System Design

The system consists of three major Parts, The sensor-infrastructure in the field, the IoT server-infrastructure for retrieving the measured data, the server-infrastructure for managing, processing, and providing the data.

Sensor infrastructure

Three types of sensors are deployed:

The sensors are supposed to send data (instantaneous) measurements every 5 minutes.

IoT server-infrastructure

The system uses the Element IoT product to manage the sensors and gateways. The system also provides an API which is used to retrieve raw data from the sensors.

Processing & visualization server-infrastructure

The system that combines all data is the D2R-API. It plugs into the Element-IoT system via an API element-iot-api and retrieves raw data every 5 minutes, combines data from separate sensors (Black Globe and ATM41) and calculates derived parameters such as thermal comfort indices using thermal-comfort.

All data is stored in a central database which also contains views for aggregating the raw measurements into hourly and daily values per station. In addition it also manages the complex relations between a stations (a geographical location where measurements are supposed to be taken), a pool of available sensors (different types and redundant spare sensors), and deployments (installation of sensors from the pool at a station).

Finally, it offers an API for retrieving the data from the network in near-realtime.

The API is also used for a dashboard which displays the current data.

The final component is a tile-map-server (TMS) that allows displaying the model results which are ingested from a powerful data-processing server. For this terracotta with a limited subset of endpoints is used.

system architecture