[Goose]

https://www.yahoo.com/news/russias-elect...00083.html

Interesting timing on this article. The fact that JDAMs were vulnerable to Russian jamming has been common and public knowledge since Iraq used them to defeat the attack on Saddam Hussein at the start of the second gulf war. There has been a little improvement on this front, but only a little. JDAMs are good because they are cheap, and making their GPS receivers more robust and capable costs money. OTOH, there is no excuse that Russian jamming systems are allowed to "live" in Ukraine. They are easy to find and relatively easy to kill. The fact that isn't happening is very, very strange IMO. FWIW, cluster munitions are ideal for that task.

Here is a more detailed discussion of the issues, possible solutions and more.

https://rusi.org/explore-our-research/pu...to%20Earth.

FWIW, the signal strength calculations in "dBm" involve assuming antenna efficiencies, both on the transmitting and receiving ends. The figure for the GPS antenna/receiver is pretty much the "generally accepted" value for your phone GPS. This may or may not reflect how the antenna(s) on the JDAM operate. The jammer signal received power is another matter. There are a lot of variables that go into estimating that, many of which are far from public domain and a few of which are very sensitive to how the jammer is operated. Makes me wonder a bit about these numbers, but I know I don't have "better" ones. In any case, there are indeed lots of things that can be done to mitigate the effects of this kind of jamming. They all cost money, and making the guidance kits more expensive (especially when you need LOTS of them) isn't a popular choice. It also isn't going to happen in the next year even if we were building them today, which AFAIK we are not.

The US has always assumed that this type of jamming wouldn't really be a problem because it is suicidal. The enemy can't know exactly where and when they will be attacked with GPS guided munitions. Generally, they don't possess enough jammers to "guard" everything, so attack what they aren't guarding. Furthermore, the jammers have to jam basically all the time, because they don't reliably and quickly know when weapons are inbound. Home-on-jam weapons can destroy them reliably and cheaply. Failing that, cluster munitions can be used. These munitions don't need to be "precision" guided. Spread them around, close counts. So, why in Ukraine does Russia appear to have "enough" jammers, and why aren't they dropping like flies? Seems a bit strange.

[Goose]

https://www.yahoo.com/news/russias-elect...00083.html

Interesting timing on this article. The fact that JDAMs were vulnerable to Russian jamming has been common and public knowledge since Iraq used them to defeat the attack on Saddam Hussein at the start of the second gulf war. There has been a little improvement on this front, but only a little. JDAMs are good because they are cheap, and making their GPS receivers more robust and capable costs money. OTOH, there is no excuse that Russian jamming systems are allowed to "live" in Ukraine. They are easy to find and relatively easy to kill. The fact that isn't happening is very, very strange IMO. FWIW, cluster munitions are ideal for that task.

Here is a more detailed discussion of the issues, possible solutions and more.

https://rusi.org/explore-our-research/pu...to%20Earth.

FWIW, the signal strength calculations in "dBm" involve assuming antenna efficiencies, both on the transmitting and receiving ends. The figure for the GPS antenna/receiver is pretty much the "generally accepted" value for your phone GPS. This may or may not reflect how the antenna(s) on the JDAM operate. The jammer signal received power is another matter. There are a lot of variables that go into estimating that, many of which are far from public domain and a few of which are very sensitive to how the jammer is operated. Makes me wonder a bit about these numbers, but I know I don't have "better" ones. In any case, there are indeed lots of things that can be done to mitigate the effects of this kind of jamming. They all cost money, and making the guidance kits more expensive (especially when you need LOTS of them) isn't a popular choice. It also isn't going to happen in the next year even if we were building them today, which AFAIK we are not.

The US has always assumed that this type of jamming wouldn't really be a problem because it is suicidal. The enemy can't know exactly where and when they will be attacked with GPS guided munitions. Generally, they don't possess enough jammers to "guard" everything, so attack what they aren't guarding. Furthermore, the jammers have to jam basically all the time, because they don't reliably and quickly know when weapons are inbound. Home-on-jam weapons can destroy them reliably and cheaply. Failing that, cluster munitions can be used. These munitions don't need to be "precision" guided. Spread them around, close counts. So, why in Ukraine does Russia appear to have "enough" jammers, and why aren't they dropping like flies? Seems a bit strange.