Overview

This article aims to cover how the Hawk can be used as an accurate, low-cost, local bushfire warning system. 

It will cover:

• How to configure a Misol WN90LP Weather Station with Device Manager
• How to use Telematics Guru (TG) to send basic weather alerts
• Explain advanced formulas that can be used for Forest Fire Danger Index (FFDI) warnings as used by the Bureau of Meteorology and Australian fire agencies.

Configuration

Wiring and Device Manager

To physically wire the sensor to the Hawk and configure it to extract the desired values from the weather station, please follow:

• The Generic Modbus Action Example - Misol Weather Station Configuration

For bush fire monitoring, the only change from the guide should be replacing the registered address of ABS pressure (0x16D or 365) with wind direction (0x16B or 363) when filling out the ‘reading function’ section of OEM.

Connecting to Telematics Guru

Select the device you wish to connect to TG, and then select the ‘Device Operations’ tab.

In the drop-down menu, choose ‘Set Connector’. 

This will provide an option to choose the connector. Choose the connector that relates to your specific TG region.

Following this, log into Telematics Guru and select ‘Assets’ from the main page.  From this page, create a new asset.  Once the asset has been created, clicking the name of the asset will bring up the option to edit it.  In the I/O Mappings tab, add an analogue mapping for each data option, ensuring the register order chosen in OEM is followed, such that the I/O mappings are as follows:

Alerts With Telematics Guru

On TG, choose the admin tab, and create an advanced new alert.  Create relevant messages for each condition, for instance, any temperature above 55°C may alert that there is an ongoing fire. 

It is important to remember the limitations of the device when setting the limits.  Both the Hawk and the Misol weather station are rated to work at temperatures up to and including 60°C, setting limits for higher temperatures than this will not produce actionable results.

Currently, alerts are limited to thresholds based on single analog measurements. For example, the previous example of alerting when a temperature rises above 55°C. 

 

 

Bush-fire Detection

It is also possible to push the sensor data to software that can perform more complex operations on the extracted values.

A use case of this would be for detecting and ranking the current environmental conditions on the forest fire danger index. A use case of this would be for detecting and ranking the current environmental conditions on the forest fire danger index.

Due to the Hawk being able to extract and hold up to 6 information registers from the weather station, it can monitor and interpret almost all the information required to calculate the FFDI of wherever it was set up.  The equations for FFDI calculation are as follows:

(Dowdy, 2017)

(M. P. Plucinski, 2023)

In these equations:

• FFDI = Forest Fire Danger Index (Low (0-12), High (12-25), Very High (25-50), Severe (50-75), Extreme (75-100)) (T.D Penman, 2014)
• T = Temperature (°C)
• RH = Relative Humidity (%)
• v = wind speed (kmh-1)
• DF = Drought Factor 
• KBDIn = KBDI for a given day
• KBDIn-1­ = KBDI for the previous day
• Peff = estimate of effective precipitation (the difference between the daily rainfall total at 9am local time and the estimated quantities that have been intercepted by vegetation and/or run off the soil)
• ET = daily evapotranspiration from the previous day
• Tmax = maximum temperature of the previous day (°C)
• Rann = annual rainfall for the site

The data the Hawk extracts from the weather sensor can be used for the temperature, humidity, wind speed, and rainfall values in the calculations, and the rest of the data can be approximated to what is provided by the Bureau of Meteorology for nearby areas.  With some code, the Hawk can transform all this information into accurate live alerts on the local FFDI.  Adding additional alerts can also assist in detecting if a fire starts, for instance, a sudden spike in temperature combined with a drop in the measured UV index could indicate fire and smoke around the sensor. 

As specified in the physical setup and OEM section of this article, for the purposes of bush-fire detection the pressure data should be excluded in favour of wind direction.  This is due to outdoor pressure being irrelevant to early warnings of bushfires, but wind direction greatly impacts the speed and direction in which a bushfire spreads.  Knowledge of the wind direction is extremely important for personal safety, evacuation planning, and informing firefighting efforts of potential changes in the behaviour of the firefront. 

Using the data from the Hawk, it is possible to not only to get region-specific FFDI rankings, but also information on the likely direction a fire would spread.  If multiple modules were set up, it would be possible to determine the rate at which a fire is spreading and have a map of its location. 

Furthermore, in the case of an ongoing fire, the UV data from multiple Hawks could act as a smoke map, based on if the UV is significantly lower than the average at that location and time.

References

Dowdy, A.J (2017). Climatological Variability of Fire Weather in Australia. Docklands, Victoria, Australia, Bureau of Meteorology

Everett, C. (2023, October 30). Generic Modbus Action Example - Misol Weather Station Configuration. Retrieved from Digital Matter Knowledge Base: https://support.digitalmatter.com/en_US/rs-485/misol

M. P. Plucinski, E. T. (2023). Exploring the influence of the Keetch-Byram Drought Index and McArthur's Drought Factor on wildfire incidence in Victoria, Australia. International Journal of Wildland Fire, Supplementary Material 2-3.

T.D Penman, M. B. (2014). National Fire Danger Rating System Probabalistic Framework Project. East Melbourne, Victoria: Bushfire & Natural Hazards Cooperative Research Centre.