Field tool

When GPS misbehaves: confirm, then report.

There is no single federal number for GPS interference — routing depends on who you are. This card puts the official channels on one page, link-checked, written for people whose job is not satellites. Print it, tape it in the ops room.

First, ten minutes of confirming

GPS Interference Response Card

In an emergency, call 911 first — this card is for the non-emergency reporting that comes after.Most outages aren’t attacks. Work the list before you escalate — your report is worth more with these boxes checked.

Check whether it's the system, not you

GPS satellite health and outage notices (NANUs) are published live. If the constellation is healthy, the problem is local — interference, equipment, or environment.

NAVCEN — GPS constellation status navcen.uscg.gov/gps-constellation
NAVCEN — NANUs & operational advisories navcen.uscg.gov/gps-nanus-almanacs-opsadvisories-sof

Check for planned testing

The U.S. government conducts authorized GPS testing and training that can interfere with receivers — scheduled interruptions are announced in advance.

NAVCEN — GPS service interruptions (incl. planned testing) navcen.uscg.gov/gps-service-interruptions

Rule out your own equipment

Power-cycle the receiver, check the antenna and cabling, confirm firmware is current. A surprising share of reported interference is a failing antenna.

See whether others are reporting the same window

NAVCEN posts reviewed problem reports publicly and searchably. Independent maps built from aircraft data show where interference was likely — useful situational awareness, with their stated caveats (aviation-altitude, daily aggregation, no attribution).

NAVCEN GUIDE — public problem-report map navcen.uscg.gov/guide-tool
gpsjam.org — independent daily map (third-party) gpsjam.org/

Then report — by who you are

The official channels.

Aviation

In flight: report to the nearest FAA air traffic control facility on frequency, immediately — ATC can trigger a “cease buzzer” halt to authorized testing. After landing, file the FAA GPS anomaly report.

FAA — Report a GPS Anomaly faa.gov/air_traffic/nas/gps_reports

Have ready: Zulu time, location (lat/long or bearing/distance), altitude, receiver make/model, what you observed, operational impact.

Maritime, land, and other civil users

File a GPS problem report with the U.S. Coast Guard Navigation Center — the designated civil GPS user point of contact. Reports are reviewed and posted publicly, which is how patterns get established.

NAVCEN — GPS Problem Report form navcen.uscg.gov/contact/gps-problem-report

Have ready: Disruption time and timezone, position, equipment make/model, antenna setup, satellites tracked, a short narrative.

Suspected deliberate jamming

Jammers are illegal to operate, market, sell, or import in the U.S. — even on private property. Report suspected use to the FCC in addition to NAVCEN. GPS.gov designates the FCC jammer-enforcement page as the complaint path; the FCC's enforcement advisory lists the tip line 1-855-55-NOJAM and jammerinfo@fcc.gov.

GPS.gov — jamming information & FCC routing gps.gov/information-about-gps-jamming
FCC enforcement advisory (DA 12-1642) docs.fcc.gov/public/attachments/DA-12-1642A1.pdf

Have ready: Location, times, what stopped working, any pattern (e.g., a passing vehicle, a fixed area).

Critical infrastructure operators

If a significant incident is in progress, call 911 first. Then report to CISA — 24/7. CISA's incident reporting form covers physical and cyber incidents affecting critical infrastructure.

CISA — report an incident (cisa.gov/report) cisa.gov/report
CISA — contact & 24/7 channels cisa.gov/about/contact-us

Have ready: Sector, systems affected, timeline, operational impact, your 24/7 callback.

Mariners in the Gulf / Red Sea / Indian Ocean region

Within UKMTO's Voluntary Reporting Area, vessels experiencing GNSS, AIS, or other PNT disruption are encouraged to log locations and times and report to UKMTO's 24/7 watch. This is the international maritime channel — not a U.S. domestic one.

UKMTO (Voluntary Reporting Area) ukmto.org/

Have ready: Positions and times of disruption; photos of affected displays if practicable.

State & local officials

There is no PNT-specific state intake. Your state fusion center takes suspicious-activity reports and connects to federal partners; your state emergency management agency owns the preparedness side. DHS publishes every fusion center's contact details.

DHS — fusion center locations & contacts dhs.gov/fusion-center-locations-and-contact-information

Have ready: What's affected, since when, geographic spread, who else has confirmed it.

What this card is: an educational summary, provided as-is, that routes you to official channels — every link loaded and verified on June 12, 2026. What it isn’t: operational, legal, or engineering advice, a reporting channel, or an endorsement by any agency listed — Diplo Space is an independent 501(c)(3) research lab, is not affiliated with any agency named here, and is not rendering professional services or assuming any duty owed by anyone to anyone else. We make no warranty of accuracy or completeness; requirements and contacts change, and the linked sources are authoritative, not this page. Rely on your own judgment, your jurisdiction’s procedures, and competent professionals. In an emergency, call 911.

Found a dead link? That’s a bug in the card — tell us and we’ll fix it and note the correction.

Rehearse it: the free tabletop exercise →