Ground stations
GPS signal strength at 25 survey stations on the ground, from Finland and the Baltic to the eastern Mediterranean and the Red Sea, read every hour and compared with the same time the day before.
Source: GPSInterference.com, https://gpsinterference.com/ground-stations. Free to reuse with this credit and a link.
What a ground station can and cannot show. Each station measures the quality of the satellite signals at one spot on the ground. It will notice a jammer close by, but it is not a jamming detector for the area around it.
A jammer's signal travels in straight lines. Aircraft high up pick it up from hundreds of kilometres away, but on the ground the curve of the earth, hills and buildings soon hide it, and survey antennas are built to ignore signals from near the horizon, where a distant jammer would be. A station that reads normal does not mean there is no jamming nearby: the aircraft map remains the better guide to where interference is.
Latest hour
From 23:00 to 00:00 UTC on 10 November 2026, compared with the same time a sidereal day before.
| Station | This hour | Change |
|---|---|---|
| Ny-Ålesund, Norway NYA200NOR | Normal | 0.0 dB |
| Istanbul, Türkiye ISTA00TUR | Normal | −0.9 dB |
| Nicosia, Cyprus NICO00CYP | Normal | −0.2 dB |
| Zimmerwald, Switzerland ZIM200CHE | Normal | −0.2 dB |
| Metsähovi, Finland METG00FIN | No data | |
| Sodankylä, Finland SOD300FIN | No data | |
| Svetloe, Russia SVTL00RUS | No data | |
| Riga, Latvia RIGA00LVA | No data | |
| Olsztyn, Poland LAMA00POL | No data | |
| Borowiec, Poland BOR100POL | No data | |
| Mårtsbo, Sweden MAR600SWE | No data | |
| Onsala, Sweden ONS100SWE | No data | |
| Kiruna, Sweden KIR000SWE | No data | |
| Bucharest, Romania BUCU00ROU | No data | |
| Ankara, Türkiye ANK200TUR | No data | |
| Mersin, Türkiye MERS00TUR | No data | |
| Zelenchukskaya, Russia ZECK00RUS | No data | |
| Garni, Armenia GARN00ARM | No data | |
| Haifa, Israel BSHM00ISR | No data | |
| Gavdos, Greece GVDG00GRC | No data | |
| Djibouti, Djibouti DJIG00DJI | No data | |
| Wettzell, Germany WTZR00DEU | No data | |
| Brussels, Belgium BRUX00BEL | No data | |
| Reykjavík, Iceland REYK00ISL | No data | |
| Greenbelt, United States GODE00USA | No data |
Today so far
2 hours read, from 22:00 to 23:59 UTC on 10 November 2026.
| Station | Today so far |
|---|---|
| Haifa, Israel BSHM00ISR | Strongly down at 22:00 UTC: −12.6 dB, 30 min in all |
| Borowiec, Poland BOR100POL | Normal in every hour read |
| Brussels, Belgium BRUX00BEL | Normal in every hour read |
| Bucharest, Romania BUCU00ROU | Normal in every hour read |
| Djibouti, Djibouti DJIG00DJI | Normal in every hour read |
| Garni, Armenia GARN00ARM | Normal in every hour read |
| Gavdos, Greece GVDG00GRC | Normal in every hour read |
| Greenbelt, United States GODE00USA | Normal in every hour read |
| Istanbul, Türkiye ISTA00TUR | Normal in every hour read |
| Kiruna, Sweden KIR000SWE | Normal in every hour read |
| Mårtsbo, Sweden MAR600SWE | Normal in every hour read |
| Metsähovi, Finland METG00FIN | Normal in every hour read |
| Nicosia, Cyprus NICO00CYP | Normal in every hour read |
| Ny-Ålesund, Norway NYA200NOR | Normal in every hour read |
| Olsztyn, Poland LAMA00POL | Normal in every hour read |
| Onsala, Sweden ONS100SWE | Normal in every hour read |
| Reykjavík, Iceland REYK00ISL | Normal in every hour read |
| Riga, Latvia RIGA00LVA | Normal in every hour read |
| Sodankylä, Finland SOD300FIN | Normal in every hour read |
| Wettzell, Germany WTZR00DEU | Normal in every hour read |
| Zimmerwald, Switzerland ZIM200CHE | Normal in every hour read |
| Ankara, Türkiye ANK200TUR | No data today |
| Mersin, Türkiye MERS00TUR | No data today |
| Svetloe, Russia SVTL00RUS | No data today |
| Zelenchukskaya, Russia ZECK00RUS | No data today |
How it is measured
Each of these stations is a permanent survey-grade GPS receiver in the International GNSS Service (IGS) network. Every hour it sends its observations to NASA's Crustal Dynamics Data Information System (CDDIS), including the strength of each satellite's signal (its carrier-to-noise ratio, C/N0).
For each station we compare every GPS satellite's L1 signal strength, every 30 seconds, with the same satellite one sidereal day earlier (23 hours 56 minutes), when it stood in the same place in the sky, so the station's antenna and surroundings cancel out. A jammer near a station lowers every satellite's signal at once and can make satellites drop out; on an ordinary day the difference is a fraction of a decibel.
- Signal down: the median signal is 3 dB or more below the day before for at least 10 minutes in the hour.
- Strongly down: 6 dB or more, or half the satellites lost, for at least 10 minutes.
- No data: the station's file for the hour, or the day before, was not in the archive. It is never counted as normal.
This page is being tried out: the thresholds may change.
The data
The latest hour: https://api.gpsinterference.com/v1/ground/latest. One day's hours, with each station's worst hour: https://api.gpsinterference.com/v1/ground/2026-11-10 (any date from 10 November 2026). Both are free to reuse with credit, as the rest of the API.