Transcript EddiCam - Observatoire de Paris

PLATO Main Electronics Units (MEU)
based on inputs from P. Plasson and the system team
J. Miguel Mas-Hesse
Centro de Astrobiología (CSIC-INTA)
On-board data processing: Introduction
• DPS goal: automatically process and extract accurate
stellar light curves from the raw, messy CCD images.
Stellar field
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November 2010
PLATO image
J. Miguel Mas-Hesse
2
On-board data processing: baseline concept
• The normal-telescopes onboard data processing system
will be formed by:
– 4 CCD + 1 FEE per focal plane (telescope)
• 32 telescopes
– 1 Data Processing Unit (DPU) per 2 focal planes
• 16 DPU boards
– 4 DPUs per 1 Main Electronics Unit (MEU)
• 4 MEU boxes
– 1 Instrument Control Unit (ICU) per 4 MEUs
• 1 ICU (+ 1 fully redundant ICU)
PLATO Kick Off
November 2010
J. Miguel Mas-Hesse
3
On-board data processing: architecture
1 N-DPU for
2 N-cameras
F-cameras
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November 2010
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On-board data processing: architecture
Present MEU baseline concept:
+ 1 DPU per 2 focal planes
+ 1 single DPU PSU box, external
to the MEU’s
SpW
To ICU-M To ICU-R
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November 2010
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PLATO MEU: FEE – DPU SpW link
• FEE – DPU link baseline:
– 2 SpaceWire links per FEE (100 Mbps)
SpW 100 Mbps
• Alternative:
– 1 SpaceWire link per FEE (200 Mbps)
• Feasibility has to be demonstrated.
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November 2010
J. Miguel Mas-Hesse
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On-board data processing: architecture
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November 2010
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On-board data processing: architecture
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November 2010
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PLATO MEU: operation
• Target count for 2 x 4 CCD per DPU (to be
processed every 25 sec.):
Nominal sample 2x(110.000 stars/telescope) = 220.000 stars/DPU
Extended sample (+50% margin)
= 330.000 stars/DPU
Background win.
Imagettes up to
Offset windows
Smearing rows
2 x 400
2 x 2.000
2 x 2 x 4 half-row (2.255 pixels)
2 x 4 x 10 overscan rows
Fullimage
Acquisition x 8
6.25
sec
2 images / 6.25 sec
6.25
sec
Window
Extraction
up to 330.000 stars / 25 sec
• Total memory requirement, including 50%
margin on star count:
250 Mbytes per DPU
Data correction
and LC extraction
6.25
sec
5400
Masks &
sec
window positions
updating
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November 2010
J. Miguel Mas-Hesse
9
PLATO MEU: CPU load
• The CPU load has been estimated for various processors,
based on current baseline for number of stars + extraction
algorithms. At this phase the %CPU load should be ≤ 50%.
Weighted mask photometry
assumed
•
The present concept seems feasible, but:
– with 1 DPU/2 telescopes, no margin on star counts acceptable.
– with 1 DPU/telescope an extended sample with +50% margin in star
counts could be considered, if required. .
PLATO Kick Off
November 2010
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PLATO MEU: open points
MEU
4 Mpx/s
4510 px
4510 px
FEE #1
ADC
ADC
SpW
I/F
N-DPU #1
180 Mbps
(2 x 64 x 1.4)
4510 px
235 kbps
To redundant ICU
FEE #2
4510 px
SpW
ADC
ADC
4510 px
N-DPU #2
235 kbps
4510 px
FEE #3
ADC
ADC
4510 px
4510 px
SpW
I/F
SpW
I/F
N-DPU #3
FEE #4
ADC
ADC
SpW
I/F
To main ICU
Space
235 kbps Wire
Router
(R)
N-DPU #4
SpW
Space
Wire
Router
(M)
<1 Mbps
235 kbps
Backup concept:
Power
Distribution
+ 1 DPU board per telescope
+ 4 DPUs per MEU
+ 8 MEU
More powerful, but too heavy
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November 2010
Cmd
HK
Test I/F - SpW
Power
Supply
(M + R)
28 V, Cmd from S/C
M+R
J. Miguel Mas-Hesse
11
PLATO MEU: open points
Baseline
Alternative
2
1
MEU-PSU
1 MEU-PSU box for 4
MEU boxes
4 MEU-PSU inside each
MEU box
FEE / DPU number of
SpaceWire links
2 SpaceWire links per
FEE (100 Mbps)
1 SpaceWire links per FEE
(200 Mbps)
RMAP
DMA transfer tables
Boot Software in PROM
Pure RMAP hardware boot
Number of telescopes per
DPU
FEE  DPU image
transfer mechanism and
protocol
DPU Boot mechanism
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November 2010
J. Miguel Mas-Hesse
12
PLATO: next steps
• The industrial MEU definition study is starting now.
• Goals:
– Definition and dimensioning of the N-DPUs
• Global architecture, choice of processors, number of
SpaceWire data links, location of PSUs, mass, power
comsumption,…
• Trade off on algorithms potential increase of complexity
– Development of simulators/breadboards for critical
interfaces
• Spacewire link FEE – DPU
Final design within mass and power budgets, but
compliant with scientific requirements!
PLATO Kick Off
November 2010
J. Miguel Mas-Hesse
13