Flightradar24’s new GPS jamming map

The map uses are color coded overlay to indicate low (green) to high (red) levels of interference with global navigation satellite systems (GNSS). Often just referred to as GPS, there are actually multiple systems beside the US GPS constellation, such as Russia’s GLONASS, Europe’s Galileo, China’s BeiDou, and others. 

Calculating GPS jamming

As part of the ADS-B messages we receive from each aircraft, the Navigation integrity category (NIC) encodes the quality and consistency of navigational data received by the aircraft. The NIC value informs how certain the aircraft is of its position by providing a radius of uncertainty. The larger the radius value, the less certain the position update. We use the NIC values broadcast by aircraft passing through a particular area over time to calculate GPS jamming and interference.

How does the Flightradar24 GPS jamming map work?

Jamming and interference can be displayed in a resolution of six (6) hours or 24 hours. Six hour resolution will show the most recent activity, while 24 hour resolution provides a broader perspective for the previous day. 

Use the selector in the upper left corner of the map to adjust the date and time for which you would like to view data. Use the forward and back buttons underneath the date selector to advance one time period in either direction or press the play button to begin a slide show from the date and time selected.

At the moment, GPS jamming is calculated only using using data from areas where there are an adequate number of flights and where there are an adequate number of Flightradar24 terrestrial ADS-B receivers. We are working on incorporating additional sources of data in the near future to further enhance the map. 

Sourced from Hackernews