ALMA Integrated Computing Team
Coordination & Planning Meeting #2
Santiago, 28-29 January 2014
Telescope Calibration Planning
Dominique Broguière
TelCal planning
 Ressources : TelCal group
 Current status
 Plan for R10.8 and 2014 releases
 Future releases (after 2014)
ICT-CPM2 28-29 January 2014
TelCal group
ICT TelCal : 1.3 FTE
 Dominique Broguiere, lead, 0.8 FTE
 Jean-Christophe Roche, developer, 0.5 FTE
SubSystem Scientists
 Denis Barkats
 Baltasar Vila Vilaro (Deputy)
Other contributions
 Robert Lucas
• Holography package
• Scientific support
ICT-CPM2 28-29 January 2014
Current status : Online calibration
Calibration
Delivered
Phase Cal
x
Ampli Cal
x
Bandpass
x
Delay
x
Pointing
x
Focus
x
- new method : holographic focus
Atmosphere
x
- Improve efficiency by using only sky
scans
WVR
x
- On-line validation in progress
- improvement : use actual frequency
range of WVR spectral channels and WVR
coupling efficiency
x
- Using side band rejection, needs a little
work in side band separation mode
- delayed until new sideband separation
mode available
Sideband
ratio
ICT-CPM2
28-29
January 2014
Status CPM1
Status CPM2
Current status : Offline calibration
Calibration
Delivered
Tower Holography
x
Astro Holography
x
Antenna Positions
x
- improved : weight scans using delay
or phase error
Pointing model
x
- option added to fit the model
Primary Beam
x
- available as a CASA task
(tc_primarybeam)
ICT-CPM2 28-29 January 2014
Status CPM1
Status CPM2
- Use on-line WVR correction :done
Current status (3/3)
 Other delivered features in R10.2, 10.4 or 10.6
 Offline TelCal Tasks features
• Plot improved (summary plots added, new options, etc...)
• Speed increased (ASDM read once, useless data not read, etc...)
• Appending results to an existing ASDM enabled
 Online features
• TelCal behaviour adapted when no wvr is available
• Performance improvements : parallelization of Bandpass engine
• Binary flags taken into account
• TelCalSpy : new results displayed
 APP features
• New event (AppPhaseReduced event), ASDM table (CalAppPhase table) and engine
(calculation of phase offsets between antennas)
• Implemented in the same way than other TelCal engines
• Successfully tested (simple phasing)
ICT-CPM2 28-29 January 2014
Plan for R10.8 and 2014 releases (1/2)
Priorities are defined in collaboration with SubSystem Scientist.
ALMA-10.8 :
 Off-line mode
 TelCal Standalone software : user-interface improvements
 Performances
 Optimizations in ATM library
 Parallelization of Atmospheric engine (Tsys calculation) needed in FDM
mode
 Redhat 6.5 upgrade
 Test needed, especially for fortran code (clic)
ICT-CPM2 28-29 January 2014
Plan for R10.8 and 2014 releases (2/2)
2014 releases :
 Dual mode
 Sharing data (totalpower and correlator data) in the same Telcal component to
improve atmospheric calibration
 Scan sequence with interspersed telescope calibration
– Provide a method to CONTROL, that returns an evaluation of computing time
for each calibration
 Engines improvements
 Zero power subscan/scan (bias detector measurement)
 Error calculations in Sideband gain measurement
 Automatic flagging of noisy basebands/ polarization in calibrations
Plan may be modified to reflect changes in priorities
ICT-CPM2 28-29 January 2014
Future releases
 Features depending on Control schedule




shadowing flag
sideband separation
subarrays (no specific development, just testing)
multi-resolution mode (no specific development, just testing)
 Improvements in calibration algorithms
 Need analysis and proposals from astronomers
 Topics :
• on-line WVR correction
• long baselines
• high frequencies
 Error calculations
 Error calculations are missing in some results
 Reduced chi square calculation gives incorrect results in Pointing engine
ICT-CPM2 28-29 January 2014