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:
Decentlab DL-ATM41 (Generation 1) - a all-in-one weather station providing all common meteorological parameters
Decentlab Black Globe DL-BLG - a black globe providing a black globe temperature for calculating $T_{mrt}$
Decentlab DL-SHT35 - a temperature and relative humidity sensor
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.