SKA Costing Future Directions

1
SKA CostingFuture Directions

• Paul Alexander, Peter Hall
• On behalf of the costing team
• Aaron Chippendale, Rosie Bolton, Tim Colgate,
  Adriaan Peens-Hough, John OSullivan

2
Costing The SKA

• Costing is crucial to the SKA project
• Peter just described ISPO sponsored a costing
  exercise
• Ideal is to have a single approach to costing
  within the SKA project
• Share expertise across the entire project
• Have a single tool we can use for comparative
  purposes
• Collaboration between SKADS, ISPO, AU and SA
  costing teams
• Two weeks work meeting in Cambridge in June/July

3
The approaches

• SKADS costing in SKA Memo 93 used a spreadsheet
  approach
• Good exposed costs to everyone involved in the
  project
• Good easy to use and modify by non-experts
• Good mapped costing onto the design elements of
  the telescope and kept the model intimately
  linked to the design
• Bad difficult to simulate, do montecarlo
  uncertainty modelling
• Bad consistency and error checking done by hand
• Bad lacks flexibility and poor scaling of
  elements of the design

4
The approaches

• ISPO modelling, SKA Memo 92
• Good simulation environment with montecarlo
  modelling
• Good scaling and model exploration
• Good consistency and error checking
• Bad difficult for non experts to alter
• Bad assumptions not easily exposed to the user
  the tool can be dangerous if the underlying model
  is wrong or not appreciated by the users
• Bad difficult to incorporate a real design or
  consider effects of design changes
• SA costing for MeerKAT
• Good used same original code base as ISPO
• Good excellent tools to visualise outputs
• Bad see ISPO

5
Structure of a new tool
SKA realisation
Design Block
Design Block
Design Block
Design Block
Design Block
Component
Component
Component
Component
6
Structure of the new tool

• Use a modified ISPO code base for the
  implementation new UI
• Python code (initially) implements the
  specifications / design of each design block
• Standard software tools provided to ensure
  consistency, error checking, uncertainty
  modelling
• GUI enables non-experts to browse, modify and
  develop components and design blocks (some python
  code needed)
• Adopt the SKADS high-level view
• System consisting of Design Blocks we combine
  together to form a realisation of the telescope
• Design blocks use costed components and/or cost
  models which are determined by domain experts
• The costing process involves everyone
• Build in the MeerKAT approach to visualisation
• Use combined expertise of everyone in the SKA
  Project

7
Design Blockreporting and design structure
Cost modelling code(python or )
Library of DBs and components(xml format)
GUI interface
8
Structure of the new tool
9
Example Model Aperture Array
10
GUI Snapshot
11
The Repository

• Develop libraries of components and design blocks
  in a repository
• Domain experts review, extend and modify these
• Expect an SKA wide repository and also
  repositories local to other projects one at least
• Individuals can have their own library or modify
  existing system realisations, design blocks and
  components

12
Using the Model

• Astronomer
• Use an existing design of the SKA and investigate
  cost and performance tradeoffs within the design,
  output performance information/statistics
• System designer or expert radio astronomer
• Construct SKA realisations (systems) out of
  existing design blocks and components
• Engineer
• Develop and review design blocks and components

13
User Interactions
14
Timeline Best Efforts

• End September
• Include basic AA description into costing tool
• Mid October
• GUI to browse component library
• Underlying change to system architecture
• Mid November
• GUI to browse / modify design block library
• January/February 2008
• First release of an integrated tool