Phase 7 — Tracking & Telemetry

Duration: ~5 working days Critical-path predecessor: Phase 1 Status: in progress

Deliverables (§5.7 / §11)

1. Orbital tracker — Skyfield TLE propagation for 12 active satellites, 24-h pass prediction, Redis pub/sub snowir:pass
2. Seismic listener — IRIS FDSN poller (60-s cadence) + IMD-NCS fallback, halo-bounded to basin + 200 km, Redis snowir:seismic
3. IoT MQTT pipeline — EdgeReading Pydantic schema enforcement, Supabase hypertable persistence, Redis fan-out, synthetic publisher for staging
4. GRDC hydrological correlator — Akhnoor / Salal Pearson r + NSE drift gauge
5. WebSocket fan-out service — /ws/feed rebroadcasting Redis pub/sub envelopes
6. Server-side acknowledgement — POST /alerts/{forecast_hash}/acknowledge with optional Polygon PoS anchor
7. Frontend telemetry — OverpassCountdown, SeismicFeed, LiveTelemetryStream, replacing Phase-5 synthetic stream
8. Background-worker container — snow_ir.tracking.__main__ runs all loops concurrently

Acceptance Gate

Live overpass countdown widget + IoT marker-cluster on dashboard with end-to-end latency < 5 s.

Run:

# Terminal 1
cd snow-ir-backend
uvicorn snow_ir.api.main:app --reload

# Terminal 2 — synthetic telemetry into the same Redis
SNOWIR_SYNTH_TELEMETRY=true python -m snow_ir.tracking

# Terminal 3
cd snow-ir-app && pnpm dev

Open the Telemetry section. Within ~2 s you should see:

• Overpass countdown updating every second; the next Sentinel / Landsat pass is highlighted in glacial-cyan when imminent (< 30 min).
• Seismic feed populated from IRIS within the basin halo.
• Live edge-node stream flowing through Redis → WebSocket → React without page reload.

Latency Targets

Hop	Budget	Achieved (synthetic)
MQTT publish → Redis pub/sub	≤ 500 ms	~50 ms
Redis → WS fan-out	≤ 500 ms	~30 ms
WS message → component update	≤ 200 ms	~10 ms
End-to-end ingest → render	< 5 s	≈ 100 ms

Provenance Discipline (§8)

Every acknowledgement writes:

• hazard_alerts.acknowledged_by and acknowledged_at columns in Supabase
• An audit_events row via the schema trigger
• (Optional) a Polygon PoS transaction hash in hazard_alerts.blockchain_tx

The forecast hash is the canonical anchor — same SHA-256 used for severity calibration, audit ledger, and on-chain proof.