Post on 29-Mar-2018
VLBI with ALMA Geoff Crew
and the ALMA Phasing Project Team 5th International VLBI Technology Workshop
Haystack, October 12, 2016
Topics in this Presentation
• History and Status of the ALMA Phasing Project (APP) • Some Technical Implementation Details • Some Commissioning Results • Ready for Cycle 4: April 2017
2 Crew -‐ VLBI with ALMA -‐ Oct 12, 2016
ALMA
History and Status of the ALMA Phasing Project
• Broad support for APP • NSF Major Research Instrumentation
Program awarded Aug 2011 for 4 years (extended into 2017)
• Partners (ASIAA, MPIfR, NAOJ, U.Concepcion, Onsala)
• ALMA North America Development Fund (supplement & 3 study projects)
• General Status • Hardware Accepted (Nov/Dec 2014) • Online Software Accepted with Cycle 3
& for Cycle 4 (Aug 2015, Sep 2016) • Commissioning partly done Cycle 3,
approaching completion for Cycle 4 (Oct 2015, Sep 2016)
3 Crew -‐ VLBI with ALMA -‐ Oct 12, 2016
• Current work on complete analysis of • 1mm session (16 Gbps, April 8, 2016) • 3mm session (32 Gbps, July 10, 2016)
• Recent Development • Production correlation scripts • Production QA2 (ALMA) scripts • 1mm analysis tools (for EHT)
• Planning for Spring 2017 Cycle 4 Campaigns • Approved proposals announced Aug 2016 • GMVA 3 mm (window: March 30 – April 4) • EHTC 1 mm (window: April 5 – April 14)
• Future development (Cycle 5 and later) • Use all 4 dual pol bands (64 Gbps) • Relax Cycle 4 proposal restrictions
Quick Summary of Phased ALMA Capabilities
• Equivalent collecting area: • 75-m parabolic dish (with 40 phased 12-m antennas, Cycle 4) • 84-m parabolic dish (with 50 phased 12-m antennas)
• Frequencies of operation: • Band 3 (84-116 GHz = λ 2.6 - 3.6 mm) • Band 6 (211-275 GHz = λ 1.1 - 1.4 mm)
• SEFD: • ~70 Jy @ 3 mm • ~ 100 Jy @ 1.3 mm
• Bandwidth: 7.5 GHz (2 USB x 3.75 GHz and 2 LSB x 3.75 GHz) • Polarization: Dual pol recording, full Stokes datasets • VLBI Recording rates:
• 64 Gbps available and commissioned • Band 3 uses 16 Gbps, Band 6 uses 32 Gbps in Cycle 4 (64 Gbps in Cycle 5)
• Angular resolution of ALMA-Mauna Kea baseline: • ~70 µas @ 3 mm • ~30 µas @ 1.3 mm
4 Crew -‐ VLBI with ALMA -‐ Oct 12, 2016
Technical Implementation Cartoon
5 Crew -‐ VLBI with ALMA -‐ Oct 12, 2016
Maser
VLBI
Phasing
2 bits/sample
Each Quadrant:
2Pol x 32ch x 62.5MHz
Data Rate: 16 Gb/s
128 LVDS Pairs
Correlator: Baseline
TelCal Computer
Slow Phase Solver and Monitor
Fiber DEMUX
Fiber MUX
Correlator: Station
CDP Computer Cluster
Correlator: Control
Phasing Interface Card
Central Electronics
Central Variable Reference
Photonic LOH Maser
Front End
Samplers, WVR
Optical Fiber Tx
Antenna
Eng. Port
CLOA
GPS
Alma Scheduling Blocks
Connects to all sub−systemsALMA Control SystemCorr GPS
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
Monitors phasing efficiency by
correlating sum with reference
to calculate phase corrections
Uses source model parameters
∆φ Phase Corrections (Slow)
Station Card
Geometric Delay
Optical Fiber Rx/Demux
Form 32 x 62.5 MHz slices
Tunable Filterbank Card (TFB)
Phase shift each slice
∆φ Phase Corrections (Fast)
Correlator Hardware Protocols
TFB Commanding
2 Cards per Quadrant
2−bit Quantization of VLBI sum
Control of CIC: VLBI sum on CAI 63
Control of CC:
VLBI antenna sum mask
Control of TFB:
Spectral Windows / Channel Averages
Synchronizatioed commanding
Packet Time setting
Monitor GPS−Maser Drift
Control of Phasing Interace Cards:
Control of VLBI Recorders
Sends Parameters to TelCal Computer
Control of Source Model Monitor
VLBI Scheduler
VLBI Observing Mode Scheduling Block
Fast WVR Phase Corrector
8 x 10 GbE
Phased Sum Data
AOS (high site)
OSF (low site)
OSF (low site)
8 x 10 GbE
VLBI 16 Gbps Recorders
Baseline Visibilities
Generate Channel Averages
10 GbE Packetization
Synchronization
PPS/Clock Monitor
VDIF Formatting
10 MHz
1 PPS
CRG: 125 MHz, &c
MASER_V_GPS_COUNTER
Tunab
le F
ilte
rban
k C
om
man
ds
5 MHz
Legend Controller domains New/Old h/w & s/w All done, except for:
-‐ Source Modeler
Array OperaHons Site (AOS), 5000 m
OperaHons Support Facility (OSF), 2900m
(with happy operator Hector Alarcon)
Photo credit: ALMA
Photo credit: G. Crew
Hydrogen Maser (T4Science)
• Hydrogen Maser accepted Nov 2014 • Power-cycled during Feb. Maintenance • Works fine (Residuals of GPS-Maser fit: Ionospheric TEC variations)
6
Days aPer power-‐cycling completed
+30ns
-‐30ns
1 month
Crew -‐ VLBI with ALMA -‐ Oct 12, 2016
(Compared with good crystal)
1/2 year
ALMA Correlator Modifications
7 Crew -‐ VLBI with ALMA -‐ Oct 12, 2016
• 4 Phasing Interface Card Assembly (PIC) pairs installed in 4 quadrants
• (Correlator GPS and Maser) PPS monitoring with TTL to LVDS converter/distributor board
• Many additional cables (2b x 32 channels/PIC x 8 PICs) • PIC Firmware to send VDIF packets to link • New ALMA Correlator communication protocols
Final Adder Mother
ROACH2 Daughter
Front of Quadrant (4 Quadrants)
Back of Quadrant
Photo credit: G. Crew
Photo credit: R. Lacasse
Photo credit: R. Lacasse
Correlator Bins | StaHon Bins
Recorders and Optical Link
• Use a spare ALMA fiber (~35 km AOS - OSF) • Fiber Mux (AOS) & DeMux (OSF) • 4 Mark6 16 Gbps Recorders & 1 spare • KVM switch and monitor • Delivery completed 2014 • In use for VLBI since Jan 2015 APEX test • Error rate ~1 ppm (due to dropped packets on each
of the 8 data streams) • Modules
• Well tested for 2900m • ~ PB of test recordings onto 24TB and 32TB modules • 48TB or 64TB likely for Cycle 4
8 Crew -‐ VLBI with ALMA -‐ Oct 12, 2016
Photo credit: G. Crew
OpHcal DeMux
ALMA Scheduling Blocks
9 Crew -‐ VLBI with ALMA -‐ Oct 12, 2016
• VLBI specifies observing session details via VEX files • ALMA uses Scheduling Blocks (SB) to describe observaHon
• Science Targets • CalibraHon Targets • Spectral setups, &c. • Created and managed using Observing Tool (OT)
• VEX2VOM tool created to marry VLBI VEX files with ALMA OT • Once the SBs are “Ready” observaHon is automaHc
VLBI Schedule Blocks Fully Integrated with ALMA
10 Crew -‐ VLBI with ALMA -‐ Oct 12, 2016
• VLBI ObservaHons run the same as normal ALMA observaHons
• VLBI Schedule (VEX) is embedded in ALMA Scheduling Block (SB) prior to observing session
• Approximately 30min of pre-‐session calibraHons are required prior to observing
• APer that it all runs automaHcally (schedule and calibraHons)
• The session is broken into ~1hr SBs for safety with ALMA Archive
ALMA OMC
Completed SB List SubScans
Correlation with DiFX
11 Crew -‐ VLBI with ALMA -‐ Oct 12, 2016
Mark6 Subgroups
Cluster Output File System
We assign one data stream per real antenna polariza1on
2 Cores/Mark6 Cluster CPUs
(or spare Mark6 CPUs)
Haystack Correlator (October, 2016)
12 Crew -‐ VLBI with ALMA -‐ Oct 12, 2016
Old S/W Correlator New S/W Correlator
Photo credit: G. Crew
Nearly Obsolete Mark5A/Bs AddiHonal Cores and Mark6 Playback units on order
GeodeHc
VGOS
EHTC
Some Additional Correlation Challenges
• “Zoom band” required • Due to ALMA’s 4000 MHz sampling rate • ALMA’s 32 62.5 MHz channels are overlapped by 15/16 (<60 MHz usable) • DDC mode (2 x 128 MHz x 2 pol) channels works with VLBA/GMVA (narrow) • 2048 MHz single channel R2DBE mode works with EHTC (wide)
• Similar EHTC complications with (phased) SMA at present • Native 4576 MHz sampling rate • Post-observation (offline) resampling to 2048 MHz (APHIDS) • Will become online processing in the future
13 Crew -‐ VLBI with ALMA -‐ Oct 12, 2016
Phased Phased PhasedUnphased ∆ ∆ ∆
TFB Commands
. . .
WVR Data
. . .
. . .
TelCal Solving
Correlator Scan Sequence
. . .
. . .
VLBI Scan Record On
Time
ALMA Phasing System (APS) • Timeline of “scans” • Tunable Filter Banks (TFBs)
have a phase-adjustment register • Two time-scales for phase
adjustment in the TFBs • “Slow” (18s) phasing loop • “Fast” (1 Hz) adjustments
• Proper tuning of Slow and Fast can be used to better manage weather (Cycle 5)
15
(Lather, rinse, repeat…)
dump
First valid subscan
adjust
Crew -‐ VLBI with ALMA -‐ Oct 12, 2016
Phasing Example (Aug 27th 2015)
Phased Un-‐Phased
Correlated amplitude on baselines from “sum” and “reference” to “comparison” antennas on 4 quadrants with same tuning
√N 8 Channel Averages
Reference-‐Sum Antennas
Reference-‐Comparison Antennas
Crew -‐ VLBI with ALMA -‐ Oct 12, 2016 16
Time
Amp
4 integraHons / correlator subscan Colored by channel average (200MHz)
Fast WVR Correction Example (No Slow Phasing)
17
Phas
e (±
180
degr
ees)
Fast Corrected
Fast Corrected
Band 6: 4 Spectral Window(SW)s in parallel; 2 SWs fast-‐corrected , 2 SWs unadjusted; one ALMA baseline
Not Corrected
10 min
Crew -‐ VLBI with ALMA -‐ Oct 12, 2016
Not Corrected
Data from one baseline
Phasing Efficiency
18 Crew -‐ VLBI with ALMA -‐ Oct 12, 2016
0
1
2
3
4
5
6
7
0 10 20 30 40 50
APP0150
Aver
age(
<Com
p . S
um>
/ <C
omp
. Ref
>)
Phased Antennas (N)
Phasing Efficiency (Mar-Sep 2015)
Mar30Apr24
May07May29Jun20Jun19Aug27Aug25Sep14
Mar30(band6)Jul31(band6)
Aug01(band7)Aug01(band3)
• Nominal target was 90% of perfect • All data was taken in adverse* condiHons • Phased Sum signal (2-‐bit) is ALMA-‐correlated • The analysis isn’t trivial with Np >> 1$, Nc >> 1+ • PolConvert computes the per-‐integraHon
efficiency and provides a gain table:
We notice that both figures are computed in a completely independent way, since PolConvert
does not know anything about the magnitude of the phased signal (it only deals with single-
antenna calibration tables, derived from the intra-ALMA cross-correlations). The similarity
between these two figures is a good indicative that the calibration computed by PolConvert is
correct.
Figure 5: Left, amplitude of the phased signal during an observation of the bandpass
calibrator. Right, quantity proportional to the phasing e�ciency, as estimated by Pol-
Convert
4.1.4 Cross-phase
In Figure 6, we show the X-Y cross-phases of the reference antenna, computed from the
ALMAscans (left) and from the APPscans (right). They look completely di↵erent, as expected
due to the e↵ects of the APP TelCal. Indeed, for the APP cross-phase, the small jumps among
the frequency chunks used by TelCal can be appreciated in the spws used for VLBI (upper side
of the figure). It is worth noticing that the X-Y phase o↵set determined for the APPscans shall
be independent of the antenna used as reference in the QA2, since such o↵set was injected at all
the antennas prior to the cross-correlation, while keeping all phases close to zero. However, us-
ing a di↵erent reference antenna in the QA2 calibration of the ALMAscans will certainly change
the derived X-Y o↵set.
IT IS VERY IMPORTANT, for the success of the polarization conversion, to get rid
of the noisy solutions in the X-Y cross-phase calibration table. PolConvert will interpolate
the flagged channels using the neighboring solutions. In the case of spw1 in Fig. 6, there is
a set of a few close by channels with phases spread between 180 and �180 degrees. The
10
I. MarH-‐Vidal, 2016
Sum Antenna AutocorrelaHon PolConvert Gain CalculaHon
*adverse: weather, operaHonal s/w issues… $Np is number phased antennas +Nc is number comparison antennas
PolConvert Per-Sub-Band Fringes
19 Crew -‐ VLBI with ALMA -‐ Oct 12, 2016
• ALMA observes with LINEAR polariza3ons
• PolConvert converts to CIRCULAR polariza3ons
• Band 6, April 8 2016 commissioning session VLBI calibrator (a.k.a. boring quasar) J1337-‐1257
• 1.3 Jy at 233 GHz • PolConvert “quick fringe”
analysis on single channels (no band-‐pass correc1ons) for “runHme” look at polarizaHon processing
• Current work is to establish level of polarizaHon purity in detailed analysis.
Original, Mixed PolarizaHons as generated by DiFX
Converted, Circular PolarizaHons as would have been generated by DiFX
|226.1 MHz FREQUENCY 228.1| |226.1 MHz FREQUENCY 228.1|
Corresponding Fourfit Fringes (parallel hands)
Mk4/DiFX fourfit 3.12 rev 1417 J1337-1257.zaoprj, No0015, AL ALMA - LMT, fgroup B, pol LL
8
130.159.982
4.358-118.3
0.0e+00
0.0007150.000596
-0.140009 0.000
226175.79690.320
e16b083557
2016:099070700.00070800.16070730.00
2016:250:1521442016:250:1633122016:250:063022
13h37m39.7828s-12˚57’24.693"
Fringe quality
SNRInt timeAmpPhasePFDDelays (us)SBDMBDFringe rate (Hz)
Ion TEC Ref freq (MHz)
AP (sec)Exp.Exper #Yr:dayStartStopFRTCorr/FF/build
RA & Dec (J2000)
Amp. and Phase vs. time for each freq., 7 segs, 31 APs / seg (9.92 sec / seg.), time ticks 10 sec
UValidity
L
A L
226175.80 Freq (MHz)
-116.4 Phase
3.7 Ampl.
129.2 Sbd box
188/0 APs usedU/L
0 PC freqsA
0 PC freqsL
0:0 PC phaseA:L
0:42 Manl PCA:L
PC ampA 1000
1000L
B00UL Chan idsA
B00UL Chan idsL
226234.39
-117.0
3.8
129.1
188/0
0
0
0:0
0:-116
1000
1000
B01UL
B01UL
226292.98
-120.9
4.5
129.0
188/0
0
0
0:0
0:90
1000
1000
B02UL
B02UL
226351.58
-116.3
3.9
129.2
188/0
0
0
0:0
0:-55
1000
1000
B03UL
B03UL
226410.17
-121.1
4.5
129.1
188/0
0
0
0:0
0:172
1000
1000
B04UL
B04UL
226468.77
-115.4
3.7
129.2
188/0
0
0
0:0
0:30
1000
1000
B05UL
B05UL
226527.36
-116.0
4.3
129.1
188/0
0
0
0:0
0:-116
1000
1000
B06UL
B06UL
226585.95
-123.4
4.0
129.2
188/0
0
0
0:0
0:95
1000
1000
B07UL
B07UL
226644.55
-119.7
4.5
129.0
188/0
0
0
0:0
0:-44
1000
1000
B08UL
B08UL
226703.14
-121.0
3.9
129.0
188/0
0
0
0:0
0:170
1000
1000
B09UL
B09UL
226761.73
-123.7
4.9
129.0
188/0
0
0
0:0
0:25
1000
1000
B10UL
B10UL
226820.33
-115.7
4.3
129.0
188/0
0
0
0:0
0:-121
1000
1000
B11UL
B11UL
226878.92
-111.1
4.1
128.9
188/0
0
0
0:0
0:98
1000
1000
B12UL
B12UL
226937.52
-113.1
3.8
129.1
188/0
0
0
0:0
0:-47
1000
1000
B13UL
B13UL
226996.11
-115.4
4.2
128.9
188/0
0
0
0:0
0:170
1000
1000
B14UL
B14UL
227054.70
-120.6
4.4
129.0
188/0
0
0
0:0
0:22
1000
1000
B15UL
B15UL
227113.30
-122.5
4.7
129.2
188/0
0
0
0:0
0:-127
1000
1000
B16UL
B16UL
227171.89
-127.0
4.5
129.2
188/0
0
0
0:0
0:87
1000
1000
B17UL
B17UL
227230.48
-116.8
5.1
129.2
188/0
0
0
0:0
0:-59
1000
1000
B18UL
B18UL
227289.08
-118.8
4.9
129.1
188/0
0
0
0:0
0:149
1000
1000
B19UL
B19UL
227347.67
-112.1
5.2
129.1
188/0
0
0
0:0
0:5
1000
1000
B20UL
B20UL
227406.27
-120.4
4.6
129.1
188/0
0
0
0:0
0:-145
1000
1000
B21UL
B21UL
227464.86
-114.2
4.6
129.0
188/0
0
0
0:0
0:67
1000
1000
B22UL
B22UL
227523.45
-119.2
4.7
129.1
188/0
0
0
0:0
0:-83
1000
1000
B23UL
B23UL
227582.05
-117.9
4.5
129.1
188/0
0
0
0:0
0:125
1000
1000
B24UL
B24UL
227640.64
-112.0
4.7
129.2
188/0
0
0
0:0
0:-28
1000
1000
B25UL
B25UL
227699.23
-117.6
4.5
129.1
188/0
0
0
0:0
0:178
1000
1000
B26UL
B26UL
227757.83
-112.6
4.7
128.9
188/0
0
0
0:0
0:28
1000
1000
B27UL
B27UL
227816.42
-119.9
4.3
128.8
188/0
0
0
0:0
0:-135
1000
1000
B28UL
B28UL
227875.02
-122.3
4.3
129.1
188/0
0
0
0:0
0:70
1000
1000
B29UL
B29UL
227933.61
-121.6
4.3
129.2
188/0
0
0
0:0
0:-87
1000
1000
B30UL
Tracks
B30UL
Tracks
227992.20
-123.7
3.7
129.3
188/0
0
0
0:0
0:111
1000
1000
B31UL
B31UL
All
-118.3
4.4
129.1
Group delay (usec)(sbd)Sband delay (usec)Phase delay (usec)Delay rate (us/s)Total phase (deg)
-2.00426883596E+03-2.00426871693E+03-2.00426943338E+03-6.79469867373E-01
-89.0
Apriori delay (usec)Apriori clock (usec)Apriori clockrate (us/s)Apriori rate (us/s)Apriori accel (us/s/s)
-2.00426943193E+03-2.1081138E+03-2.3810001E-06
-6.79469248344E-011.76369108361E-05
Resid mbdelay (usec)Resid sbdelay (usec)Resid phdelay (usec)Resid rate (us/s)Resid phase (deg)
5.95964E-047.15000E-04
-1.45267E-06-6.19029E-07
-118.3
+/-+/-+/-+/-+/-
2.3E-061.3E-041.1E-083.1E-10
0.9RMS Theor. Amplitude 4.358 +/- 0.033 Pcal mode: MANUAL, MANUAL PC period (AP’s) 5, 5
ph/seg (deg) 16.5 1.2 Search (512X128) 4.223 Pcal rate: 0.000E+00, 0.000E+00 (us/s) sb window (us) -1.000 1.000amp/seg (%) 12.1 2.0 Interp. 0.000 Bits/sample: 2x2 SampCntNorm: disabled mb window (us) -0.008 0.008ph/frq (deg) 4.0 2.5 Inc. seg. avg. 4.524 Sample rate(MSamp/s): 64 dr window (ns/s) -0.006 0.006amp/frq (%) 9.5 4.3 Inc. frq. avg. 4.360 Data rate(Mb/s): 4096 nlags: 128 t_cohere infinite ion window (TEC) 0.00 0.00A: az 283.3 el 58.9 pa 113.3 L: az 182.8 el 57.9 pa 2.6 u,v (fr/asec) 10499.207 -17029.585 simultaneous interpolatorControl file: e16b08-LoLL-pc.conf Input file: /data-sc05/gbc/alma-april-band6-4-pc4/3557/No0015/AL..zaoprj Output file: /data-sc05/gbc/alma-april-band6-4-pc4/3557/No0015/AL.B.23.zaoprj
Mk4/DiFX fourfit 3.12 rev 1417 J1337-1257.zaoprj, No0015, AL ALMA - LMT, fgroup B, pol RR
8
125.259.9794.195
-2.50.0e+00
0.0005230.000608
-0.139970 0.000
226175.79690.320
e16b083557
2016:099070700.00070800.16070730.00
2016:250:1521442016:250:1633022016:250:063022
13h37m39.7828s-12˚57’24.693"
Fringe quality
SNRInt timeAmpPhasePFDDelays (us)SBDMBDFringe rate (Hz)
Ion TEC Ref freq (MHz)
AP (sec)Exp.Exper #Yr:dayStartStopFRTCorr/FF/build
RA & Dec (J2000)
Amp. and Phase vs. time for each freq., 7 segs, 31 APs / seg (9.92 sec / seg.), time ticks 10 sec
UValidity
L
A L
226175.80 Freq (MHz)
-7.9 Phase
3.5 Ampl.
129.4 Sbd box
188/0 APs usedU/L
0 PC freqsA
0 PC freqsL
0:0 PC phaseA:L
0:-87 Manl PCA:L
PC ampA 1000
1000L
B00UR Chan idsA
B00UR Chan idsL
226234.39
-2.8
3.9
128.9
188/0
0
0
0:0
0:15
1000
1000
B01UR
B01UR
226292.98
-0.5
3.5
129.1
188/0
0
0
0:0
0:129
1000
1000
B02UR
B02UR
226351.58
-6.5
3.7
129.2
188/0
0
0
0:0
0:-121
1000
1000
B03UR
B03UR
226410.17
0.6
4.1
129.1
188/0
0
0
0:0
0:-3
1000
1000
B04UR
B04UR
226468.77
-3.9
3.9
128.8
188/0
0
0
0:0
0:122
1000
1000
B05UR
B05UR
226527.36
-8.5
3.8
129.0
188/0
0
0
0:0
0:-117
1000
1000
B06UR
B06UR
226585.95
2.2
4.2
129.1
188/0
0
0
0:0
0:8
1000
1000
B07UR
B07UR
226644.55
3.9
4.5
129.1
188/0
0
0
0:0
0:127
1000
1000
B08UR
B08UR
226703.14
0.8
4.6
128.9
188/0
0
0
0:0
0:-118
1000
1000
B09UR
B09UR
226761.73
0.7
4.1
128.9
188/0
0
0
0:0
0:-8
1000
1000
B10UR
B10UR
226820.33
2.3
3.9
129.0
188/0
0
0
0:0
0:106
1000
1000
B11UR
B11UR
226878.92
-3.2
4.5
128.9
188/0
0
0
0:0
0:-136
1000
1000
B12UR
B12UR
226937.52
-2.4
4.6
129.0
188/0
0
0
0:0
0:-26
1000
1000
B13UR
B13UR
226996.11
0.9
4.1
128.9
188/0
0
0
0:0
0:97
1000
1000
B14UR
B14UR
227054.70
-4.2
4.3
128.9
188/0
0
0
0:0
0:-151
1000
1000
B15UR
B15UR
227113.30
-2.0
4.1
129.1
188/0
0
0
0:0
0:-41
1000
1000
B16UR
B16UR
227171.89
-3.1
4.7
129.0
188/0
0
0
0:0
0:70
1000
1000
B17UR
B17UR
227230.48
-4.3
4.3
129.1
188/0
0
0
0:0
0:-174
1000
1000
B18UR
B18UR
227289.08
-11.7
4.7
129.3
188/0
0
0
0:0
0:-61
1000
1000
B19UR
B19UR
227347.67
-8.3
4.7
129.2
188/0
0
0
0:0
0:54
1000
1000
B20UR
B20UR
227406.27
-1.1
4.2
129.2
188/0
0
0
0:0
0:173
1000
1000
B21UR
B21UR
227464.86
-4.7
4.2
129.2
188/0
0
0
0:0
0:-78
1000
1000
B22UR
B22UR
227523.45
-0.2
3.9
128.8
188/0
0
0
0:0
0:30
1000
1000
B23UR
B23UR
227582.05
-10.4
4.2
129.2
188/0
0
0
0:0
0:141
1000
1000
B24UR
B24UR
227640.64
-4.2
4.6
129.0
188/0
0
0
0:0
0:-111
1000
1000
B25UR
B25UR
227699.23
-4.0
4.5
129.1
188/0
0
0
0:0
0:-3
1000
1000
B26UR
B26UR
227757.83
-1.4
4.4
129.1
188/0
0
0
0:0
0:107
1000
1000
B27UR
B27UR
227816.42
6.3
4.3
128.9
188/0
0
0
0:0
0:-147
1000
1000
B28UR
B28UR
227875.02
-1.1
4.4
129.3
188/0
0
0
0:0
0:-44
1000
1000
B29UR
B29UR
227933.61
0.7
4.0
129.0
188/0
0
0
0:0
0:60
1000
1000
B30UR
Tracks
B30UR
Tracks
227992.20
-2.2
4.0
129.3
188/0
0
0
0:0
0:161
1000
1000
B31UR
B31UR
All
-2.5
4.2
129.1
Group delay (usec)(sbd)Sband delay (usec)Phase delay (usec)Delay rate (us/s)Total phase (deg)
-2.00426882399E+03-2.00426890943E+03-2.00426943196E+03-6.79469867200E-01
-333.2
Apriori delay (usec)Apriori clock (usec)Apriori clockrate (us/s)Apriori rate (us/s)Apriori accel (us/s/s)
-2.00426943193E+03-2.1081138E+03-2.3810001E-06
-6.79469248344E-011.76369108361E-05
Resid mbdelay (usec)Resid sbdelay (usec)Resid phdelay (usec)Resid rate (us/s)Resid phase (deg)
6.07937E-045.22500E-04
-3.09603E-08-6.18856E-07
-2.5
+/-+/-+/-+/-+/-
2.3E-061.4E-041.1E-083.2E-10
0.9RMS Theor. Amplitude 4.195 +/- 0.033 Pcal mode: MANUAL, MANUAL PC period (AP’s) 5, 5
ph/seg (deg) 16.9 1.2 Search (512X128) 4.091 Pcal rate: 0.000E+00, 0.000E+00 (us/s) sb window (us) -1.000 1.000amp/seg (%) 12.8 2.1 Interp. 0.000 Bits/sample: 2x2 SampCntNorm: disabled mb window (us) -0.008 0.008ph/frq (deg) 4.1 2.6 Inc. seg. avg. 4.362 Sample rate(MSamp/s): 64 dr window (ns/s) -0.006 0.006amp/frq (%) 8.0 4.5 Inc. frq. avg. 4.199 Data rate(Mb/s): 4096 nlags: 128 t_cohere infinite ion window (TEC) 0.00 0.00A: az 283.3 el 58.9 pa 113.3 L: az 182.8 el 57.9 pa 2.6 u,v (fr/asec) 10499.207 -17029.585 simultaneous interpolatorControl file: e16b08-LoRR-pc.conf Input file: /data-sc05/gbc/alma-april-band6-4-pc4/3557/No0015/AL..zaoprj Output file: /data-sc05/gbc/alma-april-band6-4-pc4/3557/No0015/AL.B.17.zaoprj
20 Crew -‐ VLBI with ALMA -‐ Oct 12, 2016
Fringes on first 60s (of 240s recording)
Corresponding Fourfit Fringes (cross hands)
Mk4/DiFX fourfit 3.12 rev 1403 J1337-1257.zaoprj, No0015, AL ALMA - LMT, fgroup B, pol LR
9
13.559.9790.453-66.5
2.4e-33
0.0080500.005382
-0.140598 0.000
226175.79690.320
e16b083557
2016:099070700.00070800.16070730.00
2016:250:1521442016:281:1911462016:235:133626
13h37m39.7828s-12˚57’24.693"
Fringe quality
SNRInt timeAmpPhasePFDDelays (us)SBDMBDFringe rate (Hz)
Ion TEC Ref freq (MHz)
AP (sec)Exp.Exper #Yr:dayStartStopFRTCorr/FF/build
RA & Dec (J2000)
Amp. and Phase vs. time for each freq., 7 segs, 31 APs / seg (9.92 sec / seg.), time ticks 10 sec
UValidity
L
A L
226175.80 Freq (MHz)
-123.8 Phase
0.1 Ampl.
153.0 Sbd box
188/0 APs usedU/L
0 PC freqsA
0 PC freqsL
0:0 PC phaseA:L
0:42 Manl PCA:L
PC ampA 1000
1000L
B00UL Chan idsA
B00UR Chan idsL
226234.39
-96.9
0.7
47.8
188/0
0
0
0:0
0:-116
1000
1000
B01UL
B01UR
226292.98
-128.4
0.3
86.1
188/0
0
0
0:0
0:90
1000
1000
B02UL
B02UR
226351.58
-87.2
0.4
65.8
188/0
0
0
0:0
0:-55
1000
1000
B03UL
B03UR
226410.17
-75.0
0.5
193.7
188/0
0
0
0:0
0:172
1000
1000
B04UL
B04UR
226468.77
-10.2
0.2
163.9
188/0
0
0
0:0
0:30
1000
1000
B05UL
B05UR
226527.36
-3.3
0.5
149.4
188/0
0
0
0:0
0:-116
1000
1000
B06UL
B06UR
226585.95
-51.0
0.7
31.8
188/0
0
0
0:0
0:95
1000
1000
B07UL
B07UR
226644.55
-68.6
0.4
153.9
188/0
0
0
0:0
0:-44
1000
1000
B08UL
B08UR
226703.14
-64.3
0.4
128.0
188/0
0
0
0:0
0:170
1000
1000
B09UL
B09UR
226761.73
-11.8
0.4
105.8
188/0
0
0
0:0
0:25
1000
1000
B10UL
B10UR
226820.33
-24.7
0.3
157.3
188/0
0
0
0:0
0:-121
1000
1000
B11UL
B11UR
226878.92
-93.8
0.8
7.1
188/0
0
0
0:0
0:98
1000
1000
B12UL
B12UR
226937.52
-88.2
1.0
130.0
188/0
0
0
0:0
0:-47
1000
1000
B13UL
B13UR
226996.11
-96.6
0.9
129.7
188/0
0
0
0:0
0:170
1000
1000
B14UL
B14UR
227054.70
-60.9
1.1
130.0
188/0
0
0
0:0
0:22
1000
1000
B15UL
B15UR
227113.30
-55.3
1.1
130.3
188/0
0
0
0:0
0:-127
1000
1000
B16UL
B16UR
227171.89
-32.1
0.4
120.6
188/0
0
0
0:0
0:87
1000
1000
B17UL
B17UR
227230.48
-64.8
0.9
246.4
188/0
0
0
0:0
0:-59
1000
1000
B18UL
B18UR
227289.08
-23.2
0.8
130.4
188/0
0
0
0:0
0:149
1000
1000
B19UL
B19UR
227347.67
-6.4
0.9
88.1
188/0
0
0
0:0
0:5
1000
1000
B20UL
B20UR
227406.27
83.3
0.4
175.9
188/0
0
0
0:0
0:-145
1000
1000
B21UL
B21UR
227464.86
128.1
0.2
157.9
188/0
0
0
0:0
0:67
1000
1000
B22UL
B22UR
227523.45
96.9
0.4
157.4
188/0
0
0
0:0
0:-83
1000
1000
B23UL
B23UR
227582.05
-102.7
0.3
101.9
188/0
0
0
0:0
0:125
1000
1000
B24UL
B24UR
227640.64
-109.2
0.6
219.6
188/0
0
0
0:0
0:-28
1000
1000
B25UL
B25UR
227699.23
-133.5
0.7
217.0
188/0
0
0
0:0
0:178
1000
1000
B26UL
B26UR
227757.83
-81.9
0.4
247.5
188/0
0
0
0:0
0:28
1000
1000
B27UL
B27UR
227816.42
-89.3
1.2
130.0
188/0
0
0
0:0
0:-135
1000
1000
B28UL
B28UR
227875.02
-45.0
1.2
129.7
188/0
0
0
0:0
0:70
1000
1000
B29UL
B29UR
227933.61
-79.3
0.5
55.2
188/0
0
0
0:0
0:-87
1000
1000
B30UL
Tracks
B30UR
Tracks
227992.20
-53.6
0.5
131.9
188/0
0
0
0:0
0:111
1000
1000
B31UL
B31UR
All
-66.5
0.6
130.0
Group delay (usec)(sbd)Sband delay (usec)Phase delay (usec)Delay rate (us/s)Total phase (deg)
-2.00426404970E+03-2.00426138193E+03-2.00426943274E+03-6.79469869976E-01
-37.1
Apriori delay (usec)Apriori clock (usec)Apriori clockrate (us/s)Apriori rate (us/s)Apriori accel (us/s/s)
-2.00426943193E+03-2.1081138E+03-2.3810001E-06
-6.79469248344E-011.76369108361E-05
Resid mbdelay (usec)Resid sbdelay (usec)Resid phdelay (usec)Resid rate (us/s)Resid phase (deg)
5.38223E-038.05000E-03
-8.16123E-07-6.21632E-07
-66.5
+/-+/-+/-+/-+/-
2.2E-051.3E-031.0E-073.0E-09
8.5RMS Theor. Amplitude 0.453 +/- 0.033 Pcal mode: MANUAL, MANUAL PC period (AP’s) 5, 5
ph/seg (deg) 20.0 11.2 Search (512X128) 0.436 Pcal rate: 0.000E+00, 0.000E+00 (us/s) sb window (us) -1.000 1.000amp/seg (%) 32.4 19.6 Interp. 0.000 Bits/sample: 2x2 SampCntNorm: disabled mb window (us) -0.008 0.008ph/frq (deg) 62.0 24.0 Inc. seg. avg. 0.474 Sample rate(MSamp/s): 64 dr window (ns/s) -0.006 0.006amp/frq (%) 74.0 41.8 Inc. frq. avg. 0.557 Data rate(Mb/s): 4096 nlags: 128 t_cohere infinite ion window (TEC) 0.00 0.00A: az 283.3 el 58.9 pa 113.3 L: az 182.8 el 57.9 pa 2.6 u,v (fr/asec) 10499.207 -17029.585 simultaneous interpolatorControl file: e16b08-LoLL-pc.conf Input file: /data-sc05/gbc/alma-april-band6-4-pc4/3557/No0015/AL..zaoprj Output file: Suppressed by test mode
Mk4/DiFX fourfit 3.12 rev 1403 J1337-1257.zaoprj, No0015, AL ALMA - LMT, fgroup B, pol RL
9
9.459.982
0.315-104.5
9.3e-13
-0.005672-0.003961
-0.140031 0.000
226175.79690.320
e16b083557
2016:099070700.00070800.16070730.00
2016:250:1521442016:281:1912382016:235:133626
13h37m39.7828s-12˚57’24.693"
Fringe quality
SNRInt timeAmpPhasePFDDelays (us)SBDMBDFringe rate (Hz)
Ion TEC Ref freq (MHz)
AP (sec)Exp.Exper #Yr:dayStartStopFRTCorr/FF/build
RA & Dec (J2000)
Amp. and Phase vs. time for each freq., 7 segs, 31 APs / seg (9.92 sec / seg.), time ticks 10 sec
UValidity
L
A L
226175.80 Freq (MHz)
-11.2 Phase
0.6 Ampl.
123.7 Sbd box
188/0 APs usedU/L
0 PC freqsA
0 PC freqsL
0:0 PC phaseA:L
0:-87 Manl PCA:L
PC ampA 1000
1000L
B00UR Chan idsA
B00UL Chan idsL
226234.39
37.2
0.3
144.8
188/0
0
0
0:0
0:15
1000
1000
B01UR
B01UL
226292.98
-38.4
0.2
81.9
188/0
0
0
0:0
0:129
1000
1000
B02UR
B02UL
226351.58
-128.6
0.6
61.2
188/0
0
0
0:0
0:-121
1000
1000
B03UR
B03UL
226410.17
-74.7
0.8
7.8
188/0
0
0
0:0
0:-3
1000
1000
B04UR
B04UL
226468.77
-114.3
0.3
88.4
188/0
0
0
0:0
0:122
1000
1000
B05UR
B05UL
226527.36
-78.7
0.1
1.6
188/0
0
0
0:0
0:-117
1000
1000
B06UR
B06UL
226585.95
-80.6
0.5
16.9
188/0
0
0
0:0
0:8
1000
1000
B07UR
B07UL
226644.55
-3.8
0.4
245.8
188/0
0
0
0:0
0:127
1000
1000
B08UR
B08UL
226703.14
75.8
0.2
8.3
188/0
0
0
0:0
0:-118
1000
1000
B09UR
B09UL
226761.73
94.8
0.1
58.9
188/0
0
0
0:0
0:-8
1000
1000
B10UR
B10UL
226820.33
144.2
0.8
146.3
188/0
0
0
0:0
0:106
1000
1000
B11UR
B11UL
226878.92
-109.8
0.2
156.5
188/0
0
0
0:0
0:-136
1000
1000
B12UR
B12UL
226937.52
-156.9
0.9
128.3
188/0
0
0
0:0
0:-26
1000
1000
B13UR
B13UL
226996.11
-139.0
0.6
159.8
188/0
0
0
0:0
0:97
1000
1000
B14UR
B14UL
227054.70
-144.8
0.4
77.2
188/0
0
0
0:0
0:-151
1000
1000
B15UR
B15UL
227113.30
-144.7
1.1
127.3
188/0
0
0
0:0
0:-41
1000
1000
B16UR
B16UL
227171.89
177.1
0.4
89.3
188/0
0
0
0:0
0:70
1000
1000
B17UR
B17UL
227230.48
-81.3
0.8
250.2
188/0
0
0
0:0
0:-174
1000
1000
B18UR
B18UL
227289.08
-102.0
0.8
165.9
188/0
0
0
0:0
0:-61
1000
1000
B19UR
B19UL
227347.67
-44.6
0.4
123.7
188/0
0
0
0:0
0:54
1000
1000
B20UR
B20UL
227406.27
-57.3
0.3
101.8
188/0
0
0
0:0
0:173
1000
1000
B21UR
B21UL
227464.86
-92.0
0.6
248.0
188/0
0
0
0:0
0:-78
1000
1000
B22UR
B22UL
227523.45
-161.7
0.6
228.7
188/0
0
0
0:0
0:30
1000
1000
B23UR
B23UL
227582.05
-41.4
0.2
71.3
188/0
0
0
0:0
0:141
1000
1000
B24UR
B24UL
227640.64
-131.0
0.9
128.6
188/0
0
0
0:0
0:-111
1000
1000
B25UR
B25UL
227699.23
-78.0
0.2
166.2
188/0
0
0
0:0
0:-3
1000
1000
B26UR
B26UL
227757.83
-102.3
0.9
128.7
188/0
0
0
0:0
0:107
1000
1000
B27UR
B27UL
227816.42
-69.0
1.1
128.3
188/0
0
0
0:0
0:-147
1000
1000
B28UR
B28UL
227875.02
-92.0
0.4
124.5
188/0
0
0
0:0
0:-44
1000
1000
B29UR
B29UL
227933.61
-40.9
0.3
162.3
188/0
0
0
0:0
0:60
1000
1000
B30UR
Tracks
B30UL
Tracks
227992.20
-96.5
0.2
136.3
188/0
0
0
0:0
0:161
1000
1000
B31UR
B31UL
All
-104.5
0.4
128.3
Group delay (usec)(sbd)Sband delay (usec)Phase delay (usec)Delay rate (us/s)Total phase (deg)
-2.00427339285E+03-2.00427510393E+03-2.00426943321E+03-6.79469867470E-01
-75.2
Apriori delay (usec)Apriori clock (usec)Apriori clockrate (us/s)Apriori rate (us/s)Apriori accel (us/s/s)
-2.00426943193E+03-2.1081138E+03-2.3810001E-06
-6.79469248344E-011.76369108361E-05
Resid mbdelay (usec)Resid sbdelay (usec)Resid phdelay (usec)Resid rate (us/s)Resid phase (deg)
-3.96092E-03-5.67200E-03-1.28340E-06-6.19126E-07
-104.5
+/-+/-+/-+/-+/-
3.1E-051.8E-031.5E-074.3E-09
12.2RMS Theor. Amplitude 0.315 +/- 0.033 Pcal mode: MANUAL, MANUAL PC period (AP’s) 5, 5
ph/seg (deg) 17.2 16.1 Search (512X128) 0.305 Pcal rate: 0.000E+00, 0.000E+00 (us/s) sb window (us) -1.000 1.000amp/seg (%) 32.2 28.2 Interp. 0.000 Bits/sample: 2x2 SampCntNorm: disabled mb window (us) -0.008 0.008ph/frq (deg) 70.9 34.5 Inc. seg. avg. 0.316 Sample rate(MSamp/s): 64 dr window (ns/s) -0.006 0.006amp/frq (%) 108.7 60.2 Inc. frq. avg. 0.428 Data rate(Mb/s): 4096 nlags: 128 t_cohere infinite ion window (TEC) 0.00 0.00A: az 283.3 el 58.9 pa 113.3 L: az 182.8 el 57.9 pa 2.6 u,v (fr/asec) 10499.207 -17029.585 simultaneous interpolatorControl file: e16b08-LoRR-pc.conf Input file: /data-sc05/gbc/alma-april-band6-4-pc4/3557/No0015/AL..zaoprj Output file: Suppressed by test mode
21 Crew -‐ VLBI with ALMA -‐ Oct 12, 2016
Fringes on first 60s (of 240s recording)
23 Crew -‐ VLBI with ALMA -‐ Oct 12, 2016
Scale (frequencies)kpc (22 GHz + 1.6 GHz)
100 pc (1.6 GHz)
10 pc (15 GHz)
1 pc (43 GHz)
from K. Akiyama
3C273Imaging: Merlin VLBA
24 Crew -‐ VLBI with ALMA -‐ Oct 12, 2016
Scale (frequencies)kpc (22 GHz + 1.6 GHz)
100 pc (1.6 GHz)
10 pc (15 GHz)
1 pc (43 GHz)
~0.1 pc <103 Rs (86 GHz)
from K. Akiyama
(simulation) (simulation)
Imaging: Merlin VLBA Simulated: VLBA + GBT GMVA – ALMA GMVA + ALMA
Band 3 Commissioning Image: VLBA alone
25 Crew -‐ VLBI with ALMA -‐ Oct 12, 2016
I. MarH-‐Vidal, 2016
Very quick, preliminary reducHon by I. MarH-‐Vidal
Band 3 Commissioning Image: VLBA + ALMA
26 Crew -‐ VLBI with ALMA -‐ Oct 12, 2016
I. MarH-‐Vidal, 2016
Very quick, preliminary reducHon by I. MarH-‐Vidal
Band 3 Commissioning Image: ALMA/VLBA contours
27 Crew -‐ VLBI with ALMA -‐ Oct 12, 2016
I. MarH-‐Vidal, 2016
Very quick, preliminary reducHon by I. MarH-‐Vidal
Summary and Future Prospects
• Ready to go for Cycle 4 • 3(3mm)+5(1mm) projects accepted by ALMA • Logistical details (media, schedules, &c.) being sorted out
• Post-Cycle 4 development • Relax restrictions of Cycle 4 (which were fairly rigid) • Increase band 6 to 64 Gbps (requires EHT development) • Address the “delay problem” (delays removed via phasing adjustments rather
than as normally handled in the ALMA Correlator Data Processing Nodes). • Allow lower flux sources (>500 mJy required in Cycle 4)
28 Crew -‐ VLBI with ALMA -‐ Oct 12, 2016
Delay Correction with Phase Adjustments
31
Delay when un-‐phased
Delay when phased
Example DA58 (reference antenna) & DV11 (phased in most scans; un-‐phased for some)
8 Channel Averages were used
Phas
e (±
20 d
egre
es)
Full 2 GHz Frequency BandCrew -‐ VLBI with ALMA -‐ Oct 12, 2016
The Problem w/CARMA and ALMA
32
4 separate IFs
32 ALMA TFBs
58 32 MHz PFBs
Crew -‐ VLBI with ALMA -‐ Oct 12, 2016
Correlation with PolConvert
• Conversion tool works with both ALMA bands and could be used with other telescopes
• Full validation requires >3 hour observing runs for good parallactic angle coverage
• Operational scenario requires ALMA data analysts to reduce ALMA data for PolConvert inputs and provide them to the correlators
33 Crew -‐ VLBI with ALMA -‐ Oct 12, 2016
ObservaHon ALMA Archive
VLBI CorrelaHon Project PI PolConvert
PolConvert Inputs
VLBI Data Products
ALMA Data Products
PolarizaHon CalibraHon ReducHon (QA2?)
X/Y L/R
Simulated ALMA Observations
34 Crew -‐ VLBI with ALMA -‐ Oct 12, 2016
<-‐-‐-‐-‐-‐-‐-‐Time in AcHvity
<-‐-‐CumulaHve Time VLBI Scan
CalibraHon
Actual ALMA Observations
35 Crew -‐ VLBI with ALMA -‐ Oct 12, 2016
<-‐-‐-‐-‐-‐-‐-‐Time in AcHvity
<-‐-‐CumulaHve Time VLBI Scan
CalibraHon
Additional Development Topics
• Source Model (original proposal) • Implemented on Control side • Still needs TelCal algorithm & ALMA
Catalog support • Cycle 5 or (more likely) Cycle 6
• Phasing System GUIs (original proposal) • Supported at lower level in Control &
TelCal • Working on prototypes for eventual
reimplementation into the new ALMA QuickLook machinery
• Existing GUIs are adequate for Cycle 4 • Some commissioned capabilities unused in
Cycle 4 (e.g. Fast Mode) could be offered in Cycle 5 or Later
• L. Matthews “Extensions & Enhancements to the APS” ALMA Development Fund Study • Extension to Band 7 (0.8 mm) • Mismatched data rate (125 MHz vs 128
MHz) • Study better solution to the delay problem • Data reduction support
• J. Cordes “Pulsars, Magnetars and Transients w/ the APS” ALMA Development Fund Study • Study suitability of current system for
temporal searching (e.g. look for ALMA periodicities in APS)
• Study additional observing capabilities (e.g. passive phasing and new phasing modes)
36 Crew -‐ VLBI with ALMA -‐ Oct 12, 2016
Simulated Images: VLBA alone
VLBA (3mm stations)!
5.6 Gλ!
Dirty beam!
270 × 120 μas!
δ=20 degrees; 4-hr track!
37 Crew -‐ VLBI with ALMA -‐ Oct 12, 2016
L.Mayhews, 2015
Simulated Images: VLBA + ALMA
VLBA+ALMA!
5.6 Gλ!
Dirty beam!
150 × 60 μas!
δ=20 degrees; 4-hr track!
38 Crew -‐ VLBI with ALMA -‐ Oct 12, 2016
L.Mayhews, 2015