DVA Series Work Flow

P. DewdneyApr 15, 2010

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

End15

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