minimize data will products evolve (some to ofuser include community these the and are following the TBC technical and capabilities depend of on the the SKARAB evolving platform): requirements of the Early array releases will implement ahttp://public.ska.ac.za/meerkat/meerkat-schedule subset of this functionality (see: for the most up-to date deployment schedule). back-ends that can subscribe to anytelescope of voltages, the data visibilities products and flowing throughallows tied-array the for voltages. switch, the including expansion raw The of Clos thisrialize. facility architecture in of the the future, should core more switch user-provided equipment mate- MeerKAT “X-engines” and “B-engines” respectively (the XX/B and engines). B operations The actually channelized co-existswitch data on so composite is that re-ordered individual nodes and can routedfrequency process dual-polarization by sub-band. data corner-turner Full from Stokes logic all processing and receptors is within the performed a core by given both the X-modity and B-engines. network devices (the coreprocessing switch) nodes. to handle The digital coreswitches data switch transfer arranged and is as re-ordering implemented a between usingthat Clos provides a crossbar. full-crossbar, non-blocking large functionality, number This and that ofload-balancing arrangement is algorithm commodity multicast allows is capable. 40GbE for employed A to an customized minimizefull extendable packet MeerKAT collisions. CBF switch will The fabric be processing nodes SKARABgate for boards array the fitted (FPGA). with The the SKARAB Virtex boards 7CBF can SX690T implementation support field-programmable only up one to 16 40GbE 40GbE portarray ports, per releases but card of for is MeerKAT the will needed MeerKAT have tois a connect fitted reduced to with capability the the CBF core Virtex based 6 switch. on SX475T Early the FPGA. ROACH 2 board that PoS(MeerKAT2016)001 Justin L. Jonas 16 Karoo Telescope Time (KTT): Thethe KTT digitizers facility to time-stamp provides the the voltagequired 1 samples. for PPS This long-term is signal pulsar a that timing precise experiments, ishardware time that used service, components is primarily by traceable used re- to to within providetransfer 5 KTT ns GPS of are receivers. UTC. two Key hydrogen Thetime, maser the GPS clocks KTT common-view and maser methodology two clocksInstitute against time- is the of used UTC(ZA) South to clocks Africa located (NMISA). monitor,between at This in the real-time UTC(ZA) real National time and Metrology transfer UTC, isthat subject and makes to use high the of precision the time monthly offset timing tablesTFR from requires has BIPM instrumentation retrospective that for provide calibration measuring the the UTC-UTC(ZA) round-tripdigitizers. offset. delay The The of the digitizer 1 time PPS stamp signalspective to can off-line individual be calibration traced correcting to for1 UTC the PPS to delays. UTC(ZA)-UTC a offset precision and of the 5 ns receptor/TFR afterADC retro- sample clocks: Theprovided sample by clocks the are hydrogen derived masersplitters from clocks. provides the the A 64 5 tree phase-matched GHz networkare replicas reference sent of of to frequency the RF the 1 splitters, digitizers PPS on lasers and the and sample receptors optical clock (onePTP set signals Grandmaster: per that receiver Two band). GPS-disciplined rubidiumused clocks by provide the telescope PTP components reference suchmonitoring that as software. is the antenna control units and telescope control and Observation planning and scheduling. Telescope configuration and observation execution. The MeerKAT time and frequency reference (TFR) subsystem provides the time and frequency The control and monitoring (CAM) subsystem supervises the coordinated operation of all of • • • • • references that are needed byTFR the include: various components of the telescope. The services provided by All of the critical TFRshielded components room are that located provides in precision a temperaturereference purpose-built control. hardware compartment from This within isolates the the the temperaturea KAPB clocks cycling and characteristic of frequency of the standard mainon digital data pneumatic equipment vibration centre rack damping HVAC tables area equipment.EMC to that shielding reduce is of acoustic The the modulation hydrogen sample ofphase clock masers the noise generation reference are caused and frequency. by mounted distribution coupling componentsThe to is TFR the necessary design hostile to EMI employs avoid environment redundancysupply inside and of temperature the all control KAPB instrumentation, critical shielded to components room. ensure and a stable functions, and4.7 including reliable KTT power Control service. and Monitoring the telescope components. The key functions of CAM include: MeerKAT 4.6 Time and Frequency Reference PoS(MeerKAT2016)001 Justin L. Jonas 17 A block diagram of the science data processor (SDP) elements and data flow. The SPEAD protocol Ingest and pre-processing of visibilitiesaveraging, RFI from flagging, CBF, van including Vleck correction baseline and dependent data visibility quality monitoring. Voltage data capture. Signal displays. Data archiving. Calibration and imaging pipeline. Persistence of configuration and calibration data. Monitoring the status of all telescope components and infrastructure elements. Interfaces to operators, maintainers, developers and observers. The functions of the science data processing (SDP) element include: • • • • • • • • 4.8 Science Data Processing (Streaming Protocol for Exchanging Astronomicalexport Data) SDP is data used products. for SDP data data transfer is from stored CBF in to HDF5 SDP, format. and to Figure 3: The KATCP communications protocol is implemented ona all common MeerKAT subsystems and so consistent that interface there withobserving is CAM. modes, will The evolve functionality throughout of the CAM, deployment including of the the available MeerKAT array releases. MeerKAT PoS(MeerKAT2016)001 Justin L. Jonas elevation derived from L-band measurements ◦ 18 The spectrum of the SEFD of a single receptor at 37 shows the architecture of the MeerKAT SP subsystem. The processing nodes are a mixture 3 Dedicated ingest processors are assigned to the three variants of CBF data products: full dig- The calibration nodes use double-buffering to allow sufficient processing time to obtain ro- Although there will be a standard MeerKAT processing pipeline, a set of tools is being devel- Figure 4: made of Tau A, smoothedusing three over different 1 L-band MHz receivers. The frequencymeasurements error made bins. bars with on all The the three measured measurements receivers. curves were represent the made total on range antenna of all M062 itized bandwidth visibilities (Wb), five sub-bandessary visibilities because (Nb) CBF and can tied produce array allthe (BF). of data This these from is products the nec- simultaneously.node. The various SP ingest Visibilities core processors are switch to initially directs bufferedvoltage an in data appropriate disk store storage storage is location and usedVLBI and/or then for experiments. calibration transferred non-imaging to observations a and tape can library. be The exported in VDIF formatbust for calibration solutions in real-time.pipeline. The The imaging post-calibration pipeline capitalizes data on isalgorithms, the then inherently and parallel streamed consists nature to of of the thefinal visibility data imaging images buffers, and are imaging imaging transferred nodes to the and science a archive. dedicated switch fabric. The oped to allow an external userbased to on run the their Docker own platform. applications on the SDP hardware. These tools are MeerKAT Figure of CPUs and GPUs,capital and and operations novel cost processor ofExchanging options the Astronomical are SDP Data) subsystem. is currently used The being fordata SPEAD data investigated is protocol transfer stored to throughout (Streaming in the lower HDF5 Protocol SDP format for the subsystem, on and disks SDP and tape. PoS(MeerKAT2016)001 elevation ◦ Justin L. Jonas were made at a 4 19 . Tipping curve measurements show that the SEFD at 15 ◦ shows the results of L-band SEFD measurements made with MeerKAT 4 A histogram of all referenced pointing measurements made to date on all integrated receptors This improvement in sensitivity over the original specification was a result of the design A hierarchy of tests against the required specifications and functionality are performed as MeerKAT was optimized for point-source sensitivity because this was a common requirement relatively low elevation of 37 is less than 20% higher than at zenith over all L-band frequencies. Figure 5: under all operating conditions. receptor M062, the second MeerKAT receptorThis to plot be shows installed that and the integrated SEFDfrequency (the is range, first far and better was than M063). that the thepredicted original curves measured were specification curves derived across from the follow simulations entire the andThe L-band measured predicted large data deviations performance for in components quite the such well as measuredstations, LNAs). curves (the and are Galactic due HI to RFI (at from 1420 satellites MHz). and mobile The phone measurements base shown in Figure individual telescope components are assembled intoacceptance increasingly tests complex are functional units. performedare on Initial performed low-level as devices, subsystem and and system moresubsystems assembly sophisticated to progresses. and prove Qualification that extensive tests are tests theachieves performed the design on required and performance and manufacturing functionality, processes andarticles that have this are resulted compliance produced. is in repeatable an as Theare more article majority allocated that of to the the most receptor,this important comprising reason MeerKAT the this performance section dish specifications will structure, focus feed on horn, MeerKAT receptor receiver qualification and tests. digitizer.for For all of the LSPs.density (SEFD) The was original 12.55 Jy. specification For for theSEFD the 64-element MeerKAT of MeerKAT array aggregate this 800 corresponds system-equivalent Jy. to flux a Figure per-receptor MeerKAT 5. Telescope Performance PoS(MeerKAT2016)001 Justin L. Jonas summarizes all point- 5 23 dB specification, and that − 20 compares the beam pattern at 1350 MHz predicted 6 5" equaling the specification for ideal operating conditions. Short time-scale pointing Comparison of the simulated MeerKAT L-band (1350 MHz) primary beam derived using electro- ∼ The characteristics of the receptor L-band primary beam pattern were derived using various The key receptor performance factors affecting imaging dynamic range are telescope pointing 10 dBi being recorded over a large fraction of the sky. These excellent beam characteristics the cross-polarization specifications are exceededspecification). by Raster a scan large measurements of margin the (inshowed far fact that sidelobes they using the a exceed 0 satellite the beacon− dBi goal at specification 1549 MHz was exceededvindicate over the 99% selection of of the the Gregorian sky, offset with optical configuration levels and of sub-octave feeds. less than techniques, including holography. Figure Figure 6: magnetic simulations (left) and thewas beam made of prior receptor to M062 final measured collimation of using the holography. reflector The surfaces measurement and feed receiver indexer. using a full-wave electromagnetic simulation against themeasured beam using pattern of L-band MeerKAT receptor holography M062 show (the that reference the measured source beamM062 was pattern was a known matches satellite to the beacon). have simulationspatterns a indicate very that collimation the These closely, second problem despite sidelobe plots at is the comfortably the less fact than time the that of the measurement. The measured ing error measurements made to date for(these all measurements commissioned employed receptors offset under reference pointing, all as observing definedcation). conditions in The the receptor MeerKAT receptors pointing specifi- clearly exceederror the of required specification, with the“jitter” mean pointing was quantified using ansecond optical period the camera jitter to was observe shown to bright be stars less while than tracking. 2". Over a 10 accuracy and stability, and the primary beam pattern characteristics. Figure MeerKAT choices made at the CoDR and PDRoptics, stages sub-octave of receivers the and project, G-M specifically cryo-coolers. the choice Ku-bandusing of holography Gregorian a measurements offset satellite were made beacon signalqualification in tests order showed to that characterize the APE Ruzespecification. exceeds effects MeerKAT receptors 95% at will at higher function 14.5 frequeincies. well GHz, at and These frequencies hence up exceeds to the and original above 25 GHz. PoS(MeerKAT2016)001 compares the Justin L. Jonas 2 1 km/s resolution /K (UHF-band) /K (L-Band) . 2 2 0 2 ≈ 2 provide As-built value 64 13.965 m 0.71–0.79 (UHF-band) 0.75-0.81 (L-band) 5 deg 0.85 deg 27–20 K (UHF-band) 22–18 K (L-Band) 241–366 m 305–339 m 29 m 7.7 km 0.58–1.015 GHz (UHF-band) 0.9–1.67 GHz (L-Band) 0.544-1.088 GHz (UHF-band) 0.856–1.712 GHz (L-band) 32768 (wideband mode) narrow-band zoom modes will 1.75–3.5 GHz. 21 ≈ ]. The rational methodology used during the MeerKAT /K 1 2 2 2 – 16 384 0.7 6 deg 1 deg 30 K 200 m 20 m 8 km (60 km with “spur”) 0.58–2.5 GHz 2009 value 80 (+ 7 along a “spur”) 12 m (array) sys Key MeerKAT system parameters for UHF and L-band operation for both the 2009 reference T / e Number of channels Minimum baseline Maximum baseline Frequency range Processed band Field of view at 1.4 GHz System temperature A Number of antennas Antenna diameter Aperture efficiency Field of view at 0.58 GHz Quantity The conceptualization, design, construction and commissioning of the MeerKAT telescope key parameters of the as-builtoriginal MeerKAT against call the for the large survey reference proposals design [ figures presented in the and associated infrastructure were basedquirements on were the extracted principles from of a system prioritizedinto engineering. science specifications Key case, allocated science and to re- these the requirementswere various were driven telescope by converted components. rational optimization Design processes andement and technology testing critical choices and assessment system of commissioning technology have maturity. been El- thorough and rigorous. Table design and the as-built telescope. TheAstronomy S-band will receiver extend being the provided frequency by coverage the to Max Planck Institute for Radio 6. Conclusion Table 2: design and deployment has lead toover the the significant increase original in 2009 thesult reference telescope point-source of value. sensitivity budget constraints Other (e.g. changeschannels). maximum in Construction baseline) the and and telescope commissioning technology of developmentsclosely, parameters and (e.g. MeerKAT were early is correlator user-proposed the following science the re- will planned commence schedule in very 2018. MeerKAT PoS(MeerKAT2016)001 Justin L. Jonas (2014) EuCAP. A Decade of Developing (2016) (2012) ICEAA, Cape Town. (Oct 1976) IEEE AP-S ]. MeerKAT Key Project Science, 22 Offset dual reflector antennas arXiv0910.2935B The design of the MeerKAT L-band feed The Design of the MeerKAT UHF Band Feed (2009) [ (2009) 1522-1530. 97 ] MeerKAT - The South African Array With Composite Dishes and Wide-Band Single Pixel IEEE Proceedings , arXiv:1611.01826 Radio-Astronomy Instrumentation using CASPER Open-Source Technology [ R. S. Domagalski, J. Ford, G.G. Foster, Jones, D. F. George, Kapp, J. H. Greenberg, Kriel, L.R. R. Greenhill, McCullough, Lacasse, A. M. A. Isaacson, V. Lutomirski, Muley, H. W. D. New, Jiang, V MacMahon, A. Van J. Parsons, Tonder, L. D. Manley, A. Vertatschitsch, C. M. Martens, Price, Wagner, J. R. Weintroub A. and Primiani, D. J. Werthimer, Ray, A. Siemion, International Symposium Digest. Feeds Specifications, and Proposals [2] J. L. Jonas, [3] Y. Mizugutch, M. Akagawa and H. Yokoi, [5] R. Lehmensiek and I. P. Theron, [6] J. Hickish, Z. Abdurashidova, Z. Ali, K. D. Buch, S. C. Chaudhari, H. Chen, M. Dexter, [1] R. S. Booth, W. J. G. de Block, J. L. Jonas and B. Fanaroff, [4] R. Lehmensiek and I. P. Theron, MeerKAT References