GPS jamming greatly affected the war
When the Iraq War began in 2003, the Iraqi Army caused a stir by using a Russian-made GPS signal jammer system to disrupt the U.S. military’s guided weapons systems. South Korean military authorities are racking their brains to work out a counter solution, worried that the device could cause similar disruptions for the South and its allies if war broke out.
GPS receivers are so sensitive that there have even been cases of unintentional jamming. In one case no less than three separate jamming signals were being generated by VHF/UHF television antenna preamplifiers on boats in California’s Monterey Bay. The signals from the preamplifiers were strong enough to completely jam GPS within a one-kilometer radius at sea level. The authors of the report speculate that a similar source, if transmitted using an omni-directional antenna, could interfere with aviation GPS receivers at a range of 50 kilometers.
Long-range air-to-ground cruise missiles, including Tomahawk cruise missiles, are also GPS-guided. The strength of GPS-based weapons systems is their accuracy in hitting targets despite bad weather or challenging terrain. Their weakness is that they can be jammed easily, by even a weak signal.
North Korea has been jamming GPS signals in South Korea since March 31, threatening the safety of civilian aircraft and vessels and violating international agreements, Seoul told the United Nations Security Council in a letter released on Monday.
South Korean U.N. Ambassador Oh Joon said the electronic cell phone signal jammer signals have come from five North Korean regions – Haeju, Yonan, Pyongyang, Kumgang and Kaesong – and “dangerously affect” the Global Positioning System.
The South Korean government report said the DPRK had imported “about 20 communications and radar jamming devices from the old Soviet Union.” Such units mounted on vehicles had been deployed near the border and disrupted GPS signals within a range of between 50- and 100 kilometers, the report said, according to Yonhap.
Several years ago, when satellites were being touted as aviation’s sole means of navigation from takeoff to touchdown, former FAA Administrator Langhorne Bond painted a picture of a dark winter’s night with below-limits weather up and down the east coast. In that scenario, he stated, terrorist GPS jammers could become “weapons of mass destruction.” The FAA shrugged it off as unfounded speculation. But in a recent report on the GPS-dependent ADS-B, the DOT’s Inspector General took the matter much more seriously, calling on the FAA to “work with the U.S. intelligence community to assess such potential threats.”