Cocal is a service developed by OGS in collaboration with Trieste Trasporti Spa that enables real-time monitoring of air quality in the Trieste area.

The system is based on low-cost sensors that transmit information on the concentration of particulate matter (PM2.5 and PM10) to the OGS computer systems, which reconstruct a real-time map of air quality in the area accessible by the city's public transport buses.