Live Drone Telemetry — 3D Map Explorer

MAVLink telemetry receiver

A real ground-station viewer — read-only, by design

The receiver binds a UDP port (QGroundControl's 14550 default — the same port SITL, mavlink-router, and companion computers stream to) or connects out over TCP to a serial-to-network bridge. Frames are parsed with a hand-rolled, air-gapped MAVLink v1/v2 decoder — no NuGet package, no native dependency — and folded into a per-aircraft track that fans out over SSE to the map overlay.

UDP & TCP transports — bind a local port for a telemetry radio or SITL, or connect out to mavlink-router / a networked radio. Serial (USB SiK/RFD900) is a documented Phase-2 add-on.
MAVLink v1 + v2 — the parser handles both protocol versions, including v2's 24-bit message IDs and extension fields. CRC16/X.25 with the per-message CRC_EXTRA table, transcribed from the reference C library.
Read-only by design — this is a situational-awareness viewer, not a flight controller. No arm/disarm, no mode changes, no mission upload, no failsafe override. The operator stays pilot-in-command.
Distinct from Remote ID — Remote ID shows other drones broadcasting in your area; MAVLink shows your drone at full rate, with attitude, battery, and mode that RID never carries.
Stale-track pruning — tracks age out on a configurable TTL; the overlay marks a lost link (slate) vs a live fix (green) vs armed (red) at a glance.

MAVLink → /api/mavlink/tracks

// autopilot → UDP 14550 → live track
{
  "sysid": 1,
  "callsign": "ALPHA-1",
  "latitude":  38.8978,
  "longitude": -77.0367,
  "altAglM":   50.0,
  "mode":      "AUTO.MISSION",
  "armed":     true,
  "batteryPct": 87,
  "fixType":   "3D",
  "sats":      14
}
→ green heading-wedge on the map

What you see

The full C2 downlink, decoded correctly

The decoder was audited field-by-field against the official MAVLink C library headers — every byte offset, every signed/unsigned width, every flight-mode enum. No silent misalignments.

📍

Position & velocity

Fused WGS84 position (lat/lon/alt-MSL/alt-AGL), ground speed, vertical speed, and heading from GLOBAL_POSITION_INT — the same fused estimate the autopilot flies on.

🧭

Attitude

Roll, pitch, yaw, and body rates from ATTITUDE — the raw material for a live attitude indicator or a 3D model orientation.

🔋

Battery & health

Voltage, current, and remaining percent from SYS_STATUS — with the signed -1 "not measured" sentinel handled correctly, not rendered as 655 A.

🛰️

GPS fix & sats

Fix type (NO_GPS through RTK_FLOAT), HDOP/VDOP, and satellite count from GPS_RAW_INT — decoded in MAVLink wire order, not XML source order.

🎯

Flight mode

ArduPilot's flat enum and PX4's packed main_mode | (sub_mode << 16) — so a PX4 drone shows AUTO.RTL, not a wrong flat-enum label.

⚡

Armed & link

The SAFETY_ARMED bit from HEARTBEAT, rendered as a red track when armed — and heartbeat-driven link-loss detection that flags a stale track.

Team situational awareness

Your drone, on everyone's TAK map

Every position update is published as a Cursor-on-Target event — the a-f-A-M-U friendly-UAS type, the same one Remote ID uses — so the drone appears on every connected ATAK / WinTAK / TAK-X device alongside the rest of the blue-force picture. One MAVLink feed in, the whole team sees the aircraft.

📡

CoT publication

Each decoded position becomes a CoT event via the existing TAK client — STOMP wss to a TAK Server or UDP multicast for server-less team interop.

🌐

SSE fan-out

Tracks stream over /api/mavlink/tracks/events Server-Sent Events — the same fan-out pattern the Remote ID and feeds layers use.

🟢

Visual distinction

MAVLink ownship = green heading-wedge. Remote ID traffic = purple triangle. ADS-B manned = blue. Three populations, three colors, one map.

Honest scope

A viewer, not a controller

This layer is situational awareness only — it issues no commands and changes no vehicle state. It does not relieve the pilot of the drone's own Remote ID broadcast obligation (14 CFR Part 89), and it does not grant any operational authority the pilot doesn't already hold. The PIC's eyes and the aircraft's own warnings remain authoritative.

REST surface

Profiles, tracks, and live events — over HTTP

Every capability is a localhost route. The receiver is opt-in — it never binds on startup. Select a connection profile, start reception, and the tracks flow.

Capability	Endpoint	Notes
Capabilities	GET /api/mavlink/capabilities	Receiver state, serial availability (Phase 2), bound endpoint
Profile CRUD	GET/POST/PUT/DELETE /api/mavlink/profiles	Connection profiles (transport, host, port, callsign)
Start reception	POST /api/mavlink/polling/start	Bind UDP / connect TCP for the selected profile
Stop reception	POST /api/mavlink/polling/stop	Unbind + tear down the receive loop
Track snapshot	GET /api/mavlink/tracks	Latest decoded state per sysid (position, mode, battery…)
Live track stream	GET /api/mavlink/tracks/events	SSE fan-out — the map overlay subscribes here