AeroGuard — Air Quality Monitoring Platform

AeroGuard is a full-stack environmental monitoring platform built as an Express/React monorepo. It ingests real-time sensor telemetry, evaluates air quality against EPA and ASHRAE standards, fires instant WebSocket alerts, and compiles downsampled trend metrics for interactive dashboards. Includes a high-fidelity Python simulator for environmental telemetry.

Air quality monitoring systems often lack real-time alerting, proper threshold mapping to standards, and realistic sensor simulation for testing. Existing solutions are either too simple or too expensive for portfolio/demo use.

The repository evidence points to these observable boundaries and technologies:

• Express + React monorepo with npm workspaces
• Decoupled Controller-Service-Repository backend
• MongoDB for time-series data with aggregation pipelines
• WebSocket server for real-time alert broadcasting
• React/Vite frontend with Recharts visualizations
• Python simulator for environmental telemetry generation

• Real-time telemetry ingestion with per-device API tokens
• Multi-level EPA/ASHRAE threshold alert system
• WebSocket-based instant alert notifications
• Dynamic time-series downsampling (15m, 1h, 1d intervals)
• Mathematical sensor simulator with diurnal cycles and AR(1) noise
• Responsive dashboard with device status and alert resolution

• Decoupling ingestion from alerting without message loss
• Mapping raw particulate values to EPA breakpoints accurately
• Simulating realistic cross-variable environmental correlations
• WebSocket connection management at scale

• Functional telemetry ingestion with schema validation
• Threshold alerts mapping to EPA/ASHRAE standards
• WebSocket alerts broadcasting to connected clients
• MongoDB aggregation for downsampled analytics
• Python simulator generating realistic sensor data

Environmental monitoring requires careful threshold semantics — raw values need domain-standard interpretation. Simulation is as important as the monitoring stack for demos.