[Goose]

Daily GPS jam info is shown at https://gpsjam.org

The site https://spoofing.skai-data-services.com/ shows (some of) current GPS/GLONASS spoofing.  AIUI, it does this by detecting multiple aircraft reporting their positions as the same.

In the last 12 hours, it shows about 500 aircraft with spoofed locations near Israel, about 50 over the Black Sea, but interestingly, 144 near Moscow. The lines show the last reported position of the aircraft before they started reporting the spoofed location.   My supposition is that Russia is spoofing GPS in the area around Moscow as a defensive measure.

It makes sense that Russia would do that.

I hadn't realized that GPS spoofing causes a plane's Inertia Reference System to be unusable (since its last "real" position was fake).  The Serious Threat Of GPS Spoofing: An Analysis  Presumably, if you know to turn off GPS reception before you get in range of spoofing, the IRS can work.  I presume the same thing is true of a (simplistic) GPS + INS on a missile.

The article is misleading. Military grade GPS-INS systems do not unconditionally update the INS position based on the apparent validity of GPS data. The "spoofed" GPS position essentially always contains a discontinuity. This discontinuity is introduced when the spoofing signal "takes over" from the real signal. The spoofed position is so far from the INS position that INS drift cannot be the cause. The nav system software detects that it is being "spoofed" and quits using GPS until it gets back into a position that the GPS fix is believably close to the INS fix. Your cell phone and commercial navigation systems in general do not have this protection. Commercial nav systems could/should have their software modified to take into account possible spoofing. Using more than a 4 satellite constellation (when possible) also makes spoofing more difficult.

Do we know that it is GPS jamming that is causing the problems for the Ukrainian missiles, or could it be GPS spoofing?

I am sure the US Technical Elint people know. I suspect most of the EU states know too (independent of the US telling them). I don't know, FWIW. On the missiles that have both a GPS and an INS, I suspect the results would be similar. No valid GPS fix would result in falling back to INS, and a "spoofed" GPS fix will be rejected as "impossible" and cause a fallback to INS alone until a "reasonable" GPS fix was maintained for several seconds.

[Goose]

Daily GPS jam info is shown at https://gpsjam.org

The site https://spoofing.skai-data-services.com/ shows (some of) current GPS/GLONASS spoofing.  AIUI, it does this by detecting multiple aircraft reporting their positions as the same.

In the last 12 hours, it shows about 500 aircraft with spoofed locations near Israel, about 50 over the Black Sea, but interestingly, 144 near Moscow. The lines show the last reported position of the aircraft before they started reporting the spoofed location.   My supposition is that Russia is spoofing GPS in the area around Moscow as a defensive measure.

It makes sense that Russia would do that.

I hadn't realized that GPS spoofing causes a plane's Inertia Reference System to be unusable (since its last "real" position was fake).  The Serious Threat Of GPS Spoofing: An Analysis  Presumably, if you know to turn off GPS reception before you get in range of spoofing, the IRS can work.  I presume the same thing is true of a (simplistic) GPS + INS on a missile.

The article is misleading. Military grade GPS-INS systems do not unconditionally update the INS position based on the apparent validity of GPS data. The "spoofed" GPS position essentially always contains a discontinuity. This discontinuity is introduced when the spoofing signal "takes over" from the real signal. The spoofed position is so far from the INS position that INS drift cannot be the cause. The nav system software detects that it is being "spoofed" and quits using GPS until it gets back into a position that the GPS fix is believably close to the INS fix. Your cell phone and commercial navigation systems in general do not have this protection. Commercial nav systems could/should have their software modified to take into account possible spoofing. Using more than a 4 satellite constellation (when possible) also makes spoofing more difficult.

Do we know that it is GPS jamming that is causing the problems for the Ukrainian missiles, or could it be GPS spoofing?

I am sure the US Technical Elint people know. I suspect most of the EU states know too (independent of the US telling them). I don't know, FWIW. On the missiles that have both a GPS and an INS, I suspect the results would be similar. No valid GPS fix would result in falling back to INS, and a "spoofed" GPS fix will be rejected as "impossible" and cause a fallback to INS alone until a "reasonable" GPS fix was maintained for several seconds.