Hmm, I wonder to what extent a GPS "device" can be jammed (as in the Russians jamming GPS signals in Ukraine). And where is the jam, at the satellite level or the receiver level? Would it affect non-targets since satellites orbit? So many technical questions. I know, I know, off-topic, but it does relate to the previous thread in my daily digest about determining where you are while riding a train.
You can search what the FAA tells us about GPS outages, locations and radius, here is one place
https://notams.aim.faa.gov/notamSearch/nsapp.html#/
So, you can put in Location, Predefined Query, GPS NOTAMS, Search.
This is for instance how to decode these:
!GPS 04/055 ZDV NAV GPS (NATLID GPS 22-01) (INCLUDING WAAS, GBAS, AND ADS-B) MAY NOT BE AVBL WI A 306NM RADIUS CENTERED AT 433430N1125830W (IDA260040) FL400-UNL, 257NM RADIUS AT FL250, 187NM RADIUS AT 10000FT, 189NM RADIUS AT 4000FT AGL, 160NM RADIUS AT 50FT AGL. DLY 1000-1500 2204221000-2204281500
The 433430N1125830W are coordinates and this particular one is west of Idaho Falls.
For ground level, 160NM RADIUS AT 50FT AGL gives us the radius of the outage, and AGL = Above Ground Level.
DLY=Daily
1000-1500 I beleive is the time range, in Zulu time!
2204221000-2204281500 is the dates, year 22, month 04, days 22-28.
And, "stop buzzer" is what you request from ATC if it is causing too much danger for you!
Large assumption=the different radius at different altitudes I think would give clues as to where the jamming originates for these? The way it cones up would lead me to guess this one is jammed from the surface up?