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ADS-B technology informs the SGF in-sky aircraft safety system

Aircraft transmit real-time updates of their positions and velocities which are monitored for early warnings in case they approach the SLR laser beam.

A test project is under development at the SGF to use the Automatic Dependent Surveillance-Broadcast (ADS-B) technology to inform the SLR observer of nearby aircraft and to make real time predictions to avoid pointing the laser beam in the direction of an aircraft.

This system is in addition to and does not replace the long-standing radar safety system in continual operation during laser ranging at the SGF. Aircraft carrying ADS-B equipment broadcast binary messages containing their identification, position and velocity at approximately one second intervals. These signals are sent on a frequency of 1090MHz and can be intercepted by a radio antenna.

The SGF uses a SBS-3 receiver, manufactured by Kinetic Avionics, which translates the raw binary messages and makes them available to software through the local network. The latitudes, longitudes and altitudes are converted to in-sky azimuths and elevations and plotted for the SLR observer.

The broadcast velocity components allow predictions to be made and warnings to be sent in advance of an approaching aircraft.


The SGF is making its server client software package 'listen2planes' available for download and further development in GitHub HERE and the Python display code HERE.

A SLR station can run this software locally and by following the instructions and making some system changes it can use the real-time display and aircraft warning alarm.

Please read our disclaimer before download.