LISA SRD: Actions Requested of LIST WG1a

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LISA SRDActions Requested of LIST WG1a

• Tom Prince
• US LISA Mission Scientist
• September 12, 2005

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High-Level Actions (in Priority Order)

• Establish prioritization for requirements
• Purpose to support assessment of science impact
  of tradeoff studies
• Format for requirements priorities to be
  determined by WG1A
• Write sections on Science Goals and Science
  Requirements
• Link to existing Observational Requirements
• Revise document to conform to 3-levels of
  requirements (as defined by SE)
• Minimum Requirements
• Baseline Requirements
• Issue Definition. Verification level?
• Goals (must be added to SRD)

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Detailed Issues

• 1. Introduction
• Define Baseline Requirements, Minimum
  Requirements, Goals in Introduction
• Re-introduce more explicit definition of Shf
  into Introduction
• 2. Requirements Summary
• 3. Baseline Requirements by Source Type
• 3.1 Verification Binaries
• S1.2 Reformulate (make more quantitative)
• Develop observational requirement for SNR for
  verification binaries in one month, for
  performance verification
• 3.2 Galactic Binaries
• S2.1 Reformulate (SNR requirement for resolvable
  binaries)
• 3.3 Supermassive Black Hole Binaries
• S3.5 Reassess latency requirement for BH mergers
• M3.6 Reassess 4 day requirement for system
  availability
• 3.4 Intermediate Mass/Seed Black Holes
• 3.5 Extreme Mass Ratio Inspiral
• 3.6 Cosmological Backgrounds and Bursts
• S6.1 Assess Change frequency range?
• M6.2 Assess feasibility of requirement
• Minimum Requirements

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Additional Issues

• Questions on format/content
• Formulate requirements on reliability?
• Should there be a requirement on
  non-stationarity?
• Change numbering scheme for requirements?
• Should the SRD specify required level of
  testing/verification?
• Additional Checks
• Check on 1-arm vs 2-arm consistency for Pre-Phase
  A performance assumptions

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Backup Slides
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Next 3 slides are from Ahmed/Gianolio
presentation at the Bern LIST meeting July 2005
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Framework for Mission Requirements (1/3)

• Mission and Science Requirements cover a dominant
  aspect of the Mission Formulation
• A clear definition of requirements, minimum
  requirements and goals is necessary to avoid
  confusion

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Framework for Mission Requirements (2/3)

• Baseline Requirement
• Specification of a condition, parameter, or
  capability with which the System Design must be
  compliant, verifiable, and have a demonstrated
  achievement during the mission
• Verified using some combination of the
  project-accepted verification methods
• These are typically Analysis, Test,
  Demonstration, and Inspection
• Minimum Requirement
• The minimum performance floor acceptable for
  maturing the mission
• Descopes, IF necessary, must meet these levels
• Minimum Requirements are not designed to, and
  therefore are not directly verified.
• Encompassed in the verification of baseline
  requirements
• Due to a descope, a miniumum requirement may be
  converted into a baseline requirement

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Framework for Mission Requirements (3/3)

• Goal
• Nice-to-have capabilities, over and above the
  baseline requirements
• Do not drive mission design
• Project attempts a mission design that does not
  preclude achieving the goals
• Tracked so if resources/capabilities allow,
  better performance may be achieved
• Goals are not required to be verified, as there
  is no commitment by the project to meet them
• When possible, performance is reported against
  the goals based on analysis or extrapolation of
  test results
• When the stated performance drops below a goal,
  the project may choose to expend resources to
  improve the performance but the expenditure is
  not required

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Future Work (cont)

• Science objectives and science requirements
• Working group should write a rigorous discussion
  of science objectives for LISA
• A start already exists in the WG1 Science
  Requirements Document
• Working group should formulate a set of science
  requirements which lead to a set of quantitative
  observational requirements
• Need to establish priorities
• Goals
• Formulate set of goals
• A start on this exists in WG1 Science
  Requirements Document
• Observational and measurement requirements
• Requirements for calibration, noise
  determination, etc. (e.g. the ancillary
  requirements needed for science observations)
• Gaps, duty cycle, and latency
• Testing issues

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Future Work(cont)

• Measurement Requirements (Detail)
• Calibration (e.g. Schutz notes Spero feedback
  on SRD)
• What ancillary measurements are needed to ensure
  that the science results are adequately
  calibrated? (Need to state precision/accuracy
  requirement and what measurements are needed to
  achieve the requirement, including how often).
• What housekeeping/engineering data is required?
• Includes pre-launch testing and characterization?
• Noise characterization
• How well does the noise spectrum vs time need to
  be known?
• Should there be requirements on non-stationarity
  and non-Gaussianity?
• Redundancy/Failure modes/Reliability (e.g.
  Schumaker notes)
• When are three arms sufficient vs two? When are
  five links sufficient vs six? Include clock
  synchronization in this analysis.
• Gaps, Duty Cycle, and Latency
• These need to be rigorously stated in the SRD

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Future Work Formulation Items (from Jennrich)
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Next Steps

• Aim for discussion/adoption of next set of
  proposed revisions at Dec 2005 LIST meeting
• Working group on requirements needs to prioritize
  tasks, identify people to work issues, and
  produce schedule
• Working group needs to provide draft of proposed
  revisions to entire LIST at least 2 weeks before
  LIST meeting