There are things that will naturally interfere with GPS and they are fairly well known. The FAA provides an expected outage map [1] (a forecast, if you will) for pilots that may need that info. Jamming is an act by humans to intentionally disrupt the GPS signal.
Could be. I was directly answering "what's the difference?"
It's hard to know intentionality without also knowing where there is expected+natural interference. Of course, when a region is surrounded by persistent GNSS issues and is a known war-zone with large actors, intentionality is fairly reasonably assumed.
The GPS jamming map linked to in the article[1] discusses this somewhat, in the "About the data" box:
- ADS-B messages include position information from Global Navigation Satellite Systems (GNSS), like GPS, Galileo, GLONASS, BeiDou, etc.
- It is not possible to directly measure GNSS interference, but we do calculate the NIC (Navigation integrity category) for ADS-B messages.
- The NIC value encodes the quality and consistency of navigational data received by the aircraft.
- Poor NIC values alone might indicate a problem with an aircraft’s equipment or unfavorable positioning. However, when observed in multiple aircraft in close proximity during the same time frame, it suggests the presence of a radio signal interfering with normal GNSS operation.
[1] https://sapt.faa.gov/outages.php?outageType=129001450&outage...