North Korean GPS jamming of South Korean aviation, shipping and telecommunications (2016)
What happened
From 31 March 2016 North Korea transmitted GPS-jamming signals across the border into South Korea from ground-based transmitters operating on frequencies overlapping those used by the GPS satellites, continuing intermittently for about six days. South Korea's Defence Ministry located the transmissions at Haeju, a southwestern port city, and at Mount Kumgang on the east coast; five locations along the border were identified as sources, one at roughly 740 m elevation and about 30 km from Incheon International Airport. Reported effects were on civil aviation, fishing vessels and mobile base-station timing. Counts differ between sources: the Korea Times, citing military and ICT-sector officials, gave 962 aircraft, nearly 700 fishing ships and 1,786 mobile base stations; the Voice of America, reporting three days earlier, gave more than 50 airliners and hundreds of fishing boats, some of which returned to port. An unnamed intelligence source described jamming sent on approximately 100 occasions with maximum output above 45 decibels and signal strength constantly lessening or increasing. Seoul called the activity dangerous and reckless and raised it with the UN Security Council. Comparable episodes were recorded three times between 2010 and 2012.
Confidence is moderate on the record rather than on the event, which is not in doubt. The two sources read give materially different counts of affected aircraft and vessels three days apart, and neither states a cumulative window, so the record carries both figures rather than reconciling them. Attribution is by the affected state: South Korea's Defence Ministry located the transmitters and Seoul raised the matter at the UN Security Council. Pyongyang denied comparable earlier allegations. No independent technical attribution is cited. The commissioning brief gave this incident 5 SPARTA references; the measured figure is 4.
Attack vector
Ground-based transmitters inside North Korea radiating on frequencies overlapping the GPS civil signal, at intervals, from at least five locations along the inter-Korean border.
Operational impact
Loss or degradation of GPS position and timing at civilian receivers over about six days: aircraft navigation, fishing-vessel navigation, and mobile base-station timing. Source counts differ; see the record's figures note. Some fishing vessels returned to port. Aircraft continued to operate.
Affected segments
user, link
Disclosed
2016-04-01
SPARTA techniques evidenced
Each row is a technique this record evidences, with the reasoning and the source that attests to it.
What relationship, confidence, and evidence mean on the rows below
- Relationship
What kind of link this is between the technique and the target.
Mitigates: the target actively prevents, detects, or recovers from the technique.
Addresses: the target governs the technique or is relevant to it, without interdicting it. Most governance and policy obligations sit here.
Triggers obligation: the technique occurring is what triggers the duty the target imposes.
Relates to: related to the technique, but the target neither interdicts nor governs it. Used sparingly.
- Confidence
How strongly the source supports this mapping, not how severe the technique is.
High: the source supports the mapping squarely.
Moderate: supported, with a qualification such as a cross-tactic reading that stays operationally sound.
Low: the source reaches the technique only in part.
- Evidence
How close to the source text the mapping was made.
Direct: a verbatim excerpt of the cited source was read against the technique, and the rationale argues from that excerpt.
Derived: the mapping follows from the source's scope or structure, with no on-point excerpt addressing the technique.
Inferred: reached by composition through another framework, or by domain reasoning the source does not support on its face.
VOA describes North Korea sending signals from ground-based transmitters on frequencies overlapping those used by GPS satellites, with the result that aircraft and vessel GPS failed. That is EX-0016.03's own description of raising the noise floor in GNSS bands so satellite navigation signals are not acquired or tracked. The technique's consequence clause, degraded or unavailable position, velocity and time solutions, is written receiver-agnostically, which is why this edge is direct while the PNT spoofing edges elsewhere in this batch are derived. Follows the precedent set for EX-0016.03 in gnss-interference-european-aviation-2022-2026.
IMP-0002 is temporary impairment of the use of or access to a system. The sources record about six days of intermittent GPS loss across civil aviation, fishing vessels and mobile base-station timing, after which the ICT ministry reported no major disruption. The impairment is temporary and fully reversible, which is the distinction SPARTA draws between IMP-0002 and IMP-0003.
Considered and not mapped
These techniques were considered for this record because a source, a related record or SPARTA's own catalogue pointed at them. Each was read against what the sources say and not mapped. The reason is given in full.
The technique is fielding a ground system that transmits mission-compatible signals, matched bands, modulation, coding, framing and beacon structure, so that over-the-air traffic appears valid at the RF and protocol layers, in order to reach a spacecraft. A broadband GPS-band jammer transmits nothing valid to anything.
SPARTA distinguishes denial from disruption on the ground that denial "seeks to deny communications entirely". The sourced picture is intermittent interference over six days with aircraft continuing to fly and VOA recording that the jamming "did not cause any significant, widespread effect". Some fishing boats did return to port, which is the strongest case for denial in the record, but it is a subset effect and mapping IMP-0003 alongside IMP-0002 would assert both readings at once. Consistent with the rejection of IMP-0003 in
gnss-interference-european-aviation-2022-2026.The technique describes assembling an RF ground stack for reaching a spacecraft: steerable mounts with auto-track, TT&C modems, band-appropriate feeds. A jamming transmitter is not that. Rejected on the same reasoning in
gnss-spoofing-maritime-2016-2019andgnss-interference-european-aviation-2022-2026.
Sources
The published accounts this record rests on. The tier is SafeMode Space's own assessment of the source, and the reason for it is given beside it. What the tiers mean and how they are assigned: the source tiers.
A source is listed when a mapped technique rests on it, or when it disputes the account. One the curators read but neither cited nor recorded as disputing the record is not listed, so an absence here means neither is true rather than that nobody looked.
Tier 2: Named US government-funded international broadcaster with a Seoul dateline and a named correspondent, reporting South Korean Defence Ministry findings including the transmitter locations. Not a government record and not peer-reviewed, so not Tier 1.
Tier 3: National English-language daily reporting figures and technical characterisation attributed to military and ICT-sector officials, with the key technical claims sourced to an unnamed intelligence source.
Tier 3: Newspaper of record. The live URL refuses anonymous requests; the text was read on 2026-08-23 from the Wayback capture at 20160402203009, and reports South Korea's account of GPS interference attributed to the North.
Every source SafeMode Space reproduces, and on what terms: sources and attribution.