US sells advanced GPS jammers
China and Russia sell GPS jammers. Some of the latest Russian GPS jammers have recently been deployed in eastern Ukraine. In 2007, China introduced a powerful GPS jamming system for trucks. These "GPS jammers" are designed to form a bubble of protection in the area where the truck is located. Sales are slow. A year before the 2003 invasion of Iraq, it is believed that Saddam purchased numerous GPS jammers to counter US JDAM GPS smart bombs. It's no secret that JDAM has a backup INS. GPS jamming work in Iraq did not have a substantial impact on the 2003 campaign.
Although the US military hasn't encountered too many GPS outages (if any) on the battlefield, the threat still exists. The clearest evidence comes from North Korea, which has a long history of manufacturing, selling and using GPS jammers. In 2012, North Korea launched a large-scale GPS jamming activity against South Korea. The outage began in early 2012 and lasted over two weeks. It was confirmed in less than a day that the signal came from North Korea, mainly for the South Korean capital (Seoul). The interference has almost no effect on the city itself (the ground interference signal is blocked by buildings and hills), only hundreds of planes taking off and landing from the local airport, and more than a hundred ships operating at sea noticed it. In all of these cases, ships and aircraft have backup navigation systems, which are activated when GPS becomes unreliable. This is how navigation systems are designed, especially those based on external signals (satellites). This is the third time that North Korea has used GPS interference against South Korea. For most of March 2011, North Korea sent GPS jamming signals to Seoul. A separate gsm jammer targets mobile phone traffic. GPS jamming signals can be detected 100 kilometers south of the DMZ. This is the third time that North Korea has used GPS interference against South Korea. For most of March 2011, North Korea sent GPS jamming signals to Seoul. A separate jammer targets mobile phone traffic. GPS jamming signals can be detected 100 kilometers south of the DMZ. This is the third time that North Korea has used GPS interference against South Korea. For most of March 2011, North Korea sent GPS jamming signals to Seoul. A separate jammer targets mobile phone traffic. GPS jamming signals can be detected 100 kilometers south of the DMZ.
