What Did North Korea Aim for with GPS Signal Jamming? [Yang Nak-gyu's Defence Club]

Radio interference direction usually west, not south
Output strength at 30% of previous interference level

North Korea has recently been attempting to jam Global Positioning System (GPS) signals, with the direction of the signals pointing not south but towards the northern West Sea coast and other areas. The military views this provocation as targeting unmanned aerial vehicles (UAVs) rather than jamming signals aimed at South Korean vessels and commercial aircraft.

Yonhap News

According to the military on the 11th, North Korea launched GPS jamming attacks directed southward for five consecutive days around the Northern Limit Line (NLL) in the West Sea from late May to early June, when it first began releasing balloons carrying waste and garbage towards the South this year. The direction and signal strength of these jamming attacks clearly indicated provocations aimed southward.

However, on the 8th and 9th, North Korea’s attempts to jam GPS signals near Haeju and Kaesong differed from before. The jamming signals were directed not only south but also in various other directions, and the signal strength was about one-third of what it was in May. Although some disruptions occurred to South Korean vessels and commercial flights, the military analyzes that it is ambiguous to consider these as full-scale attacks.

Considering that North Korea began sending such jamming signals in early last month, there is an analysis that these movements may be related to the South Korean UAVs that North Korea claims appeared over Pyongyang. On the 11th of last month, North Korea’s Ministry of Foreign Affairs issued a statement asserting, "South Korea sent UAVs to intrude into the airspace over Jung-gu District in Pyongyang during late-night hours on October 3rd, 9th, and 10th."

Since the recent North Korean GPS jamming signals have been directed towards areas including the northern sea near Baengnyeongdo, it can be seen that North Korea is sending jamming signals along the UAV intrusion routes they claim. The attendance of a commander from the Electronic Warfare Detection Unit, presumed to be responsible for GPS jamming, at the “Council on Defense and Security” convened by Chairman Kim Jong-un on the 14th of last month to respond to South Korean UAVs also supports this view.

A military official stated, "The impact on our side is minimal, but since the signals are detected, we are monitoring them closely," adding, "We are analyzing possibilities such as it being a routine training exercise, or a kind of show-of-force air defense intended to justify their UAV claims domestically and internationally after publicly announcing them."