LOFAR-UK on Sky at Night

Related to the previous post, LOFAR-UK will also feature in the upcoming episode of Sky at Night after Chris Lintott helped with the LBA installation in June.

LOFAR-UK in Sky at Night Magazine

There is a 6 page article about LOFAR-UK and Chilbolton in the September issue of Sky at Night Magazine.

LOFAR-UK on the main LOFAR website

The main LOFAR website ran a story this week about the Chilbolton Opening.

We are also featured in the ASTRON Daily Image for today.

(After today you can find this and other daily images about Chilbolton by going to the Archive (link at top of the Daily Image page) and searching for "Chilbolton".)

Derek's Talk at the Opening

On Monday I filmed the speech given by Derek McKay-Bukowski (LOFAR-UK Project Manager) at the evening event in the Intech planetarium. Thanks are owed from all of use to Derek for making LOFAR-UK such a success.

Video of Soundbite Interviews

At the opening on Monday I filmed short "soundbite" interviews with many of the scientists involved in LOFAR-UK. The resulting video is a nice summary of the excitement felt within the UK community (and wider) about our involvement in LOFAR.

Video of Ribbon Cutting at Chilbolton

This video shows hi-lights from the part of the LOFAR-UK opening on Monday 20th September 2010 which took place at the Chilbolton Observatory itself. This included a ribbon cutting by Dame Jocelyn Bell-Burnell, and some real time observations of a bright pulsar (as explained by Dr. Aris Karastergiou).

Coverage of the Opening

There has been some online coverage of the opening events on Monday. Here's a collection of links. If you have something to add let me know.

BBC Science Article

Redorbit (Science, Space, Technology and Health News and Information)

Space Daily

Sify News (Indian News)

LOFAR-UK links:

Universities:

Birmingham,
Edinburgh,
Portsmouth,
Southampton,
Sussex

STFC Press Release (which includes a video of the ribbon cutting and the first pulsar observations)

Official LOFAR-UK Opening

Yesterday was a big day for LOFAR-UK. The station at Chilbolton was officially handed over (as per an earlier blog report) and was also officially opened by Dame Jocelyn Bell Burnell in a ribbon cutting ceremony out in the field.


(Picture taken by James West, SEPnet)

This ribbon cutting was followed by real time observations of one of the brightest pulsars in the sky (thanks to Aris Karastergiou from Oxford Univ. who had worked very hard and set up some impressive computing to process the data to show us in real time). Jocelyn seemed very pleased to see the telescope worked, and was very excited particularly about it's potential to detect new transient radio emitters.


(Picture taken by James West, SEPnet)

After the Chilbolton event was a celebratory event held at the nearby Intech Science Centre. Rob Fender (LOFAR-UK PI, Southampton Uni), John Womersley (STFC), Mike Garrett (ASTRON) and Derek McKay-Bukoswki (Chilbolton Station Project Manager) all gave talks, and then Jenny Shipway (Intech Planetarium Manager) gave us a wonderful planetarium show specially adapted to include links to LOFAR science. I think I can speak for most astronomers in the room by saying that we don't get to see planetarium shows very often, and it was a wonderful reminder of the inspirational science behind why most of us got into this game in the first place.

Also we had cake.

(Picture taken by Bob Nichol, Portsmouth).

Well done to everyone involved.

Sign of the times

The finishing touch on the LOFAR field was putting up the sign. On it, apart from the station name (LOFAR-UK Chilbolton) and number (UK608), there are the logos/names of all the contributing organisations.

Official hand over from ASTRON

On the morning of 20th September 2010, just ahead of the official opening, the delegation from ASTRON arrived at Chilbolton Observatory to review the progress and hand over the LOFAR station formally to STFC and LOFAR-UK. Part of this included an inspection of the site and the comments were all extremely positive concerning the professional work done, efficiency of the build and the final presentation and attention to detail. During the handover meeting itself, Corina Vogt (the ASTRON representative) said that the only thing she had to say about the field was "Wow!"

Caption : Corina Vogt, Michiel van Haarlem and Harm Munk at LOFAR Station UK608.

Ready for a new era of British Astronomy

The LOFAR Chilbolton Radio Telescope now stands ready for the official opening, which is due to be held on Monday 20th September 2010. Although the opening is but a single moment in a long programme of construction, installation and commissioning, it is a significant one. And now is a good time to pause and reflect on the past few months and what work has been achieved. To have come so far so quickly has been fantastic and everyone involved in this project should be proud of all that we have accomplished and look forward to the significance and celebration that will follow.


Caption : Looking through the LBA field at sunset. The monolith on the horizon is the RF container and in the distance the silhouette of the 25m dish can be seen.

Replacement Signal Processing Board

During the commissioning work, we discovered that one of the network connections on one of the digital signal processing boards was not working correctly. By exchange modules with others, we could determine that the fault was located in this particular board. As soon as we have completed the detective work, ASTRON were notified and a replacement board was sent out immediately.


Caption: This new board has now arrived and was fitted and initialised. The photograph shows the board as it was being unpacked. The new component is now fully fitted and is working correctly.

Aerial at dusk

This photograph is a close-up shot of one of the low-noise amplifier (LNA) modules that is found at the head of each low-band array (LBA) aerial. This particular one is number #76, the number of which can be discerned in amongst the other code sequences on the bar-coded label.

More commissioning work

With only a few days until the official opening, everyone is really putting in the hours to ensure that as much commissioning work is being accomplished as possible.


Caption: Aris Karastergiou works late into the evening with the configuration of the Local Control Unit in the RF-container.

Front desk

At the front desk at Chilbolton Observatory is Jan Lass. Now, Jan is just great; she is the friendly smile whenever our visitors or colleagues arrive at the site and she ensures that everything remains organised and efficient. Jan has been instrumental in sorting out some of the important contracts that were placed for the LOFAR project and we have only managed to get this far because of her work behind the scenes.

Caption: Many thanks Jan, we really appreciate all you have done for the LOFAR Chilbolton project!

Installing the data processing system

The data processing system for the LOFAR Chilbolton station is being developed by Oxford University. When complete, it will be a large system with multiple server and control computers as well as a small cluster of GPU blades to do the heavy-duty number crunching. As part of the initial commissioning work, a small part of the final system is set up temporarily in the comms room at the Chilbolton Observatory, in order to test the system.


Caption : Aris Karastergiou (left) and Alan Doo at work on the installation of the two GPU blades in the rack on the left. The tangled bundles of cables on the right are NOT part of the LOFAR system!

Checking the polarisation

There are a lot of connections within the system and it is important to check that they are all working. One that is difficult to notice is the polarisation of the signal. In order to test this, a temporary test transmitter is setup, which sends out a low-power signal. This is then used to check that the correct signal is going through the correct chain in the electronics.


Caption : Here is the test aerial. The RF-container can be seen in the background.

Skip nothing

On 2nd September 2010, the skip that was located at the LOFAR field site was removed and brought back to the main Observatory compound. From there, it was loaded with a few more items which needed disposing of from there. However there was very little waste to be removed.


Caption : Here the skip is about to be loaded onto the lorry for the last time before leaving the site.

Setting up the networks

During the work on the LBA and HBA, there was a parallel task of establishing the network connections. These are for within the RF-container itself, but also between the RF-container and the main Observatory building.


Caption : Klaas Stuurwold takes some notes during the network set-up process.

First signals

On 1st September 2010, at 11:38 UTC (12:38 local time), we measured the first signal from the completed LBA array at Chilbolton. These data are from all 192 channels (96 aerials, 2 polarisations each) and show the expected bandpasses from all elements functioning normally. Although not a sky image just yet, this is an important milestone in the development of the project. Thanks go to Menno Norden, Klaas Stuurwold, Henri Meulman and the local commissioning team for their work in getting to this point. However, this is also a moment for everyone involved in any way throughout the entire installation of the LBA. Without your contributions, this would have been impossible. Well done!

Caption 1 : The first signal. Although just a blurry photograph of a computer monitor, this is the first moment where radio signals have been correctly received, amplified, digitised and processed.



Caption 2 : Some of the commissioning team. From left-to-right: Menno Norden, Klaas Stuurwold, Matthew Davies and Alejo Martinez-Sansigre.

HBA testing

Like the Low-Band Array (LBA), the High-Band Array (HBA) also needs to be tested and the commissioning work finished. This means checking the response of the HBA elements and making sure that they respond correctly and give the correct signal output.


Caption 1 : In the event of a problem, an engineer needs to go out onto the array, find the unresponsive tile and repair it.



Caption 2 : Henri Meulman completes the work on one of the HBA tiles. It is possible to see the polystyrene skeleton of the open HBA tile.

LBA-commissioning

On 31-Aug-2010, a crew of three engineers from ASTRON started work on the final RF commissioning work. This meant establishing that all the low-noise amplifiers (LNAs) are functioning and that the signal can be processed through the electronics in the RF-container. Once that work has been done, then we are ready to start testing the system as a telescope.

During this work a number of polarisations were discovered to be not functioning. This is to be expected, as there are often problems with the response of the LNAs or issues with the connections. In total we discovered four polarisations between three aerials that needed attention.

There was one worrying moment when we though the problem might be the cable, not the LNA unit, but the concerns were unfounded. Within a few hours all the systems had been checked and working correctly.



Caption 1: Menno Norden fits a new LNA cap to one of the aerial posts.



Caption 2 : Sarah James reconnects a new LNA cap.



Caption 3 : Henri Meulman uses a Time-Domain Reflectometer to test a cable for possible defects.

Foggy start, fiery finish

Caption 1 : On the 31st August 2010, the Observatory began the day with an eerie start. As the sun rose and started burning off the fog, the shapes of the landscape gradually began to emerge into view. By about 08:00 hours, the fog had vanished.


Caption 2 : 12 hours later on the same day, there was a spectacular sunset, with high cloud and a blaze of sunshine from the western horizon. This photograph was taken from near the camera that points to the LOFAR field, looking back over the Observatory buildings.

Off-road

As part of the final work on the field, the Land Rover was used to travel around the site edge to gather in all the remaining debris and left-over fencing material. This photograph is looking down over the bonnet of the vehicle.

A new vista

This panorama of the LOFAR-Chilbolton field was taken on the morning on 28th August 2010. It shows both LOFAR fields; the solid-packed HBA on the left and the sparse LBA to the right. In the background is the 25m dish at the main Chilbolton Observatory compound. In the picture there are two containers. The blue one directly behind the HBA is the skip where surplus construction materials are stored. It will be removed from the site soon. The other, just beyond the right-hand edge of the HBA field is the RF-container. The main Chilbolton Observatory building is just to the left of the 25m dish.

IT rack

On 27th August 2010, work started on installing the IT equipment in the main building. Here are the first two modules to be added. The top one is the optical fibre patch panel for the 8-core fibre that runs between the LOFAR field and the Main Building. Below it is the 10-Gbit/s network switch.

Good moon rising

On the evening of the 24th August 2010, one of the site security cameras caught this photograph of the moon rising over the LOFAR field. There seem to be three containers in the photograph. The raised one on the left is an WWII ex-RAF water tower. The middle one, with the white box on the side of it, is the RF-container. This is where the bulk of the LOFAR signal processing occurs. The white box is the air-conditioning unit. The battered-looking container on the right is the construction skip, where the surplus and waste materials are temporarily stored.

Compound cleared

As of 24 August 2010, the hard-standing at the end of the LOFAR field has now been completely cleared. It is certainly strange to see it as it was before the construction equipment moved in last March (ref: http://blog.lofar-uk.org/2010/03/ground-works-start-at-chilbolton.html). The white box and dish in the far distance on the right-hand side is the Chilbolton 4.5m ground station.

Data link

On 16th August 2010, the ISDN control line was established. Between the Chilbolton site and the supercomputing centre in Groningen, there is 10 Gbit/s link. However, this link is mono-directional. We can send data to the Netherlands, but there is no way to send data back. For the data itself, this is fine. However, it is also necessary to send back control signals. For the telescope a conventional Internet connection is used. However, for the control of the 10 Gbit/s transmission equipment a second ISDN line is required.

Caption 1 : The lines run through a tunnel on the site. This view is looking down the tunnel in the direction of the termination point, where the BT lines first come onto the site.



Caption 2 : BT engineer fitting the ISDN connection in the room where the terminations are.

Clean again

Ah, what would we do without the trusty Land Rover! The amount of hauling of equipment, supplies, people, rubbish, tools and so on has been incredible. Well, at the end of July, with the site mostly clear and bulk of the messy work done, the local Chilbolton staff gave it a thorough wash and clean!


Caption : Sun-glasses are now required.

Parched earth

In sharp contrast to the recent misty rain (ref: http://blog.lofar-uk.org/2010/07/droplets.html), when the sunshine returns and the mud dries out there are some amazing patterns to be seen in the crust that forms in dried out puddles and dips around the construction site.


Caption : This close-up was taken on the LOFAR construction compound.

Tour of Chilbolton LOFAR Station

Almost two weeks ago, Alejo and myself went up to Chilbolton to make a short video tour of the site explaining the three main components. We've now released the video on You Tube.



Hope you like it.

The digger departs

This was definitely an "end of an era" moment. After months of having the throb of the diesel engine and the clanking of the great tracks, the 18-tonne digger was taken from the site for the last time on Wednesday 21 July 2010. Although "the beast" (as this machine was affectionately known) had been away for a brief spell during the gap between the LBA and HBA builds, this departure was the final one.


Caption 1 : Going... The digger is driven up onto the low-loader.



Caption 2 : Going... Digger driver John Murray checks that the giant buckets are secured prior to departure.



Caption 3 : Gone... And then the lorry started up and drove it away. Admittedly, this was a poignant moment.

Site clearing

Although the recent installation work is done, so much clearing up needs to be completed on the site. All the cabins, building materials, fuel tank, water bowser, dismantled fencing and plant and equipment need to be removed from the site.

Caption 1 : Izabela Bukowska packs the Land Rover with another load of dismantled packing timber.


Caption 2 : Another load is ready.

Timing is everything

Because of the distance between the stations, the LOFAR telescope uses a GPS-satellite-based clock/time source. The GPS receiver generates the time signal for the local computer and a 1-pulse per second signal (1PPS). Although not accurate over short timescales, this can be used to synchronise the station. For short times, a Rubidium reference is used to generate a 10 MHz reference signal. This is used by all the equipment to ensure simultaneous and accurate sampling throughout the system.



Caption 1 : The small GPS-antenna atop the RF-container.




Caption 2 : The Rubidium reference source within the equipment racks.

End of a busy week

Although the work had been proceeding at a relentless, demanding pace, the week from the 12th to 16th of July had been particularly demanding. With a full crew on the HBA, clearing operations, ground works, deliveries and removals, data fibre drawing, RF-container installation, disasters and triumphs, a bit of media attention, some unusually inclement weather and a few other little incidents to spice things up, it had been both a harrowing and exhilarating few days.



However, at the end of it all, the skies cleared a little and those left clearing up on Friday evening were treated to this serenely beautiful view across the golden wheat fields.

Electronics installation completed

By the evening of Thursday 15th July 2010, pretty much all of the electronics and cabling in the RF-container had been completed. Within the space of a few days, it had gone from an empty shell, through a period of seemingly chaotic installation to a completed and ordered system. It was a rapid and stunning transfer and our thanks goes to the ASTRON and Excel Assemblies team for their work.



Caption 1 : Midway through the work. Here the signal cables from both the LBA and HBA patch panels have been fitted, while the data network infrastructure is just being started.




Caption 2 : The view at the end of the week, with all cables complete and the floor panels back down. A very professional finish!



Caption 3 : And finally, this tiny little label appeared on the inside of the RF-cabin on the final day. Another milestone for UK608.

Dressing the edges

Around the edge of the HBA, there is a circle of weed suppressant fabric, covered with a layer of gravel. Apart from making the completed field look nice, this helps maintain the edge of the field, allowing easier access and better control of surrounding vegetation.

Caption : (left to right) Richard Whittaker, Martin Murphy and Matthew Hambly work on the HBA field edging.

The last lorry

It seems quite a while since the first HBA lorry arrived (ref: http://blog.lofar-uk.org/2010/06/first-hba-tiles-arrive-in-chilbolton.html) but eventually on 16th July 2010 the last of them departed, loaded with pallets to be returned for the next HBA deployment on the international LOFAR project.



Caption 1: The last lorry leaves the construction compound for its journey back to the Netherlands.



Caption 2 : With the narrow country roads and single-lane tracks, it would be all too easy to forget a few things that are second nature to the locals. This little reminder was placed on the final gate for all the international installation crews and delivery lorries to see on their way out (it says "Drive on Left").

Data link

Between the RF-container and the main building at Chilbolton Observatory, there is the LOFAR data link. This is a high-capacity optical fibre and the data rate is typically up to 10 gigabits per second. With the electronics mostly installed, it was time to start getting this fibre run through the ducts and conduits between the two locations.



Caption 1 : The contractor vehicles assemble in the main observatory car park.




Caption 2 : Preparing to start spooling the fibre through one of the draw pits.



Caption 3 : The drawing of the fibre lasted the entire day, through the rain too. However, by the end of the day, the line was in place ready for termination at each end.

Clean-up operations

With the HBA installation complete, the final work on the field is the clean-up. To be fair, this has mostly been going on continuously during the entire build process. After each tile is unwrapped, the packing material is collected and either reused, recycled or disposed of.


Caption 1 : Pallets are either nailed together or dismantled for use in supporting other pallets. Here Jon Eastment (left) and Matthew Hambley sort out and dismantle some of the pallets.




Caption 2 : The bulk of the pallets are nailed together and then are shipped back on some of the returning lorries. They are then used on the HBA tile deliveries for the next station.




Caption 3 : The remaining material is gathered and sorted. Some of it is disposed of, but the bulk of it is actually reused or recycled. In fact, given the sheer scale of the operation, remarkably little waste is generated.