embrace@nançaysatorchi.net/skads/francechina_embrace_20111103.pdf · 15 france-china ska workshop,...
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1France-China SKA Workshop, Meudon 2-3 November 2011
Preparing for SKAEMBRACE@Nançay
Steve Torchinsky
EMBRACE@NançaySteve Torchinsky
Station de radioastronomie de NançayObservatoire de Paris
2France-China SKA Workshop, Meudon 2-3 November 2011
Preparing for SKAEMBRACE@Nançay
Steve Torchinsky
EMBRACE@Nançay
3France-China SKA Workshop, Meudon 2-3 November 2011
Preparing for SKAEMBRACE@Nançay
Steve Torchinsky
Electronic MultBeam Radio Astronomy ConcEpt
(EMBRACE) EMBRACE is an AAmid Pathfinder for SKA
Largely funded within EC FP6 Project SKADS (2005-09)
For EMBRACE:
ASTRON: Project Leader, overall architecture, antennas,
industrialization,...
Nançay: Beamformer Chip, Monitoring and Control Software
MPI Bonn and INAF Medicina: design of multiplexing circuits for
RF transport, down conversion, and command/control
Two demonstrators built. One at Westerbork (144 tiles) and one at
Nançay (64 tiles currently)
4France-China SKA Workshop, Meudon 2-3 November 2011
Preparing for SKAEMBRACE@Nançay
Steve Torchinsky
EMBRACE@Nançay 4608 Vivaldi antenna elements Single polarization (second polarization antennas are
there for a total of 9216 elements, but only one polarization has a complete signal chain)
4 level hierarchical analog beamforming/signal summing Beamformer chip:
− 4 inputs, 2 outputs (2 independent beams)− 45º phase steps
Analog summing output from 3 beamformer chips Analog summing of 6 inputs = 1 tile (72 elements) 15m cable → Analog summing of 4 inputs = 1 tileset Down conversion → 16 inputs to LOFAR backend
5France-China SKA Workshop, Meudon 2-3 November 2011
Preparing for SKAEMBRACE@Nançay
Steve Torchinsky
EMBRACE@Nançay 500 – 1500 MHz
– But high pass filter at 900 MHz to avoid digital television 70 m2 (10.5m X 10.5m) Instantaneous RF band: 100 MHz Maximum instantaneous beam formed:
– 36 MHz x 2 directions (single polarization)
– 186 “beamlets” each of 195.3 kHz bandwidth
– ie. 3 “lanes” for high speed data from RSP
– Can trade off beam width vs. number of beams
6France-China SKA Workshop, Meudon 2-3 November 2011
Preparing for SKAEMBRACE@Nançay
Steve Torchinsky
EMBRACE@Nançay
7France-China SKA Workshop, Meudon 2-3 November 2011
Preparing for SKAEMBRACE@Nançay
Steve Torchinsky
Hierarchical beamforming
4 elements phasedTogether in theBeamformermicrochip
8France-China SKA Workshop, Meudon 2-3 November 2011
Preparing for SKAEMBRACE@Nançay
Steve Torchinsky
Nançay Beamformer Chip
9France-China SKA Workshop, Meudon 2-3 November 2011
Preparing for SKAEMBRACE@Nançay
Steve Torchinsky
Hierarchical beamforming
4 elements phasedTogether in theBeamformermicrochip
10France-China SKA Workshop, Meudon 2-3 November 2011
Preparing for SKAEMBRACE@Nançay
Steve Torchinsky
Hierarchical beamforming
3 beamchips on aHexboard(12 elements)
11France-China SKA Workshop, Meudon 2-3 November 2011
Preparing for SKAEMBRACE@Nançay
Steve Torchinsky
Hierarchical beamforming
6 hexboardsin a tile(72 elements)
12France-China SKA Workshop, Meudon 2-3 November 2011
Preparing for SKAEMBRACE@Nançay
Steve Torchinsky
Hierarchical beamforming
4 tilesin a tileset(288 elements)
13France-China SKA Workshop, Meudon 2-3 November 2011
Preparing for SKAEMBRACE@Nançay
Steve Torchinsky
4th stage analog beam forming
14France-China SKA Workshop, Meudon 2-3 November 2011
Preparing for SKAEMBRACE@Nançay
Steve Torchinsky
Control and Down Conversion● Last stage analog summing of four
tiles● 2-stage mixing to convert RF down to
150 MHz +/- 50MHz● Ethernet protocol for beamformer
chip parameters and housekeeping● 48V DC● RF + Digital Commands + Power
ALL ON THE SAME COAX!
CDC cards designed by INAF-IRA/MPIfR/ASTRON
15France-China SKA Workshop, Meudon 2-3 November 2011
Preparing for SKAEMBRACE@Nançay
Steve Torchinsky
Control & Down Conversion
● CDC cards group 4 tiles together (tileset)● RF and control/command multiplexed
16France-China SKA Workshop, Meudon 2-3 November 2011
Preparing for SKAEMBRACE@Nançay
Steve Torchinsky
LOFAR Backend
● Output from CDC goes to LOFAR Receiver Unit (RCU) boards for digitization
● And then to LOFAR Remote Station Processing (RSP) boards for digital beamforming
17France-China SKA Workshop, Meudon 2-3 November 2011
Preparing for SKAEMBRACE@Nançay
Steve Torchinsky
System Control and Data
• Enormous flexibility with the dense array– Multi-beam– Instantaneous reconfiguration– Real time calibration– Multiple observing mode possibilities with tradeoff
between bandwidth, number of beams, field of view
18France-China SKA Workshop, Meudon 2-3 November 2011
Preparing for SKAEMBRACE@Nançay
Steve Torchinsky
System Control and Data
• Extension of LOFAR Local Control Unit Software– More complex task with EMBRACE especially
regarding beamformer chip control
• Station Control Unit software– Python modules
– User interface simple, but highly adaptive using python scripts
– Statistics saved in FITS files
19France-China SKA Workshop, Meudon 2-3 November 2011
Preparing for SKAEMBRACE@Nançay
Steve Torchinsky
Antenna dataFrom RCU
2N x 200 Ms/s12 b.
SeparateSubbands
SelectSubbands
FormBeams
OutputBeams
ComputeSubbandsStatistics
ComputeCross
Correlations
ComputeBeams
Statistics
Correct forCalibration
Nulling ofInterferers
CalculateInitial vector forBeam forming
CalculateCalibration
DetectInterferer
CalculateProjection
Matrices for nulling
Subbandfrequency
Array geometry
Subbandfrequency
Array geometry
Source coordinates Interferers coordinates
Station Control Unit
SubbandTo be processed
Output modeTime stamp
LO1 beam A
LO1 beam B
LO2
Data recordingPost processing
LocalControl
Unit
N cells of combined tiles
2 RF beams
Store Store Store
Tile arraysettings
CalculateTile arraysettings
Source coordinates
ExternalCorrelatorInterface
Mark V recording
EMBRACE Monitoring & Control
20France-China SKA Workshop, Meudon 2-3 November 2011
Preparing for SKAEMBRACE@Nançay
Steve Torchinsky
Phase Calibration using GPS
● GPS BIIA-nn: ● Strong carrier at 1227.6MHz● Narrow band
● GPS BIIF-1:● Strong carrier at 1175.6 MHz● Wider band (~7 MHz)
21France-China SKA Workshop, Meudon 2-3 November 2011
Preparing for SKAEMBRACE@Nançay
Steve Torchinsky
Without Phase Calibration
● Subband statistics
● 100 MHz band per tileset
● Each tileset pointing differently (or not properly)
22France-China SKA Workshop, Meudon 2-3 November 2011
Preparing for SKAEMBRACE@Nançay
Steve Torchinsky
With Phase Calibration
● Tilesets are together● Next step: level equalization
23France-China SKA Workshop, Meudon 2-3 November 2011
Preparing for SKAEMBRACE@Nançay
Steve Torchinsky
Drift Scan of GPS BIIF-1
● 2 beams formed● Second beam is 4 time minutes ahead in the path of the satellite
24France-China SKA Workshop, Meudon 2-3 November 2011
Preparing for SKAEMBRACE@Nançay
Steve Torchinsky
Drift Scan of Cas-A
● Gaussian main lobe● FWHM 1.476º
● 1.2λ/D = 1.486º
25France-China SKA Workshop, Meudon 2-3 November 2011
Preparing for SKAEMBRACE@Nançay
Steve Torchinsky
Drift Scan of Cyg-A
26France-China SKA Workshop, Meudon 2-3 November 2011
Preparing for SKAEMBRACE@Nançay
Steve Torchinsky
Pulsar B0329+54
Pulsar B0329+54
EMBRACE@Nançay connected to ARTEMIS backend (courtesy U. Oxford)
27France-China SKA Workshop, Meudon 2-3 November 2011
Preparing for SKAEMBRACE@Nançay
Steve Torchinsky
Continuing AAmid Microelectronic Developments
Next generation beamformer chip: 22.5º phase steps Chips delivered and undergoing test
28France-China SKA Workshop, Meudon 2-3 November 2011
Preparing for SKAEMBRACE@Nançay
Steve Torchinsky
Aperture Array Integrated Receiver Proposal to French National Funding Agency Successful! 816k€ over 4 years Partners: Nançay (coordinator),Bordeaux, NXP, ASTRON Beamformer chip with time delay instead of phase shifting for
wide bandwidth System-in-Package:
ADC with Serializer LNA with filter
Ultimate goal (timescale of the AIP): AAmid tile with digital output Reduce power consumption, and data transport/command complexity
29France-China SKA Workshop, Meudon 2-3 November 2011
Preparing for SKAEMBRACE@Nançay
Steve Torchinsky
Objectifs: Montrer la faisabilité d’une électronique intégrée destinée aux applications de réseaux phasés.Validation du concept par la réalisation d’un mini réseau de démonstration utilisant 12 à 16 antennes élémentaires.
Tuile RF 1m² Amplification, filtrage, beamforming Interface de commande
Micromodule(s) ~qq mm²
Aperture Array Integrated Receiver
30France-China SKA Workshop, Meudon 2-3 November 2011
Preparing for SKAEMBRACE@Nançay
Steve Torchinsky
Aperture Array Integrated Receiver
31France-China SKA Workshop, Meudon 2-3 November 2011
Preparing for SKAEMBRACE@Nançay
Steve Torchinsky
Science Data Model v2
• Collaboration with Obs Paris - LERMA (F. Viallefond)– Evolution of the ALMA SDM– SDMv1 currently used on ALMA and EVLA– Mathematics of “categories”– Naturally object oriented– XML and Schema– See CALIM2011 for more details:
http://www2.skatelescope.org/indico/conferenceOtherViews.py?view=standard&confId=171
32France-China SKA Workshop, Meudon 2-3 November 2011
Preparing for SKAEMBRACE@Nançay
Steve Torchinsky
Science Data Model v2 - Goals
Generalised model for any radio telescope Single dish Aperture synthesis
− (eg. ALMA, EVLA, PdB, ...) VLBI Aperture plane phased arrays (eg. EMBRACE) Focal Plane Arrays
− Feed clusters (eg. Parkes, Arecibo, Effelsberg, ...)− Phased array feeds (eg. ASKAP, APERTIF)
33France-China SKA Workshop, Meudon 2-3 November 2011
Preparing for SKAEMBRACE@Nançay
Steve Torchinsky
SDMv2 - Overview Enum
Categorized enumerators PhysQuan (Physical Quantities)
Collections of physical quantities (eg. Temperatures) and measures (eg. QDirections)
Virtual Quantities (eg. Phase_Dir, Staircase for OTF) Values with uncertainties (eg. Position, Length)
SDM Ensemble of Tables
− Relations within tables, and between tables Normalization
− Allows queries in a database Set/subset based
34France-China SKA Workshop, Meudon 2-3 November 2011
Preparing for SKAEMBRACE@Nançay
Steve Torchinsky
Science Data Model v2 - components Meta data
eg. definition of a configuration Auxilliary data
eg. instrument diagnostics (temperatures, encoder values, etc)
Data eg. visibilities, autocorrelations
Objects and Types persist and remain accessible
35France-China SKA Workshop, Meudon 2-3 November 2011
Preparing for SKAEMBRACE@Nançay
Steve Torchinsky
EMBRACE@Nançay
4608 antenna elements Hierarchical beam forming Organised into tilesets
16 tilesets Each tileset is 4 tiles of 72 elements each “statistics” include
− Cross correlations between tilesets (imaging)
Lots of flexibility regarding bandpass, pointing, number of pointings
36France-China SKA Workshop, Meudon 2-3 November 2011
Preparing for SKAEMBRACE@Nançay
Steve Torchinsky
SDMv2 Main Features
Can be easily pruned for a specific instrument
Can be applied to any instrument of any complexity or simplicityeg. future radio telescopes: ASKAP, APERTIF, EMBRACE,
ALMA, EVLA, VLBI, etc
eg. for SKA: It will be composed of multiple technologies, but all can produce data in SDMv2
37France-China SKA Workshop, Meudon 2-3 November 2011
Preparing for SKAEMBRACE@Nançay
Steve Torchinsky
SDMv2 - Implementation 3 levels
Meta model: generic parameters (XML Schema) Model: instance of the meta model (XML) Data set: instance of the model (XML + binaries)
Code generation from the model (c++ template) c++ classes XML Schema (Type definitions)
− eg. Dataset<Sdm>, Dataset<Sdm,EMBRACE> Python interface
38France-China SKA Workshop, Meudon 2-3 November 2011
Preparing for SKAEMBRACE@Nançay
Steve Torchinsky
EMBRACE@Nançay
39France-China SKA Workshop, Meudon 2-3 November 2011
Preparing for SKAEMBRACE@Nançay
Steve Torchinsky
EMBRACE@NançaySteve Torchinsky
Station de radioastronomie de NançayObservatoire de Paris