Adding Vessels

CLAUDE.md

@@ -0,0 +1,122 @@
+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## Project Overview
+
+INTERCEPT is a web-based Signal Intelligence (SIGINT) platform providing a unified Flask interface for software-defined radio (SDR) tools. It supports pager decoding, 433MHz sensors, ADS-B aircraft tracking, ACARS messaging, WiFi/Bluetooth scanning, and satellite tracking.
+
+## Common Commands
+
+### Setup and Running
+```bash
+# Initial setup (installs dependencies and configures SDR tools)
+./setup.sh
+
+# Run the application (requires sudo for SDR/network access)
+sudo -E venv/bin/python intercept.py
+
+# Or activate venv first
+source venv/bin/activate
+sudo -E python intercept.py
+```
+
+### Testing
+```bash
+# Run all tests
+pytest
+
+# Run specific test file
+pytest tests/test_bluetooth.py
+
+# Run with coverage
+pytest --cov=routes --cov=utils
+
+# Run a specific test
+pytest tests/test_bluetooth.py::test_function_name -v
+```
+
+### Linting and Formatting
+```bash
+# Lint with ruff
+ruff check .
+
+# Auto-fix linting issues
+ruff check --fix .
+
+# Format with black
+black .
+
+# Type checking
+mypy .
+```
+
+## Architecture
+
+### Entry Points
+- `intercept.py` - Main entry point script
+- `app.py` - Flask application initialization, global state management, process lifecycle, SSE streaming infrastructure
+
+### Route Blueprints (routes/)
+Each signal type has its own Flask blueprint:
+- `pager.py` - POCSAG/FLEX decoding via rtl_fm + multimon-ng
+- `sensor.py` - 433MHz IoT sensors via rtl_433
+- `adsb.py` - Aircraft tracking via dump1090 (SBS protocol on port 30003)
+- `acars.py` - Aircraft datalink messages via acarsdec
+- `wifi.py`, `wifi_v2.py` - WiFi scanning (legacy and unified APIs)
+- `bluetooth.py`, `bluetooth_v2.py` - Bluetooth scanning (legacy and unified APIs)
+- `satellite.py` - Pass prediction using TLE data
+- `aprs.py` - Amateur packet radio via direwolf
+- `rtlamr.py` - Utility meter reading
+
+### Core Utilities (utils/)
+
+**SDR Abstraction Layer** (`utils/sdr/`):
+- `SDRFactory` with factory pattern for multiple SDR types (RTL-SDR, LimeSDR, HackRF, Airspy, SDRPlay)
+- Each type has a `CommandBuilder` for generating CLI commands
+
+**Bluetooth Module** (`utils/bluetooth/`):
+- Multi-backend: DBus/BlueZ primary, fallback for systems without BlueZ
+- `aggregator.py` - Merges observations across time
+- `tracker_signatures.py` - 47K+ known tracker fingerprints (AirTag, Tile, SmartTag)
+- `heuristics.py` - Behavioral analysis for device classification
+
+**TSCM (Counter-Surveillance)** (`utils/tscm/`):
+- `baseline.py` - Snapshot "normal" RF environment
+- `detector.py` - Compare current scan to baseline, flag anomalies
+- `device_identity.py` - Track devices despite MAC randomization
+- `correlation.py` - Cross-reference Bluetooth and WiFi observations
+
+**WiFi Utilities** (`utils/wifi/`):
+- Platform-agnostic scanner with parsers for airodump-ng, nmcli, iw, iwlist, airport (macOS)
+- `channel_analyzer.py` - Frequency band analysis
+
+### Key Patterns
+
+**Server-Sent Events (SSE)**: All real-time features stream via SSE endpoints (`/stream_pager`, `/stream_sensor`, etc.). Pattern uses `queue.Queue` with timeout and keepalive messages.
+
+**Process Management**: External decoders run as subprocesses with output threads feeding queues. Use `safe_terminate()` for cleanup. Global locks prevent race conditions.
+
+**Data Stores**: `DataStore` class with TTL-based automatic cleanup (WiFi: 10min, Bluetooth: 5min, Aircraft: 5min).
+
+**Input Validation**: Centralized in `utils/validation.py` - always validate frequencies, gains, device indices before spawning processes.
+
+### External Tool Integrations
+
+| Tool | Purpose | Integration |
+|------|---------|-------------|
+| rtl_fm | FM demodulation | Subprocess, pipes to multimon-ng |
+| multimon-ng | Pager decoding | Reads from rtl_fm stdout |
+| rtl_433 | 433MHz sensors | JSON output parsing |
+| dump1090 | ADS-B decoding | SBS protocol socket (port 30003) |
+| acarsdec | ACARS messages | Output parsing |
+| airmon-ng/airodump-ng | WiFi scanning | Monitor mode, CSV parsing |
+| bluetoothctl/hcitool | Bluetooth | Fallback when DBus unavailable |
+
+### Configuration
+- `config.py` - Environment variable support with `INTERCEPT_` prefix
+- Database: SQLite in `instance/` directory for settings, baselines, history
+
+## Testing Notes
+
+Tests use pytest with extensive mocking of external tools. Key fixtures in `tests/conftest.py`. Mock subprocess calls when testing decoder integration.

app.py

@@ -36,6 +36,7 @@ from utils.constants import (
     MAX_AIRCRAFT_AGE_SECONDS,
     MAX_WIFI_NETWORK_AGE_SECONDS,
     MAX_BT_DEVICE_AGE_SECONDS,
+    MAX_VESSEL_AGE_SECONDS,
     QUEUE_MAX_SIZE,
 )
 import logging
@@ -139,6 +140,11 @@ rtlamr_process = None
 rtlamr_queue = queue.Queue(maxsize=QUEUE_MAX_SIZE)
 rtlamr_lock = threading.Lock()
 
+# AIS vessel tracking
+ais_process = None
+ais_queue = queue.Queue(maxsize=QUEUE_MAX_SIZE)
+ais_lock = threading.Lock()
+
 # TSCM (Technical Surveillance Countermeasures)
 tscm_queue = queue.Queue(maxsize=QUEUE_MAX_SIZE)
 tscm_lock = threading.Lock()
@@ -166,6 +172,9 @@ bt_services = {}     # MAC -> list of services (not auto-cleaned, user-requested
 # Aircraft (ADS-B) state - using DataStore for automatic cleanup
 adsb_aircraft = DataStore(max_age_seconds=MAX_AIRCRAFT_AGE_SECONDS, name='adsb_aircraft')
 
+# Vessel (AIS) state - using DataStore for automatic cleanup
+ais_vessels = DataStore(max_age_seconds=MAX_VESSEL_AGE_SECONDS, name='ais_vessels')
+
 # Satellite state
 satellite_passes = []  # Predicted satellite passes (not auto-cleaned, calculated)
 
@@ -175,6 +184,7 @@ cleanup_manager.register(wifi_clients)
 cleanup_manager.register(bt_devices)
 cleanup_manager.register(bt_beacons)
 cleanup_manager.register(adsb_aircraft)
+cleanup_manager.register(ais_vessels)
 
 
 # ============================================
@@ -501,6 +511,7 @@ def health_check() -> Response:
             'pager': current_process is not None and (current_process.poll() is None if current_process else False),
             'sensor': sensor_process is not None and (sensor_process.poll() is None if sensor_process else False),
             'adsb': adsb_process is not None and (adsb_process.poll() is None if adsb_process else False),
+            'ais': ais_process is not None and (ais_process.poll() is None if ais_process else False),
             'acars': acars_process is not None and (acars_process.poll() is None if acars_process else False),
             'aprs': aprs_process is not None and (aprs_process.poll() is None if aprs_process else False),
             'wifi': wifi_process is not None and (wifi_process.poll() is None if wifi_process else False),
@@ -508,6 +519,7 @@ def health_check() -> Response:
         },
         'data': {
             'aircraft_count': len(adsb_aircraft),
+            'vessel_count': len(ais_vessels),
             'wifi_networks_count': len(wifi_networks),
             'wifi_clients_count': len(wifi_clients),
             'bt_devices_count': len(bt_devices),
@@ -518,17 +530,18 @@ def health_check() -> Response:
 @app.route('/killall', methods=['POST'])
 def kill_all() -> Response:
     """Kill all decoder and WiFi processes."""
-    global current_process, sensor_process, wifi_process, adsb_process, acars_process
+    global current_process, sensor_process, wifi_process, adsb_process, ais_process, acars_process
     global aprs_process, aprs_rtl_process
 
-    # Import adsb module to reset its state
+    # Import adsb and ais modules to reset their state
     from routes import adsb as adsb_module
+    from routes import ais as ais_module
 
     killed = []
     processes_to_kill = [
         'rtl_fm', 'multimon-ng', 'rtl_433',
         'airodump-ng', 'aireplay-ng', 'airmon-ng',
-        'dump1090', 'acarsdec', 'direwolf'
+        'dump1090', 'acarsdec', 'direwolf', 'AIS-catcher'
     ]
 
     for proc in processes_to_kill:
@@ -553,6 +566,11 @@ def kill_all() -> Response:
         adsb_process = None
         adsb_module.adsb_using_service = False
 
+    # Reset AIS state
+    with ais_lock:
+        ais_process = None
+        ais_module.ais_running = False
+
     # Reset ACARS state
     with acars_lock:
         acars_process = None

routes/__init__.py

@@ -10,6 +10,7 @@ def register_blueprints(app):
     from .bluetooth import bluetooth_bp
     from .bluetooth_v2 import bluetooth_v2_bp
     from .adsb import adsb_bp
+    from .ais import ais_bp
     from .acars import acars_bp
     from .aprs import aprs_bp
     from .satellite import satellite_bp
@@ -27,6 +28,7 @@ def register_blueprints(app):
     app.register_blueprint(bluetooth_bp)
     app.register_blueprint(bluetooth_v2_bp)  # New unified Bluetooth API
     app.register_blueprint(adsb_bp)
+    app.register_blueprint(ais_bp)
     app.register_blueprint(acars_bp)
     app.register_blueprint(aprs_bp)
     app.register_blueprint(satellite_bp)

routes/ais.py

@@ -0,0 +1,480 @@
+"""AIS vessel tracking routes."""
+
+from __future__ import annotations
+
+import json
+import os
+import queue
+import shutil
+import socket
+import subprocess
+import threading
+import time
+from typing import Generator
+
+from flask import Blueprint, jsonify, request, Response, render_template
+
+import app as app_module
+from utils.logging import get_logger
+from utils.validation import validate_device_index, validate_gain
+from utils.sse import format_sse
+from utils.sdr import SDRFactory, SDRType
+from utils.constants import (
+    AIS_TCP_PORT,
+    AIS_TERMINATE_TIMEOUT,
+    AIS_SOCKET_TIMEOUT,
+    AIS_RECONNECT_DELAY,
+    AIS_UPDATE_INTERVAL,
+    SOCKET_BUFFER_SIZE,
+    SSE_KEEPALIVE_INTERVAL,
+    SSE_QUEUE_TIMEOUT,
+    SOCKET_CONNECT_TIMEOUT,
+    PROCESS_TERMINATE_TIMEOUT,
+)
+
+logger = get_logger('intercept.ais')
+
+ais_bp = Blueprint('ais', __name__, url_prefix='/ais')
+
+# Track AIS state
+ais_running = False
+ais_connected = False
+ais_messages_received = 0
+ais_last_message_time = None
+ais_active_device = None
+_ais_error_logged = False
+
+# Common installation paths for AIS-catcher
+AIS_CATCHER_PATHS = [
+    '/usr/local/bin/AIS-catcher',
+    '/usr/bin/AIS-catcher',
+    '/opt/homebrew/bin/AIS-catcher',
+    '/opt/homebrew/bin/aiscatcher',
+]
+
+
+def find_ais_catcher():
+    """Find AIS-catcher binary, checking PATH and common locations."""
+    # First try PATH
+    for name in ['AIS-catcher', 'aiscatcher']:
+        path = shutil.which(name)
+        if path:
+            return path
+    # Check common installation paths
+    for path in AIS_CATCHER_PATHS:
+        if os.path.isfile(path) and os.access(path, os.X_OK):
+            return path
+    return None
+
+
+def parse_ais_stream(port: int):
+    """Parse JSON data from AIS-catcher TCP server."""
+    global ais_running, ais_connected, ais_messages_received, ais_last_message_time, _ais_error_logged
+
+    logger.info(f"AIS stream parser started, connecting to localhost:{port}")
+    ais_connected = False
+    ais_messages_received = 0
+    _ais_error_logged = False
+
+    while ais_running:
+        try:
+            sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+            sock.settimeout(AIS_SOCKET_TIMEOUT)
+            sock.connect(('localhost', port))
+            ais_connected = True
+            _ais_error_logged = False
+            logger.info("Connected to AIS-catcher TCP server")
+
+            buffer = ""
+            last_update = time.time()
+            pending_updates = set()
+
+            while ais_running:
+                try:
+                    data = sock.recv(SOCKET_BUFFER_SIZE).decode('utf-8', errors='ignore')
+                    if not data:
+                        logger.warning("AIS connection closed (no data)")
+                        break
+                    buffer += data
+
+                    while '\n' in buffer:
+                        line, buffer = buffer.split('\n', 1)
+                        line = line.strip()
+                        if not line:
+                            continue
+
+                        try:
+                            msg = json.loads(line)
+                            vessel = process_ais_message(msg)
+                            if vessel:
+                                mmsi = vessel.get('mmsi')
+                                if mmsi:
+                                    app_module.ais_vessels.set(mmsi, vessel)
+                                    pending_updates.add(mmsi)
+                                    ais_messages_received += 1
+                                    ais_last_message_time = time.time()
+                        except json.JSONDecodeError:
+                            if ais_messages_received < 5:
+                                logger.debug(f"Invalid JSON: {line[:100]}")
+
+                    # Batch updates
+                    now = time.time()
+                    if now - last_update >= AIS_UPDATE_INTERVAL:
+                        for mmsi in pending_updates:
+                            if mmsi in app_module.ais_vessels:
+                                try:
+                                    app_module.ais_queue.put_nowait({
+                                        'type': 'vessel',
+                                        **app_module.ais_vessels[mmsi]
+                                    })
+                                except queue.Full:
+                                    pass
+                        pending_updates.clear()
+                        last_update = now
+
+                except socket.timeout:
+                    continue
+
+            sock.close()
+            ais_connected = False
+        except OSError as e:
+            ais_connected = False
+            if not _ais_error_logged:
+                logger.warning(f"AIS connection error: {e}, reconnecting...")
+                _ais_error_logged = True
+            time.sleep(AIS_RECONNECT_DELAY)
+
+    ais_connected = False
+    logger.info("AIS stream parser stopped")
+
+
+def process_ais_message(msg: dict) -> dict | None:
+    """Process AIS-catcher JSON message and extract vessel data."""
+    # AIS-catcher outputs different message types
+    # We're interested in position reports and static data
+
+    mmsi = msg.get('mmsi')
+    if not mmsi:
+        return None
+
+    mmsi = str(mmsi)
+
+    # Get existing vessel data or create new
+    vessel = app_module.ais_vessels.get(mmsi) or {'mmsi': mmsi}
+
+    # Extract common fields
+    if 'lat' in msg and 'lon' in msg:
+        try:
+            lat = float(msg['lat'])
+            lon = float(msg['lon'])
+            # Validate coordinates (AIS uses 181 for unavailable)
+            if -90 <= lat <= 90 and -180 <= lon <= 180:
+                vessel['lat'] = lat
+                vessel['lon'] = lon
+        except (ValueError, TypeError):
+            pass
+
+    # Speed over ground (knots)
+    if 'speed' in msg:
+        try:
+            speed = float(msg['speed'])
+            if speed < 102.3:  # 102.3 = not available
+                vessel['speed'] = round(speed, 1)
+        except (ValueError, TypeError):
+            pass
+
+    # Course over ground (degrees)
+    if 'course' in msg:
+        try:
+            course = float(msg['course'])
+            if course < 360:  # 360 = not available
+                vessel['course'] = round(course, 1)
+        except (ValueError, TypeError):
+            pass
+
+    # True heading (degrees)
+    if 'heading' in msg:
+        try:
+            heading = int(msg['heading'])
+            if heading < 511:  # 511 = not available
+                vessel['heading'] = heading
+        except (ValueError, TypeError):
+            pass
+
+    # Navigation status
+    if 'status' in msg:
+        vessel['nav_status'] = msg['status']
+    if 'status_text' in msg:
+        vessel['nav_status_text'] = msg['status_text']
+
+    # Vessel name (from Type 5 or Type 24 messages)
+    if 'shipname' in msg:
+        name = msg['shipname'].strip().strip('@')
+        if name:
+            vessel['name'] = name
+
+    # Callsign
+    if 'callsign' in msg:
+        callsign = msg['callsign'].strip().strip('@')
+        if callsign:
+            vessel['callsign'] = callsign
+
+    # Ship type
+    if 'shiptype' in msg:
+        vessel['ship_type'] = msg['shiptype']
+    if 'shiptype_text' in msg:
+        vessel['ship_type_text'] = msg['shiptype_text']
+
+    # Destination
+    if 'destination' in msg:
+        dest = msg['destination'].strip().strip('@')
+        if dest:
+            vessel['destination'] = dest
+
+    # ETA
+    if 'eta' in msg:
+        vessel['eta'] = msg['eta']
+
+    # Dimensions
+    if 'to_bow' in msg and 'to_stern' in msg:
+        try:
+            length = int(msg['to_bow']) + int(msg['to_stern'])
+            if length > 0:
+                vessel['length'] = length
+        except (ValueError, TypeError):
+            pass
+
+    if 'to_port' in msg and 'to_starboard' in msg:
+        try:
+            width = int(msg['to_port']) + int(msg['to_starboard'])
+            if width > 0:
+                vessel['width'] = width
+        except (ValueError, TypeError):
+            pass
+
+    # Draught
+    if 'draught' in msg:
+        try:
+            draught = float(msg['draught'])
+            if draught > 0:
+                vessel['draught'] = draught
+        except (ValueError, TypeError):
+            pass
+
+    # Rate of turn
+    if 'turn' in msg:
+        try:
+            turn = float(msg['turn'])
+            if -127 <= turn <= 127:  # Valid range
+                vessel['rate_of_turn'] = turn
+        except (ValueError, TypeError):
+            pass
+
+    # Message type for debugging
+    if 'type' in msg:
+        vessel['last_msg_type'] = msg['type']
+
+    # Timestamp
+    vessel['last_seen'] = time.time()
+
+    return vessel
+
+
+@ais_bp.route('/tools')
+def check_ais_tools():
+    """Check for AIS decoding tools and hardware."""
+    has_ais_catcher = find_ais_catcher() is not None
+
+    # Check what SDR hardware is detected
+    devices = SDRFactory.detect_devices()
+    has_rtlsdr = any(d.sdr_type == SDRType.RTL_SDR for d in devices)
+
+    return jsonify({
+        'ais_catcher': has_ais_catcher,
+        'ais_catcher_path': find_ais_catcher(),
+        'has_rtlsdr': has_rtlsdr,
+        'device_count': len(devices)
+    })
+
+
+@ais_bp.route('/status')
+def ais_status():
+    """Get AIS tracking status for debugging."""
+    process_running = False
+    if app_module.ais_process:
+        process_running = app_module.ais_process.poll() is None
+
+    return jsonify({
+        'tracking_active': ais_running,
+        'active_device': ais_active_device,
+        'connected': ais_connected,
+        'messages_received': ais_messages_received,
+        'last_message_time': ais_last_message_time,
+        'vessel_count': len(app_module.ais_vessels),
+        'vessels': dict(app_module.ais_vessels),
+        'queue_size': app_module.ais_queue.qsize(),
+        'ais_catcher_path': find_ais_catcher(),
+        'process_running': process_running
+    })
+
+
+@ais_bp.route('/start', methods=['POST'])
+def start_ais():
+    """Start AIS tracking."""
+    global ais_running, ais_active_device
+
+    with app_module.ais_lock:
+        if ais_running:
+            return jsonify({'status': 'already_running', 'message': 'AIS tracking already active'}), 409
+
+    data = request.json or {}
+
+    # Validate inputs
+    try:
+        gain = int(validate_gain(data.get('gain', '40')))
+        device = validate_device_index(data.get('device', '0'))
+    except ValueError as e:
+        return jsonify({'status': 'error', 'message': str(e)}), 400
+
+    # Find AIS-catcher
+    ais_catcher_path = find_ais_catcher()
+    if not ais_catcher_path:
+        return jsonify({
+            'status': 'error',
+            'message': 'AIS-catcher not found. Install from https://github.com/jvde-github/AIS-catcher/releases'
+        }), 400
+
+    # Get SDR type from request
+    sdr_type_str = data.get('sdr_type', 'rtlsdr')
+    try:
+        sdr_type = SDRType(sdr_type_str)
+    except ValueError:
+        sdr_type = SDRType.RTL_SDR
+
+    # Kill any existing process
+    if app_module.ais_process:
+        try:
+            pgid = os.getpgid(app_module.ais_process.pid)
+            os.killpg(pgid, 15)
+            app_module.ais_process.wait(timeout=PROCESS_TERMINATE_TIMEOUT)
+        except (subprocess.TimeoutExpired, ProcessLookupError, OSError):
+            try:
+                pgid = os.getpgid(app_module.ais_process.pid)
+                os.killpg(pgid, 9)
+            except (ProcessLookupError, OSError):
+                pass
+        app_module.ais_process = None
+        logger.info("Killed existing AIS process")
+
+    # Build command using SDR abstraction
+    sdr_device = SDRFactory.create_default_device(sdr_type, index=device)
+    builder = SDRFactory.get_builder(sdr_type)
+
+    bias_t = data.get('bias_t', False)
+    tcp_port = AIS_TCP_PORT
+
+    cmd = builder.build_ais_command(
+        device=sdr_device,
+        gain=float(gain),
+        bias_t=bias_t,
+        tcp_port=tcp_port
+    )
+
+    # Use the found AIS-catcher path
+    cmd[0] = ais_catcher_path
+
+    try:
+        logger.info(f"Starting AIS-catcher with device {device}: {' '.join(cmd)}")
+        app_module.ais_process = subprocess.Popen(
+            cmd,
+            stdout=subprocess.DEVNULL,
+            stderr=subprocess.PIPE,
+            start_new_session=True
+        )
+
+        # Wait for process to start
+        time.sleep(2.0)
+
+        if app_module.ais_process.poll() is not None:
+            stderr_output = ''
+            if app_module.ais_process.stderr:
+                try:
+                    stderr_output = app_module.ais_process.stderr.read().decode('utf-8', errors='ignore').strip()
+                except Exception:
+                    pass
+            error_msg = 'AIS-catcher failed to start. Check SDR device connection.'
+            if stderr_output:
+                error_msg += f' Error: {stderr_output[:200]}'
+            return jsonify({'status': 'error', 'message': error_msg}), 500
+
+        ais_running = True
+        ais_active_device = device
+
+        # Start TCP parser thread
+        thread = threading.Thread(target=parse_ais_stream, args=(tcp_port,), daemon=True)
+        thread.start()
+
+        return jsonify({
+            'status': 'started',
+            'message': 'AIS tracking started',
+            'device': device,
+            'port': tcp_port
+        })
+    except Exception as e:
+        logger.error(f"Failed to start AIS-catcher: {e}")
+        return jsonify({'status': 'error', 'message': str(e)}), 500
+
+
+@ais_bp.route('/stop', methods=['POST'])
+def stop_ais():
+    """Stop AIS tracking."""
+    global ais_running, ais_active_device
+
+    with app_module.ais_lock:
+        if app_module.ais_process:
+            try:
+                pgid = os.getpgid(app_module.ais_process.pid)
+                os.killpg(pgid, 15)
+                app_module.ais_process.wait(timeout=AIS_TERMINATE_TIMEOUT)
+            except (subprocess.TimeoutExpired, ProcessLookupError, OSError):
+                try:
+                    pgid = os.getpgid(app_module.ais_process.pid)
+                    os.killpg(pgid, 9)
+                except (ProcessLookupError, OSError):
+                    pass
+            app_module.ais_process = None
+            logger.info("AIS process stopped")
+        ais_running = False
+        ais_active_device = None
+
+    app_module.ais_vessels.clear()
+    return jsonify({'status': 'stopped'})
+
+
+@ais_bp.route('/stream')
+def stream_ais():
+    """SSE stream for AIS vessels."""
+    def generate() -> Generator[str, None, None]:
+        last_keepalive = time.time()
+
+        while True:
+            try:
+                msg = app_module.ais_queue.get(timeout=SSE_QUEUE_TIMEOUT)
+                last_keepalive = time.time()
+                yield format_sse(msg)
+            except queue.Empty:
+                now = time.time()
+                if now - last_keepalive >= SSE_KEEPALIVE_INTERVAL:
+                    yield format_sse({'type': 'keepalive'})
+                    last_keepalive = now
+
+    response = Response(generate(), mimetype='text/event-stream')
+    response.headers['Cache-Control'] = 'no-cache'
+    response.headers['X-Accel-Buffering'] = 'no'
+    return response
+
+
+@ais_bp.route('/dashboard')
+def ais_dashboard():
+    """Popout AIS dashboard."""
+    return render_template('ais_dashboard.html')

setup.sh

@@ -203,6 +203,7 @@ check_tools() {
   check_optional "rtlamr"      "Utility meter decoder (requires Go)" rtlamr
   check_required "dump1090"    "ADS-B decoder" dump1090
   check_required "acarsdec"    "ACARS decoder" acarsdec
+  check_required "AIS-catcher" "AIS vessel decoder" AIS-catcher aiscatcher
 
   echo
   info "GPS:"
@@ -412,7 +413,7 @@ install_multimon_ng_from_source_macos() {
 }
 
 install_macos_packages() {
-  TOTAL_STEPS=13
+  TOTAL_STEPS=14
   CURRENT_STEP=0
 
   progress "Checking Homebrew"
@@ -458,6 +459,13 @@ install_macos_packages() {
   progress "Installing acarsdec"
   (brew_install acarsdec) || warn "acarsdec not available via Homebrew"
 
+  progress "Installing AIS-catcher"
+  if ! cmd_exists AIS-catcher && ! cmd_exists aiscatcher; then
+    (brew_install aiscatcher) || warn "AIS-catcher not available via Homebrew"
+  else
+    ok "AIS-catcher already installed"
+  fi
+
   progress "Installing aircrack-ng"
   brew_install aircrack-ng
 
@@ -577,6 +585,34 @@ install_acarsdec_from_source_debian() {
   )
 }
 
+install_aiscatcher_from_source_debian() {
+  info "AIS-catcher not available via APT. Building from source..."
+
+  apt_install build-essential git cmake pkg-config \
+    librtlsdr-dev libusb-1.0-0-dev libcurl4-openssl-dev zlib1g-dev
+
+  # Run in subshell to isolate EXIT trap
+  (
+    tmp_dir="$(mktemp -d)"
+    trap 'rm -rf "$tmp_dir"' EXIT
+
+    info "Cloning AIS-catcher..."
+    git clone --depth 1 https://github.com/jvde-github/AIS-catcher.git "$tmp_dir/AIS-catcher" >/dev/null 2>&1 \
+      || { warn "Failed to clone AIS-catcher"; exit 1; }
+
+    cd "$tmp_dir/AIS-catcher"
+    mkdir -p build && cd build
+
+    info "Compiling AIS-catcher..."
+    if cmake .. >/dev/null 2>&1 && make >/dev/null 2>&1; then
+      $SUDO install -m 0755 AIS-catcher /usr/local/bin/AIS-catcher
+      ok "AIS-catcher installed successfully."
+    else
+      warn "Failed to build AIS-catcher from source. AIS vessel tracking will not be available."
+    fi
+  )
+}
+
 install_rtlsdr_blog_drivers_debian() {
   # The RTL-SDR Blog drivers provide better support for:
   # - RTL-SDR Blog V4 (R828D tuner)
@@ -684,7 +720,7 @@ install_debian_packages() {
     export NEEDRESTART_MODE=a
   fi
 
-  TOTAL_STEPS=18
+  TOTAL_STEPS=19
   CURRENT_STEP=0
 
   progress "Updating APT package lists"
@@ -815,6 +851,13 @@ install_debian_packages() {
   fi
   cmd_exists acarsdec || install_acarsdec_from_source_debian
 
+  progress "Installing AIS-catcher"
+  if ! cmd_exists AIS-catcher && ! cmd_exists aiscatcher; then
+    install_aiscatcher_from_source_debian
+  else
+    ok "AIS-catcher already installed"
+  fi
+
   progress "Configuring udev rules"
   setup_udev_rules_debian
 

templates/index.html

@@ -95,6 +95,11 @@
                             <span class="mode-name">Aircraft</span>
                             <span class="mode-desc">ADS-B tracking</span>
                         </a>
+                        <a href="/ais/dashboard" class="mode-card" style="text-decoration: none;">
+                            <span class="mode-icon icon"><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M2 20a2 2 0 0 0 2 2h16a2 2 0 0 0 2-2v-8l-4-6H6L2 12v8z"/><path d="M12 4v4"/><path d="M8 4v2"/><path d="M16 4v2"/></svg></span>
+                            <span class="mode-name">Vessels</span>
+                            <span class="mode-desc">AIS ship tracking</span>
+                        </a>
                         <button class="mode-card" onclick="selectMode('wifi')">
                             <span class="mode-icon icon"><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M5 12.55a11 11 0 0 1 14.08 0"/><path d="M1.42 9a16 16 0 0 1 21.16 0"/><path d="M8.53 16.11a6 6 0 0 1 6.95 0"/><circle cx="12" cy="20" r="1" fill="currentColor" stroke="none"/></svg></span>
                             <span class="mode-name">WiFi</span>
@@ -271,6 +276,7 @@
                 <button class="mode-nav-btn" onclick="switchMode('sensor')"><span class="nav-icon icon"><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><circle cx="12" cy="12" r="2"/><path d="M16.24 7.76a6 6 0 0 1 0 8.49m-8.48-.01a6 6 0 0 1 0-8.49m11.31-2.82a10 10 0 0 1 0 14.14m-14.14 0a10 10 0 0 1 0-14.14"/></svg></span><span class="nav-label">433MHz</span></button>
                 <button class="mode-nav-btn" onclick="switchMode('rtlamr')"><span class="nav-icon icon"><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M22 12h-4l-3 9L9 3l-3 9H2"/></svg></span><span class="nav-label">Meters</span></button>
                 <a href="/adsb/dashboard" class="mode-nav-btn" style="text-decoration: none;"><span class="nav-icon icon"><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M21 16v-2l-8-5V3.5a1.5 1.5 0 0 0-3 0V9l-8 5v2l8-2.5V19l-2 1.5V22l3.5-1 3.5 1v-1.5L13 19v-5.5l8 2.5z"/></svg></span><span class="nav-label">Aircraft</span></a>
+                <a href="/ais/dashboard" class="mode-nav-btn" style="text-decoration: none;"><span class="nav-icon icon"><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M2 20a2 2 0 0 0 2 2h16a2 2 0 0 0 2-2v-8l-4-6H6L2 12v8z"/><path d="M12 4v4"/><path d="M8 4v2"/><path d="M16 4v2"/></svg></span><span class="nav-label">Vessels</span></a>
                 <button class="mode-nav-btn" onclick="switchMode('aprs')"><span class="nav-icon icon"><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M20 10c0 6-8 12-8 12s-8-6-8-12a8 8 0 0 1 16 0Z"/><circle cx="12" cy="10" r="3"/></svg></span><span class="nav-label">APRS</span></button>
                 <button class="mode-nav-btn" onclick="switchMode('satellite')"><span class="nav-icon icon"><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M13 7L9 3 5 7l4 4"/><path d="m17 11 4 4-4 4-4-4"/><path d="m8 12 4 4 6-6-4-4-6 6"/><path d="m16 8 3-3"/><path d="M9 21a6 6 0 0 0-6-6"/></svg></span><span class="nav-label">Satellite</span></button>
                 <button class="mode-nav-btn" onclick="switchMode('listening')"><span class="nav-icon icon"><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><rect x="3" y="3" width="18" height="18" rx="2"/><path d="M3 9h18"/><path d="M9 21V9"/></svg></span><span class="nav-label">Listening Post</span></button>
@@ -330,6 +336,7 @@
         <button class="mobile-nav-btn" data-mode="sensor" onclick="switchMode('sensor')"><span class="icon icon--sm"><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><circle cx="12" cy="12" r="2"/><path d="M16.24 7.76a6 6 0 0 1 0 8.49m-8.48-.01a6 6 0 0 1 0-8.49"/></svg></span> 433MHz</button>
         <button class="mobile-nav-btn" data-mode="rtlamr" onclick="switchMode('rtlamr')"><span class="icon icon--sm"><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><path d="M22 12h-4l-3 9L9 3l-3 9H2"/></svg></span> Meters</button>
         <a href="/adsb/dashboard" class="mobile-nav-btn" style="text-decoration: none;"><span class="icon icon--sm"><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><path d="M21 16v-2l-8-5V3.5a1.5 1.5 0 0 0-3 0V9l-8 5v2l8-2.5V19l-2 1.5V22l3.5-1 3.5 1v-1.5L13 19v-5.5l8 2.5z"/></svg></span> Aircraft</a>
+        <a href="/ais/dashboard" class="mobile-nav-btn" style="text-decoration: none;"><span class="icon icon--sm"><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><path d="M2 20a2 2 0 0 0 2 2h16a2 2 0 0 0 2-2v-8l-4-6H6L2 12v8z"/><path d="M12 4v4"/></svg></span> Vessels</a>
         <button class="mobile-nav-btn" data-mode="aprs" onclick="switchMode('aprs')"><span class="icon icon--sm"><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><path d="M20 10c0 6-8 12-8 12s-8-6-8-12a8 8 0 0 1 16 0Z"/><circle cx="12" cy="10" r="3"/></svg></span> APRS</button>
         <button class="mobile-nav-btn" data-mode="wifi" onclick="switchMode('wifi')"><span class="icon icon--sm"><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><path d="M5 12.55a11 11 0 0 1 14.08 0"/><path d="M8.53 16.11a6 6 0 0 1 6.95 0"/><circle cx="12" cy="20" r="1" fill="currentColor"/></svg></span> WiFi</button>
         <button class="mobile-nav-btn" data-mode="bluetooth" onclick="switchMode('bluetooth')"><span class="icon icon--sm"><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><polyline points="6.5 6.5 17.5 17.5 12 22 12 2 17.5 6.5 6.5 17.5"/></svg></span> BT</button>
@@ -446,6 +453,8 @@
 
                 {% include 'partials/modes/tscm.html' %}
 
+                {% include 'partials/modes/ais.html' %}
+
                 <button class="preset-btn" onclick="killAll()"
                     style="width: 100%; margin-top: 10px; border-color: #ff3366; color: #ff3366;">
                     Kill All Processes
@@ -2046,6 +2055,7 @@
             document.getElementById('listeningPostMode')?.classList.toggle('active', mode === 'listening');
             document.getElementById('aprsMode')?.classList.toggle('active', mode === 'aprs');
             document.getElementById('tscmMode')?.classList.toggle('active', mode === 'tscm');
+            document.getElementById('aisMode')?.classList.toggle('active', mode === 'ais');
             const pagerStats = document.getElementById('pagerStats');
             const sensorStats = document.getElementById('sensorStats');
             const satelliteStats = document.getElementById('satelliteStats');
@@ -2075,7 +2085,8 @@
                 'bluetooth': 'BLUETOOTH',
                 'listening': 'LISTENING POST',
                 'aprs': 'APRS',
-                'tscm': 'TSCM'
+                'tscm': 'TSCM',
+                'ais': 'AIS VESSELS'
             };
             const activeModeIndicator = document.getElementById('activeModeIndicator');
             if (activeModeIndicator) activeModeIndicator.innerHTML = '<span class="pulse-dot"></span>' + (modeNames[mode] || mode.toUpperCase());
@@ -2108,7 +2119,8 @@
                 'bluetooth': 'Bluetooth Scanner',
                 'listening': 'Listening Post',
                 'aprs': 'APRS Tracker',
-                'tscm': 'TSCM Counter-Surveillance'
+                'tscm': 'TSCM Counter-Surveillance',
+                'ais': 'AIS Vessel Tracker'
             };
             const outputTitle = document.getElementById('outputTitle');
             if (outputTitle) outputTitle.textContent = titles[mode] || 'Signal Monitor';
@@ -10495,6 +10507,8 @@
                     </div>
                     <div class="icon-item"><span class="icon">✈️</span><span class="desc">Aircraft - Opens ADS-B
                             Dashboard</span></div>
+                    <div class="icon-item"><span class="icon">🚢</span><span class="desc">Vessels - Opens AIS
+                            Dashboard</span></div>
                     <div class="icon-item"><span class="icon">📍</span><span class="desc">APRS - Amateur radio
                             tracking</span></div>
                     <div class="icon-item"><span class="icon">🛰️</span><span class="desc">Satellite - Pass
@@ -10671,6 +10685,7 @@
                     <li><strong>Utility Meters:</strong> RTL-SDR, rtl_tcp, rtlamr</li>
                     <li><strong>Aircraft (ADS-B):</strong> RTL-SDR, dump1090 or rtl_adsb</li>
                     <li><strong>Aircraft (ACARS):</strong> Second RTL-SDR, acarsdec</li>
+                    <li><strong>Vessels (AIS):</strong> RTL-SDR, AIS-catcher</li>
                     <li><strong>APRS:</strong> RTL-SDR, direwolf or multimon-ng</li>
                     <li><strong>Satellite:</strong> Internet for Celestrak (optional), skyfield</li>
                     <li><strong>WiFi:</strong> Monitor-mode adapter, aircrack-ng suite</li>

templates/partials/modes/ais.html

@@ -0,0 +1,119 @@
+<!-- AIS VESSEL TRACKING MODE -->
+<div id="aisMode" class="mode-content" style="display: none;">
+    <div class="section">
+        <h3>AIS Vessel Tracking</h3>
+        <div class="info-text" style="margin-bottom: 15px;">
+            Track ships and vessels via AIS (Automatic Identification System) on 161.975 / 162.025 MHz.
+        </div>
+        <a href="/ais/dashboard" target="_blank" class="run-btn" style="display: inline-block; text-decoration: none; text-align: center; margin-bottom: 15px;">
+            Open AIS Dashboard
+        </a>
+    </div>
+
+    <div class="section">
+        <h3>Settings</h3>
+        <div class="form-group">
+            <label>Gain (dB, 0 = auto)</label>
+            <input type="number" id="aisGainInput" value="40" min="0" max="50" placeholder="0-50">
+        </div>
+    </div>
+
+    <div class="section">
+        <h3>Status</h3>
+        <div id="aisStatusDisplay" class="info-text">
+            <p>Status: <span id="aisStatusText" style="color: var(--accent-yellow);">Standby</span></p>
+            <p>Vessels: <span id="aisVesselCount">0</span></p>
+        </div>
+    </div>
+
+    <button class="run-btn" id="startAisBtn" onclick="startAisTracking()">
+        Start AIS Tracking
+    </button>
+    <button class="stop-btn" id="stopAisBtn" onclick="stopAisTracking()" style="display: none;">
+        Stop AIS Tracking
+    </button>
+</div>
+
+<script>
+    let aisEventSource = null;
+    let aisVessels = {};
+
+    function startAisTracking() {
+        const gain = document.getElementById('aisGainInput').value || '40';
+        const device = document.getElementById('deviceSelect')?.value || '0';
+
+        fetch('/ais/start', {
+            method: 'POST',
+            headers: { 'Content-Type': 'application/json' },
+            body: JSON.stringify({ device, gain })
+        })
+        .then(r => r.json())
+        .then(data => {
+            if (data.status === 'started' || data.status === 'already_running') {
+                document.getElementById('startAisBtn').style.display = 'none';
+                document.getElementById('stopAisBtn').style.display = 'block';
+                document.getElementById('aisStatusText').textContent = 'Tracking';
+                document.getElementById('aisStatusText').style.color = 'var(--accent-green)';
+                startAisSSE();
+            } else {
+                alert(data.message || 'Failed to start AIS tracking');
+            }
+        })
+        .catch(err => alert('Error: ' + err.message));
+    }
+
+    function stopAisTracking() {
+        fetch('/ais/stop', { method: 'POST' })
+        .then(r => r.json())
+        .then(() => {
+            document.getElementById('startAisBtn').style.display = 'block';
+            document.getElementById('stopAisBtn').style.display = 'none';
+            document.getElementById('aisStatusText').textContent = 'Standby';
+            document.getElementById('aisStatusText').style.color = 'var(--accent-yellow)';
+            document.getElementById('aisVesselCount').textContent = '0';
+            if (aisEventSource) {
+                aisEventSource.close();
+                aisEventSource = null;
+            }
+            aisVessels = {};
+        });
+    }
+
+    function startAisSSE() {
+        if (aisEventSource) aisEventSource.close();
+
+        aisEventSource = new EventSource('/ais/stream');
+        aisEventSource.onmessage = function(e) {
+            try {
+                const data = JSON.parse(e.data);
+                if (data.type === 'vessel') {
+                    aisVessels[data.mmsi] = data;
+                    document.getElementById('aisVesselCount').textContent = Object.keys(aisVessels).length;
+                }
+            } catch (err) {}
+        };
+
+        aisEventSource.onerror = function() {
+            setTimeout(() => {
+                if (document.getElementById('stopAisBtn').style.display === 'block') {
+                    startAisSSE();
+                }
+            }, 2000);
+        };
+    }
+
+    // Check initial status
+    fetch('/ais/status')
+    .then(r => r.json())
+    .then(data => {
+        if (data.tracking_active) {
+            document.getElementById('startAisBtn').style.display = 'none';
+            document.getElementById('stopAisBtn').style.display = 'block';
+            document.getElementById('aisStatusText').textContent = 'Tracking';
+            document.getElementById('aisStatusText').style.color = 'var(--accent-green)';
+            document.getElementById('aisVesselCount').textContent = data.vessel_count || 0;
+            startAisSSE();
+        }
+    })
+    .catch(() => {});
+</script>

utils/constants.py

@@ -203,6 +203,32 @@ SBS_RECONNECT_DELAY = 2.0
 # Default pager log file
 DEFAULT_PAGER_LOG_FILE = 'pager_messages.log'
 
+
+# =============================================================================
+# AIS (Vessel Tracking)
+# =============================================================================
+
+# AIS-catcher TCP server port
+AIS_TCP_PORT = 10110
+
+# AIS stream update interval
+AIS_UPDATE_INTERVAL = 0.5
+
+# AIS reconnect delay on error
+AIS_RECONNECT_DELAY = 2.0
+
+# AIS socket timeout
+AIS_SOCKET_TIMEOUT = 5
+
+# AIS frequencies (MHz)
+AIS_FREQUENCIES = [161.975, 162.025]
+
+# Maximum age for vessel data before cleanup
+MAX_VESSEL_AGE_SECONDS = 600  # 10 minutes
+
+# AIS process termination timeout
+AIS_TERMINATE_TIMEOUT = 5
+
 # WiFi capture temp path prefix
 WIFI_CAPTURE_PATH_PREFIX = '/tmp/intercept_wifi'
 

utils/dependencies.py

@@ -209,6 +209,20 @@ TOOL_DEPENDENCIES = {
             }
         }
     },
+    'ais': {
+        'name': 'Vessel Tracking (AIS)',
+        'tools': {
+            'AIS-catcher': {
+                'required': True,
+                'description': 'AIS receiver and decoder',
+                'install': {
+                    'apt': 'Download .deb from https://github.com/jvde-github/AIS-catcher/releases',
+                    'brew': 'brew install aiscatcher',
+                    'manual': 'https://github.com/jvde-github/AIS-catcher/releases'
+                }
+            }
+        }
+    },
     'aprs': {
         'name': 'APRS Tracking',
         'tools': {

utils/sdr/airspy.py

@@ -155,6 +155,36 @@ class AirspyCommandBuilder(CommandBuilder):
 
         return cmd
 
+    def build_ais_command(
+        self,
+        device: SDRDevice,
+        gain: Optional[float] = None,
+        bias_t: bool = False,
+        tcp_port: int = 10110
+    ) -> list[str]:
+        """
+        Build AIS-catcher command for AIS vessel tracking with Airspy.
+
+        Uses AIS-catcher with SoapySDR support.
+        """
+        device_str = self._build_device_string(device)
+
+        cmd = [
+            'AIS-catcher',
+            '-d', f'soapysdr -d {device_str}',
+            '-S', str(tcp_port),
+            '-o', '5',
+            '-q',
+        ]
+
+        if gain is not None and gain > 0:
+            cmd.extend(['-gr', 'tuner', str(int(gain))])
+
+        if bias_t:
+            cmd.extend(['-gr', 'biastee', '1'])
+
+        return cmd
+
     def get_capabilities(self) -> SDRCapabilities:
         """Return Airspy capabilities."""
         return self.CAPABILITIES

utils/sdr/base.py

@@ -159,6 +159,28 @@ class CommandBuilder(ABC):
         """
         pass
 
+    @abstractmethod
+    def build_ais_command(
+        self,
+        device: SDRDevice,
+        gain: Optional[float] = None,
+        bias_t: bool = False,
+        tcp_port: int = 10110
+    ) -> list[str]:
+        """
+        Build AIS decoder command for vessel tracking.
+
+        Args:
+            device: The SDR device to use
+            gain: Gain in dB (None for auto)
+            bias_t: Enable bias-T power (for active antennas)
+            tcp_port: TCP port for JSON output server
+
+        Returns:
+            Command as list of strings for subprocess
+        """
+        pass
+
     @abstractmethod
     def get_capabilities(self) -> SDRCapabilities:
         """Return hardware capabilities for this SDR type."""

utils/sdr/hackrf.py

@@ -155,6 +155,36 @@ class HackRFCommandBuilder(CommandBuilder):
 
         return cmd
 
+    def build_ais_command(
+        self,
+        device: SDRDevice,
+        gain: Optional[float] = None,
+        bias_t: bool = False,
+        tcp_port: int = 10110
+    ) -> list[str]:
+        """
+        Build AIS-catcher command for AIS vessel tracking with HackRF.
+
+        Uses AIS-catcher with SoapySDR support.
+        """
+        device_str = self._build_device_string(device)
+
+        cmd = [
+            'AIS-catcher',
+            '-d', f'soapysdr -d {device_str}',
+            '-S', str(tcp_port),
+            '-o', '5',
+            '-q',
+        ]
+
+        if gain is not None and gain > 0:
+            cmd.extend(['-gr', 'tuner', str(int(gain))])
+
+        if bias_t:
+            cmd.extend(['-gr', 'biastee', '1'])
+
+        return cmd
+
     def get_capabilities(self) -> SDRCapabilities:
         """Return HackRF capabilities."""
         return self.CAPABILITIES

utils/sdr/limesdr.py

@@ -134,6 +134,34 @@ class LimeSDRCommandBuilder(CommandBuilder):
 
         return cmd
 
+    def build_ais_command(
+        self,
+        device: SDRDevice,
+        gain: Optional[float] = None,
+        bias_t: bool = False,
+        tcp_port: int = 10110
+    ) -> list[str]:
+        """
+        Build AIS-catcher command for AIS vessel tracking with LimeSDR.
+
+        Uses AIS-catcher with SoapySDR support.
+        Note: LimeSDR does not support bias-T, parameter is ignored.
+        """
+        device_str = self._build_device_string(device)
+
+        cmd = [
+            'AIS-catcher',
+            '-d', f'soapysdr -d {device_str}',
+            '-S', str(tcp_port),
+            '-o', '5',
+            '-q',
+        ]
+
+        if gain is not None and gain > 0:
+            cmd.extend(['-gr', 'tuner', str(int(gain))])
+
+        return cmd
+
     def get_capabilities(self) -> SDRCapabilities:
         """Return LimeSDR capabilities."""
         return self.CAPABILITIES

utils/sdr/rtlsdr.py

@@ -157,6 +157,41 @@ class RTLSDRCommandBuilder(CommandBuilder):
 
         return cmd
 
+    def build_ais_command(
+        self,
+        device: SDRDevice,
+        gain: Optional[float] = None,
+        bias_t: bool = False,
+        tcp_port: int = 10110
+    ) -> list[str]:
+        """
+        Build AIS-catcher command for AIS vessel tracking.
+
+        Uses AIS-catcher with TCP JSON output for real-time vessel data.
+        AIS operates on 161.975 MHz and 162.025 MHz (handled automatically).
+        """
+        if device.is_network:
+            raise ValueError(
+                "AIS-catcher does not support rtl_tcp. "
+                "For remote AIS, run AIS-catcher on the remote machine."
+            )
+
+        cmd = [
+            'AIS-catcher',
+            '-d', str(device.index),
+            '-S', str(tcp_port),  # TCP server with JSON output
+            '-o', '5',  # JSON output format
+            '-q',  # Quiet mode (less console output)
+        ]
+
+        if gain is not None and gain > 0:
+            cmd.extend(['-gr', 'tuner', str(int(gain))])
+
+        if bias_t:
+            cmd.extend(['-gr', 'biastee', '1'])
+
+        return cmd
+
     def get_capabilities(self) -> SDRCapabilities:
         """Return RTL-SDR capabilities."""
         return self.CAPABILITIES

utils/sdr/sdrplay.py

@@ -133,6 +133,36 @@ class SDRPlayCommandBuilder(CommandBuilder):
 
         return cmd
 
+    def build_ais_command(
+        self,
+        device: SDRDevice,
+        gain: Optional[float] = None,
+        bias_t: bool = False,
+        tcp_port: int = 10110
+    ) -> list[str]:
+        """
+        Build AIS-catcher command for AIS vessel tracking with SDRPlay.
+
+        Uses AIS-catcher with SoapySDR support.
+        """
+        device_str = self._build_device_string(device)
+
+        cmd = [
+            'AIS-catcher',
+            '-d', f'soapysdr -d {device_str}',
+            '-S', str(tcp_port),
+            '-o', '5',
+            '-q',
+        ]
+
+        if gain is not None and gain > 0:
+            cmd.extend(['-gr', 'tuner', str(int(gain))])
+
+        if bias_t:
+            cmd.extend(['-gr', 'biastee', '1'])
+
+        return cmd
+
     def get_capabilities(self) -> SDRCapabilities:
         """Return SDRPlay capabilities."""
         return self.CAPABILITIES