Australia Telescope Users Committee - Technologies Report - May 2008
Staff changes
• Graham Moorey retired late December ’08.
• Mark Bowen is the new Front End Group leader.
• Santiago Castillo hired as a new technician.
• Yoon Chung hired as a new engineer and is working on CABB
with Peter Axtens.
• Scott Saunders, firmware writer with Dick Ferris, left in Dec ’08.
Overarching issues
• Though fabrication of equipment for CABB has been ongoing and operation
as a spectrometer has been proven, cross correlation with phase correction
has not been achieved at the Compact Array.
• A review of the effort needed to complete CABB estimates a significant
proportion of the staff engaged in the project require a further 6 -8 months to
complete their tasks. This makes an October installation untenable and a
realistic date is mid-January 2009.
• Interface modules to make the signals from the existing centimetre
receivers suitable for input to the CABB system are associated with the ATCA
20/13 and 6/3 cm Receiver Upgrade project but need to be viewed as vital to
the implementation of CABB. These interface modules have had little
development as the resources allocated to them have been utilised on the
Parkes 13 mm Receiver project with an installation due in late May.
• The absence of these interface modules would leave the array without
centimetre capability so effort on the Parkes 13 mm receiver will be slowed
considerably as design engineers and technical staff redirect their effort to the
modules. It is uncertain at this stage but the Parkes 13 mm receiver might still
be available for observing in September.
Compact Array Broadband Backend
(CABB) 1
Previously…“Given the history of the
project it is difficult to predict when the
full changeover can occur without
having information from tests with
three antennas. Our current best
estimate is October 2008.”
DSP
boards
The final production run of
instrumentation is well underway.
A system test facility in the Marsfield
laboratories emulates the array setup
and is being used to check functionality.
Digitiser
module
Compact Array Broadband Backend
(CABB) 2
A significant amount of equipment has
been installed on antennas and at the
central site. We will be able to support
LunaSKA observing starting on May 17
with Antennas 1, 3 and 5 .
IF module
A mid-May equipment installation will
equip antennas 2 and 4 with the
majority of modules to make them
functional. Further installations during
ensuing maintenance periods will aim
to allow the Stage 1, single frequency
engineering system to be implemented
before it is required by observers in
July.
equaliser
Currently, phase correction only awaits the implementation of fine delay and
fringe rotation. A software test period using the antennas is envisaged after the
mid-May outfitting.
RTM
DSP
Board
DSP
Board
RTM
O/E
RTM
DSP
Board
DSP
Board
RTM
O/E
O/E
RTM
DSP
Board
DSP
Board
RTM
O/E
O/E
RTM
DSP
Board
DSP
Board
RTM
O/E
O/E
RTM
DSP
Board
DSP
Board
RTM
O/E
O/E
RTM
DSP
Board
DSP
Board
RTM
O/E
O/E
RTM
DSP
Board
DSP
Board
RTM
O/E
O/E
Conversion
WD
DM
sampling
Local
oscillator
distribution
(antenna)
Electrical to
optical
scheme
WDM
WD
DM
Conversion
Local
oscillator
distribution
(antenna)
WD
DM
Electrical to
optical
scheme
WD
DM
WDM
Local
oscillator
distribution
(antenna)
Conversion
RTM
DSP
Board
DSP
Board
RTM
O/E
O/E
RTM
DSP
Board
DSP
Board
RTM
O/E
O/E
RTM
DSP
Board
DSP
Board
RTM
O/E
O/E
RTM
DSP
Board
DSP
Board
RTM
O/E
O/E
RTM
DSP
Board
DSP
Board
RTM
O/E
WD
DM
Conversion
sampling
O/E
sampling
Electrical to
optical
scheme
O/E
sampling
WD
DM
WDM
Electrical to
optical
scheme
WDM
Local
oscillator
distribution
(antenna)
Advanced Telecom Compute Architecture (ATCA) rack
Conversion
Conversion
Local oscillator
distribution
(Control building)
32 MHz
distribution
sampling
Local
oscillator
distribution
(antenna)
Electrical to
optical
scheme
WDM
sampling
WDM
WDM
WDM
WDM
WDM
WDM
Patch Panel
Electrical to
optical
scheme
WDM
Local
oscillator
distribution
(antenna)
LSCX Upgrade
Three sections:
1. OMT refit
2. Interface modules for CABB
3. Broadbanding the front end
• One OMT is fitted to a Compact Array antenna. Parts for two
others are fabricated but await assembly and testing.
• Others will be fabricated as workshop time allows.
• Interface module electrical designs are being finalised to allow
technicians to procure parts and design layouts.
• A broadband L/S amplifier design has been completed and a
prototype fabricated. Initial, basic testing shows it works at room
temperature as modelled but it awaits more extensive room
temperature and cryogenic testing.
Parkes 13 mm receiver (1)
Waiting on the conversion module and
subsequently it’s integration with the
completed LO module. All electronic and
mechanical designs are completed and
housings are being machined now.
This will require a further three weeks
fabrication. All components will be on
hand ready for assembly.
LO
module
Parkes 13 mm receiver (2)
• A noise spike in the bandpass at ~18
GHz needs resolution. It is suspected
the waveguide noise coupler is
creating a mismatch . A transition
section of waveguide may solve this
problem but room temperature and
cryogenic testing is required.
Control and
monitor
electronics
• Frames are undergoing surface
finishing and the electronics is
substantially complete.
• Discussions are underway for a trial
installation at Parkes ‘sans LO and
conversion’ in May/June.
• Expectation of a functioning system
for September observers.
Cryostat
internals
7mm spares for Mopra upgrade
Completed for Narrabri staff to
refit and now operational.
LunaSKA – looking for Ultra High
Energy Neutrinos
LUNASKA team (Ron Ekers,
Paul Roberts and Chris Phillips
from ATNF, Clancy James and
Ray Protheroe from Adelaide,
and Rebecca McFadden from
Melbourne) are currently using
the prototype elements of the
Compact Array Broadband
Backend on the ATCA as a
testbed to develop the highly
specialised methods required to
undertake radio astronomy
activities in a billionth of a
second.
Already, these “tests” have had
a lower energy threshold than
any previous such experiment,
and further improvements will
result with the installation of
further CABB equipment.
Next observing starts 17th May
PDFB External contracts
Five systems in total are being constructed for Jodrell,
Effelsburg, Sardinia, Urumqi and Miyun.
Engineers from Jodrell (1) and Urumqi (2) expected on
May 26th for training and final assembly.
Testing at Parkes ~11th June.
Control
computer
assembly
Chassis
being
outfitted
ASKAP 12m test bed
Undergoing acceptance
testing now
An intention for George
Hobbs’ team to use it for
pulsar observations with
a 40 element FPA should
it be ready. A single pixel
feed is available if the
FPA is not available.
Water Vapour Radiometers
Assessment of existing units initiated.
Phil Edwards will have more detail.
Mopra Multibeam study
Undertaken for Michael Burton of
University of New South Wales.
A feed study by the ICT centre
under Trevor Bird.
Looked at the required effort to
fabricate a 3mm multibeam
receiver through replication of the
hardware used for the current
receiver.
Further consideration was given to
configurations required for the
backend, specifically the MOPS
spectrometer.
Compact Array 115 GHz Upgrade
Operations Projects
We need to keep in mind that there is the prospect of
technical effort required to achieve some goals of the
change in operations.
Parkes 2010
Parkes 2008
2007
2008
2009
2010
ATCA 7mm upgrade
7mm upgrade for Mopra
Parkes 13 mm receiver
PDFB3
PDFB external contracts
CABB
20/13 and 6/3 cm upgrade
ASKAP
Water Vapour Radiometers
CA Upgrade to 115 GHz
Mopra Multibeam
Operations projects ??
FPA for Parkes
or
Study
Fabrication