SKA Phase 1 Generic Configuration
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Rosie Bolton 1 SKA 1 Layout WP2 Meeting Oxford October 2010 SKA Phase 1 Generic Configuration Rosie Bolton, Rob Millenaar
Transcript of SKA Phase 1 Generic Configuration
Rosie Bolton 1SKA1 LayoutWP2 Meeting Oxford October 2010
SKA Phase 1 Generic
Configuration
Rosie Bolton, Rob Millenaar
Rosie Bolton 2SKA1 LayoutWP2 Meeting Oxford October 2010
Configuration work
• Site specific configurations are under development –
CTF has worked with both the Aus and SA teams over
the summer to develop preliminary layouts for both sites.
• These layouts are as close as possible to the generic
configurations, after taking into account the various
constraints (waterways, roads, towns etc).
• However, we are waiting for one final mask layer before
finishing the layouts.
• …so, we have developed example layouts at a generic
location with no constraints, that can be used for
preliminary investigations.
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Quick overview• Phase 2:
– 300 dishes, 2400 of which are within 180km of array centre.
• PAF capable dishes (so PAFs would sit on an undetermined sub
set of these 3000 dishes).
– 250 AA stations for each AAlo and AAmid
• Separate cores for all collector technologies, separated by a few km
(>6km centre-centre)
• Phase 1:
– 250 Dishes, all within 100km of array centre.
• 125 within 500m radius
• 175 within 2500m radius
• 75 dishes clustered into groups of 5 sitting on 3 spiral arms,
logarithmically spaced from 2.5km to 100km. (15 clumps)
– AA (Low freq): 50 stations assumed, each 180m in diameter.
• 25 within 500m radius, 35 within 2.5km radius, remaining 15 co-
located with dish clumps.
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SKA P2 Dish layout
Core:600 dishes within 500m radius
•Inner region: 1500
dishes within 2500m
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Mid range: 900 dishes between 2.5km
and 180km radius
“Skirt” from 2.5 to
13km (350 dishes)
•Beyond 13km
dishes are grouped
into clumps of 11
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5 spiral arms out to
180km radius
50 clumps of dishes
(not assumed to be
beamformed)
Logarithmic
distribution in radius
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Shadowing in the centre• Worst case dish cannot
see 50% of the sky (dark
red)
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Shadowing in the centre
• No shadowing at 45
degrees elevation or
higher
• 400 dishes shadowed at
15 degrees elevation
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Phase 1 Dish layout
Randomly filled gaussian core with 125 dishes
within 500m radius
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Phase 1 Dish layout
175 dishes within 2500m radius
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Phase 1 Dish layout
Beyond 2.5km radius,
there are a further 75
dishes. These are
placed in groups of 5,
along 3 of the 5 Phase
2 spiral arms.
These dish positions
have been selected
from the available
generic Phase 2
positions…
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Phase 1 Dish layout
…so the three spiral
arms are not equally
spaced, and the dish
placement is not
perfectly logarithmic
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P1 Dish uv coverage
• 5km
scale
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P1 Dish uv coverage
• 10km
scale
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P1 Dish uv coverage
• 20km
scale
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P1 Dish uv coverage
• 100km
scale
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P1 Dish uv coverage
• 5km
scale
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P1 Dish uv coverage
• 10km
scale
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P1 Dish uv coverage
• 20km
scale
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P1 Dish uv coverage
• 100km
scale
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P1 Dish and AA layout
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AA Core: 25 in 500m radius
Requirement for 25
AA stations within
500m radius leads
to a close-packed
layout on a 190m
triangular grid.
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AA P1 Core snapshot uv
Uv plane gridding at D/2.4 (=75m)
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AA uv coverage
5km
scale
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AA uv coverage
5km
scale
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AA uv coverage
10km
scale
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AA uv coverage
10km
scale
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AA uv coverage
20km
scale
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AA uv coverage
20km
scale
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AA uv coverage
100km
scale
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AA uv coverage
100km
scale
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