Advanced Lightning Warning System (ALWS)


    The TOA Advanced Lightning Warning System (ALWS) typically consists of three or more TOA electrical field mills (EFM) which continually measure the changes in atmospheric electrical fields out to a range of 6 or more miles from the sensor.  A photo of the EFM appears below.

    Analysis and display of the atmospheric charge data collected from all of the EFM sensors in the ALWS are provided by the Lightning Warning Processor (LWP) which produces a broad range of analyses and warning outputs.  Such outputs include trend charts, site alarms and sensor status reports.  A typical ALWS airport installation is shown in the diagram which follows.

Electric Field Mill

TOA Electrical Field Mill Technical Specifications
Operational:
Accuracy
  0.5% of reading
Range
 Dependent on conditions, minimum of 6 miles
Reliability
 100% notification of field change
Response Time
 Programmable (based on user selected options)
Signal Interface
 2 digital communications ports and 1 analog
Measuring Range
 Programmable from (0 to 1 kV/m) to (0 to 30 kV/m)
User Selectable Options:
Readings per second
1 to 50 (software selectable)
Calibration procedure
 Software based
Software Upgrades
 Remote software installable
Remote Diagnostic
 Operating temperature
Power supply voltages
Motor turning indication
DAC operations
Factory low level diagnostics