EAS Station Visual Documentation

This page provides an index of all professional diagrams and flowcharts available in the EAS Station documentation. These visual resources complement the written documentation and help understand system architecture, workflows, and deployment configurations.

📊 Professional SVG Diagrams

System Architecture & Workflows

1. Alert Processing Pipeline

• External CAP feed sources
• XML parsing and schema validation
• Geometry processing (polygon/circle/SAME codes)
• Duplicate detection
• Spatial intelligence with PostGIS
• Database persistence

• Understanding how alerts enter the system
• Debugging alert ingestion issues
• Planning CAP feed integrations

2. EAS Broadcast Workflow

• Alert source selection (manual vs. CAP)
• Message configuration
• SAME header generation and validation
• Optional TTS narration
• Complete audio assembly (header × 3, attention signal, narration, EOM × 3)
• Operator approval process
• Transmission via GPIO-controlled transmitter

• Training new operators
• Understanding broadcast procedures
• Troubleshooting workflow errors

3. SDR Setup & Configuration Flow

• Phase 1: Hardware setup (RTL-SDR, Airspy, antennas)
• Phase 2: Software configuration via web UI
• Access settings
• Run diagnostics
• Discover devices
• Apply presets
• Fine-tune parameters
• Phase 3: Testing and verification
• Monitor receiver status
• Verify signal quality
• Troubleshooting guide

• Initial SDR receiver setup
• Adding new receivers
• Troubleshooting receiver issues

4. Audio Source Routing Architecture

• Audio Sources: SDR, ALSA, PulseAudio, File playback
• Source Adapters: Convert various formats to unified PCM
• Audio Controller: Priority selection and buffer management
• Monitoring: Peak/RMS metering, silence detection, health scoring
• Database Integration: Metrics, health status, alerts
• Web UI: Real-time monitoring and API access

• Understanding audio pipeline architecture
• Configuring audio sources
• Debugging audio issues
• Implementing new source types

5. Hardware Deployment Architecture

• Raspberry Pi 5 Core: 8GB RAM, Docker containers
• USB Peripherals: RTL-SDR, Airspy, USB audio DAC
• GPIO Connections: Relay HAT for transmitter control
• Storage: NVMe SSD via PCIe Gen 2
• Network: Gigabit Ethernet
• Display: HDMI monitor support
• External Systems: FM transmitter, LED signs, web browser access
• Cost Analysis: ~$585 vs. $5,000-$7,000 for commercial systems

• Planning hardware purchases
• Physical installation
• Understanding connections
• Troubleshooting hardware issues

🗺️ Legacy Architecture Diagrams (SVG)

These diagrams were created earlier and provide high-level system overviews:

System Architecture Overview

Core Services Overview

📐 Mermaid Diagrams in Documentation

In addition to the professional SVG diagrams above, the following documentation files contain embedded Mermaid.js diagrams that render in GitHub, GitLab, and compatible markdown viewers:

Data Flow Sequences (Mermaid) ⭐ NEW

• Alert Processing Data Flow - Complete CAP alert path from fetch to storage
• SDR Continuous Monitoring Data Flow - RF signal to digital samples conversion
• Multi-Source Audio Ingest Data Flow - Audio from multiple sources through adapters
• Radio Capture Coordination Data Flow - Coordinated capture triggering during broadcast
• EAS Message Generation Data Flow - Alert to SAME to audio file generation
• Complete Alert-to-Broadcast Pipeline - End-to-end flow with all components

• ✅ GitHub: Native Mermaid rendering in markdown
• ✅ MkDocs Site: Automatic rendering via pymdownx.superfences
• ✅ Local Viewing: Renders in any Mermaid-compatible markdown viewer

• Understanding how data moves through the system
• Tracing data transformations at each stage
• Debugging data flow issues
• Onboarding developers to system architecture
• Planning modifications to data processing paths

System Architecture (Mermaid)

• High-level architecture graph
• Component dependency map
• Alert processing sequence diagram
• Alert ingestion flowchart
• Spatial processing flowchart
• Audio ingest architecture
• Audio source lifecycle state diagram
• Audio metrics sequence diagram
• EAS workflow flowchart
• SAME generation flowchart
• Audio generation pipeline sequence
• SDR capture & verification flowchart
• Verification workflow sequence
• Database entity-relationship diagram
• Data flow diagrams
• Web request flow sequence
• System health monitoring flowchart
• Multi-service coordination diagram
• Deployment architecture diagrams

Theory of Operation (Mermaid)

• High-level flow diagram
• Conceptual overview of system operation
• Historical context and SAME protocol details

README Architecture (Mermaid)

• Simple architecture overview
• Component technology stack

📖 Usage Guidelines

Viewing Diagrams

• On GitHub/GitLab: All diagrams render automatically
• Locally: Open SVG files in any modern web browser
• In Documentation: Embedded images display inline
• Full Size: Click any diagram to view at full resolution

Embedding Diagrams

To embed these diagrams in your own documentation:

Or with a link to full-size view:

%%%IMAGE8%%%

Diagram Standards

All professional SVG diagrams follow these standards:

• Format: SVG 1.1 with embedded metadata
• Accessibility: Include <title> and <desc> tags
• Resolution: Optimized for both web and print
• Color Scheme: Consistent palette across all diagrams
• Typography: Arial/sans-serif for maximum compatibility
• Icons: Semantic shapes and colors for clarity

Contributing New Diagrams

When adding new diagrams:

1. Save as SVG in docs/assets/diagrams/ directory
2. Use consistent color scheme and typography
3. Include accessibility metadata (title, description)
4. Add to this index page
5. Reference in relevant documentation
6. Update the changelog

🔗 Related Documentation

• System Architecture - Complete technical architecture with Mermaid diagrams
• Theory of Operation - Conceptual overview and operational theory
• SDR Setup Guide - Radio receiver configuration
• Audio Documentation - Audio system details
• README - Project overview and quick start