05-06-2023, 10:27 AM
Interesting info. My read on the Improved Hawk is that it is taking so long it probably won't matter. The condition of the systems must be real bad if it is taking this long to get them ready, and lots of the parts are so obsolete finding them is going to be difficult. I will believe it when I see it. Obviously the Sea Sparrow isn't an anti-ship missile. It is a SAM that operates from ships, or anywhere else it can. How many BUKs will get FrankenSAMed is unknown. The Sea Sparrow is SARAH, as are the native missiles for the BUK. Most things that are “MacGyvered” don't work very well, especially things that are complex to begin with. It will be interesting to see if this is an exception.
The main reason the I HAWK was declared obsolete and the BUK deprecated in Russian service is that conventional wisdom says any ground-based SARAH system with an illuminator won't survive in action for a week, if that long. The migration toward fire and forget missiles with their own illuminators was the result. Obviously that isn't the case in Ukraine. The capabilities available to both countries are so substandard that the "rules" don't apply.
The problems with Russian GPS jamming OTOH is larger than the US was prepared for. This has evolved over the course of the war to be more of a problem than anticipated. It was known and expected that Russia had a relatively large number of high powered GPS jammers that could provide wide area coverage. What was not expected was the even larger number of low to medium power jammers that have come online in response to the drone threat. The expectation was that our active SEAD would destroy most of these jammers in short order. The Ukrainians don't really have the weapons to do that. They also don't have the ESM aircraft to locate these jammers in real time and task other aircraft with eliminating them. The current improvised system in Ukraine isn't working all that effectively it appears. The USAF tacitly assumes their ESM aircraft can locate these jammers and F-35s can get close enough to destroy them without being targeted. The Ukraine has neither.
The performance of the INS in the US munitions has not been at a premium, as the GPS performance was always going to be "better". As a result, the INS performance isn't the "latest and greatest". It is also true that INS cost money, typically more than a GPS receiver. Both are "consumable" in the weapon, so there is a tradeoff. That said, the INS performance is normally "good enough", especially for HIMARS use.
The JDAMS being more susceptible to this problem is probably (IMO) partly due to a "bad fix" at launch. Since they are dropped from altitude, they may well be in the jammer effective field at launch. The INS is only as good as it's initial fix. If that fix is "bad" and there are no subsequent GPS updates, it is going to miss by at least the error in the initial fix. We also don't know to what degree the Ukraine's aircraft can supply an initial fix via the control bus to the weapon(s). MIGs don't come from the factory with a GPS and a 1553 bus :-). If the JDAM needs to acquire a fix after launch, things just get worse in the presence of jamming. It may not happen at all and the weapon "goes stupid". The JDAMS also have a longer flight time, in general, because they "fly" slower. This gives the INS more time to accumulate error.
The HARM missile does have the ability to target GPS jammers. This has been true for many years and is not classified. How well it works is not publicly known, one way or another. To what degree this is available to Ukrainian users, I do not know.
The main reason the I HAWK was declared obsolete and the BUK deprecated in Russian service is that conventional wisdom says any ground-based SARAH system with an illuminator won't survive in action for a week, if that long. The migration toward fire and forget missiles with their own illuminators was the result. Obviously that isn't the case in Ukraine. The capabilities available to both countries are so substandard that the "rules" don't apply.
The problems with Russian GPS jamming OTOH is larger than the US was prepared for. This has evolved over the course of the war to be more of a problem than anticipated. It was known and expected that Russia had a relatively large number of high powered GPS jammers that could provide wide area coverage. What was not expected was the even larger number of low to medium power jammers that have come online in response to the drone threat. The expectation was that our active SEAD would destroy most of these jammers in short order. The Ukrainians don't really have the weapons to do that. They also don't have the ESM aircraft to locate these jammers in real time and task other aircraft with eliminating them. The current improvised system in Ukraine isn't working all that effectively it appears. The USAF tacitly assumes their ESM aircraft can locate these jammers and F-35s can get close enough to destroy them without being targeted. The Ukraine has neither.
The performance of the INS in the US munitions has not been at a premium, as the GPS performance was always going to be "better". As a result, the INS performance isn't the "latest and greatest". It is also true that INS cost money, typically more than a GPS receiver. Both are "consumable" in the weapon, so there is a tradeoff. That said, the INS performance is normally "good enough", especially for HIMARS use.
The JDAMS being more susceptible to this problem is probably (IMO) partly due to a "bad fix" at launch. Since they are dropped from altitude, they may well be in the jammer effective field at launch. The INS is only as good as it's initial fix. If that fix is "bad" and there are no subsequent GPS updates, it is going to miss by at least the error in the initial fix. We also don't know to what degree the Ukraine's aircraft can supply an initial fix via the control bus to the weapon(s). MIGs don't come from the factory with a GPS and a 1553 bus :-). If the JDAM needs to acquire a fix after launch, things just get worse in the presence of jamming. It may not happen at all and the weapon "goes stupid". The JDAMS also have a longer flight time, in general, because they "fly" slower. This gives the INS more time to accumulate error.
The HARM missile does have the ability to target GPS jammers. This has been true for many years and is not classified. How well it works is not publicly known, one way or another. To what degree this is available to Ukrainian users, I do not know.