background+on+the+alma+phasing+project · 2016. 5. 4. · maser vlbi phasing correlator: control...
TRANSCRIPT
• Background on the ALMA Phasing Project – Delivers an ALMA Phasing System to allow – All the antenna signals to be combined to allow – ALMA to join in 3mm & 1mm VLBI networks
• Current Status & Near Future • Cycle 5/6 Development • OpKons to move beyond that
Overview of the talk
May 3, 2016 G. Crew, the ALMA Phasing System
General Acknowledgement to the great many people who have brought us to this point
2
Project Timeline and Milestones
• Fall 2011: Project incepKon • November 2012: Preliminary Design Review & ALMA Board Approval • May 2013: CriKcal Design Review • January 2014: IniKal phasing system (R10.6) and first VLBI recordings • June 2014: InstallaKon of Hydrogen Maser • July 2014: Switchover of ALMA to Maser • October 2014: CompleKon of Hardware installaKon; So\ware verificaKon of all major
features completed (R2014.4) • November 2014: Hydrogen Maser Acceptance Review • December 2014: Hardware Acceptance Review (CondiKonal Pass) • January 2015: Start of Commissioning and Science VerificaKon (R2014.6) • March 2015: First InterconKnental Fringes with Phased System • July/August 2015: Band 3/Band 6 VLBI Commissioning • October 2015: “Incremental S/W Acceptance” (Cycle 3) • December 2015: DemonstraKon of SB operaKon • April 2016: Band 6 SB-‐driven VLBI ObservaKon (R2015.8) • Sept 2016: Cycle 4 Acceptance • Oct 2016 – Sep 2017: Cycle 4
May 3, 2016 G. Crew, the ALMA Phasing System 3
Maser
VLBI
Phasing
Correlator: Control
Central Electronics
Central Variable Reference
Photonic LO
2 bits/sample
Each Quadrant:
2Pol x 32ch x 62.5MHz
Data Rate: 16 Gb/s
128 LVDS Pairs
Correlator: Baseline
H Maser
EPC
CDP Computer Cluster
Fast Phase Solver
TelCal Computer
Slow Phase Solver and Monitor
Fiber DEMUX
Fiber MUX
Correlator: Station
Front End
Samplers, WVR
Optical Fiber Tx
Antenna
Phasing Interface Card
GPS
Alma Observing Blocks
Connects to all sub−systemsALMA Control System
Correlator Hardware Protocols
TFB Commanding
Correlator Card (CC)
Cross Correlation
Form VLBI Sum
Delay to align VLBI sum
VLBI sum antenna mask
Scaling of VLBI Sum
Route data to corr cards
VLBI sum input
Correlator Interface Card (CIC)
Long Term Accum/Final Add
∆φ Phase Corrections (Fast)
Monitors phasing efficiency by
correlating sum with reference
to calculate phase corrections
Uses source model parameters
∆φ Phase Corrections (Slow)
Scaling of VLBI sum
Delay control for CIC input
Interface with Phasing Calculators
Synchronization command
Time setting
Monitor GPS−Maser Drift
VLBI Scheduler
Control of VLBI Recorders
Control of CIC VLBI sum input
Control of CC:
VLBI antenna sum mask
Control of TFB:
VLBI Observing Block
Sends Parameters to TelCal Computer
Control of Phasing Interace Cards:
Control of Source Model Monitor
Phase offsets
Station Card
Geometric Delay
Optical Fiber Rx/Demux
Form 32 x 62.5 MHz slices
Tunable Filterbank Card (TFB)
Phase shift each slice 2 Cards per Quadrant
8 x 10 GbE
Phased Sum Data
10 GbE Packetization
Synchronization
PPS/Clock Monitor
VDIF Formatting
Baseline Visibilities
Generate Channel Averages
AOS (high site)
OSF (low site)
OSF (low site)
8 x 10 GbE
VLBI 16 Gbps Recorders
Tu
nab
le F
ilte
rban
k C
om
man
ds
10 MHz
1 PPS
5 MHz
CRG: 125 MHz, &c
MASER_V_GPS_COUNTER
APP System Block Diagram
FuncKonal area
Exists New
Timing
Back End
Phase sum
Phase soluKon
Observing block
May 3, 2016 G. Crew, the ALMA Phasing System 4
APP So\ware Block Diagram
PI
Control Device
Hardware Side
Control Device
Correlator
Scheduler
Operator
Correlator
TelCal
ALMA Operator Display
VOM Schedule Block
Maser−GPS Monitor
Maser
AOSTiming
VLBI Recorder
VLBI OFLS
LTA Protocol
PIC Control
VLBI Observing Mode (VOM)
Phase Solver
Efficiency Monitor
Source Modeler
VEX2VOM Translator
VLBI Observation Status
VLBI Hardware Status
TelCal Results Display
CCC Phase Updates
VOM Observing ScriptVOM Configuration Data
VEX file
Configures ALMA for VLBIRuns the experiment
Phase Update (TFB)
Data Pathways
Prepares ALMA Sched BlockIngests VEX & PI intents
Maser
VLBIController
InterferometryController
PhasingController
Phasing
VLBI
Data
ChannelAverage
PhasingCorrections
FuncKonal area
Exists New
May 3, 2016 G. Crew, the ALMA Phasing System 5
VLBI Observing Mode, new in Cycle 4
May 3, 2016 G. Crew, the ALMA Phasing System
Standard Interferometry
Standard VLBI
Standard Single Dish
Standard Solar (is also new in Cycle 4)
6
The VLBI inherits from Interferometry to pull in antenna control, &c....
Some APS Nomenclature
• Scan Hierarchy – VLBI Scans refer to the recordings – Correlator Sub Scans – “Slow” Scan phase correcKons from TelCal – “Fast” phase correcKons made by CORR
• DisKnguished Antennas – Reference Antenna – Phased Antennas (N of these) – The “Analog” Sum Antenna – Comparison Antennas
• (<Sum . Comp>) / (<Ref . Comp>) ~ Sqrt(N)
May 3, 2016 G. Crew, the ALMA Phasing System 7
Scan Strategy
Phased Phased PhasedUnphased ∆ ∆ ∆
TFB Commands
. . .
WVR Data
. . .
. . .
TelCal Solving
Correlator Scan Sequence
. . .
. . .
VLBI Scan Record On
Time
Slow Loop
Fast Loop
May 3, 2016 G. Crew, the ALMA Phasing System 8
TelCal Phasing Engine
Active!
Source'2'VLBI scan
ALMA scan (= subscan)
TelCal activity
Phasing solution validity
flagged data interval
Time
Active! Active!Active! Active! Active! Active! Active!
Source'1'
G. Crew, the ALMA Phasing System
TelCalResults*
Engines*
Libraries*
TelCalPublisher*
GetTelCalResult*
Control*
DataCapture*
Correlator*
Bulk*
TelCalDataManager*
ParameterTuning*
ReceivingDataManager*ReceivingDataManager*
ReceivingDataManager*
use
Bulk data
Meta data
• TelCal driven by scan intents • Least-‐squares-‐fijer exists in a
TelCal library • On each scan the engine solves
for slow phase (and delay) errors which remain a\er fast WVR correcKons
• Publishes (new) ASDM table • Provides feedback on quality
(phasing efficiency, opKmal antenna choices, &c.)
Data are flagged relaKve to phase adjustments for the
benefit of fimng engine
May 3, 2016 9
Phase CorrecKons from TelCal
May 3, 2016 G. Crew, the ALMA Phasing System 10
This scan had CM, DA, DV and PM antennas
INPUT OUTPUT
General Phasing Sequence
«CORBAInterface»:SingleFieldInterferometryObservingMode
«CORBAInterface»:ObservationControl
Operator
Scheduling «CORBAInterface»:AutomaticArray2
«CORBAInterfa...:ParameterTuning
«CORBAInterfa...:GetTelCalResults
«CORBAInterface»:ReceivingDataManager
«CORBAInterfa...:ScriptExecutor
«CORBAInterfa...:DataCapturer
«CORBAInterfa...:ExecutionState
callback
«CORBAInte...:SkyDelayServer
corrSubscanSeqCalback
createArray()
startSB()
observeNow(sbId, sessionId)
runObservationScriptAsync(script, callback)
beginExecution()
startSB(arrayName, startTime)
ExecBlockStarted()
«event»
getSFIOffshoot() :SingleFieldInterferometryObservingMode
setAppSumAntenna(location, cableDelay)
setAppParameters(sourceModel, algorithm)
setSubArray(subarrayId, antennaList, bdStreamInfo)
setAppParameters(subarrayId, mask, refAntenna, algorithmMode)
doScanSequence(ScanSpecSeq, SimpleCallback) :Time
wait()
beginScan(ScanIntentDataSeq)
ScanStarted()
«event»parseIntents()
sendAppParametersData(mask, refAntenna)
getReconfigurationTimes(subarrayId, calibrations, durations) :SubscanTimingSeq
compute timings()
startSubscanSequence(subarrayId, startTime, executeBlockID, executeBlockNumber, subscanInfos, callback)
startSubscanSequence(arrayName, subscanIntents)
binary data()
report(status)
sendSubScanCorrelatorData(arrayId, subscanNumber, data)
ScanProcessedEvent()
«event»
getFinalMetaDataQL(scanNum) :ASDMDataSetIDL
publishAppResults()
isAppPhaseResultAvailable()
AppPhaseReducedEvent()
«event»
getAppPhaseResult()
AppPhaseReducedEvent()
«event»getAppPhaseResult()
setAppSlow(subarrayId, mask, refAntenna, phaseSeq)
sendAppParametersData(mask, refAntenna)
binary data()
report(status)
report()
May 3, 2016 G. Crew, the ALMA Phasing System 11
Too much detail to present—see the Design Document
Time
Different So\ware Components
Correlator Phasing Sequence
Corr HW «CORBAInte...:Node
«CORBAInte...:Master
PhasingCallback
«CORBAInterf...:ObservationControl
«CORBAInterface»:SingleFieldInterferometryObservingMode
consider one ALMA subscan
loop for each ALMA scan
loop fast phase corrections
setSubArray(subarrayId, antennaList, bdStreamInfo)
setSubArray(array, bddStreamInfo)
setArray(array)
setAppParameters(subarrayId, mask, refAntenna)
configureLTA(mask, scalingData)
setupPIC(VDIFchannels)
setPICcontrol()
setPICheader()
doAppScanSequence(...)
setAppScanParameters(algorithmMode)setAppMode(algorithmMode)
setAppMode(algorithmMode)
beginScan(intents)
getReconfigurationTimes(subarrayId, calibrations,durations) :SubscanTimingSeq
computeTimings()
startSubscanSequence(subarrayId, startTime, executeBlockID,executeBlockNumber, subscanInfos, callback)
startSubscanSequence(arrayId, startTime, executeBlockID,executeBlockNumber, subscanInfos, callback)
startSubscanSequence(arrayId, startTime, subscanInfos)configureLTA(sumSwitch=on)
flagDataInvalid()subscanStarted()
slowPhaseLoop()
setAppSlow(subarrayId, mask, refAntenna, phaseSeq, interval) :timestamp
configureLTA(mask, scalingData)
applyTFBPhases(phaseSeq)
setAppSlow(arrayId, phaseSeq, timestamp, cb)
setAppSlow(arrayId, phaseSeq, timestamp)
flagDataValid()
calculatePhases()updatePhases(phaseSeq)
updatePhases(phaseSeq)
applyTFBPases(phaseSeq)
report(status)
May 3, 2016 G. Crew, the ALMA Phasing System 12
TelCal Phasing Sequence
«CORBAInter...:GetTelCalResults
«CORBAInterface»:ReceivingDataManager
«CORBAInterf...:ParameterTuning
«CORBAInte...:DataCapturer
«CORBAInterface»:SingleFieldInterferometryObservingMode
«CORBAInte...:ExecutionState
«CORBAInterf...:ObservationControl
consider first ALMA scan
loop for each ALMA scan
consider asynchronos processing
Phase processing done.
setSubArray(subarrayId, antennaList, bdStreamInfo)
setAppParameters(subarrayId, mask, refAntenna)
sendAppParametersData(mask, refAntenna, timestamp)
doAppScanSequence(...)
setAppScanParameter(sourceModel, algorithmMode)
setAppScanParameters(sourceModel, algorithmMode)
beginScan(intents)ScanStarted()
«event»
parseIntents()
startSubscanSequence(arrayName, subscanIntents)
startSubscanSequence(subarrayId, startTime, executeBlockID, executeBlockNumber, subscanInfos, callback)
report(status)
sendSubScanCorrelatorData(arrayId, subscanNumber, data)
ScanProcessedEvent()
«event»
getFinalMetaDataQL(scanNum) :ASDMDataSetIDL
calculatePhaseResults()
beginScan(intents)
ScanStarted()
«event»startSubscanSequence(arrayName, subscanIntents)
startSubscanSequence(subarrayId, startTime, executeBlockID, executeBlockNumber, subscanInfos, callback)
publishAppResults()
isAppPhaseResultAvailable()
AppPhasedReducedEvent()
«event»
AppPhaseReducedEvent()
«event»
getAppPhaseResult()
getAppPhaseResult() :AppPhaseResultgetAppPhaseResult() :AppPhaseResult
analyzePhaseResults()
setAppSlow(subarrayId, mask, refAntenna, phaseSeq, interval) :timestamp
sendAppParametersData(mask, refAntenna, timestamp)
*fastPhaseLoop()
report(status)
sendSubScanCorrelatorData(arrayId, subscanNumber, data)
ScanProcessedEvent()
«event»May 3, 2016 G. Crew, the ALMA Phasing System 13
Project Timeline and Milestones
• Fall 2011: Project incepKon • November 2012: Preliminary Design Review & ALMA Board Approval • May 2013: CriKcal Design Review • January 2014: IniKal phasing system (R10.6) and first VLBI recordings • June 2014: InstallaKon of Hydrogen Maser • July 2014: Switchover of ALMA to Maser • October 2014: CompleKon of Hardware installaKon; So\ware verificaKon of all major
features completed (R2014.4) • November 2014: Hydrogen Maser Acceptance Review • December 2014: Hardware Acceptance Review (CondiKonal Pass) • January 2015: Start of Commissioning and Science VerificaKon (R2014.6) • March 2015: First InterconKnental Fringes with Phased System • July/August 2015: Band 3/Band 6 VLBI Commissioning • October 2015: “Incremental S/W Acceptance” (Cycle 3) • December 2015: DemonstraKon of SB operaKon • April 2016: Band 6 SB-‐driven VLBI ObservaKon (R2015.8) • Sept 2016: Cycle 4 Acceptance • Oct 2016 – Sep 2017: Cycle 4
May 3, 2016 G. Crew, the ALMA Phasing System 14
We are here
Immediate Next Steps
• Correlate and analyze April 1mm session – “Sample” Cycle4 1mm observaKon – Bring PolConvert to OperaKonal Readiness
• SKll need to capture 3mm session (June/July?) – DemonstraKng that VEX2VOM’d phase2 schedule blocks play nicely with the Archive
– Need to finalize VLBI operaKonal details (reconciling VLBI scheduling with ALMA)
• Ready for Cycle 4, except for – Final details for operaKng the VLBI arrays, and…
May 3, 2016 G. Crew, the ALMA Phasing System 15
ICT-‐5401: Aug 27th phasing (25 ant. phased)
May 3, 2016 G. Crew, the ALMA Phasing System 16
March 23, 2016 (VLBI Regression Test)
May 3, 2016 G. Crew, the ALMA Phasing System 17
Appear to have resolved some things
May 3, 2016 G. Crew, the ALMA Phasing System
ICT-‐7128 remains
18
Amp v Time for <Sum . Comp> for 9 comparison antennas
Working on ICT-‐7218 (side discussion…)
May 3, 2016 G. Crew, the ALMA Phasing System 19
CASA Plots of Real v Imag visibiliKes for 6 phased antennas during one scan, colors by integraKon
DGCK fine delays as logged at several of these antennas, integrated, linear fit subtracted
Colors bars correspond to sub-‐scans reported by Controller or CCC
Things which follow the sine qua non for Cycle 4
• Le\-‐over from APP – GUI (Python version) – Source Modeler (could appear as needed)
• ADF Cycle 3 Study (Majhews): – Turn Baseband Delay back on in CDP – Mismatched Channel OpKons – Band 7 (see next slide) – Analysis Support for Observers
• ADF Cycle 3 Study (Cordes): – Using the APS for pulsar work
May 3, 2016 G. Crew, the ALMA Phasing System 20
Second Band7 Session (Aug 2015) Amplitude of small array on (3 sources)
1337-‐129, 3c279, 1337-‐129
May 3, 2016 G. Crew, the ALMA Phasing System 21
Example DA58 (reference antenna) & DV11
We used 8 channel averages; We can use 16 or 32 on bright sources (phased in most scans; un-‐phased for some)
Delay when un-‐phased
Delay when phased
15
Bejer Baseband Delay Fix
May 3, 2016 G. Crew, the ALMA Phasing System 22
Frequency
CDP Residual Delay CorrecKon normally also includes the much larger Baseband delay
Cycle 5/6 under Discussion (at OBSMODE)
• Implement the Delay Fix – TelCal looks up Baseband Delays the same way that the CDP does and undoes the CDP work prior to calculaKng phases
– Requires some changes to the phase pack/unpack library • Remove the current 500 mJy restricKon • Add a Spectral Line mode for VLBI – Mostly a data-‐rate, OT limitaKon – Spectral averaging puts line details into oblivion – Spectral Setup is currently aimed at conKnuum – We should be using the FDM Frequency agility [or MulK-‐resoluKon modes (see Ray/Rich talks)].
May 3, 2016 G. Crew, the ALMA Phasing System 23
Beyond Cycle 6: Sub-‐arrays
VLBI does not play well with sub-‐arrays. • OperaKonal: required “start” Kme • There is only one “sum” antenna • There is only one LTA “sum” antenna switch • PICs are not owned by any sub-‐array • Slow phasing adjustments assume no other CAN bus traffic
• WVR correcKons assumes a single array • hjps://ictwiki.alma.cl/twiki/bin/view/Control/AppMulKSubarrays • hjps://ictwiki.alma.cl/twiki/bin/view/Control/AppPhase2TaskIdeas
May 3, 2016 G. Crew, the ALMA Phasing System 24