C-BASS South Commissioning
A blog following the commissioning of a radio telescope called CBASS South, the southern hemisphere part of the C-Band All Sky Survey at 5 GHz. Follow us as we finish testing in Oxford then get the receiver working and attached to the dish at Hartebeesthoek Radio Observatory, near Johannesburg South Africa.
So far we have been commissioning the telescope from HartRAO, outside Johannesburg. However, this is not C-BASS south's final resting place. In a few months we will be moving the receiver and digital back end from it's current dish to an identical one in the Karoo desert (circa 900km away)... a lovely dry spot with little interference from pesky mobile phone signals or wifi.
It was essential we check the site in the desert and begin preparations for the antenna's arrival. This required a 3 day road trip! So we took our tiny little hire car on an epic journey.
Luke, Mike and I have travelled back to South Africa to hopefully do the final testing of the C-BASS antenna. We want to try and test the response of the telescope to something we know - a transmitter on a hillside - so that we can then compare that to what we measure in the sky. It's a fairly tricky experiment to do as you need to transmit a signal that you know the brightness and angle of very accurately. You also want to make sure that you don't pick up reflections from everything around you.
Angela and Mike took me (Luke – their new Dphil student) to HartRAO in November where we met up with Charles for an intense two weeks of commissioning.
For the first half of our visit things went to plan. We got rid of some high system temperature features at around 5.3 GHz which turned out to be caused by radiation leaking through little thermal breaks inside the cryostat. We stopped this leakage with a bit of cutting and sticking of loaded silicone absorber - I never would have guessed that my first trip to a telescope as a graduate student would require so much arts and crafts!
So after a busy trip, Jamie and I had to come back to the UK to cover our teaching commitments but most importantly to try and recruit a new research student to work with us on C-BASS.
Testing carried on all week and Charlie also got all the electronics in the lab working again too.
I spoke too soon about the weather! It does rain here...
It been a busy few days as we slowly unpacked all the crates and start to put C-BASS back together again.
Jamie and I landed in Johannesberg at 10am this morning and were met by Charles at the airport. We drove over to the observtory and by complete chance arrived at the exact same time as C-BASS was being delivered.
So the C-BASS shipping crates flew over the weekend and arrived in Johannesberg on the 19th February. It took a couple of days for them to get cleared through customs but they made it and are due to be delivered to the observatory on Monday.
The day has finally arrived to pack everything up. Charles has already left for South Africa and Mike is away at a meeting in Australia, so it's left to Jamie and I to pack everything up (with a bit of help from the shipping company and our helpful colleagues in the Physics workshop and stores).