Scope statement
In scope (programme)
- Research and methodology for crowdsourced passenger rail noise
- London-first pilot with dense repeated coverage over shallow network-wide scrape
- iOS-first local recording → review → consent → derived upload
- Versioned open datasets with provenance, quality tiers, and uncertainty
- Public map that refuses false precision
- Generic railway schema capable of later cities/modes without Tube-only core types
Out of scope (for now)
- Claiming TfL endorsement or official operator status
- Replacing professional / regulatory surveys
- Premature Android, Watch, AirPods, or worldwide network support as launch requirements
- Silent upload of raw audio or unexplained blended “risk scores”
- Product feature implementation during the docs-only research execution
Initial product components (owned across repos)
| Component | Primary repo |
|---|---|
| A. Mobile recorder | tunes-ios |
| B. Data-processing pipeline | tunes-web (runtime); schemas/releases in tunes |
| C. Public map | tunes-web |
| D. Research / methodology publication | Content in tunes; presentation may be hosted via tunes-web |
| E. Contributor community mechanisms | Designed in tunes; implemented later across apps |
Canonical comparison unit (working assumption)
Station-to-station section with explicit duration — aligned with professional survey practice (see acoustic-survey-methodology.md). Test in research; do not abandon without ADR.
Privacy default (working assumption)
Derived-only upload after local review and explicit consent. Raw audio leaves the device only under a separate, restricted tier if ever justified.
Recommendation
Lock London-first + portable schema + three-repo ownership for planning. ADR-001 defers launch breadth; ADR-004/005 make raw-on-device and derived-only upload the defaults. Remaining edge cases stay in ../01-assumptions-and-open-questions.md.
Confidence: High for defaults above; Medium for Underground-only vs all London rail at public launch.
Depends on experiment/legal/user-test? Yes for network breadth UX and legal retention.
Links: project-charter.md; repos.md.