Lightning detection

The Government of Alberta partners with the following outside agencies to upgrade the provincial lightning detection network and share the real-time data:

• Alberta Electrical System Operator
• Altalink
• Fortis
• ATCO Electric
• Parks Canada

In addition, real-time, raw data is shared with the Northwest Territories Department of Renewable Resources to enhance the capabilities of the networks operated by both agencies.

The system uses a unique characteristic of cloud-to-ground lightning – its waveform – to accurately differentiate it from cloud-to-cloud discharges and calculate its location.

The initiation of the cloud-to-ground strike releases an intense, short burst of electrical energy. This rapid burst of energy travels through the atmosphere much as radio waves do. The most unique characteristic of the waveform is its extremely rapid rise to peak energy.

This distinctive feature of cloud-to-ground lightning provides the means for real-time detection. The sensors also use time of arrival of the lightning signature and GPS location to accurately determine the position.

Lightning sensor analyzer map (JPG, 68 KB)

Raw lightning data is received and processed by a sophisticated system. The lightning sensor is the key component of this complex system. The lightning waveform is detected through 3 antennae:

• flat plate electrical field
• GPS receiver
• vertical orthogonal loop

As the waveform passes through the antennae, electrical currents are induced and channelled to the processing electronics. The waveform is then analyzed according to return stroke peak energy rise time and other criteria. Non-lightning waveforms such as radio transmissions are filtered out by this procedure.

When a valid lightning signal is detected, the station records its:

• exact time
• intensity
• number of return strokes
• polarity (negative or positive)
• true bearing from the station are recorded

Dedicated communication lines to the CP7000 then transmit all the data.

The CP7000 processes the sensor data to determine lightning locations. It also continuously monitors the status of the sensors and provides synchronization between their internal clocks.

The CP7000 requires data from only 2 sensors to determine a specific flash location. The CP7000 can determine which of the system’s sensors have detected the same flash by comparing the time of the event recorded at each sensor.

The time coincident sensor data are then analyzed to determine the latitude/longitude of the flash. The CP7000 distributes the location data to the various display systems throughout the province.

The Forestry Division uses PC-based display software located at the Alberta Wildfire Coordination Centre (AWCC) and at each of the Forest Area Fire Centres. Fire managers can monitor current lightning activity in real time on the display, and they can print hard copy maps for use by aerial patrols.