12 KiB
MeshCore SAR: Off-Grid Communication for Search & Rescue Operations
When the grid goes down, lives are on the line. MeshCore SAR is a revolutionary mobile application that enables search and rescue teams to communicate, coordinate, and share critical information—even when cellular networks and internet connectivity are completely unavailable.
Built on cutting-edge mesh networking technology, MeshCore SAR transforms ordinary smartphones into powerful off-grid communication devices using low-power radio hardware. Whether you're coordinating a wilderness rescue, managing a disaster response, or operating in remote areas, MeshCore SAR keeps your team connected when it matters most.
Why MeshCore SAR?
Traditional communication systems fail when you need them most:
- Cellular networks collapse during disasters or don't exist in remote wilderness
- Satellite phones are expensive and have limited messaging capabilities
- Radio systems require licensing and lack modern features like GPS integration
MeshCore SAR solves these problems by creating a resilient, self-healing mesh network that:
- ✅ Works completely off-grid - No cellular, WiFi, or internet required
- ✅ Extends range through mesh routing - Messages hop through nearby devices
- ✅ Integrates GPS tracking - Real-time location sharing on offline maps
- ✅ Specializes in SAR operations - Purpose-built features for emergency response
- ✅ Uses affordable hardware - Low-cost LoRa radios via Bluetooth
🗨️ Messages: Reliable Communication When Networks Fail
[Image placeholder: Messages screen showing conversation with delivery status]
At the heart of MeshCore SAR is a robust messaging system designed for mission-critical communication.
Key Features:
🎯 Multiple Communication Modes
- Direct Messages: Private one-to-one communication with team members
- Public Channel: Broadcast updates to all nearby devices
- Rooms: Persistent message storage for coordination centers
📡 Smart Message Delivery
- Intelligent routing: Messages automatically find the best path through the mesh network
- Delivery confirmation: Know when your message reaches its destination with ACK tracking
- Automatic retries: Failed messages retry automatically with progressive timeouts
- Flood fallback: Critical messages use broadcast mode if routing fails
🚨 SAR Marker Messages Send location-tagged alerts with a simple message format:
- 🧑 Found Person:
S:🧑:37.7749,-122.4194:Survivor located, needs medical attention - 🔥 Fire Location:
S:🔥:40.7128,-74.0060:Wildfire spreading rapidly northeast - 🏕️ Staging Area:
S:🏕️:34.0522,-118.2437:Base camp established with supplies
These special messages automatically appear as markers on the map, making critical information instantly visual for the entire team.
📊 Message Status Tracking Every message shows its delivery status:
- ⏳ Sending - Message is being transmitted
- ✅ Sent - Message queued with expected acknowledgment
- ✔️✔️ Delivered - Confirmation received with round-trip time
- 🔄 Retrying - Automatic retry in progress
- ❌ Failed - Delivery unsuccessful after all attempts
🌍 Multilingual Support Full localization in English, Croatian (Hrvatski), and Slovenian (Slovenščina) ensures teams can communicate in their native language.
👥 Contacts: Know Your Team's Status and Location
[Image placeholder: Contacts list showing team members with GPS locations and battery levels]
MeshCore SAR's contact system goes beyond simple names and numbers—it provides real-time situational awareness for your entire team.
Contact Intelligence:
📍 Real-Time Location Tracking
- GPS coordinates automatically broadcast at configurable intervals
- Location history tracking (last 100 positions per contact)
- Distance and bearing calculations from your position
- "Last seen" timestamps for situational awareness
🔋 Battery Monitoring
- Battery percentage displayed for each team member
- Voltage telemetry via Cayenne LPP format
- Early warning when team members need to conserve power
🛤️ Mesh Network Routing The app shows routing information for each contact:
- Direct (0 hops): Connected directly to your radio
- Good path (1-2 hops): Reliable routing through 1-2 intermediate devices
- Medium/Long path (3-5+ hops): Extended range through multiple hops
- No path (flood mode): Messages broadcast to entire network
👔 Role-Based Identification
- Add emoji prefixes to names (🧑🏻🚒 for firefighter, 👮 for police, 🏥 for medical)
- Instant visual identification on map and in contact lists
- Customizable display names
📡 Contact Types
- Chat (Team Members): Standard team members shown on map
- Repeater: Network infrastructure nodes that extend range
- Room: Message servers with persistent storage and login capabilities
📞 Contact Sharing
- Export contacts as business cards
- Share contacts directly over the mesh network
- Import contacts from other team members
🗺️ Map: Offline Navigation and Tactical Awareness
[Image placeholder: Map screen showing team members, SAR markers, and offline terrain]
The map is where everything comes together—combining team locations, SAR events, and offline navigation into a single, comprehensive tactical display.
Map Features:
🗺️ Offline Vector Maps
- MBTiles format: Lightweight vector maps that work completely offline
- Multiple layers: Street maps (OpenStreetMap), topographic (OpenTopoMap), satellite imagery (ESRI)
- High zoom levels: Street-level detail up to zoom level 19
- Smart caching: Tiles cached locally for 30 days
📍 Team Member Tracking Each team member appears on the map with:
- Blue circle markers with role emoji
- Battery level badge (green/yellow/red indicators)
- Distance from your location
- Tap to view detailed information and message directly
🚨 SAR Event Markers Critical events appear as color-coded markers:
- 🟢 Green - Found Person
- 🔴 Red - Fire Location
- 🔵 Blue - Staging Area
- 🟣 Purple - Object
- Time elapsed since report
- Tap to navigate and view details
✏️ Map Drawing Tools Collaborative tactical planning:
- Line drawings: Sketch routes, boundaries, or directions
- Rectangle areas: Mark zones, perimeters, or sectors
- 8 color palette: Red, blue, green, yellow, orange, purple, pink, cyan
- Share drawings: Send to channel or specific rooms via mesh network
- Collaborative editing: All team members see drawings in real-time
- Ultra-compact format: Efficient JSON encoding reduces bandwidth usage by 37%
🧭 Detailed Compass Dialog Ultra-compact location display:
- Current GPS coordinates
- Toggle between Decimal Degrees (DD) and Degrees/Minutes/Seconds (DMS)
- Tap outside to close (no buttons needed)
- Perfect for quick location checks
📡 User Location Tracking
- Blue pulsing circle shows your current position
- Navigation icon for direction
- Tap to center and track your movement
- Configurable accuracy settings
📊 Map Legend Collapsible legend in top-right corner:
- Team member count
- SAR marker count by type
- Quick reference for marker colors
🎯 Smart Navigation
- Tap any SAR marker in messages to navigate on map
- Automatic tab switching
- Map centers and zooms to selected location
- Clears navigation after viewing
🔧 Technical Innovation
Mesh Network Protocol
- MeshCore Protocol: Open-source, battle-tested mesh networking
- LoRa Radio: Long-range, low-power wireless technology
- BLE Connection: Smartphone connects to companion radio via Bluetooth
- Intelligent routing: Self-healing paths through the network
- Flood mode fallback: Guaranteed delivery for critical messages
Smart Features
- Adaptive location broadcasting: Only sends updates when you move significantly
- Progressive retry logic: Failed messages retry with increasing timeouts
- Cayenne LPP telemetry: Standardized sensor data format
- Contact synchronization: Automatic contact list updates
- Message persistence: Rooms store messages for later retrieval
Built for Reliability
- Provider-based architecture: Efficient state management
- Automatic reconnection: Handles radio disconnections gracefully
- Message queue management: Synchronizes messages in order
- Battery optimization: Configurable tracking intervals
- Memory management: Automatic history cleanup
🌟 Real-World Applications
Search & Rescue Operations
- Wilderness rescue coordination
- Missing person searches
- Cave rescue operations
- Mountain rescue teams
Disaster Response
- Hurricane and flood response
- Earthquake emergency communication
- Infrastructure failure scenarios
- Mass casualty incidents
Remote Operations
- Forestry operations
- Mining site communication
- Border patrol and security
- Wildlife management
Training & Exercises
- Team coordination drills
- Radio discipline training
- Navigation exercises
- Emergency preparedness
🚀 Getting Started
MeshCore SAR works with affordable LoRa companion radios that connect to your smartphone via Bluetooth. The app handles all the complexity—you just:
- Connect your radio via Bluetooth
- Add contacts to your team
- Start messaging and tracking locations
- Download maps for your area
- Coordinate your mission
No cellular service. No internet. No limits.
🌍 Open Source & Community-Driven
MeshCore SAR is built on the open-source MeshCore protocol, fostering a community of developers and users who contribute to its continuous improvement. Whether you're a first responder, amateur radio enthusiast, or outdoor adventurer, you're part of a global network working to keep people connected when it matters most.
💡 The Future of Off-Grid Communication
In a world increasingly dependent on fragile infrastructure, MeshCore SAR represents a paradigm shift: resilient, decentralized communication that works when everything else fails. As climate change drives more frequent disasters and teams operate in increasingly remote locations, mesh networking isn't just an alternative—it's essential.
MeshCore SAR isn't just an app. It's a lifeline.
MeshCore SAR is compatible with iOS 13+ and Android API 21+. Requires compatible LoRa companion radio hardware.
Repository: github.com/meshcore-dev/meshcore.js
📸 Screenshots
[Placeholder sections for images]
Messages
Screenshot showing conversation with delivery status, SAR marker messages, and message options
Contacts
Screenshot showing contact list with GPS locations, battery levels, and routing information
Map - Team View
Screenshot showing map with multiple team members, distance indicators, and user location
Map - SAR Markers
Screenshot showing map with various SAR markers (person, fire, staging area) and color coding
Map - Drawing Tools
Screenshot showing map with line and rectangle drawings, color palette, and toolbar
Map - Offline Layers
Screenshot showing different map layers (street, topographic, satellite) selection
Settings
Screenshot showing connection status, radio parameters, and location tracking settings
Contact Details
Screenshot showing detailed contact information, telemetry data, and message history
Ready to experience off-grid communication? Connect your radio and join the mesh network today.