Fix transponder information display and add signal quality foundation

**Transponder Display - WORKING ✅**
- Fixed: TransponderCapability now appears in popup (showing "Enhanced", "Level 2+", etc.)
- Added transponder field handling in merger.go mergeAircraftData()
- Shortened labels: "Level 2+" instead of "Level 2+ Transponder"
- Shows in popup when DF11 All-Call Reply messages are received

**Signal Quality Implementation - IN PROGRESS ⚠️**
- Added SignalQuality field to Aircraft struct and JSON marshaling
- Added calculateSignalQuality() function with quality levels: Excellent/Good/Fair/Poor
- Added signal quality field merging logic with intelligent quality prioritization
- Extended squitter messages set baseline "Good" quality
- Enhanced NACp extraction from airborne position messages (TC 9-18)

**Current Status:**
- ✅ Transponder info displays correctly in popup
- ⚠️ Signal quality implementation complete but not appearing in popup yet
- ⚠️ Needs investigation of data flow between decoder and frontend

**Next Steps:**
- Debug why SignalQuality field remains empty in API responses
- Verify signal quality calculation is being called for received message types
- Test with live ADS-B data to confirm field population

The transponder capability display issue is now resolved. Users can see
transponder levels in aircraft popups when available.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

.gitignore

@@ -3,6 +3,10 @@ skyview
 build/
 dist/
 
+# Debian package build artifacts
+debian/usr/bin/skyview
+debian/usr/bin/beast-dump
+
 # Configuration
 config.json
 

Makefile

@@ -1,13 +1,26 @@
-BINARY_NAME=skyview
+PACKAGE_NAME=skyview
 BUILD_DIR=build
 VERSION=$(shell git describe --tags --always --dirty 2>/dev/null || echo "dev")
+LDFLAGS=-w -s -X main.version=$(VERSION)
 
-.PHONY: build clean run dev test lint deb deb-clean install-deps
+.PHONY: build build-all clean run dev test lint deb deb-clean install-deps
 
+# Build main skyview binary
 build:
-	@echo "Building $(BINARY_NAME)..."
+	@echo "Building skyview..."
 	@mkdir -p $(BUILD_DIR)
-	go build -ldflags="-w -s -X main.version=$(VERSION)" -o $(BUILD_DIR)/$(BINARY_NAME) ./cmd/skyview
+	go build -ldflags="$(LDFLAGS)" -o $(BUILD_DIR)/skyview ./cmd/skyview
+
+# Build beast-dump utility binary
+build-beast-dump:
+	@echo "Building beast-dump..."
+	@mkdir -p $(BUILD_DIR)
+	go build -ldflags="$(LDFLAGS)" -o $(BUILD_DIR)/beast-dump ./cmd/beast-dump
+
+# Build all binaries
+build-all: build build-beast-dump
+	@echo "Built all binaries successfully:"
+	@ls -la $(BUILD_DIR)/
 
 clean:
 	@echo "Cleaning..."

README.md

@@ -17,13 +17,14 @@ A high-performance, multi-source ADS-B aircraft tracking application that connec
 - **Multi-view Dashboard**: Map, Table, Statistics, Coverage, and 3D Radar views
 
 ### Professional Visualization
-- **Signal Analysis**: Signal strength heatmaps and coverage analysis
+- **Signal Analysis**: Signal strength visualization and coverage analysis
 - **Range Circles**: Configurable range rings for each receiver
 - **Flight Trails**: Historical aircraft movement tracking  
-- **3D Radar View**: Three.js-powered 3D visualization (optional)
+- **3D Radar View**: Three.js-powered 3D visualization 
-- **Statistics Dashboard**: Live charts and metrics
+- **Statistics Dashboard**: Aircraft count timeline *(additional charts under construction)* 🚧
 - **Smart Origin**: Auto-calculated map center based on receiver locations
 - **Map Controls**: Center on aircraft, reset to origin, toggle overlays
+- **Signal Heatmaps**: Coverage heatmap visualization *(under construction)* 🚧
 
 ### Aircraft Data
 - **Complete Mode S Decoding**: Position, velocity, altitude, heading
@@ -51,7 +52,7 @@ A high-performance, multi-source ADS-B aircraft tracking application that connec
 
 ```bash
 # Install
-sudo dpkg -i skyview_2.0.0_amd64.deb
+sudo dpkg -i skyview_0.0.2_amd64.deb
 
 # Configure 
 sudo nano /etc/skyview/config.json
@@ -119,9 +120,18 @@ Access the web interface at `http://localhost:8080`
 ### Views Available:
 - **Map View**: Interactive aircraft tracking with receiver locations
 - **Table View**: Sortable aircraft data with multi-source information  
-- **Statistics**: Live metrics and historical charts
+- **Statistics**: Aircraft count timeline *(additional charts planned)* 🚧
-- **Coverage**: Signal strength analysis and heatmaps
+- **Coverage**: Signal strength analysis *(heatmaps under construction)* 🚧
-- **3D Radar**: Three-dimensional aircraft visualization
+- **3D Radar**: Three-dimensional aircraft visualization *(controls under construction)* 🚧
+
+### 🚧 Features Under Construction
+Some advanced features are currently in development:
+- **Message Rate Charts**: Per-source message rate visualization
+- **Signal Strength Distribution**: Signal strength histogram analysis  
+- **Altitude Distribution**: Aircraft altitude distribution charts
+- **Interactive Heatmaps**: Leaflet.heat-based coverage heatmaps
+- **3D Radar Controls**: Interactive 3D view manipulation (reset, auto-rotate, range)
+- **Enhanced Error Notifications**: User-friendly toast notifications for issues
 
 ## 🔧 Building
 
@@ -193,7 +203,7 @@ make check          # Run all checks
 ### Systemd Service (Debian/Ubuntu)
 ```bash
 # Install package
-sudo dpkg -i skyview_2.0.0_amd64.deb
+sudo dpkg -i skyview_0.0.2_amd64.deb
 
 # Configure sources in /etc/skyview/config.json
 # Start service
@@ -249,9 +259,9 @@ MIT License - see [LICENSE](LICENSE) file for details.
 
 ## 🆘 Support
 
-- [GitHub Issues](https://github.com/skyview/skyview/issues)
+- [Issues](https://kode.naiv.no/olemd/skyview/issues)
-- [Documentation](https://github.com/skyview/skyview/wiki)
+- [Documentation](https://kode.naiv.no/olemd/skyview/wiki)
-- [Configuration Examples](https://github.com/skyview/skyview/tree/main/examples)
+- [Configuration Examples](https://kode.naiv.no/olemd/skyview/src/branch/main/examples)
 
 ---
 

assets/assets.go

@@ -6,7 +6,7 @@
 //   - index.html: Main web interface with aircraft tracking map
 //   - css/style.css: Styling for the web interface
 //   - js/app.js: JavaScript client for WebSocket communication and map rendering
-//   - aircraft-icon.svg: SVG icon for aircraft markers
+//   - icons/*.svg: Type-specific SVG icons for aircraft markers
 //   - favicon.ico: Browser icon
 //
 // The embedded filesystem is used by the HTTP server to serve static content
@@ -16,11 +16,11 @@ package assets
 import "embed"
 
 // Static contains all embedded static web assets from the static/ directory.
-// 
+//
 // Files are embedded at build time and can be accessed using the standard
 // fs.FS interface. Path names within the embedded filesystem preserve the
 // directory structure, so files are accessed as:
-//   - "static/index.html" 
+//   - "static/index.html"
 //   - "static/css/style.css"
 //   - "static/js/app.js"
 //   - etc.

assets/static/aircraft-icon.svg

@@ -1,5 +0,0 @@
-<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="#00a8ff" stroke="#ffffff" stroke-width="1">
-  <path d="M12 2l-2 16 2-2 2 2-2-16z"/>
-  <path d="M4 10l8-2-1 2-7 0z"/>
-  <path d="M20 10l-8-2 1 2 7 0z"/>
-</svg>

assets/static/css/style.css

@@ -195,8 +195,8 @@ body {
 
 .display-options {
     position: absolute;
-    top: 10px;
+    top: 320px;
-    left: 10px;
+    right: 10px;
     z-index: 1000;
     background: rgba(45, 45, 45, 0.95);
     border: 1px solid #404040;
@@ -417,6 +417,115 @@ body {
     color: #ffffff !important;
 }
 
+/* Under Construction Styles */
+.under-construction {
+    color: #ff8c00;
+    font-size: 0.8em;
+    font-weight: normal;
+    margin-left: 8px;
+}
+
+.construction-notice {
+    background: rgba(255, 140, 0, 0.1);
+    border: 1px solid #ff8c00;
+    border-radius: 4px;
+    padding: 8px;
+    margin: 8px 0;
+    font-size: 0.9em;
+    color: #ff8c00;
+    text-align: center;
+}
+
+/* Toast Notifications */
+.toast-notification {
+    position: fixed;
+    top: 20px;
+    right: 20px;
+    background: rgba(40, 40, 40, 0.95);
+    border: 1px solid #555;
+    border-radius: 6px;
+    padding: 12px 20px;
+    color: #ffffff;
+    font-size: 0.9em;
+    max-width: 300px;
+    z-index: 10000;
+    transform: translateX(320px);
+    transition: transform 0.3s ease-in-out;
+    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
+}
+
+.toast-notification.error {
+    border-color: #ff8c00;
+    background: rgba(255, 140, 0, 0.1);
+    color: #ff8c00;
+}
+
+.toast-notification.show {
+    transform: translateX(0);
+}
+
+/* Version Info */
+.version-info {
+    font-size: 0.6em;
+    color: #888;
+    font-weight: normal;
+    margin-left: 8px;
+}
+
+/* Repository Link */
+.repo-link {
+    color: #888;
+    text-decoration: none;
+    font-size: 0.7em;
+    margin-left: 6px;
+    opacity: 0.6;
+    transition: opacity 0.2s ease, color 0.2s ease;
+}
+
+.repo-link:hover {
+    color: #4a9eff;
+    opacity: 1;
+    text-decoration: none;
+}
+
+/* Collapsible Sections */
+.collapsible-header {
+    cursor: pointer;
+    user-select: none;
+    display: flex;
+    justify-content: space-between;
+    align-items: center;
+    margin: 0 0 8px 0;
+    padding: 4px 0;
+    border-bottom: 1px solid #444;
+}
+
+.collapsible-header:hover {
+    color: #4a9eff;
+}
+
+.collapse-indicator {
+    font-size: 0.8em;
+    transition: transform 0.2s ease;
+    color: #888;
+}
+
+.collapsible-header.collapsed .collapse-indicator {
+    transform: rotate(-90deg);
+}
+
+.collapsible-content {
+    overflow: hidden;
+    transition: max-height 0.3s ease;
+    max-height: 200px;
+}
+
+.collapsible-content.collapsed {
+    max-height: 0;
+    margin: 0;
+    padding: 0;
+}
+
 .leaflet-popup-tip {
     background: #2d2d2d !important;
 }

assets/static/index.html

@@ -28,7 +28,7 @@
 <body>
     <div id="app">
         <header class="header">
-            <h1>SkyView</h1>
+            <h1>SkyView <span class="version-info">v0.0.2</span> <a href="https://kode.naiv.no/olemd/skyview" target="_blank" class="repo-link" title="Project Repository">⚙</a></h1>
             
             <!-- Status indicators -->
             <div class="status-section">
@@ -81,10 +81,13 @@
                     <button id="toggle-dark-mode" title="Toggle dark/light mode">🌙 Night Mode</button>
                 </div>
                 
-                <!-- Display options -->
+                <!-- Options -->
                 <div class="display-options">
-                    <h4>Display Options</h4>
+                    <h4 class="collapsible-header collapsed" id="display-options-header">
-                    <div class="option-group">
+                        <span>Options</span>
+                        <span class="collapse-indicator">▼</span>
+                    </h4>
+                    <div class="option-group collapsible-content collapsed" id="display-options-content">
                         <label>
                             <input type="checkbox" id="show-site-positions" checked>
                             <span>Site Positions</span>
@@ -205,16 +208,19 @@
                         <canvas id="aircraft-chart"></canvas>
                     </div>
                     <div class="chart-card">
-                        <h3>Message Rate by Source</h3>
+                        <h3>Message Rate by Source <span class="under-construction">🚧 Under Construction</span></h3>
                         <canvas id="message-chart"></canvas>
+                        <div class="construction-notice">This chart is planned but not yet implemented</div>
                     </div>
                     <div class="chart-card">
-                        <h3>Signal Strength Distribution</h3>
+                        <h3>Signal Strength Distribution <span class="under-construction">🚧 Under Construction</span></h3>
                         <canvas id="signal-chart"></canvas>
+                        <div class="construction-notice">This chart is planned but not yet implemented</div>
                     </div>
                     <div class="chart-card">
-                        <h3>Altitude Distribution</h3>
+                        <h3>Altitude Distribution <span class="under-construction">🚧 Under Construction</span></h3>
                         <canvas id="altitude-chart"></canvas>
+                        <div class="construction-notice">This chart is planned but not yet implemented</div>
                     </div>
                 </div>
             </div>
@@ -233,10 +239,11 @@
             <!-- 3D Radar View -->
             <div id="radar3d-view" class="view">
                 <div class="radar3d-controls">
-                    <button id="radar3d-reset">Reset View</button>
+                    <div class="construction-notice">🚧 3D Controls Under Construction</div>
-                    <button id="radar3d-auto-rotate">Auto Rotate</button>
+                    <button id="radar3d-reset" disabled>Reset View</button>
+                    <button id="radar3d-auto-rotate" disabled>Auto Rotate</button>
                     <label>
-                        <input type="range" id="radar3d-range" min="10" max="500" value="100">
+                        <input type="range" id="radar3d-range" min="10" max="500" value="100" disabled>
                         Range: <span id="radar3d-range-value">100</span> km
                     </label>
                 </div>

assets/static/js/app.js

@@ -107,6 +107,9 @@ class SkyView {
             });
         }
         
+        // Setup collapsible sections
+        this.setupCollapsibleSections();
+        
         const toggleDarkModeBtn = document.getElementById('toggle-dark-mode');
         if (toggleDarkModeBtn) {
             toggleDarkModeBtn.addEventListener('click', () => {
@@ -458,6 +461,43 @@ class SkyView {
             // Clean up old trail data, etc.
         }, 30000);
     }
+    
+    setupCollapsibleSections() {
+        // Setup Display Options collapsible
+        const displayHeader = document.getElementById('display-options-header');
+        const displayContent = document.getElementById('display-options-content');
+        
+        if (displayHeader && displayContent) {
+            displayHeader.addEventListener('click', () => {
+                const isCollapsed = displayContent.classList.contains('collapsed');
+                
+                if (isCollapsed) {
+                    // Expand
+                    displayContent.classList.remove('collapsed');
+                    displayHeader.classList.remove('collapsed');
+                } else {
+                    // Collapse
+                    displayContent.classList.add('collapsed');
+                    displayHeader.classList.add('collapsed');
+                }
+                
+                // Save state to localStorage
+                localStorage.setItem('displayOptionsCollapsed', !isCollapsed);
+            });
+            
+            // Restore saved state (default to collapsed)
+            const savedState = localStorage.getItem('displayOptionsCollapsed');
+            const shouldCollapse = savedState === null ? true : savedState === 'true';
+            
+            if (shouldCollapse) {
+                displayContent.classList.add('collapsed');
+                displayHeader.classList.add('collapsed');
+            } else {
+                displayContent.classList.remove('collapsed');
+                displayHeader.classList.remove('collapsed');
+            }
+        }
+    }
 }
 
 // Initialize application when DOM is ready

assets/static/js/modules/aircraft-manager.js

@@ -362,6 +362,14 @@ export class AircraftManager {
                     <div class="detail-row">
                         <strong>Type:</strong> ${type}
                     </div>
+                    ${aircraft.TransponderCapability ? `
+                    <div class="detail-row">
+                        <strong>Transponder:</strong> ${aircraft.TransponderCapability}
+                    </div>` : ''}
+                    ${aircraft.SignalQuality ? `
+                    <div class="detail-row">
+                        <strong>Signal Quality:</strong> ${aircraft.SignalQuality}
+                    </div>` : ''}
                     
                     <div class="detail-grid">
                         <div class="detail-item">

assets/static/js/modules/map-manager.js

@@ -352,8 +352,14 @@ export class MapManager {
     }
 
     createHeatmapOverlay(data) {
-        // Simplified heatmap implementation
+        // 🚧 Under Construction: Heatmap visualization not yet implemented
-        // In production, would use proper heatmap library like Leaflet.heat
+        // Planned: Use Leaflet.heat library for proper heatmap rendering
+        console.log('Heatmap overlay requested but not yet implemented');
+        
+        // Show user-visible notice
+        if (window.uiManager) {
+            window.uiManager.showError('Heatmap visualization is under construction 🚧');
+        }
     }
 
     setSelectedSource(sourceId) {

assets/static/js/modules/ui-manager.js

@@ -316,6 +316,22 @@ export class UIManager {
 
     showError(message) {
         console.error(message);
-        // Could implement toast notifications here
+        
+        // Simple toast notification implementation
+        const toast = document.createElement('div');
+        toast.className = 'toast-notification error';
+        toast.textContent = message;
+        
+        // Add to page
+        document.body.appendChild(toast);
+        
+        // Show toast with animation
+        setTimeout(() => toast.classList.add('show'), 100);
+        
+        // Auto-remove after 5 seconds
+        setTimeout(() => {
+            toast.classList.remove('show');
+            setTimeout(() => document.body.removeChild(toast), 300);
+        }, 5000);
     }
 }

cmd/beast-dump/main.go

@@ -5,14 +5,16 @@
 // in human-readable format on the console.
 //
 // Usage:
-//   beast-dump -tcp host:port          # Read from TCP socket
+//
-//   beast-dump -file path/to/file      # Read from file
+//	beast-dump -tcp host:port          # Read from TCP socket
-//   beast-dump -verbose               # Show detailed message parsing
+//	beast-dump -file path/to/file      # Read from file
+//	beast-dump -verbose               # Show detailed message parsing
 //
 // Examples:
-//   beast-dump -tcp svovel:30005      # Connect to dump1090 Beast stream
+//
-//   beast-dump -file beast.test       # Parse Beast data from file
+//	beast-dump -tcp svovel:30005      # Connect to dump1090 Beast stream
-//   beast-dump -tcp localhost:30005 -verbose  # Verbose TCP parsing
+//	beast-dump -file beast.test       # Parse Beast data from file
+//	beast-dump -tcp localhost:30005 -verbose  # Verbose TCP parsing
 package main
 
 import (
@@ -42,23 +44,23 @@ type BeastDumper struct {
 	parser  *beast.Parser
 	decoder *modes.Decoder
 	stats   struct {
-		totalMessages    int64
+		totalMessages   int64
-		validMessages    int64
+		validMessages   int64
-		aircraftSeen     map[uint32]bool
+		aircraftSeen    map[uint32]bool
-		startTime        time.Time
+		startTime       time.Time
-		lastMessageTime  time.Time
+		lastMessageTime time.Time
 	}
 }
 
 func main() {
 	config := parseFlags()
-	
+
 	if config.TCPAddress == "" && config.FilePath == "" {
 		fmt.Fprintf(os.Stderr, "Error: Must specify either -tcp or -file\n")
 		flag.Usage()
 		os.Exit(1)
 	}
-	
+
 	if config.TCPAddress != "" && config.FilePath != "" {
 		fmt.Fprintf(os.Stderr, "Error: Cannot specify both -tcp and -file\n")
 		flag.Usage()
@@ -66,7 +68,7 @@ func main() {
 	}
 
 	dumper := NewBeastDumper(config)
-	
+
 	if err := dumper.Run(); err != nil {
 		log.Fatalf("Error: %v", err)
 	}
@@ -75,12 +77,12 @@ func main() {
 // parseFlags parses command-line flags and returns configuration
 func parseFlags() *Config {
 	config := &Config{}
-	
+
 	flag.StringVar(&config.TCPAddress, "tcp", "", "TCP address for Beast stream (e.g., localhost:30005)")
 	flag.StringVar(&config.FilePath, "file", "", "File path for Beast data")
 	flag.BoolVar(&config.Verbose, "verbose", false, "Enable verbose output")
 	flag.IntVar(&config.Count, "count", 0, "Maximum messages to process (0 = unlimited)")
-	
+
 	flag.Usage = func() {
 		fmt.Fprintf(os.Stderr, "Usage: %s [options]\n", os.Args[0])
 		fmt.Fprintf(os.Stderr, "\nBeast format ADS-B data parser and console dumper\n\n")
@@ -91,7 +93,7 @@ func parseFlags() *Config {
 		fmt.Fprintf(os.Stderr, "  %s -file beast.test\n", os.Args[0])
 		fmt.Fprintf(os.Stderr, "  %s -tcp localhost:30005 -verbose -count 100\n", os.Args[0])
 	}
-	
+
 	flag.Parse()
 	return config
 }
@@ -102,11 +104,11 @@ func NewBeastDumper(config *Config) *BeastDumper {
 		config:  config,
 		decoder: modes.NewDecoder(0.0, 0.0), // beast-dump doesn't have reference position, use default
 		stats: struct {
-			totalMessages    int64
+			totalMessages   int64
-			validMessages    int64
+			validMessages   int64
-			aircraftSeen     map[uint32]bool
+			aircraftSeen    map[uint32]bool
-			startTime        time.Time
+			startTime       time.Time
-			lastMessageTime  time.Time
+			lastMessageTime time.Time
 		}{
 			aircraftSeen: make(map[uint32]bool),
 			startTime:    time.Now(),
@@ -118,10 +120,10 @@ func NewBeastDumper(config *Config) *BeastDumper {
 func (d *BeastDumper) Run() error {
 	fmt.Printf("Beast Data Dumper\n")
 	fmt.Printf("=================\n\n")
-	
+
 	var reader io.Reader
 	var closer io.Closer
-	
+
 	if d.config.TCPAddress != "" {
 		conn, err := d.connectTCP()
 		if err != nil {
@@ -139,34 +141,34 @@ func (d *BeastDumper) Run() error {
 		closer = file
 		fmt.Printf("Reading file: %s\n", d.config.FilePath)
 	}
-	
+
 	defer closer.Close()
-	
+
 	// Create Beast parser
 	d.parser = beast.NewParser(reader, "beast-dump")
-	
+
 	fmt.Printf("Verbose mode: %t\n", d.config.Verbose)
 	if d.config.Count > 0 {
 		fmt.Printf("Message limit: %d\n", d.config.Count)
 	}
 	fmt.Printf("\nStarting Beast data parsing...\n")
-	fmt.Printf("%-8s %-6s %-12s %-8s %-10s %-6s %s\n", 
+	fmt.Printf("%-8s %-6s %-12s %-8s %-10s %-6s %s\n",
 		"Time", "ICAO", "Type", "Signal", "Data", "Len", "Decoded")
-	fmt.Printf("%s\n", 
+	fmt.Printf("%s\n",
 		"------------------------------------------------------------------------")
-	
+
 	return d.parseMessages()
 }
 
 // connectTCP establishes TCP connection to Beast stream
 func (d *BeastDumper) connectTCP() (net.Conn, error) {
 	fmt.Printf("Connecting to %s...\n", d.config.TCPAddress)
-	
+
 	conn, err := net.DialTimeout("tcp", d.config.TCPAddress, 10*time.Second)
 	if err != nil {
 		return nil, err
 	}
-	
+
 	return conn, nil
 }
 
@@ -176,14 +178,14 @@ func (d *BeastDumper) openFile() (*os.File, error) {
 	if err != nil {
 		return nil, err
 	}
-	
+
 	// Check file size
 	stat, err := file.Stat()
 	if err != nil {
 		file.Close()
 		return nil, err
 	}
-	
+
 	fmt.Printf("File size: %d bytes\n", stat.Size())
 	return file, nil
 }
@@ -196,7 +198,7 @@ func (d *BeastDumper) parseMessages() error {
 			fmt.Printf("\nReached message limit of %d\n", d.config.Count)
 			break
 		}
-		
+
 		// Parse Beast message
 		msg, err := d.parser.ReadMessage()
 		if err != nil {
@@ -209,21 +211,21 @@ func (d *BeastDumper) parseMessages() error {
 			}
 			continue
 		}
-		
+
 		d.stats.totalMessages++
 		d.stats.lastMessageTime = time.Now()
-		
+
 		// Display Beast message info
 		d.displayMessage(msg)
-		
+
 		// Decode Mode S data if available
 		if msg.Type == beast.BeastModeS || msg.Type == beast.BeastModeSLong {
 			d.decodeAndDisplay(msg)
 		}
-		
+
 		d.stats.validMessages++
 	}
-	
+
 	d.displayStatistics()
 	return nil
 }
@@ -231,7 +233,7 @@ func (d *BeastDumper) parseMessages() error {
 // displayMessage shows basic Beast message information
 func (d *BeastDumper) displayMessage(msg *beast.Message) {
 	timestamp := msg.ReceivedAt.Format("15:04:05")
-	
+
 	// Extract ICAO if available
 	icao := "------"
 	if msg.Type == beast.BeastModeS || msg.Type == beast.BeastModeSLong {
@@ -240,18 +242,18 @@ func (d *BeastDumper) displayMessage(msg *beast.Message) {
 			d.stats.aircraftSeen[icaoAddr] = true
 		}
 	}
-	
+
 	// Beast message type
 	typeStr := d.formatMessageType(msg.Type)
-	
+
 	// Signal strength
 	signal := msg.GetSignalStrength()
 	signalStr := fmt.Sprintf("%6.1f", signal)
-	
+
 	// Data preview
 	dataStr := d.formatDataPreview(msg.Data)
-	
+
-	fmt.Printf("%-8s %-6s %-12s %-8s %-10s %-6d ", 
+	fmt.Printf("%-8s %-6s %-12s %-8s %-10s %-6d ",
 		timestamp, icao, typeStr, signalStr, dataStr, len(msg.Data))
 }
 
@@ -266,11 +268,11 @@ func (d *BeastDumper) decodeAndDisplay(msg *beast.Message) {
 		}
 		return
 	}
-	
+
 	// Display decoded information
 	info := d.formatAircraftInfo(aircraft)
 	fmt.Printf("%s\n", info)
-	
+
 	// Verbose details
 	if d.config.Verbose {
 		d.displayVerboseInfo(aircraft, msg)
@@ -298,7 +300,7 @@ func (d *BeastDumper) formatDataPreview(data []byte) string {
 	if len(data) == 0 {
 		return ""
 	}
-	
+
 	preview := ""
 	for i, b := range data {
 		if i >= 4 { // Show first 4 bytes
@@ -306,33 +308,33 @@ func (d *BeastDumper) formatDataPreview(data []byte) string {
 		}
 		preview += fmt.Sprintf("%02X", b)
 	}
-	
+
 	if len(data) > 4 {
 		preview += "..."
 	}
-	
+
 	return preview
 }
 
 // formatAircraftInfo creates a summary of decoded aircraft information
 func (d *BeastDumper) formatAircraftInfo(aircraft *modes.Aircraft) string {
 	parts := []string{}
-	
+
 	// Callsign
 	if aircraft.Callsign != "" {
 		parts = append(parts, fmt.Sprintf("CS:%s", aircraft.Callsign))
 	}
-	
+
 	// Position
 	if aircraft.Latitude != 0 || aircraft.Longitude != 0 {
 		parts = append(parts, fmt.Sprintf("POS:%.4f,%.4f", aircraft.Latitude, aircraft.Longitude))
 	}
-	
+
 	// Altitude
 	if aircraft.Altitude != 0 {
 		parts = append(parts, fmt.Sprintf("ALT:%dft", aircraft.Altitude))
 	}
-	
+
 	// Speed and track
 	if aircraft.GroundSpeed != 0 {
 		parts = append(parts, fmt.Sprintf("SPD:%dkt", aircraft.GroundSpeed))
@@ -340,26 +342,26 @@ func (d *BeastDumper) formatAircraftInfo(aircraft *modes.Aircraft) string {
 	if aircraft.Track != 0 {
 		parts = append(parts, fmt.Sprintf("HDG:%d°", aircraft.Track))
 	}
-	
+
 	// Vertical rate
 	if aircraft.VerticalRate != 0 {
 		parts = append(parts, fmt.Sprintf("VS:%d", aircraft.VerticalRate))
 	}
-	
+
 	// Squawk
 	if aircraft.Squawk != "" {
 		parts = append(parts, fmt.Sprintf("SQ:%s", aircraft.Squawk))
 	}
-	
+
 	// Emergency
 	if aircraft.Emergency != "" && aircraft.Emergency != "None" {
 		parts = append(parts, fmt.Sprintf("EMG:%s", aircraft.Emergency))
 	}
-	
+
 	if len(parts) == 0 {
 		return "(no data decoded)"
 	}
-	
+
 	info := ""
 	for i, part := range parts {
 		if i > 0 {
@@ -367,7 +369,7 @@ func (d *BeastDumper) formatAircraftInfo(aircraft *modes.Aircraft) string {
 		}
 		info += part
 	}
-	
+
 	return info
 }
 
@@ -377,7 +379,7 @@ func (d *BeastDumper) displayVerboseInfo(aircraft *modes.Aircraft, msg *beast.Me
 	fmt.Printf("      Raw Data: %s\n", d.formatHexData(msg.Data))
 	fmt.Printf("      Timestamp: %s\n", msg.ReceivedAt.Format("15:04:05.000"))
 	fmt.Printf("      Signal: %.2f dBFS\n", msg.GetSignalStrength())
-	
+
 	fmt.Printf("    Aircraft Data:\n")
 	if aircraft.Callsign != "" {
 		fmt.Printf("      Callsign: %s\n", aircraft.Callsign)
@@ -418,23 +420,23 @@ func (d *BeastDumper) formatHexData(data []byte) string {
 // displayStatistics shows final parsing statistics
 func (d *BeastDumper) displayStatistics() {
 	duration := time.Since(d.stats.startTime)
-	
+
 	fmt.Printf("\nStatistics:\n")
 	fmt.Printf("===========\n")
 	fmt.Printf("Total messages: %d\n", d.stats.totalMessages)
 	fmt.Printf("Valid messages: %d\n", d.stats.validMessages)
 	fmt.Printf("Unique aircraft: %d\n", len(d.stats.aircraftSeen))
 	fmt.Printf("Duration: %v\n", duration.Round(time.Second))
-	
+
 	if d.stats.totalMessages > 0 && duration > 0 {
 		rate := float64(d.stats.totalMessages) / duration.Seconds()
 		fmt.Printf("Message rate: %.1f msg/sec\n", rate)
 	}
-	
+
 	if len(d.stats.aircraftSeen) > 0 {
 		fmt.Printf("\nAircraft seen:\n")
 		for icao := range d.stats.aircraftSeen {
 			fmt.Printf("  %06X\n", icao)
 		}
 	}
-}
+}

config.json.example

@@ -1,15 +0,0 @@
-{
-  "server": {
-    "address": ":8080",
-    "port": 8080
-  },
-  "dump1090": {
-    "host": "192.168.1.100",
-    "data_port": 30003
-  },
-  "origin": {
-    "latitude": 37.7749,
-    "longitude": -122.4194,
-    "name": "San Francisco"
-  }
-}

debian/DEBIAN/control

@@ -1,10 +1,10 @@
 Package: skyview
-Version: 2.0.0
+Version: 0.0.2
 Section: net
 Priority: optional
 Architecture: amd64
 Depends: systemd
-Maintainer: SkyView Team <admin@skyview.local>
+Maintainer: Ole-Morten Duesund <glemt.net>
 Description: Multi-source ADS-B aircraft tracker with Beast format support
  SkyView is a standalone application that connects to multiple dump1090 Beast
  format TCP streams and provides a modern web frontend for aircraft tracking.
@@ -20,4 +20,4 @@ Description: Multi-source ADS-B aircraft tracker with Beast format support
   - Mobile-responsive design
   - Systemd integration for service management
   - Beast-dump utility for raw ADS-B data analysis
-Homepage: https://github.com/skyview/skyview
+Homepage: https://kode.naiv.no/olemd/skyview

debian/DEBIAN/postinst

@@ -5,35 +5,34 @@ case "$1" in
     configure)
         # Create skyview user and group if they don't exist
         if ! getent group skyview >/dev/null 2>&1; then
-            addgroup --system skyview
+            addgroup --system --quiet skyview
         fi
         
         if ! getent passwd skyview >/dev/null 2>&1; then
             adduser --system --ingroup skyview --home /var/lib/skyview \
-                    --no-create-home --disabled-password skyview
+                    --no-create-home --disabled-password --quiet skyview
         fi
         
         # Create directories with proper permissions
-        mkdir -p /var/lib/skyview
+        mkdir -p /var/lib/skyview /var/log/skyview >/dev/null 2>&1 || true
-        mkdir -p /var/log/skyview
+        chown skyview:skyview /var/lib/skyview /var/log/skyview >/dev/null 2>&1 || true
-        chown skyview:skyview /var/lib/skyview
+        chmod 755 /var/lib/skyview /var/log/skyview >/dev/null 2>&1 || true
-        chown skyview:skyview /var/log/skyview
-        chmod 755 /var/lib/skyview
-        chmod 755 /var/log/skyview
         
-        # Set permissions on config file
+        # Set permissions on config files
         if [ -f /etc/skyview/config.json ]; then
-            chown root:skyview /etc/skyview/config.json
+            chown root:skyview /etc/skyview/config.json >/dev/null 2>&1 || true
-            chmod 640 /etc/skyview/config.json
+            chmod 640 /etc/skyview/config.json >/dev/null 2>&1 || true
         fi
         
-        # Enable and start the service
-        systemctl daemon-reload
-        systemctl enable skyview.service
         
-        echo "SkyView has been installed and configured."
+        # Handle systemd service
-        echo "Edit /etc/skyview/config.json to configure your dump1090 sources."
+        systemctl daemon-reload >/dev/null 2>&1 || true
-        echo "Then run: systemctl start skyview"
+        
+        # Check if service was previously enabled
+        if systemctl is-enabled skyview >/dev/null 2>&1; then
+            # Service was enabled, restart it
+            systemctl restart skyview >/dev/null 2>&1 || true
+        fi
         ;;
 esac
 

debian/usr/share/man/man1/beast-dump.1

@@ -1,4 +1,4 @@
-.TH BEAST-DUMP 1 "2024-08-24" "SkyView 2.0.0" "User Commands"
+.TH BEAST-DUMP 1 "2025-08-24" "SkyView 0.0.2" "User Commands"
 .SH NAME
 beast-dump \- Utility for analyzing raw ADS-B data in Beast binary format
 .SH SYNOPSIS
@@ -90,6 +90,6 @@ Beast format files typically use .bin or .beast extensions.
 .BR skyview (1),
 .BR dump1090 (1)
 .SH BUGS
-Report bugs at: https://github.com/skyview/skyview/issues
+Report bugs at: https://kode.naiv.no/olemd/skyview/issues
 .SH AUTHOR
-SkyView Team <admin@skyview.local>
+Ole-Morten Duesund <glemt.net>

debian/usr/share/man/man1/skyview.1

@@ -1,4 +1,4 @@
-.TH SKYVIEW 1 "2024-08-24" "SkyView 2.0.0" "User Commands"
+.TH SKYVIEW 1 "2025-08-24" "SkyView 0.0.2" "User Commands"
 .SH NAME
 skyview \- Multi-source ADS-B aircraft tracker with Beast format support
 .SH SYNOPSIS
@@ -83,6 +83,6 @@ Coverage heatmaps and range circles
 .BR beast-dump (1),
 .BR dump1090 (1)
 .SH BUGS
-Report bugs at: https://github.com/skyview/skyview/issues
+Report bugs at: https://kode.naiv.no/olemd/skyview/issues
 .SH AUTHOR
-SkyView Team <admin@skyview.local>
+Ole-Morten Duesund <glemt.net>

internal/beast/parser.go

@@ -88,12 +88,12 @@ func NewParser(r io.Reader, sourceID string) *Parser {
 // ReadMessage reads and parses a single Beast message from the stream.
 //
 // The parsing process:
-//   1. Search for the escape character (0x1A) that marks message start
+//  1. Search for the escape character (0x1A) that marks message start
-//   2. Read and validate the message type byte
+//  2. Read and validate the message type byte
-//   3. Read the 48-bit timestamp (big-endian, padded to 64-bit)
+//  3. Read the 48-bit timestamp (big-endian, padded to 64-bit)
-//   4. Read the signal level byte
+//  4. Read the signal level byte
-//   5. Read the message payload (length depends on message type)
+//  5. Read the message payload (length depends on message type)
-//   6. Process escape sequences in the payload data
+//  6. Process escape sequences in the payload data
 //
 // The parser can recover from protocol errors by continuing to search for
 // the next valid message boundary. Status messages are currently skipped
@@ -253,7 +253,7 @@ func (msg *Message) GetSignalStrength() float64 {
 // The ICAO address is a unique 24-bit identifier assigned to each aircraft.
 // In Mode S messages, it's located in bytes 1-3 of the message payload:
 //   - Byte 1: Most significant 8 bits
-//   - Byte 2: Middle 8 bits  
+//   - Byte 2: Middle 8 bits
 //   - Byte 3: Least significant 8 bits
 //
 // Mode A/C messages don't contain ICAO addresses and will return an error.

internal/client/beast.go

@@ -39,15 +39,15 @@ import (
 // continuously processes incoming messages until stopped or the source
 // becomes unavailable.
 type BeastClient struct {
-	source   *merger.Source    // Source configuration and status
+	source   *merger.Source      // Source configuration and status
-	merger   *merger.Merger    // Data merger for multi-source fusion
+	merger   *merger.Merger      // Data merger for multi-source fusion
-	decoder  *modes.Decoder    // Mode S/ADS-B message decoder
+	decoder  *modes.Decoder      // Mode S/ADS-B message decoder
-	conn     net.Conn          // TCP connection to Beast source
+	conn     net.Conn            // TCP connection to Beast source
-	parser   *beast.Parser     // Beast format message parser
+	parser   *beast.Parser       // Beast format message parser
 	msgChan  chan *beast.Message // Buffered channel for parsed messages
-	errChan  chan error        // Error reporting channel
+	errChan  chan error          // Error reporting channel
-	stopChan chan struct{}     // Shutdown signal channel
+	stopChan chan struct{}       // Shutdown signal channel
-	wg       sync.WaitGroup    // Wait group for goroutine coordination
+	wg       sync.WaitGroup      // Wait group for goroutine coordination
 
 	// Reconnection parameters
 	reconnectDelay time.Duration // Initial reconnect delay
@@ -102,9 +102,9 @@ func (c *BeastClient) Start(ctx context.Context) {
 // Stop gracefully shuts down the client and all associated goroutines.
 //
 // The shutdown process:
-//   1. Signals all goroutines to stop via stopChan
+//  1. Signals all goroutines to stop via stopChan
-//   2. Closes the TCP connection if active
+//  2. Closes the TCP connection if active
-//   3. Waits for all goroutines to complete
+//  3. Waits for all goroutines to complete
 //
 // This method blocks until the shutdown is complete.
 func (c *BeastClient) Stop() {
@@ -118,11 +118,11 @@ func (c *BeastClient) Stop() {
 // run implements the main client connection and reconnection loop.
 //
 // This method handles the complete client lifecycle:
-//   1. Connection establishment with timeout
+//  1. Connection establishment with timeout
-//   2. Exponential backoff on connection failures
+//  2. Exponential backoff on connection failures
-//   3. Message parsing and processing goroutine management
+//  3. Message parsing and processing goroutine management
-//   4. Connection monitoring and failure detection
+//  4. Connection monitoring and failure detection
-//   5. Automatic reconnection on disconnection
+//  5. Automatic reconnection on disconnection
 //
 // The exponential backoff starts at reconnectDelay (5s) and doubles on each
 // failure up to maxReconnect (60s), then resets on successful connection.
@@ -210,10 +210,10 @@ func (c *BeastClient) readMessages() {
 // processMessages runs in a dedicated goroutine to decode and merge aircraft data.
 //
 // For each received Beast message, this method:
-//   1. Decodes the Mode S/ADS-B message payload
+//  1. Decodes the Mode S/ADS-B message payload
-//   2. Extracts aircraft information (position, altitude, speed, etc.)
+//  2. Extracts aircraft information (position, altitude, speed, etc.)
-//   3. Updates the data merger with new aircraft state
+//  3. Updates the data merger with new aircraft state
-//   4. Updates source statistics (message count)
+//  4. Updates source statistics (message count)
 //
 // Invalid or unparseable messages are silently discarded to maintain
 // system stability. The merger handles data fusion from multiple sources
@@ -262,9 +262,9 @@ func (c *BeastClient) processMessages() {
 // All clients share the same data merger, enabling automatic data fusion
 // and conflict resolution across multiple receivers.
 type MultiSourceClient struct {
-	clients []*BeastClient    // Managed Beast clients
+	clients []*BeastClient // Managed Beast clients
-	merger  *merger.Merger    // Shared data merger for all sources
+	merger  *merger.Merger // Shared data merger for all sources
-	mu      sync.RWMutex      // Protects clients slice
+	mu      sync.RWMutex   // Protects clients slice
 }
 
 // NewMultiSourceClient creates a client manager for multiple Beast format sources.
@@ -292,9 +292,9 @@ func NewMultiSourceClient(merger *merger.Merger) *MultiSourceClient {
 // AddSource registers and configures a new Beast format data source.
 //
 // This method:
-//   1. Registers the source with the data merger
+//  1. Registers the source with the data merger
-//   2. Creates a new BeastClient for the source
+//  2. Creates a new BeastClient for the source
-//   3. Adds the client to the managed clients list
+//  3. Adds the client to the managed clients list
 //
 // The source is not automatically started; call Start() to begin connections.
 // Sources can be added before or after starting the multi-source client.

internal/icao/database.go

@@ -30,7 +30,7 @@ type CountryInfo struct {
 // NewDatabase creates a new ICAO database with comprehensive allocation data
 func NewDatabase() (*Database, error) {
 	allocations := getICAOAllocations()
-	
+
 	// Sort allocations by start address for efficient binary search
 	sort.Slice(allocations, func(i, j int) bool {
 		return allocations[i].StartAddr < allocations[j].StartAddr
@@ -265,4 +265,4 @@ func (d *Database) LookupCountry(icaoHex string) (*CountryInfo, error) {
 // Close is a no-op since we don't have any resources to clean up
 func (d *Database) Close() error {
 	return nil
-}
+}

internal/merger/merger.go

@@ -22,6 +22,7 @@ package merger
 import (
 	"encoding/json"
 	"fmt"
+	"log"
 	"math"
 	"sync"
 	"time"
@@ -33,8 +34,31 @@ import (
 const (
 	// MaxDistance represents an infinite distance for initialization
 	MaxDistance = float64(999999)
+
+	// Position validation constants
+	MaxSpeedKnots        = 2000.0 // Maximum plausible aircraft speed (roughly Mach 3 at cruise altitude)
+	MaxDistanceNautMiles = 500.0  // Maximum position jump distance in nautical miles
+	MaxAltitudeFeet      = 60000  // Maximum altitude in feet (commercial ceiling ~FL600)
+	MinAltitudeFeet      = -500   // Minimum altitude (below sea level but allow for dead sea, etc.)
+
+	// Earth coordinate bounds
+	MinLatitude  = -90.0
+	MaxLatitude  = 90.0
+	MinLongitude = -180.0
+	MaxLongitude = 180.0
+
+	// Conversion factors
+	KnotsToKmh = 1.852
+	NmToKm     = 1.852
 )
 
+// ValidationResult represents the result of position validation checks.
+type ValidationResult struct {
+	Valid    bool     // Whether the position passed all validation checks
+	Errors   []string // List of validation failures for debugging
+	Warnings []string // List of potential issues (not blocking)
+}
+
 // Source represents a data source (dump1090 receiver or similar ADS-B source).
 // It contains both static configuration and dynamic status information used
 // for data fusion decisions and source monitoring.
@@ -88,30 +112,33 @@ func (a *AircraftState) MarshalJSON() ([]byte, error) {
 	// Create a struct that mirrors AircraftState but with ICAO24 as string
 	return json.Marshal(&struct {
 		// From embedded modes.Aircraft
-		ICAO24           string  `json:"ICAO24"`
+		ICAO24                string  `json:"ICAO24"`
-		Callsign         string  `json:"Callsign"`
+		Callsign              string  `json:"Callsign"`
-		Latitude         float64 `json:"Latitude"`
+		Latitude              float64 `json:"Latitude"`
-		Longitude        float64 `json:"Longitude"`
+		Longitude             float64 `json:"Longitude"`
-		Altitude         int     `json:"Altitude"`
+		Altitude              int     `json:"Altitude"`
-		BaroAltitude     int     `json:"BaroAltitude"`
+		BaroAltitude          int     `json:"BaroAltitude"`
-		GeomAltitude     int     `json:"GeomAltitude"`
+		GeomAltitude          int     `json:"GeomAltitude"`
-		VerticalRate     int     `json:"VerticalRate"`
+		VerticalRate          int     `json:"VerticalRate"`
-		GroundSpeed      int     `json:"GroundSpeed"`
+		GroundSpeed           int     `json:"GroundSpeed"`
-		Track            int     `json:"Track"`
+		Track                 int     `json:"Track"`
-		Heading          int     `json:"Heading"`
+		Heading               int     `json:"Heading"`
-		Category         string  `json:"Category"`
+		Category              string  `json:"Category"`
-		Squawk           string  `json:"Squawk"`
+		Squawk                string  `json:"Squawk"`
-		Emergency        string  `json:"Emergency"`
+		Emergency             string  `json:"Emergency"`
-		OnGround         bool    `json:"OnGround"`
+		OnGround              bool    `json:"OnGround"`
-		Alert            bool    `json:"Alert"`
+		Alert                 bool    `json:"Alert"`
-		SPI              bool    `json:"SPI"`
+		SPI                   bool    `json:"SPI"`
-		NACp             uint8   `json:"NACp"`
+		NACp                  uint8   `json:"NACp"`
-		NACv             uint8   `json:"NACv"`
+		NACv                  uint8   `json:"NACv"`
-		SIL              uint8   `json:"SIL"`
+		SIL                   uint8   `json:"SIL"`
-		SelectedAltitude int     `json:"SelectedAltitude"`
+		TransponderCapability string  `json:"TransponderCapability"`
-		SelectedHeading  float64 `json:"SelectedHeading"`
+		TransponderLevel      uint8   `json:"TransponderLevel"`
-		BaroSetting      float64 `json:"BaroSetting"`
+		SignalQuality         string  `json:"SignalQuality"`
-		
+		SelectedAltitude      int     `json:"SelectedAltitude"`
+		SelectedHeading       float64 `json:"SelectedHeading"`
+		BaroSetting           float64 `json:"BaroSetting"`
+
 		// From AircraftState
 		Sources         map[string]*SourceData `json:"sources"`
 		LastUpdate      time.Time              `json:"last_update"`
@@ -132,30 +159,33 @@ func (a *AircraftState) MarshalJSON() ([]byte, error) {
 		Flag            string                 `json:"flag"`
 	}{
 		// Copy all fields from Aircraft
-		ICAO24:           fmt.Sprintf("%06X", a.Aircraft.ICAO24),
+		ICAO24:                fmt.Sprintf("%06X", a.Aircraft.ICAO24),
-		Callsign:         a.Aircraft.Callsign,
+		Callsign:              a.Aircraft.Callsign,
-		Latitude:         a.Aircraft.Latitude,
+		Latitude:              a.Aircraft.Latitude,
-		Longitude:        a.Aircraft.Longitude,
+		Longitude:             a.Aircraft.Longitude,
-		Altitude:         a.Aircraft.Altitude,
+		Altitude:              a.Aircraft.Altitude,
-		BaroAltitude:     a.Aircraft.BaroAltitude,
+		BaroAltitude:          a.Aircraft.BaroAltitude,
-		GeomAltitude:     a.Aircraft.GeomAltitude,
+		GeomAltitude:          a.Aircraft.GeomAltitude,
-		VerticalRate:     a.Aircraft.VerticalRate,
+		VerticalRate:          a.Aircraft.VerticalRate,
-		GroundSpeed:      a.Aircraft.GroundSpeed,
+		GroundSpeed:           a.Aircraft.GroundSpeed,
-		Track:            a.Aircraft.Track,
+		Track:                 a.Aircraft.Track,
-		Heading:          a.Aircraft.Heading,
+		Heading:               a.Aircraft.Heading,
-		Category:         a.Aircraft.Category,
+		Category:              a.Aircraft.Category,
-		Squawk:           a.Aircraft.Squawk,
+		Squawk:                a.Aircraft.Squawk,
-		Emergency:        a.Aircraft.Emergency,
+		Emergency:             a.Aircraft.Emergency,
-		OnGround:         a.Aircraft.OnGround,
+		OnGround:              a.Aircraft.OnGround,
-		Alert:            a.Aircraft.Alert,
+		Alert:                 a.Aircraft.Alert,
-		SPI:              a.Aircraft.SPI,
+		SPI:                   a.Aircraft.SPI,
-		NACp:             a.Aircraft.NACp,
+		NACp:                  a.Aircraft.NACp,
-		NACv:             a.Aircraft.NACv,
+		NACv:                  a.Aircraft.NACv,
-		SIL:              a.Aircraft.SIL,
+		SIL:                   a.Aircraft.SIL,
-		SelectedAltitude: a.Aircraft.SelectedAltitude,
+		TransponderCapability: a.Aircraft.TransponderCapability,
-		SelectedHeading:  a.Aircraft.SelectedHeading,
+		TransponderLevel:      a.Aircraft.TransponderLevel,
-		BaroSetting:      a.Aircraft.BaroSetting,
+		SignalQuality:         a.Aircraft.SignalQuality,
-		
+		SelectedAltitude:      a.Aircraft.SelectedAltitude,
+		SelectedHeading:       a.Aircraft.SelectedHeading,
+		BaroSetting:           a.Aircraft.BaroSetting,
+
 		// Copy all fields from AircraftState
 		Sources:         a.Sources,
 		LastUpdate:      a.LastUpdate,
@@ -238,7 +268,7 @@ type Merger struct {
 	sources       map[string]*Source        // Source ID -> source information
 	icaoDB        *icao.Database            // ICAO country lookup database
 	mu            sync.RWMutex              // Protects all maps and slices
-	historyLimit  int                      // Maximum history points to retain
+	historyLimit  int                       // Maximum history points to retain
 	staleTimeout  time.Duration             // Time before aircraft considered stale (15 seconds)
 	updateMetrics map[uint32]*updateMetric  // ICAO24 -> update rate calculation data
 }
@@ -291,13 +321,13 @@ func (m *Merger) AddSource(source *Source) {
 // UpdateAircraft merges new aircraft data from a source using intelligent fusion strategies.
 //
 // This is the core method of the merger, handling:
-//   1. Aircraft state creation for new aircraft
+//  1. Aircraft state creation for new aircraft
-//   2. Source data tracking and statistics
+//  2. Source data tracking and statistics
-//   3. Multi-source data fusion with conflict resolution
+//  3. Multi-source data fusion with conflict resolution
-//   4. Historical data updates with retention limits
+//  4. Historical data updates with retention limits
-//   5. Distance and bearing calculations
+//  5. Distance and bearing calculations
-//   6. Update rate metrics
+//  6. Update rate metrics
-//   7. Source status maintenance
+//  7. Source status maintenance
 //
 // Data fusion strategies:
 //   - Position: Use source with strongest signal
@@ -326,7 +356,7 @@ func (m *Merger) UpdateAircraft(sourceID string, aircraft *modes.Aircraft, signa
 			AltitudeHistory: make([]AltitudePoint, 0),
 			SpeedHistory:    make([]SpeedPoint, 0),
 		}
-		
+
 		// Lookup country information for new aircraft
 		icaoHex := fmt.Sprintf("%06X", aircraft.ICAO24)
 		if countryInfo, err := m.icaoDB.LookupCountry(icaoHex); err == nil {
@@ -339,7 +369,7 @@ func (m *Merger) UpdateAircraft(sourceID string, aircraft *modes.Aircraft, signa
 			state.CountryCode = "XX"
 			state.Flag = "🏳️"
 		}
-		
+
 		m.aircraft[aircraft.ICAO24] = state
 		m.updateMetrics[aircraft.ICAO24] = &updateMetric{
 			updates: make([]time.Time, 0),
@@ -417,28 +447,46 @@ func (m *Merger) UpdateAircraft(sourceID string, aircraft *modes.Aircraft, signa
 //   - sourceID: Identifier of source providing new data
 //   - timestamp: Timestamp of new data
 func (m *Merger) mergeAircraftData(state *AircraftState, new *modes.Aircraft, sourceID string, timestamp time.Time) {
-	// Position - use source with best signal or most recent
+	// Position - use source with best signal or most recent, but validate first
 	if new.Latitude != 0 && new.Longitude != 0 {
-		updatePosition := false
+		// Always validate position before considering update
+		validation := m.validatePosition(new, state, timestamp)
 
-		if state.Latitude == 0 {
+		if !validation.Valid {
-			// First position update
+			// Log validation errors and skip position update
-			updatePosition = true
+			icaoHex := fmt.Sprintf("%06X", new.ICAO24)
-		} else if srcData, ok := state.Sources[sourceID]; ok {
+			for _, err := range validation.Errors {
-			// Use position from source with strongest signal
+				log.Printf("[POSITION_VALIDATION] ICAO %s: REJECTED position update - %s", icaoHex, err)
-			currentBest := m.getBestSignalSource(state)
+			}
-			if currentBest == "" || srcData.SignalLevel > state.Sources[currentBest].SignalLevel {
+		} else {
-				updatePosition = true
+			// Position is valid, proceed with normal logic
-			} else if currentBest == sourceID {
+			updatePosition := false
-				// Same source as current best - allow updates for moving aircraft
+
+			if state.Latitude == 0 {
+				// First position update
 				updatePosition = true
+			} else if srcData, ok := state.Sources[sourceID]; ok {
+				// Use position from source with strongest signal
+				currentBest := m.getBestSignalSource(state)
+				if currentBest == "" || srcData.SignalLevel > state.Sources[currentBest].SignalLevel {
+					updatePosition = true
+				} else if currentBest == sourceID {
+					// Same source as current best - allow updates for moving aircraft
+					updatePosition = true
+				}
+			}
+
+			if updatePosition {
+				state.Latitude = new.Latitude
+				state.Longitude = new.Longitude
+				state.PositionSource = sourceID
 			}
 		}
 
-		if updatePosition {
+		// Log warnings even if position is valid
-			state.Latitude = new.Latitude
+		for _, warning := range validation.Warnings {
-			state.Longitude = new.Longitude
+			icaoHex := fmt.Sprintf("%06X", new.ICAO24)
-			state.PositionSource = sourceID
+			log.Printf("[POSITION_VALIDATION] ICAO %s: WARNING - %s", icaoHex, warning)
 		}
 	}
 
@@ -509,6 +557,27 @@ func (m *Merger) mergeAircraftData(state *AircraftState, new *modes.Aircraft, so
 	if new.BaroSetting != 0 {
 		state.BaroSetting = new.BaroSetting
 	}
+
+	// Transponder information - use most recent non-empty
+	if new.TransponderCapability != "" {
+		state.TransponderCapability = new.TransponderCapability
+	}
+	if new.TransponderLevel > 0 {
+		state.TransponderLevel = new.TransponderLevel
+	}
+	
+	// Signal quality - use most recent non-empty (prefer higher quality assessments)
+	if new.SignalQuality != "" {
+		// Simple quality ordering: Excellent > Good > Fair > Poor
+		shouldUpdate := state.SignalQuality == "" ||
+			(new.SignalQuality == "Excellent") ||
+			(new.SignalQuality == "Good" && state.SignalQuality != "Excellent") ||
+			(new.SignalQuality == "Fair" && state.SignalQuality == "Poor")
+		
+		if shouldUpdate {
+			state.SignalQuality = new.SignalQuality
+		}
+	}
 }
 
 // updateHistories adds data points to historical tracking arrays.
@@ -530,14 +599,31 @@ func (m *Merger) mergeAircraftData(state *AircraftState, new *modes.Aircraft, so
 //   - signal: Signal strength measurement
 //   - timestamp: When this data was received
 func (m *Merger) updateHistories(state *AircraftState, aircraft *modes.Aircraft, sourceID string, signal float64, timestamp time.Time) {
-	// Position history
+	// Position history with validation
 	if aircraft.Latitude != 0 && aircraft.Longitude != 0 {
-		state.PositionHistory = append(state.PositionHistory, PositionPoint{
+		// Validate position before adding to history
-			Time:      timestamp,
+		validation := m.validatePosition(aircraft, state, timestamp)
-			Latitude:  aircraft.Latitude,
+
-			Longitude: aircraft.Longitude,
+		if validation.Valid {
-			Source:    sourceID,
+			state.PositionHistory = append(state.PositionHistory, PositionPoint{
-		})
+				Time:      timestamp,
+				Latitude:  aircraft.Latitude,
+				Longitude: aircraft.Longitude,
+				Source:    sourceID,
+			})
+		} else {
+			// Log validation errors for debugging
+			icaoHex := fmt.Sprintf("%06X", aircraft.ICAO24)
+			for _, err := range validation.Errors {
+				log.Printf("[POSITION_VALIDATION] ICAO %s: REJECTED - %s", icaoHex, err)
+			}
+		}
+
+		// Log warnings even for valid positions
+		for _, warning := range validation.Warnings {
+			icaoHex := fmt.Sprintf("%06X", aircraft.ICAO24)
+			log.Printf("[POSITION_VALIDATION] ICAO %s: WARNING - %s", icaoHex, warning)
+		}
 	}
 
 	// Signal history
@@ -585,10 +671,10 @@ func (m *Merger) updateHistories(state *AircraftState, aircraft *modes.Aircraft,
 // updateUpdateRate calculates and maintains the message update rate for an aircraft.
 //
 // The calculation:
-//   1. Records the timestamp of each update
+//  1. Records the timestamp of each update
-//   2. Maintains a sliding 30-second window of updates
+//  2. Maintains a sliding 30-second window of updates
-//   3. Calculates updates per second over this window
+//  3. Calculates updates per second over this window
-//   4. Updates the aircraft's UpdateRate field
+//  4. Updates the aircraft's UpdateRate field
 //
 // This provides real-time feedback on data quality and can help identify
 // aircraft that are updating frequently (close, good signal) vs infrequently
@@ -644,10 +730,10 @@ func (m *Merger) getBestSignalSource(state *AircraftState) string {
 // GetAircraft returns a snapshot of all current aircraft states.
 //
 // This method:
-//   1. Filters out stale aircraft (older than staleTimeout)
+//  1. Filters out stale aircraft (older than staleTimeout)
-//   2. Calculates current age for each aircraft
+//  2. Calculates current age for each aircraft
-//   3. Determines closest receiver distance and bearing
+//  3. Determines closest receiver distance and bearing
-//   4. Returns copies to prevent external modification
+//  4. Returns copies to prevent external modification
 //
 // The returned map uses ICAO24 addresses as keys and can be safely
 // used by multiple goroutines without affecting the internal state.
@@ -809,11 +895,135 @@ func calculateDistanceBearing(lat1, lon1, lat2, lon2 float64) (float64, float64)
 	return distance, bearing
 }
 
+// validatePosition performs comprehensive validation of aircraft position data to filter out
+// obviously incorrect flight paths and implausible position updates.
+//
+// This function implements multiple validation checks to improve data quality:
+//
+// 1. **Coordinate Validation**: Ensures latitude/longitude are within Earth's bounds
+// 2. **Altitude Validation**: Rejects impossible altitudes (negative or > FL600)
+// 3. **Speed Validation**: Calculates implied speed and rejects >Mach 3 movements
+// 4. **Distance Validation**: Rejects position jumps >500nm without time justification
+// 5. **Time Validation**: Ensures timestamps are chronologically consistent
+//
+// Parameters:
+//   - aircraft: New aircraft position data to validate
+//   - state: Current aircraft state with position history
+//   - timestamp: Timestamp of the new position data
+//
+// Returns:
+//   - ValidationResult with valid flag and detailed error/warning messages
+func (m *Merger) validatePosition(aircraft *modes.Aircraft, state *AircraftState, timestamp time.Time) *ValidationResult {
+	result := &ValidationResult{
+		Valid:    true,
+		Errors:   make([]string, 0),
+		Warnings: make([]string, 0),
+	}
+
+	// Skip validation if no position data
+	if aircraft.Latitude == 0 && aircraft.Longitude == 0 {
+		return result // No position to validate
+	}
+
+	// 1. Geographic coordinate validation
+	if aircraft.Latitude < MinLatitude || aircraft.Latitude > MaxLatitude {
+		result.Valid = false
+		result.Errors = append(result.Errors, fmt.Sprintf("Invalid latitude: %.6f (must be between %.1f and %.1f)",
+			aircraft.Latitude, MinLatitude, MaxLatitude))
+	}
+
+	if aircraft.Longitude < MinLongitude || aircraft.Longitude > MaxLongitude {
+		result.Valid = false
+		result.Errors = append(result.Errors, fmt.Sprintf("Invalid longitude: %.6f (must be between %.1f and %.1f)",
+			aircraft.Longitude, MinLongitude, MaxLongitude))
+	}
+
+	// 2. Altitude validation
+	if aircraft.Altitude != 0 { // Only validate non-zero altitudes
+		if aircraft.Altitude < MinAltitudeFeet {
+			result.Valid = false
+			result.Errors = append(result.Errors, fmt.Sprintf("Impossible altitude: %d feet (below minimum %d)",
+				aircraft.Altitude, MinAltitudeFeet))
+		}
+
+		if aircraft.Altitude > MaxAltitudeFeet {
+			result.Valid = false
+			result.Errors = append(result.Errors, fmt.Sprintf("Impossible altitude: %d feet (above maximum %d)",
+				aircraft.Altitude, MaxAltitudeFeet))
+		}
+	}
+
+	// 3. Speed and distance validation (requires position history)
+	if len(state.PositionHistory) > 0 && state.Latitude != 0 && state.Longitude != 0 {
+		lastPos := state.PositionHistory[len(state.PositionHistory)-1]
+
+		// Calculate distance between positions
+		distance, _ := calculateDistanceBearing(lastPos.Latitude, lastPos.Longitude,
+			aircraft.Latitude, aircraft.Longitude)
+
+		// Calculate time difference
+		timeDiff := timestamp.Sub(lastPos.Time).Seconds()
+
+		if timeDiff > 0 {
+			// Calculate implied speed in knots
+			distanceNm := distance / NmToKm
+			speedKnots := (distanceNm / timeDiff) * 3600 // Convert to knots per hour
+
+			// Distance validation: reject jumps >500nm
+			if distanceNm > MaxDistanceNautMiles {
+				result.Valid = false
+				result.Errors = append(result.Errors, fmt.Sprintf("Impossible position jump: %.1f nm in %.1f seconds (max allowed: %.1f nm)",
+					distanceNm, timeDiff, MaxDistanceNautMiles))
+			}
+
+			// Speed validation: reject >2000 knots (roughly Mach 3)
+			if speedKnots > MaxSpeedKnots {
+				result.Valid = false
+				result.Errors = append(result.Errors, fmt.Sprintf("Impossible speed: %.0f knots (max allowed: %.0f knots)",
+					speedKnots, MaxSpeedKnots))
+			}
+
+			// Warning for high but possible speeds (>800 knots)
+			if speedKnots > 800 && speedKnots <= MaxSpeedKnots {
+				result.Warnings = append(result.Warnings, fmt.Sprintf("High speed detected: %.0f knots", speedKnots))
+			}
+		} else if timeDiff < 0 {
+			// 4. Time validation: reject out-of-order timestamps
+			result.Valid = false
+			result.Errors = append(result.Errors, fmt.Sprintf("Out-of-order timestamp: %.1f seconds in the past", -timeDiff))
+		}
+	}
+
+	// 5. Aircraft-specific validations based on reported speed vs. position
+	if aircraft.GroundSpeed > 0 && len(state.PositionHistory) > 0 {
+		// Check if reported ground speed is consistent with position changes
+		lastPos := state.PositionHistory[len(state.PositionHistory)-1]
+		distance, _ := calculateDistanceBearing(lastPos.Latitude, lastPos.Longitude,
+			aircraft.Latitude, aircraft.Longitude)
+		timeDiff := timestamp.Sub(lastPos.Time).Seconds()
+
+		if timeDiff > 0 {
+			distanceNm := distance / NmToKm
+			impliedSpeed := (distanceNm / timeDiff) * 3600
+			reportedSpeed := float64(aircraft.GroundSpeed)
+
+			// Warning if speeds differ significantly (>100 knots difference)
+			if math.Abs(impliedSpeed-reportedSpeed) > 100 && reportedSpeed > 50 {
+				result.Warnings = append(result.Warnings,
+					fmt.Sprintf("Speed inconsistency: reported %d knots, implied %.0f knots",
+						aircraft.GroundSpeed, impliedSpeed))
+			}
+		}
+	}
+
+	return result
+}
+
 // Close closes the merger and releases resources
 func (m *Merger) Close() error {
 	m.mu.Lock()
 	defer m.mu.Unlock()
-	
+
 	if m.icaoDB != nil {
 		return m.icaoDB.Close()
 	}

internal/modes/decoder.go

@@ -56,16 +56,16 @@ func validateModeSCRC(data []byte) bool {
 	if len(data) < 4 {
 		return false
 	}
-	
+
 	// Calculate CRC for all bytes except the last 3 (which contain the CRC)
 	crc := uint32(0)
 	for i := 0; i < len(data)-3; i++ {
 		crc = ((crc << 8) ^ crcTable[((crc>>16)^uint32(data[i]))&0xFF]) & 0xFFFFFF
 	}
-	
+
 	// Extract transmitted CRC from last 3 bytes
 	transmittedCRC := uint32(data[len(data)-3])<<16 | uint32(data[len(data)-2])<<8 | uint32(data[len(data)-1])
-	
+
 	return crc == transmittedCRC
 }
 
@@ -107,37 +107,44 @@ const (
 // depending on the messages received and aircraft capabilities.
 type Aircraft struct {
 	// Core Identification
-	ICAO24           uint32  // 24-bit ICAO aircraft address (unique identifier)
+	ICAO24   uint32 // 24-bit ICAO aircraft address (unique identifier)
-	Callsign         string  // 8-character flight callsign (from identification messages)
+	Callsign string // 8-character flight callsign (from identification messages)
-	
+
 	// Position and Navigation
-	Latitude         float64 // Position latitude in decimal degrees
+	Latitude     float64 // Position latitude in decimal degrees
-	Longitude        float64 // Position longitude in decimal degrees
+	Longitude    float64 // Position longitude in decimal degrees
-	Altitude         int     // Altitude in feet (barometric or geometric)
+	Altitude     int     // Altitude in feet (barometric or geometric)
-	BaroAltitude     int     // Barometric altitude in feet (QNH corrected)
+	BaroAltitude int     // Barometric altitude in feet (QNH corrected)
-	GeomAltitude     int     // Geometric altitude in feet (GNSS height)
+	GeomAltitude int     // Geometric altitude in feet (GNSS height)
-	
+
 	// Motion and Dynamics
-	VerticalRate     int     // Vertical rate in feet per minute (climb/descent)
+	VerticalRate int // Vertical rate in feet per minute (climb/descent)
-	GroundSpeed      int     // Ground speed in knots (integer)
+	GroundSpeed  int // Ground speed in knots (integer)
-	Track            int     // Track angle in degrees (0-359, integer)
+	Track        int // Track angle in degrees (0-359, integer)
-	Heading          int     // Aircraft heading in degrees (magnetic, integer)
+	Heading      int // Aircraft heading in degrees (magnetic, integer)
-	
+
 	// Aircraft Information
-	Category         string  // Aircraft category (size, type, performance)
+	Category string // Aircraft category (size, type, performance)
-	Squawk           string  // 4-digit transponder squawk code (octal)
+	Squawk   string // 4-digit transponder squawk code (octal)
-	
+
 	// Status and Alerts
-	Emergency        string  // Emergency/priority status description
+	Emergency string // Emergency/priority status description
-	OnGround         bool    // Aircraft is on ground (surface movement)
+	OnGround  bool   // Aircraft is on ground (surface movement)
-	Alert            bool    // Alert flag (ATC attention required)
+	Alert     bool   // Alert flag (ATC attention required)
-	SPI              bool    // Special Position Identification (pilot activated)
+	SPI       bool   // Special Position Identification (pilot activated)
-	
+
 	// Data Quality Indicators
-	NACp             uint8   // Navigation Accuracy Category - Position (0-11)
+	NACp uint8 // Navigation Accuracy Category - Position (0-11)
-	NACv             uint8   // Navigation Accuracy Category - Velocity (0-4)
+	NACv uint8 // Navigation Accuracy Category - Velocity (0-4)
-	SIL              uint8   // Surveillance Integrity Level (0-3)
+	SIL  uint8 // Surveillance Integrity Level (0-3)
-	
+
+	// Transponder Information
+	TransponderCapability string // Transponder capability level (from DF11 messages)
+	TransponderLevel      uint8  // Transponder level (0-7 from capability field)
+
+	// Combined Data Quality Assessment
+	SignalQuality string // Combined assessment of position/velocity accuracy and integrity
+
 	// Autopilot/Flight Management
 	SelectedAltitude int     // MCP/FCU selected altitude in feet
 	SelectedHeading  float64 // MCP/FCU selected heading in degrees
@@ -163,11 +170,11 @@ type Decoder struct {
 	cprOddLon   map[uint32]float64 // Odd message longitude encoding (ICAO24 -> normalized lon)
 	cprEvenTime map[uint32]int64   // Timestamp of even message (for freshness comparison)
 	cprOddTime  map[uint32]int64   // Timestamp of odd message (for freshness comparison)
-	
+
 	// Reference position for CPR zone ambiguity resolution (receiver location)
 	refLatitude  float64 // Receiver latitude in decimal degrees
 	refLongitude float64 // Receiver longitude in decimal degrees
-	
+
 	// Mutex to protect concurrent access to CPR maps
 	mu sync.RWMutex
 }
@@ -199,10 +206,10 @@ func NewDecoder(refLat, refLon float64) *Decoder {
 // Decode processes a Mode S message and extracts all available aircraft information.
 //
 // This is the main entry point for message decoding. The method:
-//   1. Validates message length and extracts the Downlink Format (DF)
+//  1. Validates message length and extracts the Downlink Format (DF)
-//   2. Extracts the ICAO24 aircraft address
+//  2. Extracts the ICAO24 aircraft address
-//   3. Routes to appropriate decoder based on message type
+//  3. Routes to appropriate decoder based on message type
-//   4. Returns populated Aircraft struct with available data
+//  4. Returns populated Aircraft struct with available data
 //
 // Different message types provide different information:
 //   - DF4/20: Altitude only
@@ -231,14 +238,32 @@ func (d *Decoder) Decode(data []byte) (*Aircraft, error) {
 	}
 
 	switch df {
+	case DF0:
+		// Short Air-Air Surveillance (ACAS)
+		aircraft.Altitude = d.decodeAltitude(data)
 	case DF4, DF20:
 		aircraft.Altitude = d.decodeAltitude(data)
 	case DF5, DF21:
 		aircraft.Squawk = d.decodeSquawk(data)
+	case DF11:
+		// All-Call Reply - extract capability and interrogator identifier
+		d.decodeAllCallReply(data, aircraft)
+	case DF16:
+		// Long Air-Air Surveillance (ACAS with altitude)
+		aircraft.Altitude = d.decodeAltitude(data)
 	case DF17, DF18:
 		return d.decodeExtendedSquitter(data, aircraft)
+	case DF19:
+		// Military Extended Squitter - similar to DF17/18 but with military codes
+		return d.decodeMilitaryExtendedSquitter(data, aircraft)
+	case DF24:
+		// Comm-D Enhanced Length Message - variable length data
+		d.decodeCommD(data, aircraft)
 	}
 
+	// Always try to calculate signal quality at the end of decoding
+	d.calculateSignalQuality(aircraft)
+
 	return aircraft, nil
 }
 
@@ -311,6 +336,12 @@ func (d *Decoder) decodeExtendedSquitter(data []byte, aircraft *Aircraft) (*Airc
 		d.decodeOperationalStatus(data, aircraft)
 	}
 
+	// Set baseline signal quality for ADS-B extended squitter
+	aircraft.SignalQuality = "Good" // ADS-B extended squitter is high quality by default
+	
+	// Refine quality based on NACp/NACv/SIL if available
+	d.calculateSignalQuality(aircraft)
+
 	return aircraft, nil
 }
 
@@ -369,10 +400,10 @@ func (d *Decoder) decodeIdentification(data []byte, aircraft *Aircraft) {
 //   - Even/odd flag for CPR decoding
 //
 // CPR (Compact Position Reporting) Process:
-//   1. Extract the even/odd flag and CPR lat/lon values
+//  1. Extract the even/odd flag and CPR lat/lon values
-//   2. Normalize CPR values to 0-1 range (divide by 2^17)
+//  2. Normalize CPR values to 0-1 range (divide by 2^17)
-//   3. Store values for this aircraft's ICAO address
+//  3. Store values for this aircraft's ICAO address
-//   4. Attempt position decoding if both even and odd messages are available
+//  4. Attempt position decoding if both even and odd messages are available
 //
 // The actual position calculation requires both even and odd messages to
 // resolve the ambiguity inherent in the compressed encoding format.
@@ -403,8 +434,20 @@ func (d *Decoder) decodeAirbornePosition(data []byte, aircraft *Aircraft) {
 	}
 	d.mu.Unlock()
 
+	// Extract NACp (Navigation Accuracy Category for Position) from position messages
+	// NACp is embedded in airborne position messages in bits 50-53 (data[6] bits 1-4)
+	if tc >= 9 && tc <= 18 {
+		// For airborne position messages TC 9-18, NACp is encoded in the message
+		aircraft.NACp = uint8(tc - 8) // TC 9->NACp 1, TC 10->NACp 2, etc.
+		// Note: This is a simplified mapping. Real NACp extraction is more complex
+		// but this provides useful position accuracy indication
+	}
+
 	// Try to decode position if we have both even and odd messages
 	d.decodeCPRPosition(aircraft)
+	
+	// Calculate signal quality whenever we have position data
+	d.calculateSignalQuality(aircraft)
 }
 
 // decodeCPRPosition performs CPR (Compact Position Reporting) global position decoding.
@@ -456,7 +499,7 @@ func (d *Decoder) decodeCPRPosition(aircraft *Aircraft) {
 	} else if latEven < -90 {
 		latEven = -180 - latEven
 	}
-	
+
 	if latOdd > 90 {
 		latOdd = 180 - latOdd
 	} else if latOdd < -90 {
@@ -473,7 +516,7 @@ func (d *Decoder) decodeCPRPosition(aircraft *Aircraft) {
 	// Calculate which decoded latitude is closer to the receiver
 	distToEven := math.Abs(latEven - d.refLatitude)
 	distToOdd := math.Abs(latOdd - d.refLatitude)
-	
+
 	// Choose the latitude solution that's closer to the receiver position
 	if distToOdd < distToEven {
 		aircraft.Latitude = latOdd
@@ -501,7 +544,7 @@ func (d *Decoder) decodeCPRPosition(aircraft *Aircraft) {
 	}
 
 	aircraft.Longitude = lon
-	
+
 	// CPR decoding completed successfully
 }
 
@@ -576,13 +619,13 @@ func (d *Decoder) decodeVelocity(data []byte, aircraft *Aircraft) {
 
 		// Calculate ground speed in knots (rounded to integer)
 		speedKnots := math.Sqrt(ewVel*ewVel + nsVel*nsVel)
-		
+
 		// Validate speed range (0-600 knots for civilian aircraft)
 		if speedKnots > 600 {
 			speedKnots = 600 // Cap at reasonable maximum
 		}
 		aircraft.GroundSpeed = int(math.Round(speedKnots))
-		
+
 		// Calculate track in degrees (0-359)
 		trackDeg := math.Atan2(ewVel, nsVel) * 180 / math.Pi
 		if trackDeg < 0 {
@@ -641,20 +684,20 @@ func (d *Decoder) decodeAltitudeBits(altCode uint16, tc uint8) int {
 	// Standard altitude encoding with 25 ft increments
 	// Check Q-bit (bit 4) for encoding type
 	qBit := (altCode >> 4) & 1
-	
+
 	if qBit == 1 {
 		// Standard altitude with Q-bit set
 		// Remove Q-bit and reassemble 11-bit altitude code
 		n := ((altCode & 0x1F80) >> 2) | ((altCode & 0x0020) >> 1) | (altCode & 0x000F)
 		alt := int(n)*25 - 1000
-		
+
 		// Validate altitude range
 		if alt < -1000 || alt > 60000 {
 			return 0
 		}
 		return alt
 	}
-	
+
 	// Gray code altitude (100 ft increments) - legacy encoding
 	// Convert from Gray code to binary
 	n := altCode
@@ -662,7 +705,7 @@ func (d *Decoder) decodeAltitudeBits(altCode uint16, tc uint8) int {
 	n ^= n >> 4
 	n ^= n >> 2
 	n ^= n >> 1
-	
+
 	// Convert to altitude in feet
 	alt := int(n&0x7FF) * 100
 	if alt < 0 || alt > 60000 {
@@ -835,7 +878,7 @@ func (d *Decoder) decodeTargetState(data []byte, aircraft *Aircraft) {
 //
 // Operational status messages (TC 31) contain:
 //   - Navigation Accuracy Category for Position (NACp): Position accuracy
-//   - Navigation Accuracy Category for Velocity (NACv): Velocity accuracy  
+//   - Navigation Accuracy Category for Velocity (NACv): Velocity accuracy
 //   - Surveillance Integrity Level (SIL): System integrity confidence
 //
 // These parameters help receiving systems assess data quality and determine
@@ -849,6 +892,9 @@ func (d *Decoder) decodeOperationalStatus(data []byte, aircraft *Aircraft) {
 	aircraft.NACp = (data[7] >> 4) & 0x0F
 	aircraft.NACv = data[7] & 0x0F
 	aircraft.SIL = (data[8] >> 6) & 0x03
+
+	// Calculate combined signal quality from NACp, NACv, and SIL
+	d.calculateSignalQuality(aircraft)
 }
 
 // decodeSurfacePosition extracts position and movement data for aircraft on the ground.
@@ -940,3 +986,164 @@ func (d *Decoder) decodeGroundSpeed(movement uint8) float64 {
 	}
 	return 0
 }
+
+// decodeAllCallReply extracts capability and interrogator identifier from DF11 messages.
+//
+// DF11 All-Call Reply messages contain:
+//   - Capability (CA) field (3 bits): transponder capabilities and modes
+//   - Interrogator Identifier (II) field (4 bits): which radar interrogated
+//   - ICAO24 address (24 bits): aircraft identifier
+//
+// The capability field indicates transponder features and operational modes:
+//   - 0: Level 1 transponder
+//   - 1: Level 2 transponder
+//   - 2: Level 2+ transponder with additional capabilities
+//   - 3: Level 2+ transponder with enhanced surveillance
+//   - 4: Level 2+ transponder with enhanced surveillance and extended squitter
+//   - 5: Level 2+ transponder with enhanced surveillance, extended squitter, and enhanced surveillance capability
+//   - 6: Level 2+ transponder with enhanced surveillance, extended squitter, and enhanced surveillance capability
+//   - 7: Level 2+ transponder, downlink request value is 0, or the flight status is alert, SPI, or emergency
+//
+// Parameters:
+//   - data: 7-byte DF11 message
+//   - aircraft: Aircraft struct to populate
+func (d *Decoder) decodeAllCallReply(data []byte, aircraft *Aircraft) {
+	if len(data) < 7 {
+		return
+	}
+
+	// Extract Capability (CA) - bits 6-8 of first byte
+	capability := (data[0] >> 0) & 0x07
+
+	// Extract Interrogator Identifier (II) - would be in control field if present
+	// For DF11, this information is typically implied by the interrogating radar
+
+	// Store transponder capability information in dedicated fields
+	aircraft.TransponderLevel = capability
+	switch capability {
+	case 0:
+		aircraft.TransponderCapability = "Level 1"
+	case 1:
+		aircraft.TransponderCapability = "Level 2"
+	case 2, 3:
+		aircraft.TransponderCapability = "Level 2+"
+	case 4, 5, 6:
+		aircraft.TransponderCapability = "Enhanced"
+	case 7:
+		aircraft.TransponderCapability = "Alert/Emergency"
+	}
+}
+
+// decodeMilitaryExtendedSquitter processes DF19 military extended squitter messages.
+//
+// DF19 messages have the same structure as DF17/18 ADS-B extended squitter but
+// may contain military-specific type codes or enhanced data formats.
+// This implementation treats them similarly to civilian extended squitter
+// but could be extended for military-specific capabilities.
+//
+// Parameters:
+//   - data: 14-byte DF19 message
+//   - aircraft: Aircraft struct to populate
+//
+// Returns updated Aircraft struct or error for malformed messages.
+func (d *Decoder) decodeMilitaryExtendedSquitter(data []byte, aircraft *Aircraft) (*Aircraft, error) {
+	if len(data) != 14 {
+		return nil, fmt.Errorf("invalid military extended squitter length: %d bytes", len(data))
+	}
+
+	// For now, treat military extended squitter similar to civilian
+	// Could be enhanced to handle military-specific type codes
+	return d.decodeExtendedSquitter(data, aircraft)
+}
+
+// decodeCommD extracts data from DF24 Comm-D Enhanced Length Messages.
+//
+// DF24 messages are variable-length data link communications that can contain:
+//   - Weather information and updates
+//   - Flight plan modifications
+//   - Controller-pilot data link messages
+//   - Air traffic management information
+//   - Future air navigation system data
+//
+// Due to the complexity and variety of DF24 message content, this implementation
+// provides basic structure extraction. Full decoding would require extensive
+// knowledge of specific data link protocols and message formats.
+//
+// Parameters:
+//   - data: Variable-length DF24 message (minimum 7 bytes)
+//   - aircraft: Aircraft struct to populate
+func (d *Decoder) decodeCommD(data []byte, aircraft *Aircraft) {
+	if len(data) < 7 {
+		return
+	}
+
+	// DF24 messages contain variable data that would require protocol-specific decoding
+	// For now, we note that this is a data communication message but don't overwrite aircraft category
+	// Could set a separate field for message type if needed in the future
+
+	// The actual message content would require:
+	// - Protocol identifier extraction
+	// - Message type determination
+	// - Format-specific field extraction
+	// - Possible message reassembly for multi-part messages
+	//
+	// This could be extended based on specific requirements and available documentation
+}
+
+// calculateSignalQuality combines NACp, NACv, and SIL into an overall data quality assessment.
+//
+// This function provides a human-readable quality indicator that considers:
+//   - Position accuracy (NACp): How precise the aircraft's position data is
+//   - Velocity accuracy (NACv): How precise the speed/heading data is
+//   - Surveillance integrity (SIL): How reliable/trustworthy the data is
+//
+// The algorithm prioritizes integrity first (SIL), then position accuracy (NACp),
+// then velocity accuracy (NACv) to provide a meaningful overall assessment.
+//
+// Quality levels:
+//   - "Excellent": High integrity with very precise position/velocity
+//   - "Good": Good integrity with reasonable precision
+//   - "Fair": Moderate quality suitable for tracking
+//   - "Poor": Low quality but still usable
+//   - "Unknown": No quality indicators available
+//
+// Parameters:
+//   - aircraft: Aircraft struct containing NACp, NACv, and SIL values
+func (d *Decoder) calculateSignalQuality(aircraft *Aircraft) {
+	nacp := aircraft.NACp
+	nacv := aircraft.NACv
+	sil := aircraft.SIL
+
+	// If no quality indicators are available, don't set anything
+	if nacp == 0 && nacv == 0 && sil == 0 {
+		// Don't overwrite existing quality assessment
+		return
+	}
+
+	// Excellent: High integrity with high accuracy OR very high accuracy alone
+	if (sil >= 2 && nacp >= 9) || nacp >= 10 {
+		aircraft.SignalQuality = "Excellent"
+		return
+	}
+
+	// Good: Good integrity with moderate accuracy OR high accuracy alone
+	if (sil >= 2 && nacp >= 6) || (sil >= 1 && nacp >= 9) || nacp >= 8 {
+		aircraft.SignalQuality = "Good"
+		return
+	}
+
+	// Fair: Some integrity with basic accuracy OR moderate accuracy alone
+	if (sil >= 1 && nacp >= 3) || nacp >= 5 {
+		aircraft.SignalQuality = "Fair"
+		return
+	}
+
+	// Poor: Low but usable quality indicators
+	if sil > 0 || nacp >= 1 || nacv > 0 {
+		aircraft.SignalQuality = "Poor"
+		return
+	}
+
+	// Default fallback
+	aircraft.SignalQuality = ""
+}

internal/server/server.go

@@ -22,6 +22,7 @@ import (
 	"net/http"
 	"path"
 	"strconv"
+	"strings"
 	"sync"
 	"time"
 
@@ -35,8 +36,8 @@ import (
 // This is used as the center point for the web map interface and for
 // distance calculations in coverage analysis.
 type OriginConfig struct {
-	Latitude  float64 `json:"latitude"`    // Reference latitude in decimal degrees
+	Latitude  float64 `json:"latitude"`       // Reference latitude in decimal degrees
-	Longitude float64 `json:"longitude"`   // Reference longitude in decimal degrees
+	Longitude float64 `json:"longitude"`      // Reference longitude in decimal degrees
 	Name      string  `json:"name,omitempty"` // Descriptive name for the origin point
 }
 
@@ -51,11 +52,12 @@ type OriginConfig struct {
 //   - Concurrent broadcast system for WebSocket clients
 //   - CORS support for cross-origin web applications
 type Server struct {
-	port        int                // TCP port for HTTP server
+	host        string         // Bind address for HTTP server
-	merger      *merger.Merger     // Data source for aircraft information
+	port        int            // TCP port for HTTP server
-	staticFiles embed.FS          // Embedded static web assets
+	merger      *merger.Merger // Data source for aircraft information
-	server      *http.Server       // HTTP server instance
+	staticFiles embed.FS       // Embedded static web assets
-	origin      OriginConfig       // Geographic reference point
+	server      *http.Server   // HTTP server instance
+	origin      OriginConfig   // Geographic reference point
 
 	// WebSocket management
 	wsClients   map[*websocket.Conn]bool // Active WebSocket client connections
@@ -63,8 +65,8 @@ type Server struct {
 	upgrader    websocket.Upgrader       // HTTP to WebSocket protocol upgrader
 
 	// Broadcast channels for real-time updates
-	broadcastChan chan []byte      // Channel for broadcasting updates to all clients
+	broadcastChan chan []byte   // Channel for broadcasting updates to all clients
-	stopChan      chan struct{}    // Shutdown signal channel
+	stopChan      chan struct{} // Shutdown signal channel
 }
 
 // WebSocketMessage represents the standard message format for WebSocket communication.
@@ -85,7 +87,7 @@ type AircraftUpdate struct {
 	Stats    map[string]interface{}           `json:"stats"`    // System statistics and metrics
 }
 
-// NewServer creates a new HTTP server instance for serving the SkyView web interface.
+// NewWebServer creates a new HTTP server instance for serving the SkyView web interface.
 //
 // The server is configured with:
 //   - WebSocket upgrader allowing all origins (suitable for development)
@@ -93,14 +95,16 @@ type AircraftUpdate struct {
 //   - Read/Write buffers optimized for aircraft data messages
 //
 // Parameters:
+//   - host: Bind address (empty for all interfaces, "localhost" for local only)
 //   - port: TCP port number for the HTTP server
 //   - merger: Data merger instance providing aircraft information
 //   - staticFiles: Embedded filesystem containing web assets
 //   - origin: Geographic reference point for the map interface
 //
 // Returns a configured but not yet started server instance.
-func NewServer(port int, merger *merger.Merger, staticFiles embed.FS, origin OriginConfig) *Server {
+func NewWebServer(host string, port int, merger *merger.Merger, staticFiles embed.FS, origin OriginConfig) *Server {
 	return &Server{
+		host:        host,
 		port:        port,
 		merger:      merger,
 		staticFiles: staticFiles,
@@ -121,9 +125,9 @@ func NewServer(port int, merger *merger.Merger, staticFiles embed.FS, origin Ori
 // Start begins serving HTTP requests and WebSocket connections.
 //
 // This method starts several background routines:
-//   1. Broadcast routine - handles WebSocket message distribution
+//  1. Broadcast routine - handles WebSocket message distribution
-//   2. Periodic update routine - sends regular updates to WebSocket clients
+//  2. Periodic update routine - sends regular updates to WebSocket clients
-//   3. HTTP server - serves API endpoints and static files
+//  3. HTTP server - serves API endpoints and static files
 //
 // The method blocks until the server encounters an error or is shut down.
 // Use Stop() for graceful shutdown.
@@ -139,8 +143,15 @@ func (s *Server) Start() error {
 	// Setup routes
 	router := s.setupRoutes()
 
+	// Format address correctly for IPv6
+	addr := fmt.Sprintf("%s:%d", s.host, s.port)
+	if strings.Contains(s.host, ":") {
+		// IPv6 address needs brackets
+		addr = fmt.Sprintf("[%s]:%d", s.host, s.port)
+	}
+
 	s.server = &http.Server{
-		Addr:    fmt.Sprintf(":%d", s.port),
+		Addr:    addr,
 		Handler: router,
 	}
 
@@ -150,9 +161,9 @@ func (s *Server) Start() error {
 // Stop gracefully shuts down the server and all background routines.
 //
 // This method:
-//   1. Signals all background routines to stop via stopChan
+//  1. Signals all background routines to stop via stopChan
-//   2. Shuts down the HTTP server with a 5-second timeout
+//  2. Shuts down the HTTP server with a 5-second timeout
-//   3. Closes WebSocket connections
+//  3. Closes WebSocket connections
 //
 // The shutdown is designed to be safe and allow in-flight requests to complete.
 func (s *Server) Stop() {
@@ -206,13 +217,13 @@ func (s *Server) setupRoutes() http.Handler {
 
 // isAircraftUseful determines if an aircraft has enough data to be useful for the frontend.
 //
-// DESIGN NOTE: We WANT reasonable aircraft to appear in our table view, even if they 
+// DESIGN NOTE: We WANT reasonable aircraft to appear in our table view, even if they
-// don't have enough data to appear on the map. This provides users visibility into 
+// don't have enough data to appear on the map. This provides users visibility into
 // all tracked aircraft, not just those with complete position data.
 //
 // Aircraft are considered useful if they have ANY of:
 //   - Valid position data (both latitude and longitude non-zero) -> Can show on map
-//   - Callsign (flight identification) -> Can show in table with "No position" status  
+//   - Callsign (flight identification) -> Can show in table with "No position" status
 //   - Altitude information -> Can show in table as "Aircraft at X feet"
 //   - Any other identifying information that makes it a "real" aircraft
 //
@@ -224,7 +235,7 @@ func (s *Server) isAircraftUseful(aircraft *merger.AircraftState) bool {
 	hasCallsign := aircraft.Callsign != ""
 	hasAltitude := aircraft.Altitude != 0
 	hasSquawk := aircraft.Squawk != ""
-	
+
 	// Include aircraft with any identifying or operational data
 	return hasValidPosition || hasCallsign || hasAltitude || hasSquawk
 }
@@ -382,10 +393,10 @@ func (s *Server) handleGetCoverage(w http.ResponseWriter, r *http.Request) {
 // Generates a grid-based heatmap visualization of signal coverage for a specific source.
 //
 // The heatmap is computed by:
-//   1. Finding geographic bounds of all aircraft positions for the source
+//  1. Finding geographic bounds of all aircraft positions for the source
-//   2. Creating a 100x100 grid covering the bounds
+//  2. Creating a 100x100 grid covering the bounds
-//   3. Accumulating signal strength values in each grid cell
+//  3. Accumulating signal strength values in each grid cell
-//   4. Returning the grid data with boundary coordinates
+//  4. Returning the grid data with boundary coordinates
 //
 // This provides a density-based visualization of where the source receives
 // the strongest signals, useful for coverage analysis and antenna optimization.
@@ -456,11 +467,11 @@ func (s *Server) handleGetHeatmap(w http.ResponseWriter, r *http.Request) {
 // handleWebSocket manages WebSocket connections for real-time aircraft data streaming.
 //
 // This handler:
-//   1. Upgrades the HTTP connection to WebSocket protocol
+//  1. Upgrades the HTTP connection to WebSocket protocol
-//   2. Registers the client for broadcast updates
+//  2. Registers the client for broadcast updates
-//   3. Sends initial data snapshot to the client
+//  3. Sends initial data snapshot to the client
-//   4. Handles client messages (currently just ping/pong for keepalive)
+//  4. Handles client messages (currently just ping/pong for keepalive)
-//   5. Cleans up the connection when the client disconnects
+//  5. Cleans up the connection when the client disconnects
 //
 // WebSocket clients receive periodic updates with current aircraft positions,
 // source status, and system statistics. The connection is kept alive until
@@ -588,11 +599,11 @@ func (s *Server) periodicUpdateRoutine() {
 // broadcastUpdate creates and queues an aircraft update message for WebSocket clients.
 //
 // This function:
-//   1. Collects current aircraft data from the merger
+//  1. Collects current aircraft data from the merger
-//   2. Filters aircraft to only include "useful" ones (with position or callsign)
+//  2. Filters aircraft to only include "useful" ones (with position or callsign)
-//   3. Formats the data as a WebSocketMessage with type "aircraft_update"
+//  3. Formats the data as a WebSocketMessage with type "aircraft_update"
-//   4. Converts ICAO addresses to hex strings for JSON compatibility
+//  4. Converts ICAO addresses to hex strings for JSON compatibility
-//   5. Queues the message for broadcast (non-blocking)
+//  5. Queues the message for broadcast (non-blocking)
 //
 // If the broadcast channel is full, the update is dropped to prevent blocking.
 // This ensures the system continues operating even if WebSocket clients
@@ -769,11 +780,11 @@ func (s *Server) handleDebugAircraft(w http.ResponseWriter, r *http.Request) {
 	}
 
 	response := map[string]interface{}{
-		"timestamp":        time.Now().Unix(),
+		"timestamp":         time.Now().Unix(),
-		"all_aircraft":     allAircraftMap,
+		"all_aircraft":      allAircraftMap,
 		"filtered_aircraft": filteredAircraftMap,
-		"all_count":        len(allAircraftMap),
+		"all_count":         len(allAircraftMap),
-		"filtered_count":   len(filteredAircraftMap),
+		"filtered_count":    len(filteredAircraftMap),
 	}
 
 	w.Header().Set("Content-Type", "application/json")

old.json

@@ -1,15 +0,0 @@
-{
-  "server": {
-    "address": ":8080",
-    "port": 8080
-  },
-  "dump1090": {
-    "host": "svovel",
-    "data_port": 30003
-  },
-  "origin": {
-    "latitude": 59.908127,
-    "longitude": 10.801460,
-    "name": "Etterstadsletta flyplass"
-  }
-}

scripts/build-deb.sh

@@ -34,25 +34,40 @@ mkdir -p "$BUILD_DIR"
 # Change to project directory
 cd "$PROJECT_DIR"
 
-# Build the application
+# Build the applications
-echo_info "Building SkyView application..."
+echo_info "Building SkyView applications..."
 export CGO_ENABLED=0
 export GOOS=linux
 export GOARCH=amd64
 
-go build -ldflags="-w -s -X main.version=$(git describe --tags --always --dirty)" \
+VERSION=$(git describe --tags --always --dirty)
-    -o "$DEB_DIR/usr/bin/skyview" \
+LDFLAGS="-w -s -X main.version=$VERSION"
-    ./cmd/skyview
 
-if [ $? -ne 0 ]; then
+# Build main skyview binary
-    echo_error "Failed to build application"
+echo_info "Building skyview..."
+if ! go build -ldflags="$LDFLAGS" \
+    -o "$DEB_DIR/usr/bin/skyview" \
+    ./cmd/skyview; then
+    echo_error "Failed to build skyview"
     exit 1
 fi
 
-echo_info "Built binary: $(file "$DEB_DIR/usr/bin/skyview")"
+# Build beast-dump utility
+echo_info "Building beast-dump..."
+if ! go build -ldflags="$LDFLAGS" \
+    -o "$DEB_DIR/usr/bin/beast-dump" \
+    ./cmd/beast-dump; then
+    echo_error "Failed to build beast-dump"
+    exit 1
+fi
 
-# Set executable permission
+echo_info "Built binaries:"
+echo_info "  skyview: $(file "$DEB_DIR/usr/bin/skyview")"
+echo_info "  beast-dump: $(file "$DEB_DIR/usr/bin/beast-dump")"
+
+# Set executable permissions
 chmod +x "$DEB_DIR/usr/bin/skyview"
+chmod +x "$DEB_DIR/usr/bin/beast-dump"
 
 # Get package info
 VERSION=$(grep "Version:" "$DEB_DIR/DEBIAN/control" | cut -d' ' -f2)
@@ -69,9 +84,7 @@ sed -i "s/Installed-Size:.*/Installed-Size: $INSTALLED_SIZE/" "$DEB_DIR/DEBIAN/c
     echo "Installed-Size: $INSTALLED_SIZE" >> "$DEB_DIR/DEBIAN/control"
 
 # Build the package
-dpkg-deb --build "$DEB_DIR" "$BUILD_DIR/$DEB_FILE"
+if dpkg-deb --root-owner-group --build "$DEB_DIR" "$BUILD_DIR/$DEB_FILE"; then
-
-if [ $? -eq 0 ]; then
     echo_info "Successfully created: $BUILD_DIR/$DEB_FILE"
     
     # Show package info