[Goose]

We may not have 5000 ATACMS to give. But we almost certainly do have 5,000 JDAM-ERs to give. After the initial fanfare, we have heard very little about JDAMs in the war except about their Russian equivalents. Reportedly this is due to  widespread GPS jamming. I hope that changing the launch platform to one it was intended for, or software changes could help counteract this.

It will help considerably. The automatic transfer of the launch platform data to the JDAM will initialize the JDAM INS accurately, which will help a lot. JDAMS can "fly" without GPS correction and be fairly useful against ground defensive positions. The CEP isn't as good as with GPS correction, but is not horrible.  https://www.af.mil/About-Us/Fact-Sheets/...bu-313238/ says a 30 meter CEP vs a 5 meter CEP. Depending on what is being attacked and how many JDAMs are used, that may be fine. Currently, Ukraine can't use lots of bombs because they can't sortie lots of planes :-). Also, I have no idea how the INS is getting initialized in a Mig. I am guessing not well. Relying on GPS initialization is not a feature I am aware of in JDAMs.

The JDAM has major problems with fairly unsophisticated GPS jamming. This has been known about JDAMs for about 20 years. Nothing was done because 1) it would cost money, and 2) the people we were fighting didn't have jammers, and 3) we have the ability to locate and target GPS jammers and destroy them. Certainly a "nuisance" but not a "show stopper".

It must be said we have yet to fight against an opponent that has significant jamming capability. However, since the enemy can't predict the target and the TOT very much in advance, the GPS jammers have to run all the time. That should, in theory, give them a very short lifetime. It is also possible to do many things (at a cost varying from a little to a lot) that would improve the JDAM resistance to jamming. However, the big "claim to fame" of the JDAM is that it is a cheap add-on to a conventional bomb. When it becomes less cheap, it becomes considerably less attractive.

The F-16 will however provide greatly improved performance to HARM missiles. The interface to the aircraft RWR and avionics will allow much better employment of these missiles. However, I have no insight into what capabilities the Ukrainians have to geolocate Russian GPS jammers. In general, you need do do this from aircraft. The FEBA is usually too far from the "important" targets to "see" the GPS jammers from the ground, although you can easily see them from the air. For various technical reasons the F-16/HARM isn't great at locating jammers by itself without getting much closer  to the GPS jammer for far longer than is "healthy" for the aircraft. Pre-briefed mode is orders of magnitude better in this scenario. I hope "somebody" has a plan for this, but for some reason I am not betting on it. OTOH, if done "properly" this could make GPS jamming much less of a problem. Will we see "дикі Мустела" (wild Weasel) in Ukraine :-)? Obviously asking a lot more to do that than practical in the short term. Just "regular" pilots with per-briefed targets will have to do. Failing that, JDAMS will still turn to INS guided bombs.

Software changes against the type of jamming the Russians are using is generally not applicable as a countermeasure.

[Goose]

We may not have 5000 ATACMS to give. But we almost certainly do have 5,000 JDAM-ERs to give. After the initial fanfare, we have heard very little about JDAMs in the war except about their Russian equivalents. Reportedly this is due to  widespread GPS jamming. I hope that changing the launch platform to one it was intended for, or software changes could help counteract this.

It will help considerably. The automatic transfer of the launch platform data to the JDAM will initialize the JDAM INS accurately, which will help a lot. JDAMS can "fly" without GPS correction and be fairly useful against ground defensive positions. The CEP isn't as good as with GPS correction, but is not horrible.  https://www.af.mil/About-Us/Fact-Sheets/...bu-313238/ says a 30 meter CEP vs a 5 meter CEP. Depending on what is being attacked and how many JDAMs are used, that may be fine. Currently, Ukraine can't use lots of bombs because they can't sortie lots of planes :-). Also, I have no idea how the INS is getting initialized in a Mig. I am guessing not well. Relying on GPS initialization is not a feature I am aware of in JDAMs.

The JDAM has major problems with fairly unsophisticated GPS jamming. This has been known about JDAMs for about 20 years. Nothing was done because 1) it would cost money, and 2) the people we were fighting didn't have jammers, and 3) we have the ability to locate and target GPS jammers and destroy them. Certainly a "nuisance" but not a "show stopper".

It must be said we have yet to fight against an opponent that has significant jamming capability. However, since the enemy can't predict the target and the TOT very much in advance, the GPS jammers have to run all the time. That should, in theory, give them a very short lifetime. It is also possible to do many things (at a cost varying from a little to a lot) that would improve the JDAM resistance to jamming. However, the big "claim to fame" of the JDAM is that it is a cheap add-on to a conventional bomb. When it becomes less cheap, it becomes considerably less attractive.

The F-16 will however provide greatly improved performance to HARM missiles. The interface to the aircraft RWR and avionics will allow much better employment of these missiles. However, I have no insight into what capabilities the Ukrainians have to geolocate Russian GPS jammers. In general, you need do do this from aircraft. The FEBA is usually too far from the "important" targets to "see" the GPS jammers from the ground, although you can easily see them from the air. For various technical reasons the F-16/HARM isn't great at locating jammers by itself without getting much closer  to the GPS jammer for far longer than is "healthy" for the aircraft. Pre-briefed mode is orders of magnitude better in this scenario. I hope "somebody" has a plan for this, but for some reason I am not betting on it. OTOH, if done "properly" this could make GPS jamming much less of a problem. Will we see "дикі Мустела" (wild Weasel) in Ukraine :-)? Obviously asking a lot more to do that than practical in the short term. Just "regular" pilots with per-briefed targets will have to do. Failing that, JDAMS will still turn to INS guided bombs.

Software changes against the type of jamming the Russians are using is generally not applicable as a countermeasure.