feat: add realtime GNSS monitor with telemetry websocket

2026-03-20 11:48:04 +08:00
parent e8846f4831
commit e81aadcd99
16 changed files with 1951 additions and 22 deletions
--- a/backend/app/api/deps.py
+++ b/backend/app/api/deps.py
@@ -27,7 +27,7 @@ SessionDep = Annotated[Session, Depends(get_db)]
 TokenDep = Annotated[str, Depends(reusable_oauth2)]


-def get_current_user(session: SessionDep, token: TokenDep) -> User:
+def resolve_user_from_token(*, session: Session, token: str) -> User:
    try:
        payload = jwt.decode(
            token, settings.SECRET_KEY, algorithms=[security.ALGORITHM]
@@ -46,6 +46,10 @@ def get_current_user(session: SessionDep, token: TokenDep) -> User:
    return user


+def get_current_user(session: SessionDep, token: TokenDep) -> User:
+    return resolve_user_from_token(session=session, token=token)
+
+
 CurrentUser = Annotated[User, Depends(get_current_user)]


--- a/backend/app/api/main.py
+++ b/backend/app/api/main.py
@@ -1,6 +1,6 @@
 from fastapi import APIRouter

-from app.api.routes import locations, login, private, users, utils
+from app.api.routes import locations, login, private, telemetry, users, utils
 from app.core.config import settings

 api_router = APIRouter()
@@ -8,8 +8,8 @@ api_router.include_router(login.router)
 api_router.include_router(users.router)
 api_router.include_router(utils.router)
 api_router.include_router(locations.router)
+api_router.include_router(telemetry.router)


 if settings.ENVIRONMENT == "local":
    api_router.include_router(private.router)
-
--- a/backend/app/api/routes/telemetry.py
+++ b/backend/app/api/routes/telemetry.py
@@ -0,0 +1,63 @@
+from __future__ import annotations
+
+import asyncio
+from typing import Any
+
+from fastapi import APIRouter, HTTPException, Query, WebSocket, status
+from fastapi.encoders import jsonable_encoder
+from fastapi.websockets import WebSocketDisconnect
+from sqlmodel import Session
+
+from app.api.deps import CurrentUser, SessionDep, resolve_user_from_token
+from app.core.db import engine
+from app.mqtt.telemetry import build_telemetry_snapshot
+
+router = APIRouter(prefix="/telemetry", tags=["telemetry"])
+STREAM_INTERVAL_SECONDS = 1.0
+
+
+@router.get("/latest")
+def read_telemetry_latest(
+    session: SessionDep,
+    _current_user: CurrentUser,
+    device_id: str | None = None,
+    limit: int = Query(default=50, ge=1, le=200),
+) -> dict[str, Any]:
+    """
+    Return the latest parsed GNSS telemetry snapshot.
+    """
+    return build_telemetry_snapshot(session=session, device_id=device_id, limit=limit)
+
+
+@router.websocket("/ws")
+async def telemetry_websocket(
+    websocket: WebSocket,
+    token: str | None = Query(default=None),
+    device_id: str | None = Query(default=None),
+    limit: int = Query(default=50, ge=1, le=200),
+) -> None:
+    if not token:
+        await websocket.close(code=status.WS_1008_POLICY_VIOLATION)
+        return
+
+    with Session(engine) as session:
+        try:
+            resolve_user_from_token(session=session, token=token)
+        except HTTPException:
+            await websocket.close(code=status.WS_1008_POLICY_VIOLATION)
+            return
+
+    await websocket.accept()
+
+    try:
+        while True:
+            with Session(engine) as session:
+                payload = build_telemetry_snapshot(
+                    session=session,
+                    device_id=device_id,
+                    limit=limit,
+                )
+            await websocket.send_json(jsonable_encoder(payload))
+            await asyncio.sleep(STREAM_INTERVAL_SECONDS)
+    except (WebSocketDisconnect, RuntimeError):
+        return
--- a/backend/app/mqtt/parsers/nmea.py
+++ b/backend/app/mqtt/parsers/nmea.py
@@ -3,6 +3,16 @@ from __future__ import annotations
 from typing import Any

 SUPPORTED_NMEA_TYPES = {"GGA", "RMC", "GSV", "GSA", "GST"}
+TALKER_TO_CONSTELLATION = {
+    "GP": "GPS",
+    "GL": "GLONASS",
+    "GA": "Galileo",
+    "GB": "BeiDou",
+    "BD": "BeiDou",
+    "GQ": "QZSS",
+    "GI": "NavIC",
+    "GN": "Mixed",
+}


 def _to_float(value: str) -> float | None:
@@ -40,19 +50,46 @@ def _parse_lat_lon(value: str, hemisphere: str) -> float | None:
    return decimal


-def _extract_sentence_type(sentence: str) -> str | None:
+def _extract_sentence_meta(sentence: str) -> tuple[str, str] | None:
    if not sentence.startswith("$"):
        return None
    if len(sentence) < 6:
        return None
+    talker = sentence[1:3].upper()
    nmea_type = sentence[3:6].upper()
    if nmea_type not in SUPPORTED_NMEA_TYPES:
        return None
-    return nmea_type
+    return talker, nmea_type


-def _parse_nmea_fields(nmea_type: str, fields: list[str]) -> dict[str, Any]:
-    payload: dict[str, Any] = {"sentence_type": nmea_type, "raw_fields": fields}
+def _parse_satellite_blocks(fields: list[str]) -> list[dict[str, Any]]:
+    satellites: list[dict[str, Any]] = []
+    for i in range(4, len(fields), 4):
+        if i + 3 >= len(fields):
+            continue
+        satellite_id = fields[i]
+        if not satellite_id:
+            continue
+        satellites.append(
+            {
+                "satellite_id": satellite_id,
+                "elevation_deg": _to_int(fields[i + 1]),
+                "azimuth_deg": _to_int(fields[i + 2]),
+                "snr_dbhz": _to_int(fields[i + 3]),
+            }
+        )
+    return satellites
+
+
+def _parse_nmea_fields(
+    *, talker: str, nmea_type: str, fields: list[str]
+) -> dict[str, Any]:
+    payload: dict[str, Any] = {
+        "sentence_type": nmea_type,
+        "talker": talker,
+        "constellation": TALKER_TO_CONSTELLATION.get(talker, "Unknown"),
+        "raw_fields": fields,
+    }

    if nmea_type == "GGA":
        payload.update(
@@ -91,23 +128,27 @@ def _parse_nmea_fields(nmea_type: str, fields: list[str]) -> dict[str, Any]:
            }
        )
    elif nmea_type == "GSV":
+        satellites = _parse_satellite_blocks(fields)
        payload.update(
            {
                "total_messages": _to_int(fields[1] if len(fields) > 1 else ""),
                "message_index": _to_int(fields[2] if len(fields) > 2 else ""),
                "satellites_in_view": _to_int(fields[3] if len(fields) > 3 else ""),
+                "satellites": satellites,
                "snr_values": [
-                    _to_int(fields[i])
-                    for i in range(7, len(fields), 4)
-                    if i < len(fields)
+                    satellite["snr_dbhz"]
+                    for satellite in satellites
+                    if satellite["snr_dbhz"] is not None
                ],
            }
        )
    elif nmea_type == "GSA":
+        used_satellite_ids = [sat_id for sat_id in fields[3:15] if sat_id]
        payload.update(
            {
                "mode": fields[1] if len(fields) > 1 else None,
                "fix_type": _to_int(fields[2] if len(fields) > 2 else ""),
+                "used_satellite_ids": used_satellite_ids,
                "pdop": _to_float(fields[15] if len(fields) > 15 else ""),
                "hdop": _to_float(fields[16] if len(fields) > 16 else ""),
                "vdop": _to_float(fields[17] if len(fields) > 17 else ""),
@@ -134,13 +175,16 @@ def parse_nmea_sentences(payload: bytes) -> list[dict[str, Any]]:
            continue

        sentence = raw_line.decode("ascii", errors="ignore").strip()
-        nmea_type = _extract_sentence_type(sentence)
-        if nmea_type is None:
+        sentence_meta = _extract_sentence_meta(sentence)
+        if sentence_meta is None:
            continue
+        talker, nmea_type = sentence_meta

        main_part = sentence.split("*", 1)[0]
        fields = main_part.split(",")
-        parsed_payload = _parse_nmea_fields(nmea_type, fields)
+        parsed_payload = _parse_nmea_fields(
+            talker=talker, nmea_type=nmea_type, fields=fields
+        )
        events.append(
            {"event_type": f"nmea_{nmea_type.lower()}", "payload": parsed_payload}
        )
--- a/backend/app/mqtt/repository.py
+++ b/backend/app/mqtt/repository.py
@@ -77,6 +77,74 @@ def mark_failed(
    session.add(row)


+def _build_satellite_signal_summary(
+    *,
+    gsv_satellites: list[dict[str, Any]],
+    satellites_in_view: int | None,
+    used_satellite_ids: set[str],
+) -> dict[str, Any]:
+    deduped: dict[tuple[str, str], dict[str, Any]] = {}
+    for satellite in gsv_satellites:
+        constellation = str(satellite.get("constellation", "Unknown"))
+        satellite_id = str(satellite.get("satellite_id", "")).strip()
+        if not satellite_id:
+            continue
+        key = (constellation, satellite_id)
+        existing = deduped.get(key)
+        if existing is None:
+            deduped[key] = satellite
+            continue
+
+        incoming_snr = satellite.get("snr_dbhz")
+        existing_snr = existing.get("snr_dbhz")
+        if isinstance(incoming_snr, int) and (
+            not isinstance(existing_snr, int) or incoming_snr > existing_snr
+        ):
+            deduped[key] = satellite
+
+    satellites = list(deduped.values())
+    satellites.sort(
+        key=lambda sat: (str(sat["constellation"]), str(sat["satellite_id"]))
+    )
+
+    snr_values: list[int] = []
+    cn0_values: list[int] = []
+    constellation_summary: dict[str, dict[str, int]] = {}
+
+    for satellite in gsv_satellites:
+        cn0_value = satellite.get("snr_dbhz")
+        if isinstance(cn0_value, int):
+            cn0_values.append(cn0_value)
+
+    for satellite in satellites:
+        constellation = str(satellite["constellation"])
+        sat_id = str(satellite["satellite_id"])
+        used_in_navigation = sat_id in used_satellite_ids
+        satellite["used_in_navigation"] = used_in_navigation
+
+        constellation_item = constellation_summary.setdefault(
+            constellation,
+            {"count": 0, "with_signal": 0, "used_in_navigation": 0},
+        )
+        constellation_item["count"] += 1
+        if used_in_navigation:
+            constellation_item["used_in_navigation"] += 1
+
+        snr_dbhz = satellite.get("snr_dbhz")
+        if isinstance(snr_dbhz, int):
+            snr_values.append(snr_dbhz)
+            constellation_item["with_signal"] += 1
+
+    return {
+        "satellites_in_view": satellites_in_view or len(satellites),
+        "snr_values": snr_values,
+        "cn0_values": cn0_values,
+        "used_satellite_ids": sorted(used_satellite_ids),
+        "constellations": constellation_summary,
+        "satellites": satellites,
+    }
+
+
 def update_device_state_from_events(
    *,
    session: Session,
@@ -96,6 +164,10 @@ def update_device_state_from_events(
    if state is None:
        state = TerminalDeviceState(device_id=row.device_id)

+    gsv_satellites: list[dict[str, Any]] = []
+    satellites_in_view: int | None = None
+    used_satellite_ids: set[str] = set()
+
    for event in events:
        payload = event.get("payload", {})
        event_type = str(event.get("event_type", "unknown"))
@@ -114,16 +186,52 @@ def update_device_state_from_events(
            if payload.get("lon") is not None:
                state.lon = payload.get("lon")
            status = payload.get("status")
-            if status is not None:
+            if status is not None and state.fix_status is None:
                state.fix_status = str(status)
        elif event_type == "nmea_gsv":
-            state.satellite_signal_summary = {
-                "snr_values": payload.get("snr_values", []),
-                "satellites_in_view": payload.get("satellites_in_view"),
+            payload_satellites = payload.get("satellites", [])
+            if isinstance(payload_satellites, list):
+                for sat in payload_satellites:
+                    if not isinstance(sat, dict):
+                        continue
+                    gsv_satellites.append(
+                        {
+                            "satellite_id": str(sat.get("satellite_id", "")),
+                            "elevation_deg": sat.get("elevation_deg"),
+                            "azimuth_deg": sat.get("azimuth_deg"),
+                            "snr_dbhz": sat.get("snr_dbhz"),
+                            "constellation": payload.get("constellation", "Unknown"),
                        }
+                    )
+            satellites_count = payload.get("satellites_in_view")
+            if isinstance(satellites_count, int):
+                satellites_in_view = max(satellites_in_view or 0, satellites_count)
+        elif event_type == "nmea_gsa":
+            for satellite_id in payload.get("used_satellite_ids", []):
+                if satellite_id is None:
+                    continue
+                used_satellite_ids.add(str(satellite_id))
        elif event_type == "rtcm_summary":
            state.rtcm_type_summary = payload.get("rtcm_types", {})

+    if gsv_satellites:
+        state.satellite_signal_summary = _build_satellite_signal_summary(
+            gsv_satellites=gsv_satellites,
+            satellites_in_view=satellites_in_view,
+            used_satellite_ids=used_satellite_ids,
+        )
+    elif used_satellite_ids and state.satellite_signal_summary:
+        current_summary = dict(state.satellite_signal_summary)
+        current_summary["used_satellite_ids"] = sorted(used_satellite_ids)
+        satellites = current_summary.get("satellites", [])
+        if isinstance(satellites, list):
+            for satellite in satellites:
+                if not isinstance(satellite, dict):
+                    continue
+                sat_id = str(satellite.get("satellite_id", ""))
+                satellite["used_in_navigation"] = sat_id in used_satellite_ids
+        state.satellite_signal_summary = current_summary
+
    state.last_event_time = row.received_at
    state.updated_at = get_datetime_utc()
    session.add(state)
--- a/backend/app/mqtt/telemetry.py
+++ b/backend/app/mqtt/telemetry.py
@@ -0,0 +1,158 @@
+from __future__ import annotations
+
+from typing import Any
+
+from sqlmodel import Session, col, select
+
+from app.models import TerminalDeviceState, get_datetime_utc
+
+
+def _to_int(value: Any) -> int | None:
+    if isinstance(value, bool):
+        return None
+    if isinstance(value, int):
+        return value
+    if isinstance(value, float):
+        return int(value)
+    if isinstance(value, str):
+        stripped = value.strip()
+        if stripped.isdigit():
+            return int(stripped)
+    return None
+
+
+def _normalize_satellite_summary(summary: Any) -> dict[str, Any]:
+    if not isinstance(summary, dict):
+        return {
+            "satellites_in_view": None,
+            "snr_values": [],
+            "cn0_values": [],
+            "constellations": {},
+            "used_satellite_ids": [],
+            "satellites": [],
+        }
+
+    raw_satellites = summary.get("satellites", [])
+    satellites: list[dict[str, Any]] = []
+    if isinstance(raw_satellites, list):
+        for satellite in raw_satellites:
+            if not isinstance(satellite, dict):
+                continue
+            satellite_id = str(satellite.get("satellite_id", "")).strip()
+            if not satellite_id:
+                continue
+            satellites.append(
+                {
+                    "satellite_id": satellite_id,
+                    "constellation": str(satellite.get("constellation", "Unknown")),
+                    "azimuth_deg": _to_int(satellite.get("azimuth_deg")),
+                    "elevation_deg": _to_int(satellite.get("elevation_deg")),
+                    "snr_dbhz": _to_int(satellite.get("snr_dbhz")),
+                    "used_in_navigation": bool(
+                        satellite.get("used_in_navigation", False)
+                    ),
+                }
+            )
+
+    snr_values: list[int] = []
+    raw_snr_values = summary.get("snr_values", [])
+    if isinstance(raw_snr_values, list):
+        for value in raw_snr_values:
+            converted = _to_int(value)
+            if converted is not None:
+                snr_values.append(converted)
+
+    cn0_values: list[int] = []
+    raw_cn0_values = summary.get("cn0_values", [])
+    if isinstance(raw_cn0_values, list):
+        for value in raw_cn0_values:
+            converted = _to_int(value)
+            if converted is not None:
+                cn0_values.append(converted)
+    if not cn0_values:
+        cn0_values = list(snr_values)
+
+    satellites_in_view = _to_int(summary.get("satellites_in_view"))
+    if satellites_in_view is None:
+        satellites_in_view = len(satellites)
+
+    constellations = summary.get("constellations", {})
+    if not isinstance(constellations, dict):
+        constellations = {}
+
+    used_satellite_ids = summary.get("used_satellite_ids", [])
+    if not isinstance(used_satellite_ids, list):
+        used_satellite_ids = []
+
+    return {
+        "satellites_in_view": satellites_in_view,
+        "snr_values": snr_values,
+        "cn0_values": cn0_values,
+        "constellations": constellations,
+        "used_satellite_ids": used_satellite_ids,
+        "satellites": satellites,
+    }
+
+
+def _build_signal_health(snr_values: list[int]) -> dict[str, Any]:
+    strong_signal_count = sum(1 for value in snr_values if value >= 40)
+    average_snr = (sum(snr_values) / len(snr_values)) if snr_values else None
+    best_snr = max(snr_values) if snr_values else None
+
+    if strong_signal_count >= 20:
+        level = "good"
+        message = "At least 20 satellites have CN0 >= 40"
+    elif strong_signal_count >= 10:
+        level = "fair"
+        message = "At least 10 satellites have CN0 >= 40"
+    else:
+        level = "poor"
+        message = "Less than 10 satellites have CN0 >= 40"
+
+    score = min(strong_signal_count * 5, 100)
+
+    return {
+        "level": level,
+        "score": score,
+        "strong_signal_count": strong_signal_count,
+        "average_snr_dbhz": round(average_snr, 1) if average_snr is not None else None,
+        "best_snr_dbhz": best_snr,
+        "message": message,
+    }
+
+
+def _serialize_device_state(state: TerminalDeviceState) -> dict[str, Any]:
+    signal_summary = _normalize_satellite_summary(state.satellite_signal_summary)
+    signal_health = _build_signal_health(signal_summary["snr_values"])
+
+    return {
+        "device_id": state.device_id,
+        "last_event_time": state.last_event_time,
+        "updated_at": state.updated_at,
+        "fix_status": state.fix_status,
+        "lat": state.lat,
+        "lon": state.lon,
+        "alt_m": state.alt_m,
+        "satellites_used": state.satellites_used,
+        "satellite_signal_summary": signal_summary,
+        "signal_health": signal_health,
+    }
+
+
+def build_telemetry_snapshot(
+    *,
+    session: Session,
+    device_id: str | None = None,
+    limit: int = 50,
+) -> dict[str, Any]:
+    statement = select(TerminalDeviceState).order_by(
+        col(TerminalDeviceState.updated_at).desc()
+    )
+    if device_id:
+        statement = statement.where(TerminalDeviceState.device_id == device_id)
+    statement = statement.limit(limit)
+
+    states = session.exec(statement).all()
+    devices = [_serialize_device_state(state) for state in states]
+
+    return {"generated_at": get_datetime_utc(), "devices": devices}
--- a/backend/tests/api/routes/test_telemetry.py
+++ b/backend/tests/api/routes/test_telemetry.py
@@ -0,0 +1,127 @@
+from datetime import datetime, timezone
+
+from fastapi.testclient import TestClient
+from sqlmodel import Session
+
+from app.core.config import settings
+from app.models import TerminalDeviceState
+
+
+def _seed_device_state(
+    db: Session, device_id: str, snr_values: list[int] | None = None
+) -> None:
+    state = db.get(TerminalDeviceState, device_id)
+    if state is None:
+        state = TerminalDeviceState(device_id=device_id)
+
+    signal_values = snr_values if snr_values is not None else [28, 31, 36, 41, 44]
+
+    state.fix_status = "5"
+    state.lat = 31.359591
+    state.lon = 120.714489
+    state.alt_m = 52.1
+    state.satellites_used = 17
+    state.satellite_signal_summary = {
+        "satellites_in_view": 22,
+        "snr_values": signal_values,
+        "constellations": {
+            "GPS": {"count": 8, "used_in_navigation": 6},
+            "BeiDou": {"count": 10, "used_in_navigation": 8},
+            "Galileo": {"count": 4, "used_in_navigation": 3},
+        },
+        "satellites": [
+            {
+                "satellite_id": "G05",
+                "constellation": "GPS",
+                "azimuth_deg": 121,
+                "elevation_deg": 29,
+                "snr_dbhz": 37,
+                "used_in_navigation": True,
+            }
+        ],
+    }
+    state.last_event_time = datetime.now(timezone.utc)
+    db.add(state)
+    db.commit()
+
+
+def test_read_telemetry_latest(
+    client: TestClient, superuser_token_headers: dict[str, str], db: Session
+) -> None:
+    device_id = "device-api-001"
+    _seed_device_state(db, device_id)
+
+    response = client.get(
+        f"{settings.API_V1_STR}/telemetry/latest",
+        headers=superuser_token_headers,
+    )
+
+    assert response.status_code == 200
+    payload = response.json()
+    assert "generated_at" in payload
+    assert len(payload["devices"]) >= 1
+    device = next(item for item in payload["devices"] if item["device_id"] == device_id)
+    assert device["fix_status"] == "5"
+    assert device["signal_health"]["level"] == "poor"
+
+
+def test_signal_health_levels_based_on_count_of_40_plus_signals(
+    client: TestClient, superuser_token_headers: dict[str, str], db: Session
+) -> None:
+    _seed_device_state(db, "device-health-good", [40] * 20 + [15] * 3)
+    _seed_device_state(db, "device-health-fair", [40] * 10 + [20] * 3)
+    _seed_device_state(db, "device-health-poor", [40] * 9 + [39])
+
+    response = client.get(
+        f"{settings.API_V1_STR}/telemetry/latest",
+        headers=superuser_token_headers,
+        params={"limit": 200},
+    )
+    assert response.status_code == 200
+    devices = {item["device_id"]: item for item in response.json()["devices"]}
+
+    assert devices["device-health-good"]["signal_health"]["level"] == "good"
+    assert devices["device-health-fair"]["signal_health"]["level"] == "fair"
+    assert devices["device-health-poor"]["signal_health"]["level"] == "poor"
+
+
+def test_signal_health_uses_satellite_level_values_for_ucenter_view(
+    client: TestClient, superuser_token_headers: dict[str, str], db: Session
+) -> None:
+    state = db.get(TerminalDeviceState, "device-health-ucenter")
+    if state is None:
+        state = TerminalDeviceState(device_id="device-health-ucenter")
+    state.fix_status = "5"
+    state.satellite_signal_summary = {
+        # u-center signal bars are per-satellite bars, not per-frequency points
+        "snr_values": [41] * 9 + [30] * 4,
+        # keep raw CN0 points for diagnostics, but health should follow bar view
+        "cn0_values": [41] * 20 + [25] * 5,
+    }
+    db.add(state)
+    db.commit()
+
+    response = client.get(
+        f"{settings.API_V1_STR}/telemetry/latest",
+        headers=superuser_token_headers,
+        params={"device_id": "device-health-ucenter"},
+    )
+    assert response.status_code == 200
+    device = response.json()["devices"][0]
+    assert device["signal_health"]["strong_signal_count"] == 9
+    assert device["signal_health"]["level"] == "poor"
+
+
+def test_telemetry_websocket_stream(
+    client: TestClient, superuser_token_headers: dict[str, str], db: Session
+) -> None:
+    _seed_device_state(db, "device-api-002")
+    token = superuser_token_headers["Authorization"].split(" ", 1)[1]
+
+    with client.websocket_connect(
+        f"{settings.API_V1_STR}/telemetry/ws?token={token}"
+    ) as websocket:
+        payload = websocket.receive_json()
+
+    assert "generated_at" in payload
+    assert len(payload["devices"]) >= 1
--- a/backend/tests/mqtt/nmea.txt
+++ b/backend/tests/mqtt/nmea.txt
@@ -0,0 +1,448 @@
+$GNRMC,015903.000,A,3121.575445,N,12042.869341,E,0.015,51.12,080126,,E,A,V*48
+$GNGGA,015903.000,3121.575445,N,12042.869341,E,1,17,1.09,51.800,M,0.000,M,,*79
+$GPGSA,A,3,04,26,28,29,31,32,,,,,,,1.54,1.09,1.08,1*1C
+$GBGSA,A,3,06,24,26,35,39,41,,,,,,,1.54,1.09,1.08,4*04
+$GAGSA,A,3,09,,,,,,,,,,,,1.54,1.09,1.08,3*04
+$GLGSA,A,3,67,75,76,85,,,,,,,,,1.54,1.09,1.08,2*0E
+$GPGSV,3,1,9,03,24,284,00,04,16,319,38,16,47,239,00,26,74,310,29,1*55
+$GPGSV,3,2,9,27,11,189,00,28,50,056,42,29,23,053,44,31,59,357,39,1*5A
+$GPGSV,3,3,9,32,34,146,20,1*6A
+$GPGSV,3,1,9,03,24,284,00,04,16,319,36,16,47,239,00,26,74,310,31,8*5B
+$GPGSV,3,2,9,27,11,189,00,28,50,056,00,29,23,053,00,31,59,357,00,8*5F
+$GPGSV,3,3,9,32,34,146,00,8*61
+$GBGSV,8,1,29,01,44,140,00,02,38,237,00,03,52,199,00,04,32,124,00,1*78
+$GBGSV,8,2,29,05,16,257,00,06,59,332,33,07,31,184,00,08,25,209,00,1*71
+$GBGSV,8,3,29,09,50,309,00,10,20,194,00,12,17,131,00,13,30,222,00,1*7A
+$GBGSV,8,4,29,14,50,202,00,24,59,014,39,25,37,278,00,26,22,058,40,1*77
+$GBGSV,8,5,29,33,58,251,00,34,12,157,00,35,11,059,40,38,17,196,00,1*71
+$GBGSV,8,6,29,39,62,002,35,40,29,169,00,41,28,312,37,42,29,177,00,1*7F
+$GBGSV,8,7,29,44,23,105,00,50,09,164,00,59,48,145,00,60,33,239,00,1*76
+$GBGSV,8,8,29,61,51,199,00,1*4F
+$GBGSV,4,1,13,24,59,014,38,25,37,278,00,26,22,058,34,33,58,251,00,4*7B
+$GBGSV,4,2,13,34,12,157,00,35,11,059,37,38,17,196,00,39,62,002,37,4*75
+$GBGSV,4,3,13,40,29,169,00,41,28,312,29,42,29,177,00,44,23,105,00,4*7A
+$GBGSV,4,4,13,50,09,164,00,4*4E
+$GAGSV,2,1,5,04,69,130,00,06,81,329,00,09,54,320,37,19,13,135,00,7*4B
+$GAGSV,2,2,5,31,78,255,00,7*79
+$GAGSV,2,1,5,04,69,130,00,06,81,329,00,09,54,320,40,19,13,135,00,1*4D
+$GAGSV,2,2,5,31,78,255,00,1*7F
+$GLGSV,2,1,8,65,39,176,00,66,72,275,00,67,21,329,36,75,13,044,43,1*47
+$GLGSV,2,2,8,76,53,352,43,77,39,277,00,85,09,055,41,86,08,112,00,1*49
+$GNGST,015903.000,0.86,8.38,1.39,81.42,32.311,7.315,13.683*43
+$GNSVD,0,0,0,118,22,22*40
+$GNRMC,015904.000,A,3121.575704,N,12042.869303,E,0.050,334.82,080126,,E,A,V*77
+$GNGGA,015904.000,3121.575704,N,12042.869303,E,1,17,1.09,51.838,M,0.000,M,,*75
+$GPGSA,A,3,04,26,28,29,31,32,,,,,,,1.54,1.09,1.08,1*1C
+$GBGSA,A,3,06,24,26,35,39,41,,,,,,,1.54,1.09,1.08,4*04
+$GAGSA,A,3,09,,,,,,,,,,,,1.54,1.09,1.08,3*04
+$GLGSA,A,3,67,75,76,85,,,,,,,,,1.54,1.09,1.08,2*0E
+$GPGSV,3,1,9,03,24,284,00,04,16,319,38,16,47,239,00,26,74,310,29,1*55
+$GPGSV,3,2,9,27,11,189,00,28,50,056,42,29,23,053,44,31,59,357,39,1*5A
+$GPGSV,3,3,9,32,34,146,19,1*60
+$GPGSV,3,1,9,03,24,284,00,04,16,319,36,16,47,239,00,26,74,310,30,8*5A
+$GPGSV,3,2,9,27,11,189,00,28,50,056,00,29,23,053,00,31,59,357,00,8*5F
+$GPGSV,3,3,9,32,34,146,00,8*61
+$GBGSV,8,1,29,01,44,140,00,02,38,237,00,03,52,199,00,04,32,124,00,1*78
+$GBGSV,8,2,29,05,16,257,00,06,59,332,33,07,31,184,00,08,25,209,00,1*71
+$GBGSV,8,3,29,09,50,309,00,10,20,194,00,12,17,131,00,13,30,222,00,1*7A
+$GBGSV,8,4,29,14,50,202,00,24,59,014,39,25,37,278,00,26,22,058,41,1*76
+$GBGSV,8,5,29,33,58,251,00,34,12,157,00,35,11,059,40,38,17,196,00,1*71
+$GBGSV,8,6,29,39,62,002,35,40,29,169,00,41,28,312,37,42,29,177,00,1*7F
+$GBGSV,8,7,29,44,23,105,00,50,09,164,00,59,48,145,00,60,33,239,00,1*76
+$GBGSV,8,8,29,61,51,199,00,1*4F
+$GBGSV,4,1,13,24,59,014,38,25,37,278,00,26,22,058,34,33,58,251,00,4*7B
+$GBGSV,4,2,13,34,12,157,00,35,11,059,37,38,17,196,00,39,62,002,37,4*75
+$GBGSV,4,3,13,40,29,169,00,41,28,312,29,42,29,177,00,44,23,105,00,4*7A
+$GBGSV,4,4,13,50,09,164,00,4*4E
+$GAGSV,2,1,5,04,69,130,00,06,81,329,00,09,54,320,37,19,13,135,00,7*4B
+$GAGSV,2,2,5,31,78,255,00,7*79
+$GAGSV,2,1,5,04,69,130,00,06,81,329,00,09,54,320,40,19,13,135,00,1*4D
+$GAGSV,2,2,5,31,78,255,00,1*7F
+$GLGSV,2,1,8,65,39,176,00,66,72,275,00,67,21,329,35,75,13,044,43,1*44
+$GLGSV,2,2,8,76,53,352,42,77,39,277,00,85,09,055,41,86,08,112,00,1*48
+$GNGST,015904.000,0.93,8.38,1.38,81.41,32.302,7.294,13.653*45
+$GNSVD,-1,2,0,350,68,71*68
+$GNRMC,015905.000,A,3121.575859,N,12042.869263,E,0.039,345.46,080126,,E,A,V*77
+$GNGGA,015905.000,3121.575859,N,12042.869263,E,1,17,1.09,51.796,M,0.000,M,,*7F
+$GPGSA,A,3,04,26,28,29,31,32,,,,,,,1.54,1.09,1.08,1*1C
+$GBGSA,A,3,06,24,26,35,39,41,,,,,,,1.54,1.09,1.08,4*04
+$GAGSA,A,3,09,,,,,,,,,,,,1.54,1.09,1.08,3*04
+$GLGSA,A,3,67,75,76,85,,,,,,,,,1.54,1.09,1.08,2*0E
+$GPGSV,3,1,9,03,24,284,00,04,16,319,38,16,47,239,00,26,74,310,29,1*55
+$GPGSV,3,2,9,27,11,189,00,28,50,056,42,29,23,053,44,31,59,357,39,1*5A
+$GPGSV,3,3,9,32,34,146,19,1*60
+$GPGSV,3,1,9,03,24,284,00,04,16,319,36,16,47,239,00,26,74,310,31,8*5B
+$GPGSV,3,2,9,27,11,189,00,28,50,056,00,29,23,053,00,31,59,357,00,8*5F
+$GPGSV,3,3,9,32,34,146,00,8*61
+$GBGSV,8,1,29,01,44,140,00,02,38,237,00,03,52,199,00,04,32,124,00,1*78
+$GBGSV,8,2,29,05,16,257,00,06,59,332,33,07,31,184,00,08,25,209,00,1*71
+$GBGSV,8,3,29,09,50,309,00,10,20,194,00,12,17,131,00,13,30,222,00,1*7A
+$GBGSV,8,4,29,14,50,202,00,24,59,014,39,25,37,278,00,26,22,058,40,1*77
+$GBGSV,8,5,29,33,58,250,00,34,12,157,00,35,11,059,40,38,17,196,00,1*70
+$GBGSV,8,6,29,39,62,002,35,40,29,169,00,41,28,312,37,42,29,177,00,1*7F
+$GBGSV,8,7,29,44,23,105,00,50,09,164,00,59,48,145,00,60,33,239,00,1*76
+$GBGSV,8,8,29,61,51,199,00,1*4F
+$GBGSV,4,1,13,24,59,014,39,25,37,278,00,26,22,058,34,33,58,250,00,4*7B
+$GBGSV,4,2,13,34,12,157,00,35,11,059,37,38,17,196,00,39,62,002,37,4*75
+$GBGSV,4,3,13,40,29,169,00,41,28,312,29,42,29,177,00,44,23,105,00,4*7A
+$GBGSV,4,4,13,50,09,164,00,4*4E
+$GAGSV,2,1,5,04,69,130,00,06,81,329,00,09,54,320,37,19,13,135,00,7*4B
+$GAGSV,2,2,5,31,78,255,00,7*79
+$GAGSV,2,1,5,04,69,130,00,06,81,329,00,09,54,320,40,19,13,135,00,1*4D
+$GAGSV,2,2,5,31,78,255,00,1*7F
+$GLGSV,2,1,8,65,39,176,00,66,72,275,00,67,21,329,35,75,13,044,43,1*44
+$GLGSV,2,2,8,76,53,352,43,77,39,277,00,85,09,055,41,86,08,112,00,1*49
+$GNGST,015905.000,0.68,8.41,1.37,81.41,32.384,7.264,13.612*45
+$GNSVD,0,1,0,409,76,76*44
+$GNRMC,015906.000,A,3121.576069,N,12042.869216,E,0.042,336.34,080126,,E,A,V*73
+$GNGGA,015906.000,3121.576069,N,12042.869216,E,1,17,1.09,51.776,M,0.000,M,,*78
+$GPGSA,A,3,04,26,28,29,31,32,,,,,,,1.54,1.09,1.08,1*1C
+$GBGSA,A,3,06,24,26,35,39,41,,,,,,,1.54,1.09,1.08,4*04
+$GAGSA,A,3,09,,,,,,,,,,,,1.54,1.09,1.08,3*04
+$GLGSA,A,3,67,75,76,85,,,,,,,,,1.54,1.09,1.08,2*0E
+$GPGSV,3,1,9,03,24,284,00,04,16,319,38,16,47,239,00,26,74,310,29,1*55
+$GPGSV,3,2,9,27,11,189,00,28,50,056,43,29,23,053,45,31,59,357,39,1*5A
+$GPGSV,3,3,9,32,34,146,20,1*6A
+$GPGSV,3,1,9,03,24,284,00,04,16,319,36,16,47,239,00,26,74,310,31,8*5B
+$GPGSV,3,2,9,27,11,189,00,28,50,056,00,29,23,053,00,31,59,357,00,8*5F
+$GPGSV,3,3,9,32,34,146,00,8*61
+$GBGSV,8,1,29,01,44,140,00,02,38,237,00,03,52,199,00,04,32,124,00,1*78
+$GBGSV,8,2,29,05,16,257,00,06,59,332,33,07,31,184,00,08,25,209,00,1*71
+$GBGSV,8,3,29,09,50,309,00,10,20,194,00,12,17,131,00,13,30,222,00,1*7A
+$GBGSV,8,4,29,14,50,202,00,24,59,014,39,25,37,278,00,26,22,058,41,1*76
+$GBGSV,8,5,29,33,58,250,00,34,12,157,00,35,11,059,40,38,17,196,00,1*70
+$GBGSV,8,6,29,39,62,002,35,40,29,169,00,41,28,312,37,42,29,177,00,1*7F
+$GBGSV,8,7,29,44,23,105,00,50,09,164,00,59,48,145,00,60,33,239,00,1*76
+$GBGSV,8,8,29,61,51,199,00,1*4F
+$GBGSV,4,1,13,24,59,014,39,25,37,278,00,26,22,058,34,33,58,250,00,4*7B
+$GBGSV,4,2,13,34,12,157,00,35,11,059,37,38,17,196,00,39,62,002,37,4*75
+$GBGSV,4,3,13,40,29,169,00,41,28,312,29,42,29,177,00,44,23,105,00,4*7A
+$GBGSV,4,4,13,50,09,164,00,4*4E
+$GAGSV,2,1,5,04,69,130,00,06,81,329,00,09,54,320,38,19,13,135,00,7*44
+$GAGSV,2,2,5,31,78,255,00,7*79
+$GAGSV,2,1,5,04,69,130,00,06,81,329,00,09,54,320,40,19,13,135,00,1*4D
+$GAGSV,2,2,5,31,78,255,00,1*7F
+$GLGSV,2,1,8,65,39,176,00,66,72,275,00,67,21,329,35,75,13,044,43,1*44
+$GLGSV,2,2,8,76,53,352,43,77,39,277,00,85,09,055,41,86,08,112,00,1*49
+$GNGST,015906.000,0.55,8.42,1.36,81.36,32.417,7.258,13.592*43
+$GNSVD,0,2,0,407,84,79*4B
+$GNRMC,015907.000,A,3121.576167,N,12042.869218,E,0.058,344.47,080126,,E,A,V*79
+$GNGGA,015907.000,3121.576167,N,12042.869218,E,1,17,1.09,51.827,M,0.000,M,,*73
+$GPGSA,A,3,04,26,28,29,31,32,,,,,,,1.54,1.09,1.08,1*1C
+$GBGSA,A,3,06,24,26,35,39,41,,,,,,,1.54,1.09,1.08,4*04
+$GAGSA,A,3,09,,,,,,,,,,,,1.54,1.09,1.08,3*04
+$GLGSA,A,3,67,75,76,85,,,,,,,,,1.54,1.09,1.08,2*0E
+$GPGSV,3,1,9,03,24,284,00,04,16,319,38,16,47,239,00,26,74,311,29,1*54
+$GPGSV,3,2,9,27,11,189,00,28,50,056,43,29,23,053,45,31,59,358,39,1*55
+$GPGSV,3,3,9,32,34,146,20,1*6A
+$GPGSV,3,1,9,03,24,284,00,04,16,319,36,16,47,239,00,26,74,311,31,8*5A
+$GPGSV,3,2,9,27,11,189,00,28,50,056,00,29,23,053,00,31,59,358,00,8*50
+$GPGSV,3,3,9,32,34,146,00,8*61
+$GBGSV,8,1,29,01,44,140,00,02,38,237,00,03,52,199,00,04,32,124,00,1*78
+$GBGSV,8,2,29,05,16,257,00,06,59,332,33,07,31,184,00,08,25,209,00,1*71
+$GBGSV,8,3,29,09,50,309,00,10,20,194,00,12,17,131,00,13,30,222,00,1*7A
+$GBGSV,8,4,29,14,50,202,00,24,59,014,39,25,37,278,00,26,22,058,40,1*77
+$GBGSV,8,5,29,33,58,250,00,34,12,157,00,35,11,059,40,38,17,196,00,1*70
+$GBGSV,8,6,29,39,62,002,35,40,29,169,00,41,28,312,37,42,29,177,00,1*7F
+$GBGSV,8,7,29,44,23,105,00,50,09,164,00,59,48,145,00,60,33,239,00,1*76
+$GBGSV,8,8,29,61,51,199,00,1*4F
+$GBGSV,4,1,13,24,59,014,39,25,37,278,00,26,22,058,34,33,58,250,00,4*7B
+$GBGSV,4,2,13,34,12,157,00,35,11,059,36,38,17,196,00,39,62,002,37,4*74
+$GBGSV,4,3,13,40,29,169,00,41,28,312,29,42,29,177,00,44,23,105,00,4*7A
+$GBGSV,4,4,13,50,09,164,00,4*4E
+$GAGSV,2,1,5,04,69,130,00,06,81,329,00,09,54,320,38,19,13,135,00,7*44
+$GAGSV,2,2,5,31,78,255,00,7*79
+$GAGSV,2,1,5,04,69,130,00,06,81,329,00,09,54,320,40,19,13,135,00,1*4D
+$GAGSV,2,2,5,31,78,255,00,1*7F
+$GLGSV,2,1,8,65,39,176,00,66,72,275,00,67,21,329,35,75,13,044,44,1*43
+$GLGSV,2,2,8,76,53,352,43,77,39,277,00,85,09,055,41,86,08,112,00,1*49
+$GNGST,015907.000,0.74,8.46,1.36,81.39,32.556,7.267,13.652*4D
+$GNSVD,0,2,1,351,70,80*43
+$GNRMC,015908.000,A,3121.576274,N,12042.869205,E,0.037,270.24,080126,,E,A,V*71
+$GNGGA,015908.000,3121.576274,N,12042.869205,E,1,17,1.09,51.877,M,0.000,M,,*74
+$GPGSA,A,3,04,26,28,29,31,32,,,,,,,1.54,1.09,1.08,1*1C
+$GBGSA,A,3,06,24,26,35,39,41,,,,,,,1.54,1.09,1.08,4*04
+$GAGSA,A,3,09,,,,,,,,,,,,1.54,1.09,1.08,3*04
+$GLGSA,A,3,67,75,76,85,,,,,,,,,1.54,1.09,1.08,2*0E
+$GPGSV,3,1,9,03,24,284,00,04,16,319,38,16,47,239,00,26,74,311,29,1*54
+$GPGSV,3,2,9,27,11,189,00,28,50,056,43,29,23,053,44,31,59,358,39,1*54
+$GPGSV,3,3,9,32,34,146,20,1*6A
+$GPGSV,3,1,9,03,24,284,00,04,16,319,36,16,47,239,00,26,74,311,31,8*5A
+$GPGSV,3,2,9,27,11,189,00,28,50,056,00,29,23,053,00,31,59,358,00,8*50
+$GPGSV,3,3,9,32,34,146,00,8*61
+$GBGSV,8,1,29,01,44,140,00,02,38,237,00,03,52,199,00,04,32,124,00,1*78
+$GBGSV,8,2,29,05,16,257,00,06,59,332,33,07,31,184,00,08,25,209,00,1*71
+$GBGSV,8,3,29,09,50,309,00,10,20,194,00,12,17,131,00,13,30,222,00,1*7A
+$GBGSV,8,4,29,14,50,202,00,24,59,014,39,25,37,278,00,26,22,058,40,1*77
+$GBGSV,8,5,29,33,58,250,00,34,12,157,00,35,11,059,40,38,17,196,00,1*70
+$GBGSV,8,6,29,39,62,002,35,40,29,169,00,41,28,312,37,42,29,177,00,1*7F
+$GBGSV,8,7,29,44,23,105,00,50,09,164,00,59,48,145,00,60,33,239,00,1*76
+$GBGSV,8,8,29,61,51,199,00,1*4F
+$GBGSV,4,1,13,24,59,014,38,25,37,278,00,26,22,058,34,33,58,250,00,4*7A
+$GBGSV,4,2,13,34,12,157,00,35,11,059,36,38,17,196,00,39,62,002,37,4*74
+$GBGSV,4,3,13,40,29,169,00,41,28,312,29,42,29,177,00,44,23,105,00,4*7A
+$GBGSV,4,4,13,50,09,164,00,4*4E
+$GAGSV,2,1,5,04,69,130,00,06,81,329,00,09,54,320,38,19,13,135,00,7*44
+$GAGSV,2,2,5,31,78,255,00,7*79
+$GAGSV,2,1,5,04,69,130,00,06,81,329,00,09,54,320,39,19,13,135,00,1*43
+$GAGSV,2,2,5,31,78,255,00,1*7F
+$GLGSV,2,1,8,65,39,176,00,66,72,275,00,67,21,329,35,75,13,044,43,1*44
+$GLGSV,2,2,8,76,53,352,43,77,39,277,00,85,09,055,41,86,08,112,00,1*49
+$GNGST,015908.000,0.73,8.42,1.35,81.41,32.460,7.222,13.595*40
+$GNSVD,-1,0,8,345,70,74*6A
+$GNRMC,015909.000,A,3121.576447,N,12042.869168,E,0.038,223.29,080126,,E,A,V*7A
+$GNGGA,015909.000,3121.576447,N,12042.869168,E,1,17,1.09,51.981,M,0.000,M,,*73
+$GPGSA,A,3,04,26,28,29,31,32,,,,,,,1.54,1.09,1.08,1*1C
+$GBGSA,A,3,06,24,26,35,39,41,,,,,,,1.54,1.09,1.08,4*04
+$GAGSA,A,3,09,,,,,,,,,,,,1.54,1.09,1.08,3*04
+$GLGSA,A,3,67,75,76,85,,,,,,,,,1.54,1.09,1.08,2*0E
+$GPGSV,3,1,9,03,24,284,00,04,16,319,39,16,47,239,00,26,74,311,30,1*5D
+$GPGSV,3,2,9,27,11,189,00,28,50,056,43,29,23,053,44,31,59,358,39,1*54
+$GPGSV,3,3,9,32,34,146,20,1*6A
+$GPGSV,3,1,9,03,24,284,00,04,16,319,36,16,47,239,00,26,74,311,31,8*5A
+$GPGSV,3,2,9,27,11,189,00,28,50,056,00,29,23,053,00,31,59,358,00,8*50
+$GPGSV,3,3,9,32,34,146,00,8*61
+$GBGSV,8,1,29,01,44,140,00,02,38,237,00,03,52,199,00,04,32,124,00,1*78
+$GBGSV,8,2,29,05,16,257,00,06,59,332,33,07,31,184,00,08,25,209,00,1*71
+$GBGSV,8,3,29,09,50,309,00,10,20,194,00,12,17,131,00,13,30,222,00,1*7A
+$GBGSV,8,4,29,14,50,202,00,24,59,014,39,25,37,278,00,26,22,058,40,1*77
+$GBGSV,8,5,29,33,58,250,00,34,12,157,00,35,11,059,40,38,17,196,00,1*70
+$GBGSV,8,6,29,39,62,002,35,40,29,169,00,41,28,312,37,42,29,177,00,1*7F
+$GBGSV,8,7,29,44,23,105,00,50,09,164,00,59,48,145,00,60,33,239,00,1*76
+$GBGSV,8,8,29,61,51,199,00,1*4F
+$GBGSV,4,1,13,24,59,014,39,25,37,278,00,26,22,058,34,33,58,250,00,4*7B
+$GBGSV,4,2,13,34,12,157,00,35,11,059,36,38,17,196,00,39,62,002,37,4*74
+$GBGSV,4,3,13,40,29,169,00,41,28,312,29,42,29,177,00,44,23,105,00,4*7A
+$GBGSV,4,4,13,50,09,164,00,4*4E
+$GAGSV,2,1,5,04,69,130,00,06,81,329,00,09,54,320,38,19,13,135,00,7*44
+$GAGSV,2,2,5,31,78,255,00,7*79
+$GAGSV,2,1,5,04,69,130,00,06,81,329,00,09,54,320,40,19,13,135,00,1*4D
+$GAGSV,2,2,5,31,78,255,00,1*7F
+$GLGSV,2,1,8,65,39,176,00,66,72,275,00,67,21,329,35,75,13,044,44,1*43
+$GLGSV,2,2,8,76,53,352,43,77,39,277,00,85,09,055,41,86,08,112,00,1*49
+$GNGST,015909.000,0.79,8.42,1.35,81.34,32.445,7.223,13.571*45
+$GNSVD,-1,-1,10,379,80,76*7D
+$GNRMC,015910.000,A,3121.576443,N,12042.869180,E,0.053,156.87,080126,,E,A,V*78
+$GNGGA,015910.000,3121.576443,N,12042.869180,E,1,17,1.09,52.067,M,0.000,M,,*7B
+$GPGSA,A,3,04,26,28,29,31,32,,,,,,,1.54,1.09,1.08,1*1C
+$GBGSA,A,3,06,24,26,35,39,41,,,,,,,1.54,1.09,1.08,4*04
+$GAGSA,A,3,09,,,,,,,,,,,,1.54,1.09,1.08,3*04
+$GLGSA,A,3,67,75,76,85,,,,,,,,,1.54,1.09,1.08,2*0E
+$GPGSV,3,1,9,03,24,284,00,04,16,319,39,16,47,239,00,26,74,311,30,1*5D
+$GPGSV,3,2,9,27,11,189,00,28,50,056,43,29,23,053,44,31,59,358,39,1*54
+$GPGSV,3,3,9,32,34,146,19,1*60
+$GPGSV,3,1,9,03,24,284,00,04,16,319,37,16,47,239,00,26,74,311,31,8*5B
+$GPGSV,3,2,9,27,11,189,00,28,50,056,00,29,23,053,00,31,59,358,00,8*50
+$GPGSV,3,3,9,32,34,146,00,8*61
+$GBGSV,8,1,29,01,44,140,00,02,38,237,00,03,52,199,00,04,32,124,00,1*78
+$GBGSV,8,2,29,05,16,257,00,06,59,332,33,07,31,184,00,08,25,209,00,1*71
+$GBGSV,8,3,29,09,50,309,00,10,20,194,00,12,17,131,00,13,30,222,00,1*7A
+$GBGSV,8,4,29,14,50,202,00,24,59,014,38,25,37,278,00,26,22,059,40,1*77
+$GBGSV,8,5,29,33,58,250,00,34,12,157,00,35,11,059,40,38,17,196,00,1*70
+$GBGSV,8,6,29,39,62,002,35,40,29,169,00,41,28,312,37,42,29,177,00,1*7F
+$GBGSV,8,7,29,44,23,105,00,50,09,164,00,59,48,145,00,60,33,239,00,1*76
+$GBGSV,8,8,29,61,51,199,00,1*4F
+$GBGSV,4,1,13,24,59,014,39,25,37,278,00,26,22,059,34,33,58,250,00,4*7A
+$GBGSV,4,2,13,34,12,157,00,35,11,059,37,38,17,196,00,39,62,002,37,4*75
+$GBGSV,4,3,13,40,29,169,00,41,28,312,29,42,29,177,00,44,23,105,00,4*7A
+$GBGSV,4,4,13,50,09,164,00,4*4E
+$GAGSV,2,1,5,04,69,130,00,06,81,329,00,09,54,320,38,19,13,135,00,7*44
+$GAGSV,2,2,5,31,78,255,00,7*79
+$GAGSV,2,1,5,04,69,130,00,06,81,329,00,09,54,320,40,19,13,135,00,1*4D
+$GAGSV,2,2,5,31,78,255,00,1*7F
+$GLGSV,2,1,8,65,39,176,00,66,72,275,00,67,21,329,35,75,13,044,44,1*43
+$GLGSV,2,2,8,76,53,352,42,77,39,277,00,85,09,055,41,86,08,112,00,1*48
+$GNGST,015910.000,0.96,8.50,1.36,81.36,32.672,7.253,13.641*4F
+$GNSVD,1,-2,8,400,77,78*65
+$GNRMC,015911.000,A,3121.576500,N,12042.869206,E,0.064,148.17,080126,,E,A,V*70
+$GNGGA,015911.000,3121.576500,N,12042.869206,E,1,17,1.09,52.146,M,0.000,M,,*73
+$GPGSA,A,3,04,26,28,29,31,32,,,,,,,1.54,1.09,1.08,1*1C
+$GBGSA,A,3,06,24,26,35,39,41,,,,,,,1.54,1.09,1.08,4*04
+$GAGSA,A,3,09,,,,,,,,,,,,1.54,1.09,1.08,3*04
+$GLGSA,A,3,67,75,76,85,,,,,,,,,1.54,1.09,1.08,2*0E
+$GPGSV,3,1,9,03,24,284,00,04,16,319,39,16,47,239,00,26,74,311,30,1*5D
+$GPGSV,3,2,9,27,11,189,00,28,50,056,43,29,23,053,45,31,59,358,40,1*5B
+$GPGSV,3,3,9,32,34,146,19,1*60
+$GPGSV,3,1,9,03,24,284,00,04,16,319,37,16,47,239,00,26,74,311,31,8*5B
+$GPGSV,3,2,9,27,11,189,00,28,50,056,00,29,23,053,00,31,59,358,00,8*50
+$GPGSV,3,3,9,32,34,146,00,8*61
+$GBGSV,8,1,29,01,44,140,00,02,38,237,00,03,52,199,00,04,32,124,00,1*78
+$GBGSV,8,2,29,05,16,257,00,06,59,332,33,07,31,184,00,08,25,209,00,1*71
+$GBGSV,8,3,29,09,50,309,00,10,20,194,00,12,17,131,00,13,30,222,00,1*7A
+$GBGSV,8,4,29,14,50,202,00,24,59,014,38,25,37,278,00,26,22,059,40,1*77
+$GBGSV,8,5,29,33,58,250,00,34,12,157,00,35,11,059,40,38,17,196,00,1*70
+$GBGSV,8,6,29,39,62,003,35,40,29,169,00,41,28,312,37,42,29,177,00,1*7E
+$GBGSV,8,7,29,44,23,105,00,50,09,164,00,59,48,145,00,60,33,239,00,1*76
+$GBGSV,8,8,29,61,51,199,00,1*4F
+$GBGSV,4,1,13,24,59,014,39,25,37,278,00,26,22,059,34,33,58,250,00,4*7A
+$GBGSV,4,2,13,34,12,157,00,35,11,059,37,38,17,196,00,39,62,003,37,4*74
+$GBGSV,4,3,13,40,29,169,00,41,28,312,29,42,29,177,00,44,23,105,00,4*7A
+$GBGSV,4,4,13,50,09,164,00,4*4E
+$GAGSV,2,1,5,04,69,130,00,06,81,329,00,09,54,320,38,19,13,135,00,7*44
+$GAGSV,2,2,5,31,78,255,00,7*79
+$GAGSV,2,1,5,04,69,130,00,06,81,329,00,09,54,320,40,19,13,135,00,1*4D
+$GAGSV,2,2,5,31,78,255,00,1*7F
+$GLGSV,2,1,8,65,39,176,00,66,72,275,00,67,21,329,34,75,13,044,43,1*45
+$GLGSV,2,2,8,76,53,352,43,77,39,277,00,85,09,055,41,86,08,112,00,1*49
+$GNGST,015911.000,0.75,8.51,1.34,81.40,32.724,7.216,13.607*40
+$GNSVD,1,-2,6,394,71,77*68
+$GNRMC,015912.000,A,3121.576672,N,12042.869211,E,0.050,221.67,080126,,E,A,V*7F
+$GNGGA,015912.000,3121.576672,N,12042.869211,E,1,17,1.09,52.182,M,0.000,M,,*78
+$GPGSA,A,3,04,26,28,29,31,32,,,,,,,1.54,1.09,1.08,1*1C
+$GBGSA,A,3,06,24,26,35,39,41,,,,,,,1.54,1.09,1.08,4*04
+$GAGSA,A,3,09,,,,,,,,,,,,1.54,1.09,1.08,3*04
+$GLGSA,A,3,67,75,76,85,,,,,,,,,1.54,1.09,1.08,2*0E
+$GPGSV,3,1,9,03,24,284,00,04,16,319,39,16,47,239,00,26,74,311,30,1*5D
+$GPGSV,3,2,9,27,11,189,00,28,50,056,43,29,23,053,44,31,59,358,40,1*5A
+$GPGSV,3,3,9,32,34,146,20,1*6A
+$GPGSV,3,1,9,03,24,284,00,04,16,319,37,16,47,239,00,26,74,311,31,8*5B
+$GPGSV,3,2,9,27,11,189,00,28,50,056,00,29,23,053,00,31,59,358,00,8*50
+$GPGSV,3,3,9,32,34,146,00,8*61
+$GBGSV,8,1,29,01,44,140,00,02,38,237,00,03,52,199,00,04,32,124,00,1*78
+$GBGSV,8,2,29,05,16,257,00,06,59,332,33,07,31,184,00,08,25,209,00,1*71
+$GBGSV,8,3,29,09,50,309,00,10,20,194,00,12,17,131,00,13,30,222,00,1*7A
+$GBGSV,8,4,29,14,50,202,00,24,59,014,38,25,37,278,00,26,22,059,40,1*77
+$GBGSV,8,5,29,33,58,250,00,34,12,157,00,35,11,058,40,38,17,196,00,1*71
+$GBGSV,8,6,29,39,62,003,35,40,29,169,00,41,28,312,37,42,29,177,00,1*7E
+$GBGSV,8,7,29,44,23,105,00,50,09,164,00,59,48,145,00,60,33,239,00,1*76
+$GBGSV,8,8,29,61,51,199,00,1*4F
+$GBGSV,4,1,13,24,59,014,38,25,37,278,00,26,22,059,34,33,58,250,00,4*7B
+$GBGSV,4,2,13,34,12,157,00,35,11,058,37,38,17,196,00,39,62,003,37,4*75
+$GBGSV,4,3,13,40,29,169,00,41,28,312,29,42,29,177,00,44,23,105,00,4*7A
+$GBGSV,4,4,13,50,09,164,00,4*4E
+$GAGSV,2,1,5,04,69,130,00,06,81,329,00,09,54,320,38,19,13,135,00,7*44
+$GAGSV,2,2,5,31,78,255,00,7*79
+$GAGSV,2,1,5,04,69,130,00,06,81,329,00,09,54,320,40,19,13,135,00,1*4D
+$GAGSV,2,2,5,31,78,255,00,1*7F
+$GLGSV,2,1,8,65,39,176,00,66,72,275,00,67,21,329,34,75,13,044,43,1*45
+$GLGSV,2,2,8,76,53,352,43,77,39,277,00,85,09,055,41,86,08,112,00,1*49
+$GNGST,015912.000,0.81,8.56,1.33,81.41,32.863,7.193,13.598*4E
+$GNSVD,-1,-1,2,463,81,80*4A
+$GNRMC,015913.000,A,3121.576893,N,12042.869268,E,0.038,116.71,080126,,E,A,V*7F
+$GNGGA,015913.000,3121.576893,N,12042.869268,E,1,17,1.09,52.385,M,0.000,M,,*73
+$GPGSA,A,3,04,26,28,29,31,32,,,,,,,1.54,1.09,1.08,1*1C
+$GBGSA,A,3,06,24,26,35,39,41,,,,,,,1.54,1.09,1.08,4*04
+$GAGSA,A,3,09,,,,,,,,,,,,1.54,1.09,1.08,3*04
+$GLGSA,A,3,67,75,76,85,,,,,,,,,1.54,1.09,1.08,2*0E
+$GPGSV,3,1,9,03,24,284,00,04,16,319,39,16,47,239,00,26,74,311,30,1*5D
+$GPGSV,3,2,9,27,11,189,00,28,50,056,43,29,23,053,45,31,59,358,39,1*55
+$GPGSV,3,3,9,32,34,146,21,1*6B
+$GPGSV,3,1,9,03,24,284,00,04,16,319,37,16,47,239,00,26,74,311,31,8*5B
+$GPGSV,3,2,9,27,11,189,00,28,50,056,00,29,23,053,00,31,59,358,00,8*50
+$GPGSV,3,3,9,32,34,146,00,8*61
+$GBGSV,8,1,29,01,44,140,00,02,38,237,00,03,52,199,00,04,32,124,00,1*78
+$GBGSV,8,2,29,05,16,257,00,06,59,332,33,07,31,184,00,08,25,209,00,1*71
+$GBGSV,8,3,29,09,50,309,00,10,20,194,00,12,17,131,00,13,30,222,00,1*7A
+$GBGSV,8,4,29,14,50,202,00,24,59,014,38,25,37,278,00,26,22,059,40,1*77
+$GBGSV,8,5,29,33,58,250,00,34,12,157,00,35,11,058,40,38,17,196,00,1*71
+$GBGSV,8,6,29,39,62,003,35,40,29,169,00,41,28,312,37,42,29,177,00,1*7E
+$GBGSV,8,7,29,44,23,105,00,50,09,164,00,59,48,145,00,60,33,239,00,1*76
+$GBGSV,8,8,29,61,51,199,00,1*4F
+$GBGSV,4,1,13,24,59,014,39,25,37,278,00,26,22,059,34,33,58,250,00,4*7A
+$GBGSV,4,2,13,34,12,157,00,35,11,058,37,38,17,196,00,39,62,003,37,4*75
+$GBGSV,4,3,13,40,29,169,00,41,28,312,29,42,29,177,00,44,23,105,00,4*7A
+$GBGSV,4,4,13,50,09,164,00,4*4E
+$GAGSV,2,1,5,04,69,130,00,06,81,329,00,09,54,320,38,19,13,135,00,7*44
+$GAGSV,2,2,5,31,78,255,00,7*79
+$GAGSV,2,1,5,04,69,130,00,06,81,329,00,09,54,320,40,19,13,135,00,1*4D
+$GAGSV,2,2,5,31,78,255,00,1*7F
+$GLGSV,2,1,8,65,39,176,00,66,72,275,00,67,21,329,34,75,13,044,43,1*45
+$GLGSV,2,2,8,76,53,352,43,77,39,277,00,85,09,055,41,86,08,112,00,1*49
+$GNGST,015913.000,0.85,8.57,1.32,81.45,32.915,7.164,13.564*44
+$GNSVD,1,0,3,396,70,75*43
+$GNRMC,015914.000,A,3121.576888,N,12042.869261,E,0.042,124.95,080126,,E,A,V*7D
+$GNGGA,015914.000,3121.576888,N,12042.869261,E,1,17,1.09,52.400,M,0.000,M,,*7D
+$GPGSA,A,3,04,26,28,29,31,32,,,,,,,1.54,1.09,1.08,1*1C
+$GBGSA,A,3,06,24,26,35,39,41,,,,,,,1.54,1.09,1.08,4*04
+$GAGSA,A,3,09,,,,,,,,,,,,1.54,1.09,1.08,3*04
+$GLGSA,A,3,67,75,76,85,,,,,,,,,1.54,1.09,1.08,2*0E
+$GPGSV,3,1,9,03,24,284,00,04,16,319,39,16,47,239,00,26,74,311,29,1*55
+$GPGSV,3,2,9,27,11,189,00,28,50,056,43,29,23,053,45,31,59,358,40,1*5B
+$GPGSV,3,3,9,32,34,146,22,1*68
+$GPGSV,3,1,9,03,24,284,00,04,16,319,37,16,47,239,00,26,74,311,31,8*5B
+$GPGSV,3,2,9,27,11,189,00,28,50,056,00,29,23,053,00,31,59,358,00,8*50
+$GPGSV,3,3,9,32,34,146,00,8*61
+$GBGSV,8,1,29,01,44,140,00,02,38,237,00,03,52,199,00,04,32,124,00,1*78
+$GBGSV,8,2,29,05,16,257,00,06,59,332,33,07,31,184,00,08,25,209,00,1*71
+$GBGSV,8,3,29,09,50,309,00,10,20,194,00,12,17,131,00,13,30,222,00,1*7A
+$GBGSV,8,4,29,14,50,202,00,24,59,014,38,25,37,278,00,26,22,059,40,1*77
+$GBGSV,8,5,29,33,58,250,00,34,12,157,00,35,11,058,40,38,17,196,00,1*71
+$GBGSV,8,6,29,39,62,003,35,40,29,169,00,41,28,312,37,42,29,177,00,1*7E
+$GBGSV,8,7,29,44,23,105,00,50,09,164,00,59,48,145,00,60,33,239,00,1*76
+$GBGSV,8,8,29,61,51,199,00,1*4F
+$GBGSV,4,1,13,24,59,014,39,25,37,278,00,26,22,059,34,33,58,250,00,4*7A
+$GBGSV,4,2,13,34,12,157,00,35,11,058,37,38,17,196,00,39,62,003,37,4*75
+$GBGSV,4,3,13,40,29,169,00,41,28,312,29,42,29,177,00,44,23,105,00,4*7A
+$GBGSV,4,4,13,50,09,164,00,4*4E
+$GAGSV,2,1,5,04,69,130,00,06,81,329,00,09,54,320,38,19,13,135,00,7*44
+$GAGSV,2,2,5,31,78,255,00,7*79
+$GAGSV,2,1,5,04,69,130,00,06,81,329,00,09,54,320,39,19,13,135,00,1*43
+$GAGSV,2,2,5,31,78,255,00,1*7F
+$GLGSV,2,1,8,65,39,176,00,66,72,275,00,67,21,329,35,75,13,044,43,1*44
+$GLGSV,2,2,8,76,53,352,43,77,39,277,00,85,09,055,41,86,08,112,00,1*49
+$GNGST,015914.000,1.04,8.64,1.32,81.48,33.129,7.180,13.627*4E
+$GNSVD,1,-1,2,115,20,22*60
+$GNRMC,015915.000,A,3121.576930,N,12042.869269,E,0.082,170.97,080126,,E,A,V*79
+$GNGGA,015915.000,3121.576930,N,12042.869269,E,1,17,1.09,52.478,M,0.000,M,,*79
+$GPGSA,A,3,04,26,28,29,31,32,,,,,,,1.54,1.09,1.08,1*1C
+$GBGSA,A,3,06,24,26,35,39,41,,,,,,,1.54,1.09,1.08,4*04
+$GAGSA,A,3,09,,,,,,,,,,,,1.54,1.09,1.08,3*04
+$GLGSA,A,3,67,75,76,85,,,,,,,,,1.54,1.09,1.08,2*0E
+$GPGSV,3,1,9,03,24,284,00,04,16,319,39,16,47,239,00,26,74,311,30,1*5D
+$GPGSV,3,2,9,27,11,189,00,28,50,056,43,29,23,053,45,31,59,358,40,1*5B
+$GPGSV,3,3,9,32,34,146,23,1*69
+$GPGSV,3,1,9,03,24,284,00,04,16,319,37,16,47,239,00,26,74,311,31,8*5B
+$GPGSV,3,2,9,27,11,189,00,28,50,056,00,29,23,053,00,31,59,358,00,8*50
+$GPGSV,3,3,9,32,34,146,00,8*61
+$GBGSV,8,1,29,01,44,140,00,02,38,237,00,03,52,199,00,04,32,124,00,1*78
+$GBGSV,8,2,29,05,16,257,00,06,59,332,33,07,31,184,00,08,25,209,00,1*71
+$GBGSV,8,3,29,09,50,309,00,10,20,194,00,12,17,131,00,13,30,222,00,1*7A
+$GBGSV,8,4,29,14,50,202,00,24,59,014,38,25,37,278,00,26,22,059,40,1*77
+$GBGSV,8,5,29,33,58,250,00,34,12,157,00,35,11,058,40,38,17,196,00,1*71
+$GBGSV,8,6,29,39,62,003,35,40,29,169,00,41,28,312,37,42,29,177,00,1*7E
+$GBGSV,8,7,29,44,23,105,00,50,09,164,00,59,48,145,00,60,33,239,00,1*76
+$GBGSV,8,8,29,61,51,199,00,1*4F
+$GBGSV,4,1,13,24,59,014,38,25,37,278,00,26,22,059,34,33,58,250,00,4*7B
+$GBGSV,4,2,13,34,12,157,00,35,11,058,37,38,17,196,00,39,62,003,37,4*75
+$GBGSV,4,3,13,40,29,169,00,41,28,312,29,42,29,177,00,44,23,105,00,4*7A
+$GBGSV,4,4,13,50,09,164,00,4*4E
+$GAGSV,2,1,5,04,69,130,00,06,81,329,00,09,54,320,38,19,13,135,00,7*44
+$GAGSV,2,2,5,31,78,255,00,7*79
+$GAGSV,2,1,5,04,69,130,00,06,81,329,00,09,54,320,39,19,13,135,00,1*43
+$GAGSV,2,2,5,31,78,255,00,1*7F
+$GLGSV,2,1,8,65,39,176,00,66,72,275,00,67,21,329,35,75,13,044,43,1*44
+$GLGSV,2,2,8,76,53,352,43,77,39,277,00,85,09,055,41,86,08,112,00,1*49
+$GNGST,015915.000,1.04,8.66,1.32,81.53,33.219,7.158,13.611*47
+$GNSVD,0,-4,0,372,67,69*69
+$GNRMC,015916.000,A,3121.576981,N,12042.869285,E,0.093,164.37,080126,,E,A,V*7D
+$GNGGA,015916.000,3121.576981,N,12042.869285,E,1,17,1.09,52.469,M,0.000,M,,*72
+$GPGSA,A,3,04,26,28,29,31,32,,,,,,,1.54,1.09,1.08,1*1C
+$GBGSA,A,3,06,24,26,35,39,41,,,,,,,1.54,1.09,1.08,4*04
+$GAGSA,A,3,09,,,,,,,,,,,,1.54,1.09,1.08,3*04
+$GLGSA,A,3,67,75,76,85,,,,,,,,,1.54,1.09,1.08,2*0E
+$GPGSV,3,1,9,03,24,284,00,04,16,319,38,16,47,239,00,26,74,311,29,1*54
+$GPGSV,3,2,9,27,11,189,00,28,50,056,42,29,23,053,45,31,59,358,39,1*54
+$GPGSV,3,3,9,32,34,146,23,1*69
+$GPGSV,3,1,9,03,24,284,00,04,16,319,37,16,47,239,00,26,74,311,31,8*5B
+$GPGSV,3,2,9,27,11,189,00,28,50,056,00,29,23,053,00,31,59,358,00,8*50
+$GPGSV,3,3,9,32,34,146,00,8*61
+$GBGSV,8,1,29,01,44,140,00,02,38,237,00,03,52,199,00,04,32,124,00,1*78
+$GBGSV,8,2,29,05,16,257,00,06,59,332,33,07,31,184,00,08,25,209,00,1*71
+$GBGSV,8,3,29,09,50,309,00,10,20,194,00,12,17,131,00,13,30,222,00,1*7A
+$GBGSV,8,4,29,14,50,202,00,24,59,014,38,25,37,278,00,26,22,059,40,1*77
+$GBGSV,8,5,29,33,58,250,00,34,12,157,00,35,11,058,40,38,17,196,00,1*71
+$GBGSV,8,6,29,39,62,003,35,40,29,169,00,41,28,312,37,42,29,177,00,1*7E
+$GBGSV,8,7,29,44,23,104,00,50,09,164,00,59,48,145,00,60,33,239,00,1*77
+$GBGSV,8,8,29,61,51,199,00,1*4F
+$GBGSV,4,1,13,24,59,014,39,25,37,278,00,26,22,059,34,33,58,250,00,4*7A
+$GBGSV,4,2,13,34,12,157,00,35,11,058,36,38,17,196,00,39,62,003,37,4*74
+$GBGSV,4,3,13,40,29,169,00,41,28,312,29,42,29,177,00,44,23,104,00,4*7B
+$GBGSV,4,4,13,50,09,164,00,4*4E
+$GAGSV,2,1,5,04,69,130,00,06,81,329,00,09,54,320,38,19,13,135,00,7*44
+$GAGSV,2,2,5,31,78,255,00,7*79
+$GAGSV,2,1,5,04,69,130,00,06,81,329,00,09,54,320,39,19,13,135,00,1*43
+$GAGSV,2,2,5,31,78,255,00,1*7F
+$GLGSV,2,1,8,65,39,176,00,66,72,274,00,67,21,329,35,75,13,044,43,1*45
+$GLGSV,2,2,8,76,53,352,43,77,39,277,00,85,09,055,41,86,08,112,00,1*49
+$GNGST,015916.000,1.05,8.75,1.31,81.60,33.492,7.151,13.627*4D
+$GNSVD,1,-4,-1,478,76,80*4E
--- a/backend/tests/mqtt/test_mixed_parser.py
+++ b/backend/tests/mqtt/test_mixed_parser.py
@@ -25,3 +25,24 @@ def test_parse_mixed_payload_returns_rtcm_summary() -> None:

    event_types = {event["event_type"] for event in events}
    assert "rtcm_summary" in event_types
+
+
+def test_parse_nmea_sentences_extracts_satellite_details_and_used_ids() -> None:
+    payload = (
+        b"$GPGSA,A,3,02,05,12,,,,,,,,,,1.50,0.90,1.20*00\r\n"
+        b"$GPGSV,1,1,04,02,17,213,40,05,29,121,37,12,66,314,44,25,14,048,39*71\r\n"
+    )
+
+    events = parse_nmea_sentences(payload)
+    gsa_event = next(event for event in events if event["event_type"] == "nmea_gsa")
+    gsv_event = next(event for event in events if event["event_type"] == "nmea_gsv")
+
+    assert gsa_event["payload"]["used_satellite_ids"] == ["02", "05", "12"]
+    assert gsv_event["payload"]["constellation"] == "GPS"
+    assert len(gsv_event["payload"]["satellites"]) == 4
+    assert gsv_event["payload"]["satellites"][0] == {
+        "satellite_id": "02",
+        "elevation_deg": 17,
+        "azimuth_deg": 213,
+        "snr_dbhz": 40,
+    }
--- a/backend/tests/mqtt/test_parser_worker.py
+++ b/backend/tests/mqtt/test_parser_worker.py
@@ -85,3 +85,65 @@ def test_worker_marks_failed_without_retry_schedule(monkeypatch) -> None:

 def test_schema_excludes_terminal_observation_event_table() -> None:
    assert "terminal_observation_event" not in SQLModel.metadata.tables
+
+
+def test_ingest_and_parse_real_nmea_sample() -> None:
+    from pathlib import Path
+
+    sample_path = Path(__file__).parent / "nmea.txt"
+    payload = sample_path.read_bytes()
+
+    with _session() as session:
+        raw = insert_raw_message(
+            session=session,
+            device_id="device-real-sample",
+            topic="terminal/device-real-sample/raw",
+            payload=payload,
+            qos=1,
+            retain=False,
+        )
+
+        processed = process_pending_batch(session=session, batch_size=10)
+        assert processed == 1
+
+        refreshed = session.get(TerminalMessageRaw, raw.id)
+        assert refreshed is not None
+        assert refreshed.parsed_at is not None
+        assert refreshed.parse_error is None
+
+        state = session.get(TerminalDeviceState, "device-real-sample")
+        assert state is not None
+        assert state.lat is not None
+        assert state.lon is not None
+
+
+def test_worker_builds_satellite_distribution_summary() -> None:
+    payload = (
+        b"$GNGGA,123519,3723.2475,N,12158.3416,W,4,12,0.8,10.0,M,-25.0,M,,*65\r\n"
+        b"$GPGSA,A,3,02,05,12,,,,,,,,,,1.50,0.90,1.20*00\r\n"
+        b"$GPGSV,1,1,04,02,17,213,40,05,29,121,37,12,66,314,44,25,14,048,39*71\r\n"
+    )
+
+    with _session() as session:
+        insert_raw_message(
+            session=session,
+            device_id="device-gsv",
+            topic="terminal/device-gsv/raw",
+            payload=payload,
+            qos=1,
+            retain=False,
+        )
+
+        processed = process_pending_batch(session=session, batch_size=10)
+
+        assert processed == 1
+        state = session.get(TerminalDeviceState, "device-gsv")
+        assert state is not None
+        assert state.fix_status == "4"
+        summary = state.satellite_signal_summary
+        assert summary is not None
+        assert summary["satellites_in_view"] == 4
+        assert summary["snr_values"] == [40, 37, 44, 39]
+        assert summary["used_satellite_ids"] == ["02", "05", "12"]
+        assert summary["constellations"]["GPS"]["count"] == 4
+        assert summary["constellations"]["GPS"]["used_in_navigation"] == 3
--- a/frontend/src/client/sdk.gen.ts
+++ b/frontend/src/client/sdk.gen.ts
@@ -3,7 +3,7 @@
 import type { CancelablePromise } from './core/CancelablePromise';
 import { OpenAPI } from './core/OpenAPI';
 import { request as __request } from './core/request';
-import type { LocationsReadLocationsData, LocationsReadLocationsResponse, LocationsCreateLocationData, LocationsCreateLocationResponse, LocationsReadLocationData, LocationsReadLocationResponse, LocationsUpdateLocationData, LocationsUpdateLocationResponse, LocationsDeleteLocationData, LocationsDeleteLocationResponse, LoginLoginAccessTokenData, LoginLoginAccessTokenResponse, LoginTestTokenResponse, LoginRecoverPasswordData, LoginRecoverPasswordResponse, LoginResetPasswordData, LoginResetPasswordResponse, LoginRecoverPasswordHtmlContentData, LoginRecoverPasswordHtmlContentResponse, PrivateCreateUserData, PrivateCreateUserResponse, UsersReadUsersData, UsersReadUsersResponse, UsersCreateUserData, UsersCreateUserResponse, UsersReadUserMeResponse, UsersDeleteUserMeResponse, UsersUpdateUserMeData, UsersUpdateUserMeResponse, UsersUpdatePasswordMeData, UsersUpdatePasswordMeResponse, UsersRegisterUserData, UsersRegisterUserResponse, UsersReadUserByIdData, UsersReadUserByIdResponse, UsersUpdateUserData, UsersUpdateUserResponse, UsersDeleteUserData, UsersDeleteUserResponse, UtilsTestEmailData, UtilsTestEmailResponse, UtilsHealthCheckResponse } from './types.gen';
+import type { LocationsReadLocationsData, LocationsReadLocationsResponse, LocationsCreateLocationData, LocationsCreateLocationResponse, LocationsReadLocationData, LocationsReadLocationResponse, LocationsUpdateLocationData, LocationsUpdateLocationResponse, LocationsDeleteLocationData, LocationsDeleteLocationResponse, LoginLoginAccessTokenData, LoginLoginAccessTokenResponse, LoginTestTokenResponse, LoginRecoverPasswordData, LoginRecoverPasswordResponse, LoginResetPasswordData, LoginResetPasswordResponse, LoginRecoverPasswordHtmlContentData, LoginRecoverPasswordHtmlContentResponse, PrivateCreateUserData, PrivateCreateUserResponse, TelemetryReadTelemetryLatestData, TelemetryReadTelemetryLatestResponse, UsersReadUsersData, UsersReadUsersResponse, UsersCreateUserData, UsersCreateUserResponse, UsersReadUserMeResponse, UsersDeleteUserMeResponse, UsersUpdateUserMeData, UsersUpdateUserMeResponse, UsersUpdatePasswordMeData, UsersUpdatePasswordMeResponse, UsersRegisterUserData, UsersRegisterUserResponse, UsersReadUserByIdData, UsersReadUserByIdResponse, UsersUpdateUserData, UsersUpdateUserResponse, UsersDeleteUserData, UsersDeleteUserResponse, UtilsTestEmailData, UtilsTestEmailResponse, UtilsHealthCheckResponse } from './types.gen';

 export class LocationsService {
    /**
@@ -235,6 +235,31 @@ export class PrivateService {
    }
 }

+export class TelemetryService {
+    /**
+     * Read Telemetry Latest
+     * Return the latest parsed GNSS telemetry snapshot.
+     * @param data The data for the request.
+     * @param data.deviceId
+     * @param data.limit
+     * @returns unknown Successful Response
+     * @throws ApiError
+     */
+    public static readTelemetryLatest(data: TelemetryReadTelemetryLatestData = {}): CancelablePromise<TelemetryReadTelemetryLatestResponse> {
+        return __request(OpenAPI, {
+            method: 'GET',
+            url: '/api/v1/telemetry/latest',
+            query: {
+                device_id: data.deviceId,
+                limit: data.limit
+            },
+            errors: {
+                422: 'Validation Error'
+            }
+        });
+    }
+}
+
 export class UsersService {
    /**
     * Read Users
--- a/frontend/src/client/types.gen.ts
+++ b/frontend/src/client/types.gen.ts
@@ -177,6 +177,15 @@ export type PrivateCreateUserData = {

 export type PrivateCreateUserResponse = (UserPublic);

+export type TelemetryReadTelemetryLatestData = {
+    deviceId?: (string | null);
+    limit?: number;
+};
+
+export type TelemetryReadTelemetryLatestResponse = ({
+    [key: string]: unknown;
+});
+
 export type UsersReadUsersData = {
    limit?: number;
    skip?: number;
--- a/frontend/src/components/Sidebar/AppSidebar.tsx
+++ b/frontend/src/components/Sidebar/AppSidebar.tsx
@@ -1,4 +1,4 @@
-import { Home, MapPin, Users } from "lucide-react"
+import { Home, MapPin, Satellite, Users } from "lucide-react"

 import { SidebarAppearance } from "@/components/Common/Appearance"
 import { Logo } from "@/components/Common/Logo"
@@ -15,6 +15,7 @@ import { User } from "./User"
 const baseItems: Item[] = [
  { icon: Home, title: "Dashboard", path: "/" },
  { icon: MapPin, title: "Locations", path: "/locations" },
+  { icon: Satellite, title: "GNSS Monitor", path: "/gnss-monitor" },
 ]

 export function AppSidebar() {
--- a/frontend/src/routeTree.gen.ts
+++ b/frontend/src/routeTree.gen.ts
@@ -17,6 +17,7 @@ import { Route as LayoutRouteImport } from './routes/_layout'
 import { Route as LayoutIndexRouteImport } from './routes/_layout/index'
 import { Route as LayoutSettingsRouteImport } from './routes/_layout/settings'
 import { Route as LayoutLocationsRouteImport } from './routes/_layout/locations'
+import { Route as LayoutGnssMonitorRouteImport } from './routes/_layout/gnss-monitor'
 import { Route as LayoutAdminRouteImport } from './routes/_layout/admin'

 const SignupRoute = SignupRouteImport.update({
@@ -58,6 +59,11 @@ const LayoutLocationsRoute = LayoutLocationsRouteImport.update({
  path: '/locations',
  getParentRoute: () => LayoutRoute,
 } as any)
+const LayoutGnssMonitorRoute = LayoutGnssMonitorRouteImport.update({
+  id: '/gnss-monitor',
+  path: '/gnss-monitor',
+  getParentRoute: () => LayoutRoute,
+} as any)
 const LayoutAdminRoute = LayoutAdminRouteImport.update({
  id: '/admin',
  path: '/admin',
@@ -71,6 +77,7 @@ export interface FileRoutesByFullPath {
  '/reset-password': typeof ResetPasswordRoute
  '/signup': typeof SignupRoute
  '/admin': typeof LayoutAdminRoute
+  '/gnss-monitor': typeof LayoutGnssMonitorRoute
  '/locations': typeof LayoutLocationsRoute
  '/settings': typeof LayoutSettingsRoute
 }
@@ -80,6 +87,7 @@ export interface FileRoutesByTo {
  '/reset-password': typeof ResetPasswordRoute
  '/signup': typeof SignupRoute
  '/admin': typeof LayoutAdminRoute
+  '/gnss-monitor': typeof LayoutGnssMonitorRoute
  '/locations': typeof LayoutLocationsRoute
  '/settings': typeof LayoutSettingsRoute
  '/': typeof LayoutIndexRoute
@@ -92,6 +100,7 @@ export interface FileRoutesById {
  '/reset-password': typeof ResetPasswordRoute
  '/signup': typeof SignupRoute
  '/_layout/admin': typeof LayoutAdminRoute
+  '/_layout/gnss-monitor': typeof LayoutGnssMonitorRoute
  '/_layout/locations': typeof LayoutLocationsRoute
  '/_layout/settings': typeof LayoutSettingsRoute
  '/_layout/': typeof LayoutIndexRoute
@@ -105,6 +114,7 @@ export interface FileRouteTypes {
    | '/reset-password'
    | '/signup'
    | '/admin'
+    | '/gnss-monitor'
    | '/locations'
    | '/settings'
  fileRoutesByTo: FileRoutesByTo
@@ -114,6 +124,7 @@ export interface FileRouteTypes {
    | '/reset-password'
    | '/signup'
    | '/admin'
+    | '/gnss-monitor'
    | '/locations'
    | '/settings'
    | '/'
@@ -125,6 +136,7 @@ export interface FileRouteTypes {
    | '/reset-password'
    | '/signup'
    | '/_layout/admin'
+    | '/_layout/gnss-monitor'
    | '/_layout/locations'
    | '/_layout/settings'
    | '/_layout/'
@@ -196,6 +208,13 @@ declare module '@tanstack/react-router' {
      preLoaderRoute: typeof LayoutLocationsRouteImport
      parentRoute: typeof LayoutRoute
    }
+    '/_layout/gnss-monitor': {
+      id: '/_layout/gnss-monitor'
+      path: '/gnss-monitor'
+      fullPath: '/gnss-monitor'
+      preLoaderRoute: typeof LayoutGnssMonitorRouteImport
+      parentRoute: typeof LayoutRoute
+    }
    '/_layout/admin': {
      id: '/_layout/admin'
      path: '/admin'
@@ -208,6 +227,7 @@ declare module '@tanstack/react-router' {

 interface LayoutRouteChildren {
  LayoutAdminRoute: typeof LayoutAdminRoute
+  LayoutGnssMonitorRoute: typeof LayoutGnssMonitorRoute
  LayoutLocationsRoute: typeof LayoutLocationsRoute
  LayoutSettingsRoute: typeof LayoutSettingsRoute
  LayoutIndexRoute: typeof LayoutIndexRoute
@@ -215,6 +235,7 @@ interface LayoutRouteChildren {

 const LayoutRouteChildren: LayoutRouteChildren = {
  LayoutAdminRoute: LayoutAdminRoute,
+  LayoutGnssMonitorRoute: LayoutGnssMonitorRoute,
  LayoutLocationsRoute: LayoutLocationsRoute,
  LayoutSettingsRoute: LayoutSettingsRoute,
  LayoutIndexRoute: LayoutIndexRoute,
--- a/frontend/src/routes/_layout.tsx
+++ b/frontend/src/routes/_layout.tsx
@@ -1,4 +1,9 @@
-import { createFileRoute, Outlet, redirect } from "@tanstack/react-router"
+import {
+  createFileRoute,
+  Outlet,
+  redirect,
+  useRouterState,
+} from "@tanstack/react-router"

 import { Footer } from "@/components/Common/Footer"
 import AppSidebar from "@/components/Sidebar/AppSidebar"
@@ -21,6 +26,11 @@ export const Route = createFileRoute("/_layout")({
 })

 function Layout() {
+  const pathname = useRouterState({
+    select: (state) => state.location.pathname,
+  })
+  const isGnssMonitorPage = pathname === "/gnss-monitor"
+
  return (
    <SidebarProvider>
      <AppSidebar />
@@ -29,7 +39,9 @@ function Layout() {
          <SidebarTrigger className="-ml-1 text-muted-foreground" />
        </header>
        <main className="flex-1 p-6 md:p-8">
-          <div className="mx-auto max-w-7xl">
+          <div
+            className={`mx-auto ${isGnssMonitorPage ? "max-w-none" : "max-w-7xl"}`}
+          >
            <Outlet />
          </div>
        </main>
--- a/frontend/src/routes/_layout/gnss-monitor.tsx
+++ b/frontend/src/routes/_layout/gnss-monitor.tsx
@@ -0,0 +1,826 @@
+import { createFileRoute } from "@tanstack/react-router"
+import { Compass, Gauge, MapPin, Radio, Satellite, Signal } from "lucide-react"
+import { useEffect, useMemo, useState } from "react"
+
+import { Badge } from "@/components/ui/badge"
+import { Button } from "@/components/ui/button"
+import {
+  Card,
+  CardContent,
+  CardDescription,
+  CardHeader,
+  CardTitle,
+} from "@/components/ui/card"
+
+type SignalHealthLevel = "good" | "fair" | "poor" | "unknown"
+
+type SignalHealth = {
+  level: SignalHealthLevel
+  score: number
+  strong_signal_count?: number
+  average_snr_dbhz: number | null
+  best_snr_dbhz: number | null
+  message: string
+}
+
+type SatellitePoint = {
+  satellite_id: string
+  constellation: string
+  azimuth_deg: number | null
+  elevation_deg: number | null
+  snr_dbhz: number | null
+  used_in_navigation: boolean
+}
+
+type SatelliteSummary = {
+  satellites_in_view: number | null
+  snr_values: number[]
+  constellations: Record<
+    string,
+    { count?: number; with_signal?: number; used_in_navigation?: number }
+  >
+  used_satellite_ids: string[]
+  satellites: SatellitePoint[]
+}
+
+type TelemetryDevice = {
+  device_id: string
+  last_event_time: string | null
+  updated_at: string
+  fix_status: string | null
+  lat: number | null
+  lon: number | null
+  alt_m: number | null
+  satellites_used: number | null
+  satellite_signal_summary: SatelliteSummary
+  signal_health: SignalHealth
+}
+
+type TelemetrySnapshot = {
+  generated_at: string
+  devices: TelemetryDevice[]
+}
+
+const CONSTELLATION_COLORS: Record<string, string> = {
+  GPS: "#f59e0b",
+  SBAS: "#9ca3af",
+  BeiDou: "#8b5cf6",
+  Galileo: "#84cc16",
+  GLONASS: "#06b6d4",
+  QZSS: "#f97316",
+  NavIC: "#ec4899",
+  Mixed: "#64748b",
+  Unknown: "#94a3b8",
+}
+
+const CONSTELLATION_ORDER = [
+  "GPS",
+  "SBAS",
+  "Galileo",
+  "BeiDou",
+  "GLONASS",
+  "QZSS",
+  "NavIC",
+  "Mixed",
+  "Unknown",
+] as const
+
+const CONSTELLATION_PREFIX: Record<string, string> = {
+  GPS: "G",
+  SBAS: "S",
+  Galileo: "E",
+  BeiDou: "B",
+  GLONASS: "R",
+  QZSS: "Q",
+  NavIC: "I",
+  Mixed: "M",
+  Unknown: "U",
+}
+
+const SIGNAL_STATUS_CLASS: Record<SignalHealthLevel, string> = {
+  good: "text-emerald-500 bg-emerald-500/10 border-emerald-500/20",
+  fair: "text-amber-500 bg-amber-500/10 border-amber-500/20",
+  poor: "text-red-500 bg-red-500/10 border-red-500/20",
+  unknown: "text-muted-foreground bg-muted border-border",
+}
+
+const FIX_STATUS_META: Record<
+  string,
+  { label: string; className: string; description: string }
+> = {
+  "0": {
+    label: "No Fix",
+    className: "text-red-500 bg-red-500/10 border-red-500/20",
+    description: "No position solution",
+  },
+  "1": {
+    label: "Single",
+    className: "text-amber-500 bg-amber-500/10 border-amber-500/20",
+    description: "Standalone GNSS fix",
+  },
+  "2": {
+    label: "DGPS",
+    className: "text-sky-500 bg-sky-500/10 border-sky-500/20",
+    description: "Differential correction active",
+  },
+  "4": {
+    label: "RTK Fixed",
+    className: "text-emerald-500 bg-emerald-500/10 border-emerald-500/20",
+    description: "Carrier fixed solution",
+  },
+  "5": {
+    label: "RTK Float",
+    className: "text-orange-500 bg-orange-500/10 border-orange-500/20",
+    description: "Carrier float solution",
+  },
+  A: {
+    label: "Valid",
+    className: "text-sky-500 bg-sky-500/10 border-sky-500/20",
+    description: "Valid navigation status",
+  },
+  V: {
+    label: "Invalid",
+    className: "text-red-500 bg-red-500/10 border-red-500/20",
+    description: "Invalid navigation status",
+  },
+}
+
+export const Route = createFileRoute("/_layout/gnss-monitor")({
+  component: GnssMonitor,
+  head: () => ({
+    meta: [
+      {
+        title: "GNSS Monitor - FastAPI Template",
+      },
+    ],
+  }),
+})
+
+function buildTelemetryWsUrl(token: string): string {
+  const apiBase = (
+    import.meta.env.VITE_API_URL || window.location.origin
+  ).replace(/\/$/, "")
+  const wsBase = apiBase.startsWith("https://")
+    ? `wss://${apiBase.slice("https://".length)}`
+    : apiBase.startsWith("http://")
+      ? `ws://${apiBase.slice("http://".length)}`
+      : apiBase
+  return `${wsBase}/api/v1/telemetry/ws?token=${encodeURIComponent(token)}`
+}
+
+function formatCoord(value: number | null): string {
+  if (value === null) {
+    return "-"
+  }
+  return value.toFixed(6)
+}
+
+function formatTime(value: string | null): string {
+  if (!value) {
+    return "-"
+  }
+  return new Date(value).toLocaleTimeString()
+}
+
+function formatAge(value: string | null): string {
+  if (!value) {
+    return "-"
+  }
+  const diffSeconds = Math.max(
+    0,
+    Math.floor((Date.now() - new Date(value).getTime()) / 1000),
+  )
+  if (diffSeconds < 60) {
+    return `${diffSeconds}s`
+  }
+  const minutes = Math.floor(diffSeconds / 60)
+  const seconds = diffSeconds % 60
+  return `${minutes}m ${seconds}s`
+}
+
+function getFixMeta(fixStatus: string | null) {
+  if (!fixStatus) {
+    return {
+      label: "Unknown",
+      className: "text-muted-foreground bg-muted border-border",
+      description: "No fix state received yet",
+    }
+  }
+  return (
+    FIX_STATUS_META[fixStatus] ?? {
+      label: `Fix ${fixStatus}`,
+      className: "text-muted-foreground bg-muted border-border",
+      description: "Unrecognized fix code",
+    }
+  )
+}
+
+function satColor(constellation: string): string {
+  return CONSTELLATION_COLORS[constellation] ?? CONSTELLATION_COLORS.Unknown
+}
+
+function satPrefix(constellation: string): string {
+  return CONSTELLATION_PREFIX[constellation] ?? CONSTELLATION_PREFIX.Unknown
+}
+
+function satelliteSortValue(satelliteId: string): number {
+  const digits = satelliteId.replace(/\D+/g, "")
+  return digits ? Number(digits) : Number.POSITIVE_INFINITY
+}
+
+function satelliteName(satellite: SatellitePoint): string {
+  const satId = satellite.satellite_id.trim()
+  if (/^[A-Za-z]/.test(satId)) {
+    return satId
+  }
+  return `${satPrefix(satellite.constellation)}${satId}`
+}
+
+function SignalBars({ satellites }: { satellites: SatellitePoint[] }) {
+  const withSnr = satellites.filter(
+    (sat) => sat.snr_dbhz !== null && sat.snr_dbhz > 0,
+  )
+
+  if (withSnr.length === 0) {
+    return (
+      <div className="h-40 flex items-center justify-center text-sm text-muted-foreground border rounded-lg">
+        No SNR data yet
+      </div>
+    )
+  }
+
+  const grouped = CONSTELLATION_ORDER.map((name) => ({
+    name,
+    satellites: withSnr
+      .filter((sat) => sat.constellation === name)
+      .sort(
+        (a, b) =>
+          satelliteSortValue(a.satellite_id) -
+          satelliteSortValue(b.satellite_id),
+      ),
+  })).filter((group) => group.satellites.length > 0)
+
+  const unknownGroup = withSnr
+    .filter(
+      (sat) =>
+        !CONSTELLATION_ORDER.includes(
+          sat.constellation as (typeof CONSTELLATION_ORDER)[number],
+        ),
+    )
+    .sort(
+      (a, b) =>
+        satelliteSortValue(a.satellite_id) - satelliteSortValue(b.satellite_id),
+    )
+  if (unknownGroup.length > 0) {
+    grouped.push({ name: "Unknown", satellites: unknownGroup })
+  }
+
+  const bars = grouped.flatMap((group, groupIndex) =>
+    group.satellites.map((satellite, index) => ({
+      groupName: group.name,
+      groupStart: groupIndex > 0 && index === 0,
+      satellite,
+    })),
+  )
+
+  const columnStyle = {
+    gridTemplateColumns: `repeat(${bars.length}, minmax(0, 1fr))`,
+  } as const
+
+  return (
+    <div className="space-y-3">
+      <div className="flex flex-wrap gap-2 text-xs">
+        {grouped.map((group) => (
+          <div
+            className="inline-flex items-center gap-1 rounded-full border px-2 py-0.5"
+            key={group.name}
+          >
+            <span
+              className="size-2 rounded-full"
+              style={{ backgroundColor: satColor(group.name) }}
+            />
+            <span>
+              {group.name} ({satPrefix(group.name)})
+            </span>
+          </div>
+        ))}
+        <div className="inline-flex items-center gap-1 rounded-full border px-2 py-0.5">
+          <span className="size-2 rounded-full border-2 border-blue-500" />
+          <span>Not used in navigation</span>
+        </div>
+      </div>
+
+      <div className="flex gap-2 min-w-0">
+        <div className="w-10 h-[200px] text-[11px] text-muted-foreground shrink-0 flex flex-col justify-between">
+          {[50, 40, 30, 20, 10, 0].map((tick) => (
+            <span className="leading-none text-right" key={tick}>
+              {tick}
+            </span>
+          ))}
+        </div>
+
+        <div className="relative h-[250px] flex-1 min-w-0">
+          <div className="absolute inset-0 pointer-events-none">
+            {[0, 10, 20, 30, 40, 50].map((tick) => (
+              <div
+                className="absolute left-0 right-0 border-t border-dashed border-border/70"
+                key={tick}
+                style={{ bottom: `${(tick / 50) * 200}px` }}
+              />
+            ))}
+          </div>
+
+          <div
+            className="relative h-full grid gap-x-1 min-w-0"
+            style={columnStyle}
+          >
+            {bars.map((entry) => {
+              const snr = entry.satellite.snr_dbhz ?? 0
+              const color = satColor(entry.groupName)
+              const height = Math.max(Math.round((snr / 50) * 200), 4)
+
+              return (
+                <div
+                  className={`min-w-0 ${entry.groupStart ? "border-l border-border/80 pl-1" : ""}`}
+                  key={`${entry.groupName}-${entry.satellite.satellite_id}`}
+                >
+                  <div className="h-[200px] flex items-end justify-center">
+                    <div
+                      className="w-full max-w-4 rounded-sm border"
+                      style={{
+                        height: `${height}px`,
+                        backgroundColor: entry.satellite.used_in_navigation
+                          ? color
+                          : `${color}33`,
+                        borderColor: entry.satellite.used_in_navigation
+                          ? color
+                          : "#2563eb",
+                        borderWidth: entry.satellite.used_in_navigation
+                          ? "1px"
+                          : "2px",
+                      }}
+                      title={`${satelliteName(entry.satellite)} • ${entry.groupName} • ${snr} dB-Hz`}
+                    />
+                  </div>
+                  <div className="mt-1 flex flex-col items-center leading-none gap-1">
+                    <span className="text-[10px] text-center whitespace-nowrap">
+                      {satelliteName(entry.satellite)}
+                    </span>
+                    <span className="text-[10px] text-muted-foreground text-center">
+                      {snr}
+                    </span>
+                  </div>
+                </div>
+              )
+            })}
+          </div>
+        </div>
+      </div>
+    </div>
+  )
+}
+
+function SkyPlot({ satellites }: { satellites: SatellitePoint[] }) {
+  const points = satellites.filter(
+    (sat) =>
+      sat.azimuth_deg !== null &&
+      sat.elevation_deg !== null &&
+      sat.elevation_deg >= 0 &&
+      sat.elevation_deg <= 90,
+  )
+
+  return (
+    <div className="relative w-full max-w-[420px] mx-auto aspect-square rounded-full border bg-muted/20">
+      <div className="absolute inset-[16%] rounded-full border border-dashed border-border" />
+      <div className="absolute inset-[33%] rounded-full border border-dashed border-border" />
+      <div className="absolute inset-[50%] rounded-full border border-dashed border-border" />
+      <div className="absolute left-1/2 top-0 -translate-x-1/2 text-xs text-muted-foreground">
+        N
+      </div>
+      <div className="absolute left-1/2 bottom-0 -translate-x-1/2 text-xs text-muted-foreground">
+        S
+      </div>
+      <div className="absolute left-1 top-1/2 -translate-y-1/2 text-xs text-muted-foreground">
+        W
+      </div>
+      <div className="absolute right-1 top-1/2 -translate-y-1/2 text-xs text-muted-foreground">
+        E
+      </div>
+      {points.map((satellite) => {
+        const azimuth = satellite.azimuth_deg ?? 0
+        const elevation = satellite.elevation_deg ?? 0
+        const radialPercent = ((90 - elevation) / 90) * 45
+        const angle = ((azimuth - 90) * Math.PI) / 180
+        const x = Math.cos(angle) * radialPercent
+        const y = Math.sin(angle) * radialPercent
+        const color = satColor(satellite.constellation)
+
+        return (
+          <div
+            className="absolute size-4 rounded-full border-2"
+            key={`${satellite.constellation}-${satellite.satellite_id}-sky`}
+            style={{
+              left: `${50 + x}%`,
+              top: `${50 + y}%`,
+              transform: "translate(-50%, -50%)",
+              backgroundColor: color,
+              borderColor: satellite.used_in_navigation
+                ? color
+                : "var(--border)",
+              opacity: satellite.used_in_navigation ? 1 : 0.5,
+            }}
+            title={`${satellite.constellation}-${satellite.satellite_id} (${satellite.snr_dbhz ?? "-"} dB-Hz)`}
+          />
+        )
+      })}
+    </div>
+  )
+}
+
+function ConnectionBadge({
+  status,
+}: {
+  status: "connecting" | "live" | "retrying"
+}) {
+  const statusText =
+    status === "live"
+      ? "Live"
+      : status === "retrying"
+        ? "Reconnecting"
+        : "Connecting"
+  const statusClass =
+    status === "live"
+      ? "text-emerald-500 bg-emerald-500/10 border-emerald-500/20"
+      : "text-amber-500 bg-amber-500/10 border-amber-500/20"
+
+  return (
+    <Badge variant="outline" className={statusClass}>
+      <Radio className="size-3" />
+      {statusText}
+    </Badge>
+  )
+}
+
+function GnssMonitor() {
+  const [snapshot, setSnapshot] = useState<TelemetrySnapshot | null>(null)
+  const [status, setStatus] = useState<"connecting" | "live" | "retrying">(
+    "connecting",
+  )
+  const [selectedDeviceId, setSelectedDeviceId] = useState<string>("")
+
+  useEffect(() => {
+    const token = localStorage.getItem("access_token")
+    if (!token) {
+      return
+    }
+
+    let reconnectTimer: number | undefined
+    let socket: WebSocket | undefined
+    let shouldReconnect = true
+
+    const connect = () => {
+      setStatus((prev) => (prev === "live" ? prev : "connecting"))
+      socket = new WebSocket(buildTelemetryWsUrl(token))
+
+      socket.onopen = () => {
+        setStatus("live")
+      }
+
+      socket.onmessage = (event) => {
+        try {
+          const payload = JSON.parse(event.data) as TelemetrySnapshot
+          setSnapshot(payload)
+          setStatus("live")
+        } catch {
+          setStatus("retrying")
+        }
+      }
+
+      socket.onclose = () => {
+        if (!shouldReconnect) {
+          return
+        }
+        setStatus("retrying")
+        reconnectTimer = window.setTimeout(connect, 2000)
+      }
+
+      socket.onerror = () => {
+        socket?.close()
+      }
+    }
+
+    connect()
+
+    return () => {
+      shouldReconnect = false
+      if (reconnectTimer) {
+        window.clearTimeout(reconnectTimer)
+      }
+      socket?.close()
+    }
+  }, [])
+
+  useEffect(() => {
+    if (!snapshot?.devices.length) {
+      setSelectedDeviceId("")
+      return
+    }
+
+    const exists = snapshot.devices.some(
+      (device) => device.device_id === selectedDeviceId,
+    )
+    if (!exists) {
+      setSelectedDeviceId(snapshot.devices[0].device_id)
+    }
+  }, [snapshot, selectedDeviceId])
+
+  const currentDevice = useMemo(() => {
+    if (!snapshot?.devices.length) {
+      return null
+    }
+    return (
+      snapshot.devices.find(
+        (device) => device.device_id === selectedDeviceId,
+      ) ?? snapshot.devices[0]
+    )
+  }, [selectedDeviceId, snapshot])
+
+  const fixMeta = getFixMeta(currentDevice?.fix_status ?? null)
+  const satellites = currentDevice?.satellite_signal_summary.satellites ?? []
+  const constellations =
+    currentDevice?.satellite_signal_summary.constellations ?? {}
+  const signalHealth = currentDevice?.signal_health
+
+  return (
+    <div className="flex flex-col gap-6">
+      <div className="flex flex-col gap-3 md:flex-row md:items-center md:justify-between">
+        <div>
+          <h1 className="text-2xl font-bold tracking-tight">GNSS Monitor</h1>
+          <p className="text-muted-foreground">
+            Real-time positioning and satellite signal watch
+          </p>
+        </div>
+        <div className="flex items-center gap-3">
+          <ConnectionBadge status={status} />
+          <Badge variant="outline">
+            {snapshot?.generated_at
+              ? `Updated ${formatTime(snapshot.generated_at)}`
+              : "Waiting for stream"}
+          </Badge>
+        </div>
+      </div>
+
+      <Card>
+        <CardHeader className="gap-3">
+          <CardTitle>Device</CardTitle>
+          <CardDescription>
+            Choose a device to inspect live fix and satellite conditions
+          </CardDescription>
+        </CardHeader>
+        <CardContent>
+          <select
+            className="h-10 rounded-md border bg-background px-3 text-sm min-w-[280px]"
+            onChange={(event) => setSelectedDeviceId(event.target.value)}
+            value={selectedDeviceId}
+          >
+            {snapshot?.devices.map((device) => (
+              <option key={device.device_id} value={device.device_id}>
+                {device.device_id}
+              </option>
+            ))}
+          </select>
+        </CardContent>
+      </Card>
+
+      {!currentDevice ? (
+        <Card>
+          <CardContent className="py-10 text-center text-muted-foreground">
+            Waiting for MQTT parsed telemetry...
+          </CardContent>
+        </Card>
+      ) : (
+        <>
+          <div className="grid gap-4 md:grid-cols-2 xl:grid-cols-4">
+            <Card>
+              <CardHeader>
+                <CardTitle className="flex items-center gap-2 text-base">
+                  <Gauge className="size-4" />
+                  Fix Status
+                </CardTitle>
+              </CardHeader>
+              <CardContent className="space-y-2">
+                <Badge variant="outline" className={fixMeta.className}>
+                  {fixMeta.label}
+                </Badge>
+                <p className="text-sm text-muted-foreground">
+                  {fixMeta.description}
+                </p>
+              </CardContent>
+            </Card>
+
+            <Card>
+              <CardHeader>
+                <CardTitle className="flex items-center gap-2 text-base">
+                  <Signal className="size-4" />
+                  Signal Health
+                </CardTitle>
+              </CardHeader>
+              <CardContent className="space-y-2">
+                <Badge
+                  variant="outline"
+                  className={
+                    SIGNAL_STATUS_CLASS[signalHealth?.level ?? "unknown"]
+                  }
+                >
+                  {(signalHealth?.level ?? "unknown").toUpperCase()}
+                </Badge>
+                <div className="space-y-1">
+                  <div className="flex items-center justify-between text-sm">
+                    <span>Score</span>
+                    <span className="font-medium">
+                      {signalHealth?.score ?? 0}
+                    </span>
+                  </div>
+                  <div className="h-2 rounded-full bg-muted overflow-hidden">
+                    <div
+                      className="h-full bg-primary transition-all duration-300"
+                      style={{ width: `${signalHealth?.score ?? 0}%` }}
+                    />
+                  </div>
+                </div>
+                <p className="text-xs text-muted-foreground">
+                  {signalHealth?.message ?? "No signal data"}
+                </p>
+              </CardContent>
+            </Card>
+
+            <Card>
+              <CardHeader>
+                <CardTitle className="flex items-center gap-2 text-base">
+                  <Satellite className="size-4" />
+                  Satellites
+                </CardTitle>
+              </CardHeader>
+              <CardContent className="space-y-2 text-sm">
+                <div className="flex justify-between">
+                  <span className="text-muted-foreground">Used in fix</span>
+                  <span>{currentDevice.satellites_used ?? "-"}</span>
+                </div>
+                <div className="flex justify-between">
+                  <span className="text-muted-foreground">In view</span>
+                  <span>
+                    {currentDevice.satellite_signal_summary
+                      .satellites_in_view ?? "-"}
+                  </span>
+                </div>
+                <div className="flex justify-between">
+                  <span className="text-muted-foreground">Best SNR</span>
+                  <span>{signalHealth?.best_snr_dbhz ?? "-"} dB-Hz</span>
+                </div>
+              </CardContent>
+            </Card>
+
+            <Card>
+              <CardHeader>
+                <CardTitle className="flex items-center gap-2 text-base">
+                  <MapPin className="size-4" />
+                  Position
+                </CardTitle>
+              </CardHeader>
+              <CardContent className="space-y-2 text-sm">
+                <div className="flex justify-between">
+                  <span className="text-muted-foreground">Latitude</span>
+                  <span>{formatCoord(currentDevice.lat)}</span>
+                </div>
+                <div className="flex justify-between">
+                  <span className="text-muted-foreground">Longitude</span>
+                  <span>{formatCoord(currentDevice.lon)}</span>
+                </div>
+                <div className="flex justify-between">
+                  <span className="text-muted-foreground">Altitude</span>
+                  <span>
+                    {currentDevice.alt_m === null
+                      ? "-"
+                      : `${currentDevice.alt_m.toFixed(2)} m`}
+                  </span>
+                </div>
+              </CardContent>
+            </Card>
+          </div>
+
+          <Card>
+            <CardHeader>
+              <CardTitle className="flex items-center gap-2">
+                <Signal className="size-4" />
+                Satellite Signal View
+              </CardTitle>
+              <CardDescription>
+                Grouped by constellation, with per-satellite CN0 bars and clear
+                non-navigation marking.
+              </CardDescription>
+            </CardHeader>
+            <CardContent>
+              <SignalBars satellites={satellites} />
+            </CardContent>
+          </Card>
+
+          <div className="grid gap-6 xl:grid-cols-[460px_1fr]">
+            <Card>
+              <CardHeader>
+                <CardTitle className="flex items-center gap-2">
+                  <Compass className="size-4" />
+                  Satellite Position View
+                </CardTitle>
+                <CardDescription>
+                  Sky plot by azimuth/elevation for quick distribution checks.
+                </CardDescription>
+              </CardHeader>
+              <CardContent className="space-y-4">
+                <SkyPlot satellites={satellites} />
+                <div className="grid grid-cols-2 gap-2 text-xs">
+                  {Object.entries(constellations).map(([name, detail]) => (
+                    <div
+                      className="rounded-md border px-2 py-1 flex items-center justify-between"
+                      key={name}
+                    >
+                      <span className="flex items-center gap-1">
+                        <span
+                          className="size-2 rounded-full"
+                          style={{ backgroundColor: satColor(name) }}
+                        />
+                        {name}
+                      </span>
+                      <span className="text-muted-foreground">
+                        {detail.used_in_navigation ?? 0}/{detail.count ?? 0}
+                      </span>
+                    </div>
+                  ))}
+                </div>
+              </CardContent>
+            </Card>
+
+            <Card>
+              <CardHeader>
+                <CardTitle>Data View</CardTitle>
+                <CardDescription>
+                  Lightweight runtime details for monitoring, without offline
+                  analysis.
+                </CardDescription>
+              </CardHeader>
+              <CardContent className="grid gap-3 text-sm md:grid-cols-2 xl:grid-cols-3">
+                <div>
+                  <p className="text-muted-foreground">Device ID</p>
+                  <p className="font-medium break-all">
+                    {currentDevice.device_id}
+                  </p>
+                </div>
+                <div>
+                  <p className="text-muted-foreground">Last Event Time</p>
+                  <p className="font-medium">
+                    {formatTime(currentDevice.last_event_time)}
+                  </p>
+                </div>
+                <div>
+                  <p className="text-muted-foreground">Data Age</p>
+                  <p className="font-medium">
+                    {formatAge(currentDevice.updated_at)}
+                  </p>
+                </div>
+                <div>
+                  <p className="text-muted-foreground">Average SNR</p>
+                  <p className="font-medium">
+                    {signalHealth?.average_snr_dbhz ?? "-"} dB-Hz
+                  </p>
+                </div>
+                <div>
+                  <p className="text-muted-foreground">{"Strong CN0 (>=40)"}</p>
+                  <p className="font-medium">
+                    {signalHealth?.strong_signal_count ?? 0}
+                  </p>
+                </div>
+                <div className="md:col-span-2 xl:col-span-3">
+                  <p className="text-muted-foreground mb-2">Map Jump</p>
+                  {currentDevice.lat === null || currentDevice.lon === null ? (
+                    <p className="text-sm text-muted-foreground">
+                      Waiting for valid coordinates
+                    </p>
+                  ) : (
+                    <Button asChild size="sm" variant="outline">
+                      <a
+                        href={`https://www.openstreetmap.org/?mlat=${currentDevice.lat}&mlon=${currentDevice.lon}&zoom=16`}
+                        rel="noreferrer"
+                        target="_blank"
+                      >
+                        Open in OpenStreetMap
+                      </a>
+                    </Button>
+                  )}
+                </div>
+              </CardContent>
+            </Card>
+          </div>
+        </>
+      )}
+    </div>
+  )
+}