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SPDO
DVP Work Flow
2
Estimate Key Antenna
Specifications
Prototype Antenna Construction
First Level Qualification
Tests
DeepVerification &
Modelling Tests
System Performance Analysis & Model
Development
Minor Antenna Modifications
Adjustments to ModelDevelop Performance Model
New PrototypeDesign
OK?
ProductionDesign
Yes
No
Highest “affordable”
quality
Manufacturability Up-Front
Requirement
Single-Antenna Tests
Time-Dependent, Parameterised
Behaviour Model
In conjunction with well
understood 2-D array.
System Model Required
Tra
ck C
osts
DVA-1
CPG
SPDO• Highest affordable quality: Use best judgement for antenna requirements for
which system performance can meet science requirements, when combined with Calibration and Imaging procedures.
• Includes capability for utilizing all the expected feed packages.
• Cost projects at the design/specification stage.• Example specifications:
– Maintainability, Reliability, Manufacturability, Power consumption
– RFI protection
– Monitor and control facilities
– Survivability and longevity
– Thermal control of equipment and thermal stability of structure
– Calibratrability.
• These specifications are expected to evolve through the DVA series.– It is very important to get close and consider all of the above the first time.
• Once the antenna requirements are set, they can be used in acceptance tests for each DVA (in particular DVA-1).
Estimate Key Antenna Specifications
3
SPDO• After specifications have been set for the prototype antenna, it
is constructed according to a prototype construction plan– In the case of DVA-1, the DVA-1 consortium construction plan.
– For later prototypes, it is likely to be a specific SKA organization.
– Potential industrial involvement for DVA-1.
– Almost certain industrial involvement for subsequent members of the series.
• Subsequent members of the series are expected converge to a production design.
• Large changes in the design will prevent this convergence.– Fresh start would have to occur.
• Very important to prepare and preserve all the design and development documentation for each step, so that requirements traceability is maintained.– Including projection of fabrication in larger numbers.
• Cost projects and tracking.– Critical aspect.
Prototype Antenna Construction
4
SPDO
DVP Work Flow
5
Estimate Key Antenna
Specifications
Prototype Antenna Construction
First Level Qualification
Tests
DeepVerification &
Modelling Tests
System Performance Analysis & Model
Development
Minor Antenna Modifications
Adjustments to ModelDevelop Performance Model
New PrototypeDesign
OK?
ProductionDesign
Yes
No
Highest “affordable”
quality
Manufacturability Up-Front
Requirement
Single-Antenna Tests
Time-Dependent, Parameterised
Behaviour Model
In conjunction with well
understood 2-D array.
System Model Required
Tra
ck C
osts
SPDO• Start with formal Acceptance Tests for the prototype in question (e.g.
DVA-1).– Verify that the antenna meets the original specifications, would could be
in a contract to a commercial organization.
• Carry out additional tests that can be done with a single antenna or potentially an interferometer for holography measurements.– See presentation on testing.– Antenna will have to be equipped with feeds and receivers.
Type of feed and receiver system will be dependent on level of testing at this stage.
e.g. A “simple” feed and RF system may suffice initially. (not what might be needed for deep testing).
First Level Qualification Tests
6
SPDO• Start the development of a model that can represent antenna
performance as a component of the system.– Parameterized model in which parameters can be derived from observations
and/or other data.
• Model based on a combination of design information and/or observed behaviour of the antenna during testing.– Could be a simple model (e.g. Pointing and rough beamshape), or it could be
more complex.
• Developed in such a way that system simulations can be done to verify as much as possible that the antenna performance is sufficient to achieve system specifications.
• Question: Can the modelling be done well enough?
Develop Performance Model
7
SPDO• Antenna has been accepted and the first cut at understanding its
behaviour, using first-level tests has been done.• Testing continues at a deeper level, starting with a continuation of
single dish testing and holography.– See next slide for examples.
• If it is possible to fully characterize the performance of the dish using these tests,
Deep Verification Tests
8
SPDO• Primarily a task for calibration and imaging groups, working in close
contact with the group actually carrying on the tests.• It is expected that this work starts soon after the first antenna models
have been put together.• The goal is to simulate the performance of the antenna system in an
array situation, given the need to solve for dish performance parameters as they change on their “characteristic time scales”.– Examples:
– Beam shape stability, including the first few sidelobes (direction dependent complex gains),
– Potential effects from far-out sidelobes,
– Beam rotation.
– Frequency dependent effects in the beam and scattering.
• This will depend both on the characteristics of the dish optics and on the feed(s). In the modelling it should (may) be possible to separate the effects of the feed and the dish optics.
• An important question is to determine the optimum processed FoV.
System Performance Analysis
9
SPDO
DVP Work Flow
10
Estimate Key Antenna
Specifications
Prototype Antenna Construction
First Level Qualification
Tests
DeepVerification &
Modelling Tests
System Performance Analysis & Model
Development
Minor Antenna Modifications
Adjustments to ModelDevelop Performance Model
New PrototypeDesign
OK?
ProductionDesign
Yes
No
Highest “affordable”
quality
Manufacturability Up-Front
Requirement
Single-Antenna Tests
Time-Dependent, Parameterised
Behaviour Model
In conjunction with well
understood 2-D array.
System Model Required
Tra
ck C
osts
SPDO• Have all the performance requirements been met?• Have all of the environmental, field, and other requirements been
met?• Are all of the requirements traceable through documentation?• Are the expected production costs well understood and acceptable?• Is there a fully developed Data Package ready for procurement?• If not, go around the loop to take appropriate action.
• Caveat:– There is no claim that we can “prove” that the SKA system can meet all the
performance specs (esp. continuum imaging dynamic range), using tests and models as outlined.
– In entering a new regime of sensitivity, it is important to be able to characterize the performance of the entire system as much as possible. The antennas and other analog systems are the main performance-determining hardware.
OK?
11
SPDO• Adjustments to the model
– Upon analysis of the data, it is likely that new insights into drivers of the dish behaviour are found and these can be incorporated into the model.
• Antenna modifications– Improvements may be made by adjustments, replacement of parts, or other
changes that do require re-building the dish.
– These could be for a variety of reasons, such as changes to make the dish less expensive to manufacture, to maintain, etc. or to improve performance.
– Once these changes are made, the dish performance is checked again.
• New Prototype Design– Once all possible information has been obtained from DVA-1, changes may be
(are likely to be) required that mean a new prototype dish is needed, which would be the second in the convergent series.
– A start on fabricating DVA-2 should be possible before testing of DVA-1 is complete.
– It would be useful to involve industry at this stage, and ensure that all the information needed to provide a contract-ready data-pack is available for this prototype.
Additional Iterations
12
SPDO• It looks as though the DVA-1 program can produce an antenna that
has passed its qualification tests, and carry out first level model development.– To be determined as part of these discussions.
• CPG:– It should be possible to make considerable progress in setting up a
framework for performance simulation.
What can we hope to accomplish with DVA-1.
13
SPDO
Time Scale
14
• Review dates are preliminary.• Need to rationalize the work flow and reviews (TBD).
CoDR
Dishes Concept Definition
Dish Sub-Sys. Definition
DVA1 Prototype Fabrication
DVA1Prototype Testing
2009 2010 2011 2012 2013 2014 2015 2016
SRR PDR
Milestones
Baseline design for Phase 1
Site decision Costed system design
2009 2010 2011 2012 2013 2014 2015 2016
CDR PR
Phase 1 Construction
Detailed Design, Prod. Eng& Tooling
SKA Preparatory Phase
Tooling and Early Fabrication
Start of Phase 1 Construction
Rev 7a2010-04-13
Phase 1 construction
approval
DVA2 development and testing
SPDO
Time Scale
16
PreliminaryDesign
Concept definition Sub-System DefinitionDetailedDesign Site Assembly, Integration and Testing
CoDR
Preliminary Design
CoDR SRR PDR
rep
ortRFI Monitoring
Site Acceptance tests including RFI qualificationSite
Engineering
Dishes
Signal Processing
Imaging ConceptSoftware Requirements DefinitionPreliminary high level architecture
On-site TestingPhase 1 Refinement and Roll-out
CoDR PDR
Software & Computing
Signal transport & Networks
Concept Definition Dishes, AAs
Dish Sub-Sys. Definition
DVA1Dish Prototype
Fabrication
DVA1Prototype Dish Testing
Site Assembly, Integration and Testing
2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
Prototype AAVS1 Testing
SRR PDR
Sub-System Definition
CoDR PDR CDR
CDR
RQZSite characteristicsAtmospheric studiesConfiguration studies
CDR
Milestones
Baseline design for Phase 1
Site decision Costed system design
AA Sub-Sys. Definition
AA Prototype Fabrication
2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
Remote Station Land Acquisition & Environmental Studies
Continued RFI and Tropo Monitoring
Temporary Software Correlator
Phase 2 Continuation
Phase 2 Continuation
Phase 2 Continuation
Phase 2 Continuation
Phase 2 Continuation
S/W Development & Roll-out for Phase 2
Baseline design for Phase 2
Phase 2 Correlator Design
Monitoring & Control
Data Storage
CDR PR
CDR PR
SRR
Hardware Correlator Early Fabrication
PRFactory Assembly, Integration and Testing
Site Assembly, Integration and Testing
SRR
PDR
Front End and Channeliser
Beamformer and Correlator
Pulsar and Transient Processor
Start of Phase 2
Construction
Phase 2 …..
Phase 1 Construction, Verification, Commissioning, Acceptance, Integration & First Science
Detailed Design, Prod. Eng& Tooling
SKA Preparatory Phase
Refine high level architecturePreliminary Design
Ops and Maintenance Facility
Tooling and Early Fabrication
Purchase or Fabrication
Detailed Design
Detailed Design, Coding, Integration with platforms and testing
Central Data Processing Facility
Science Computing Facility
Start of Phase 1 Construction
Factory Assembly, Integration and Testing
Factory Assembly, Integration and Testing
Rev 7a2010-04-13
Definition and DesignPhase 1 System Testing
SRR
System Engineering
CoDRPhase 1 Systems integration
PDR CDR
Phase 1 Verification and CommisioningSystem refinement, change management
Final SKA Deployment PlanProject management
PM Plan &
Schedule
SKA Scope definitionPrepSKA Plan Project staffing & developmentWBS, resource allocation
CoDR PDR CDR
REV REV
Science DRM Development
Revision of Science Case
REV
Refinement of Early Science Shared Risk Science Operations
REVPhase 2 Science Development
REV REV
Science / Engineering tradeoffs
Early Science Proposals
Continued System Engineering for Phase 2
Continuous Performance Evaluation
Project execution, monitor and control
Infrastructure Detailed Design (fibre & power)
Antenna Foundations and Trenching Roll out
Phase 1 construction
approval
Infrastructure Detailed Design (buildings)
CDR
Concept Definition AAsAperture Arrays
DVA2 development and testing
AAVS2 development and testing AAVS2 demo
PDRSRRCoDR CDR
DVP
SPDO• Descriptions of competing technologies and statements and justifications of
the candidate options to be carried forward
• First draft requirement specification
• Context diagram identifying all relevant interfaces (internal and external)
• First risk register and related mitigation strategies
• First draft block diagram of the relevant system, element or subsystem
• First draft requirements traceability matrix/database
• Strategy and plans for proceeding to the next phase
• First draft cost, schedule, power estimates
Conceptual Design Review
17
SPDO• Justification of the selected baseline option to be carried forward
• Finalised requirement specification
• First draft interface control documents (internal and external)
• First draft of the architectural design description document
• First draft acceptance test plan/procedure
• Updated risk register and related mitigation strategies
• Updated requirements traceability matrix/database
• Strategy and plans for proceeding to the next phase
• Updated Cost, schedule, power estimates
System Requirements Review
18