FireLess II

What is FireLess II about?

Nowadays the fire ignition and spread risk is indirectly estimated by the means of fire weather indices or by measurements provided by standard fuel stick.

FireLess II is an innovative wireless sensor network developed by EnvEve SA and WSL in collaboration with the University of Turin allowing the acquisition of real time data for monitoring fuel parameters such as litter and humus moisture in specific forest stands.

Fireless 2 Wireless consist of two sensors types for monitoring the litter and the humus layer respectively, where the LITTER sentry roughly corresponds to the FFMC of the on FWI-System) and the HUMUS sentry roughly corresponds to the DMC or the DC codes of the FWI according to the depth of positioning in the organic part of the upper soil.

When provided of a Meteostation, the FireLess II system can be additionally combined with the implementation of fire weather indices.

System components

The system is composed by 4 main components:

• Gateway
• Meteostation (facultative) − Air Temperature − Air Humidity − Wind Speed − Wind Direction − Rain (mm/h)
• LITTER Sentry − Litter Humidity − Litter Temperature
• HUMUS Sentry − Soil Moisture

• System functioning scheme

Main technical characteristics

Communication: Communication system uses two main radio bands: 433 MHz, communication between Sentries-MeteoGateway and GSM communication between

MeteoGateway - OC (Operative Central). The transmission architecture uses a Collision Detect Algorithm to identify and manage data error during transmission. The OC Operative Central update every sentry status using the transmission of heart-beat pack periodically sent by every device.

Power Supply: The gateway is provided by a solar panel for internal battery charge and a memory for 30 days data storage. A second battery is used to ensure efficiency in critical situations. Each sentry is equipped with a single battery. The operating cycle is optimized to reduce power consumption and increase the device life time (up to 5 years sentries autonomy).

Security: The system is provided with a protection against rain and high humidity, encrypted data transmission and GPS sensor mapping

Specific technical data:

• MeteoGataway

• Litter Sentry

• Humus Sentry

Contact

• Marco Conedera

• marco.conedera@wsl.ch