S. Montebugnoli 2 nd SKADS Workshop 10-11 October 2007 Stelio Montebugnoli IRA - INAF- Italy.

S. Montebugnoli2nd SKADS Workshop 10-11 October 2007

Stelio MontebugnoliIRA - INAF- Italy


Main points…Main points…

• DS6-T1: Design of subsystems • DS6-T2: Development and demonstration

• DS6-T3: Assesment of performance

• DS6-T4: Phased array on concentrators


DS-6 ScenarioDS-6 Scenario

DS-6 is aimed to the construction of 3 demonstrators, different in size, based on a large existing platform equipped with cylindrical concentrators (Northern Cross array located in Medicina, near Bologna -Italy-)


Deliverables:Deliverables:1- LNAs, Analog Optical link, IF stages2- Wideband A/D converter, at least 1 GS/sec @ 8bit3- Ultra fast data processing4- Reliability prediction

Achieved milestones Achieved milestones and deliverablesand deliverables DS6-T1 DS6-T1

IF Input (Optical link)

Intermediate Freq Block

Data Proc Cluster

Reliability Prediction

High performance Front–End

High performance Front end

Low cost Optical Link Analogue Optical link

S.Montebugnoli


Achieved milestones and Achieved milestones and deliverables DS6-T2deliverables DS6-T2

• DS-6 T2: Development and demonstration of the

BEST-1 a small platform as part of the NC (408 MHz)

BEST-1176 m2

4 rx – 1 N/S cylinder

1 Rx=¼ of NS cylinder

4 RX =1 NS cylinder

Aug. 2005



• DS-6 T2: Development and demonstration of the

BEST-2 a large SKA platform as part of the NC (408 MHz)

BEST-21410 m2

32 rx – 8 N/S cylinders

(Equivalent to a 42 mt(Equivalent to a 42 mtdish antenna)dish antenna)



• DS-6 T2: Development and demonstration of the BEST-2, a large SKA platform as part of the NC (408 MHz)

NF=0.45dB Tn=32K Gain=60dB BW=16MHz@408MHz OIP3>+33dBm

Input RL>15dB Output RL>10dB Power Supply=10-15Volt@=245mA




=1310nm NF=36dBdB Gain=-25dB BW=(0.1-1)GHz IIP3>+33dBm

Input RL>15dB Output RL>20dB Power Supply=(12-15)Volt@=75mA




Opticalfibre fromthe front-end

IFuP




4 x A/D @ 8 bit(1.0 GS/sec)



• DS-6 T2: Development and demonstration of the BEST-2, a large SKA platform as part of the NC (408 MHz).

• The final IF and data processing system for the BEST-2 demonstrator

NC telescopeprotected band3 MHz@408 MHz

BEST-2 BandwidthBEST-2 Bandwidth


Time

Receivers

Am

pli

tud

e

Transit of Cassiopeia Oct. 2007Transit of Cassiopeia Oct. 2007 (Bw=16 MHz, waterfall plot)(Bw=16 MHz, waterfall plot)

BEST-2 “FIRST LIGHT”BEST-2 “FIRST LIGHT”


Time

Rec

eive

rs

Transit of Cassiopeia Oct. 2007Transit of Cassiopeia Oct. 2007 (Bw=16 MHz, 2D plot)(Bw=16 MHz, 2D plot)

BEST-2 “FIRST LIGHT”BEST-2 “FIRST LIGHT”


DS6-T2 : future stepDS6-T2 : future step

BEST-37464 m2 (2008) (Equivalent to a 100 m(Equivalent to a 100 mdish antenna)dish antenna)

564 mt

640 mt



DS6-T3: Assessment of Performace

BEST-1: Pn obtained with . GRASP

0,0,2

0 0 0

0,0,2

; , ; , sin

; , ,; , sin

n b

ant

n

P T d d

TP d d

Tsys computed:

= 86.3 K

1 0.045 2100 94.5sys BEST eqT G Flux K Jy Jy K

261

110 0.045

2g

BEST

A K KG

k Jy Jy

Tsys measured:

F=408 MHz


Potential of FPAs for Potential of FPAs for cylinders DS-6 T4cylinders DS-6 T4

• DS4-T4:Phased array on concentrators

• This is a T0+32 task but some preliminary mechanical

considerations could simplify in a near future the installation of a 4x4 antennas (i.e. a subset of EMBRACE) on the focal line of one cilyndrical concentrator ...useful to test on the

field the deliverables from:• DS-4 T1 • DS-4 T3 • DS-4 T4• DS-4 T6


Next milestone, next deliverable

• T1 -MilestoneMilestone: - End of design BEST-3 (T0+28 m)

-Deliverables:Deliverables: - Analogue opt. links

- calibration of large array

• T2 --MilestoneMilestone: - End of construction of BEST-3 (T0+40 m)

-Deliverables-Deliverables: - L.O. & Sync distrib. Scheme

- Wide Band high res. A/D - Softw. Beamform. Algorithms

- Adapt. Beamf./RFI mit. Algorithms


ConclusionConclusion

• At this date, the DS-6 milestones are reached and At this date, the DS-6 milestones are reached and deliverables ready.deliverables ready.

• The BEST-2 seen the “first light”. Calibration, adaptive The BEST-2 seen the “first light”. Calibration, adaptive beamforming and mapping of a radio source are beamforming and mapping of a radio source are expected to be ready in a couple of monthsexpected to be ready in a couple of months

• The plan is to have BEST-3 (maturity of the technology, The plan is to have BEST-3 (maturity of the technology, costs & first astronomical observation) for Tcosts & first astronomical observation) for T00 +40 m +40 m



Simulation for BEST-1- N.sensors =4- Sensor= 16 /2 dipoles - Sensor spacing=8- Samples used for R =200- Primary beam = 2o - DOA RFI = +12DOA RFI = +12oo, -23, -23oo, +30, +30oo

SimulationDOA RFIDOA RFI

RFI mitigat.->MVDR(BEST-1)

(Connection with DS-4 T3)

Simulations for BEST-2 are in progress


Achieved milestones and Achieved milestones and deliverables T2deliverables T2

RFIs mitigat.->MSC (BEST-1)(Connection with DS-4 T3)

Prelim

inary

te

st


Achieved milestones and Achieved milestones and deliverables T2deliverables T2

• RFIs Mitigation via Polyphase filter bank (BEST-1) (Connection

with DS-4 T3)

PFB

P, Proc.

Chan.

Contr.

Channel Threshold

level

S.Montebugnoli

Preliminary test

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S. Montebugnoli 2 nd SKADS Workshop 10-11 October 2007 Stelio Montebugnoli IRA - INAF- Italy.

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