RTK / PPK Corrections — 3D Map Explorer

What it does · RTK (live)

NTRIP in → RTCM out → MAVLink to the aircraft.

The RtkService connects to one or more NTRIP casters, pulls the RTCM3 correction stream, and forwards it to the aircraft via MAVLink GPS_RTCM_DATA frames — reusing the command-send link the payload module established.

NTRIP sources — register multiple casters (mountpoint, credentials, format); CRUD over REST, persisted by NtripSourceStore.
RTCM forwarder — chunks the stream into MAVLink-sized frames and pushes when a live link exists; no-op otherwise.
Status — connection state, active mountpoint, and whether a live MAVLink link can actually deliver corrections.

POST /api/rtk/connect/{id}

// connect caster → relay RTCM3 to aircraft
GET /api/rtk/status
{
  "connected": true,
  "mountpoint": "BASE1",
  "liveLink": true,
  "forwarding": true
}
→ GPS_RTCM_DATA frames sent
→ aircraft publishes RTK Fix

What it does · PPK (post-flight)

Reprocess the trajectory against a base station.

PPK reprocesses the aircraft's recorded trajectory against a base-station RINEX observation file to recover centimeter-accurate positions the live RTK fix may have missed — dropouts, float-only epochs, re-initialization. Phase 1 is an honest degrade: it loads the trajectory (from FlightLog), decodes the base-station RINEX header, and summarizes the existing fix quality so you know whether PPK would meaningfully help.

📉

Trajectory load

Aircraft trajectory read from FlightLogService — the same logs replay uses.

📡

RINEX decode

Base-station header parsed — station, approx position, observation types (L1/L2).

📊

Fix-quality summary

What fraction of epochs were Fixed vs Float — tells you if PPK is worth running.

🎯

QC position

Base-station position surfaced for quality control / bias checks.

🧮

Honest degrade

Missing trajectory / unreadable RINEX → a result object with a clear status, never an exception.

⏳

Phase 2 · full math

Carrier-phase double-difference + LAMBDA ambiguity resolution is planned, not shipped.

REST API surface

Manage corrections from your own tools

Capability	Endpoint	Notes
Capability discovery	GET /api/rtk/capabilities	RTK relay + PPK availability
List / get sources	GET /api/rtk/sources · /sources/{id}	Registered NTRIP casters
Add source	POST /api/rtk/sources	Mountpoint, creds, format
Update / delete	PUT · DELETE /api/rtk/sources/{id}
Connect / disconnect	POST /api/rtk/connect/{id} · /disconnect	Start/stop RTCM relay
Status	GET /api/rtk/status	Connection + live-link + forwarding state
PPK post-process	POST /api/rtk/ppk	Trajectory + RINEX → fix-quality summary

RTK relay reflects RtkService / NtripClient / RtcmForwarder; PPK reflects PpkService on commit fddb81f38 (feat/rtk-ppk-corrections). PPK Phase 1 is an honest degrade — trajectory + base position + fix-quality summary, not the full carrier-phase double-difference solution (planned Phase 2). Actual cm accuracy depends on base-station quality and rover GNSS hardware.

Part of the UAS loop