Pos(10Th EVN Symposium)049

PoS(10th EVN Symposium)049 http://pos.sissa.it/ urham, smouth, Queen ex, and ores, Kent, In this brief paper we discuss ddition of extra local processing al description of the Chilbolton ted and signiﬁcantly increases the VLBI and the new generation of radio ronomy collaboration in Britain, as s well as providing a unique training on software telescopes. The station has e Commons Attribution-NonCommercial-ShareAlike Licence. ∗ [email protected] Speaker. site and testbed for british experiencebeen funded with primarily next-generati through the LOFAR-UK, the largest ast angular resolution of the International LOFAR Telescope, a well as via the South East Physics Network (SEPNET) and STFC. The LOFAR-UK station at Chilbolton has recently been comple the history and organisation ofsite, and LOFAR-UK, discuss provide how LOFAR a stations can technic capabilities be such augmented as by ARTEMIS. the a ∗ Copyright owned by the author(s) under the terms of the Creativ c

arrays September 20-24, 2010 Manchester Uk 10th European VLBI Network Symposium and EVN Users Meeting: Edinburgh, Glasgow, Hertfordshire, Leicester, Liverpool JohnManchester, Mo Newcastle, Nottingham, Open University, Oxford,Mary, Port University of London (QMUL), Sheffield,University Southampton, College Suss London as well asThe STFC/RAL South and East the England UK Physics ATC Network (SEPnet) The Science and Technology Facilities Council (STFC) The Universities of Aberystwyth, Birmingham, Cambridge, Cardiff, D LOFAR-UK Rob Fender School of Physics & Astronomy, UniversityE-mail: of Southampton PoS(10th EVN Symposium)049 Key tence and Rob Fender s identified as nnection to the ey improve the n Group of the tional array and his is an existing e goal of securing .ac.uk) also made ne of its founding the collecting area 50k). The research the project, directly t Chilbolton. At the orders of magnitude ational partners into at the low frequency k and Lord’s Bridge ed LOFAR as its key ) of the International sented in the LOFAR- ct one or more LOFAR ul anti-coincidence tests Square Kilometre Array On 12 June 2010, at the use of the term ‘software , Germany, Sweden, France ramatic increase facilitated in 300k) was also provided to the project by the ∼ 2 200k) and agreed to cover operations costs in 2011 and 2012. ∼ The site chosen for the LOFAR-UK station was the Chilbolton Observatory. T In early 2010, the Science and Technology Facilities Council (www.scitech The LOFAR-UK (www.lofar-uk.org) consortium was created in 2006 with th International stations are important for LOFAR both scientifically because th LOFAR (www.lofar.org) is a ‘next generation’ radio telescope operating 70%) is in The Netherlands. ∼ a significant contribution (GBP At this point the contracttime was signed of with writing ASTRON (March and 2011), constructioncorrelator construction began in of a Groningen the is station complete,‘stand-alone’ is and operations complete, scientific has the commissioning begun. of fibre both co interna 2.2 Chilbolton UK South East Physics Network (SEPnet,astrophysics www.sepnet.ac.uk), theme. which Figure identifi 1 illustrates the breadth of the consortium. UK involvement in LOFAR. The aim wasstations to and purchase, in construct and this conne Science way Projects allow (KSPs). UK The involvement case inUK for white LOFAR UK paper science, (Best participation et mainly in al., via LOFAR 2008).committing was the By resources pre 2009 to existing over the 20 UK project institutions (incouncil had most joined site cases funding at at Chilbolton thethe level (www.chilbolton.rl.ac.uk), of prefered in GBP site the for southwere the of also station, considered. England, although Significant wa equally funding good (GBP sites at Jodrell Ban angular resolution of the telescope,the project. and politically LOFAR stations because separated theyagainst by draw local large intern RFI distances also when actofficial making as inauguration wide-field usef of searches LOFAR, for theLOFAR fast Memorandum Telescope transients. (ILT) of was signed Understanding by (MoU partnersand from The The Netherlands United Kingdom.LOFAR can On genuinely 9 be said Novembermembers. to 2010 be the a ILT pan-European Foundation project, came with into the UK exis as2. o LOFAR-UK 2.1 Background Science and Technology Facilities Council (STFC) facility run by the Chilbolto (30–240 MHz) end of the radio spectrum.more sensitive The than telescope previous will observatories be in more this than frequencylarge two range, part a by d advances in computingtelescope’. power and LOFAR data is transport, hence also(SKA, the the www.skatelescope.org). largest low-frequency The pathfinder project( for is the led by ASTRON and most of LOFAR-UK 1. LOFAR PoS(10th EVN Symposium)049 ce ch tile is Rob Fender It comprises cast and the n be treated as 120 to 240 MHz nds 1.8m tall, with alogue beamformer -loading reasons; it e of Chilbolton near 6 aerials set out in a and Array (LBA), with ystem is 30 to 80 MHz, fields are enclosed within a, the site has a good aspect nd this range, as low as 22 gest Astronomy consortium in the 3 The institutional logos of the LOFAR-UK consortium, the lar The 80 to 120 MHz spectral region is the allocated band for FM radio broad The HBA comprises 96 square tiles, 5 by 5 metres in size with a height of 0.5m. Ea The LOFAR facility installed is what is referred to as an International Station. LOFAR system is designed to suppress thisa spectral perimeter region. The fence, antenna madeprevents incursions of by timber wildlife or and stock synthetic onto the mesh antenna to field. minimise the RF impact. The fen split into 16 cells containing crossed-bowtieto antennas. combine Each the tile signals has its fromindividual own the antennas an cell in antennas. the same Therange. way outputs A of as 97th the the passive 96 LBA.has tile tiles The no is signal can HBA located output the system in (it covers is the indicated the centre by for a RF-balancing C in and Fig wind 2). two fields of antennas. Theythe are high the and High-Band low Arraypseudo-random referring (HBA) pattern to and with Low-B the a frequency diametertwo ranges. of crossed, approximately sloped 70m. The dipoles. LBA Each comprises aerialalthough The sta 9 observations nominal have frequency range since ofMHz. been the successfully LBA carried s out beyo Figure 1: UK. Credit Martin Bell. Rutherford Appleton Laboratory. The siteStockbridge is in located Hampshire, on England. the Apart edge fromand the of all necessary the the land villag necessary are scientific infrastructure to accomplish the project. LOFAR-UK PoS(10th EVN Symposium)049 f Rob Fender -Bukowski tance from er with air- to the main nagement, site e Netherlands, port of students r and the facility ed and installed by by Excel assemblies The station’s official nnection of the local e primary contractors ted. ound works commenced e analogue RF signals, as tronics. Two coaxial cables structors. Antenna hardware 4 Installation work was carried out during the summer of 2010. The project ma From the RF container, there is an optical fibre which carries the digital data The following is a timeline of important events in the construction and commissioning o Also within the enclosure there is a converted 20-foot (6.1 m) shipping contain Construction and project management at Chilbolton was led by Derek McKay 17-Mar-2010 Start19-Apr-2010 of ground works 18-May-2010 RF-container placed in final location Laying of07-Jun-2010 all antenna signal cables complete 11-Jun-2010 Start of LBA aerial deployment 02-Jul-2010 LBA installation complete 14-Jul-2010 Start of HBA tile deployment 15-Jul-2010 HBA installation complete 01-Sep-2010 Electronics in RF container06-Sep-2010 installed First signal from antenna to fibre 20-Sep-2010 First pulsar detected using local computing 12-Oct-2010 Site officially opened by Dame Jocelyn09-Dec-2010 Network Bell installation Burnell and offsite fibre First11-Jan-2011 network packet at 10 Gbit/s18-Jan-2011 from First site fringes to between CEP UK608 and Dutch Observations core for stations first long-baseline image observatory buildings. Asystem further to network a interface commercial there fibrewhich completes is routed the where offsite. the co Central This Processing link (CEP) supercomputer extends facility to2.2.1 is Groningen loca Construction in history th UK608 Chilbolton. conditioned Faraday enclosure holding the digital signalconnect processing elec each aerial and tilewell to as the DC power central and RF-container. low-baud control These signals. carry th (SEPnet / STFC). 2.2.2 Timeline LOFAR-UK supervision and quality assurancefor was the carried ground works out being bywas Kier-Moss supplied and STFC by subcontractors staff, Autonational Coral and with Con RF(both th electronics under installation contract was from carried ASTRON). out on After 17 an initial March planning 2010. phase,of gr local In universities. early June,U. The the Manchester following LBA and month, aerials U.Cambridge. were theU.Oxford A installed HBA SEPnet (see with data tiles section acquisition the were 2.3) system,was sup installed demonstrated develop officially with opened a by assis working Dame system Jocelyndesignation Bell is in UK608. Burnell early on Septembe 20 September 2010. PoS(10th EVN Symposium)049 Rob Fender

r=36

LBA

Timber perimeter fence

North

95 54

r with a photograph of the completed

81 36

nd it, and in the distance the Chilbolton

74 20

including the LOFAR-UK control room (and

86 31

5 59

4 r=31 RF−Container

HBA

Access road

25m dish and observatory buildings

93 84

Station layout for the LOFAR station at Chilbolton, togethe

92 91 ARTEMIS), is close to the dish. Credit STFC. station. The LBA fieldradio is dish, in not the part foreground, of with the LOFAR HBA station. field behi The site building, Figure 2: LOFAR-UK PoS(10th EVN Symposium)049 Tesla n UK. Fig Rob Fender k stream. The er instruments. 00 Mbps streams, ckend to record or telescope agnostic; n also operate com- -Research Centre, has ders for the SKA, and st radio transients. The nitor and Identification igh-end NVIDIA to successfully process m international LOFAR n share some of the elec- nd for the science targets n, which are all separate processing the data in real-time, 6 Low band array – technical details High band array – technical details Table 1: Table 2: During the last year, a team from Oxford Astrophysics and the Oxford e The ARTEMIS project is led by Aris Karastergiou (Oxford). The ARTEMIS backend can behave both as a general purpose backe Antenna:Polarisations: 2 linear Longitude: 96 sloped crossed-dipoles Latitude: 1.433500703 deg W Mean height:Diameter: 176.028 51.143833512 m deg N 70 m (approx) Array:Tile:Polarisations: 2 96 linear Longitude: tiles Latitude: 16 1.434454726 crossed-bowtie deg W Mean height:Diameter: 177.048 51.143546200 m deg N 62 m (approx) put together an instrument capable ofstations, with processing the the main beamformed objective data to conduct fro instrument, large code-named field of ARTEMIS view (Advanced surveys Radio forSystem, fa Transient Event and Mo ancient Greekthe goddess full of 3.2 hunting), Gbps has3 streaming been presents bandwidth demonstrated a generated flow by diagrameach the for of LOFAR ARTEMIS. which station This is flow in fed of Chilbolto into data a is high split performance into server, four connected to 8 eight h 2.3 Artemis LOFAR-UK mentioned above, and specifically for themensally with detection other of possible transients LOFAR - observations. theit Furthermore, latter was ARTEMIS is designed ca and built withFor example LOFAR the in newly mind, constructed but EMBRACE aperture cantronic arrays, be component which easily eve design adapted of LOFAR to can fitprocess be oth data exploited by on fitting the an fly. ARTEMIS BothARTEMIS ba is EMBRACE designed and as the an LOFAR expandable arrays solution. are pathfin graphics cards (C1060). The serverswith are the possibility capable to of flag reading, interestingprocessing and events and involves also RFI write excision, out detection, toparts disk integration of or a and to modular dedispersio a software networ pipeline. PoS(10th EVN Symposium)049 nd-alone Rob Fender r free, during participation in e strong and di- nts, postdocs and (including pulsars, e mainly devoted to d in analysis of LOFAR erations with ASTRON, can become a model for ) and long-baseline tests as part of 7 LOFAR-UK White Paper: A Science case for UK involve- A flow diagram for ARTEMIS. Credit Aris Karastergiou. Figure 3: arXiv:0802.1186 , LOFAR-UK would like to acknowledge the invaluable work provided, mostly fo The LOFAR-UK collaboration should, furthermore, act as an indicator of th At the time of writing Chilbolton has completed its first test observations as both a sta the construction of the LOFAR-UK station atstaff. Chilbolton by an army of PhD stude References Best P., and the LOFAR-UK consortium, ment in LOFAR verse interest in ‘next generation’how radio we astronomy build across national the interestthe in UK. Square a This Kilometre strong Array. and energetic scientific community for Acknowledgements station and as part of thetesting ILT (see and timeline commissioning, above). with The a comingSETI number year work, will of solar also observations, further b searches stand-alone for observations bright,the rare ILT. transients In the very nearon future behalf STFC of LOFAR-UK. will Many sign tens of bilateral britishdata, agreement scientists and for are this already op number involve is growing fast. 3. The future LOFAR-UK