← Frequency Reference
The Toolbox — Frequencies
Emergency & SAR
COSPAS-SARSAT, EPIRB, ELT, PLB, AIS, GPS/GNSS, and satellite communication frequencies.
EPIRB, ELT & PLB
| Frequency | Use |
|---|---|
| 406.028 MHz | COSPAS-SARSAT — primary EPIRB/ELT/PLB satellite detection frequency |
| 121.500 MHz | EPIRB/ELT homing signal — aviation guard, direction finding |
| 243.000 MHz | Military UHF guard — military SAR coordination |
| 406 MHz (general) | All modern EPIRBs, ELTs, and PLBs — satellite detection |
AIS — Automatic Identification System
| Frequency | Use |
|---|---|
| 161.975 MHz (Ch 87B) | AIS Channel 1 — vessel identification and tracking |
| 162.025 MHz (Ch 88B) | AIS Channel 2 — vessel identification and tracking |
| 156.525 MHz (Ch 70) | AIS DSC — ship-to-ship and ship-to-shore DSC |
GPS / GNSS
| Frequency | Use |
|---|---|
| 1575.420 MHz | GPS L1 — primary civilian signal (C/A code) |
| 1227.600 MHz | GPS L2 — secondary signal, dual-frequency receivers |
| 1176.450 MHz | GPS L5 — high accuracy, aviation safety of life |
| 1602.000 MHz | GLONASS L1 (Russian GNSS) |
| 1246.000 MHz | GLONASS L2 |
| 1575.420 MHz | Galileo E1 (European GNSS) — shares GPS L1 |
| 1191.795 MHz | Galileo E5 / GPS L5 overlap |
| 1561.098 MHz | BeiDou B1 (Chinese GNSS) |
INMARSAT & Satellite Communications
| Frequency | Use |
|---|---|
| 1525 – 1559 MHz | INMARSAT downlink (shore to ship) |
| 1626.5 – 1660.5 MHz | INMARSAT uplink (ship to satellite) |
| 1616 – 1626.5 MHz | Iridium satellite phone (LEO constellation) |
| 1610 – 1626.5 MHz | Globalstar uplink |
| 2483.5 – 2500 MHz | Globalstar downlink |
COSPAS-SARSAT
| Frequency | Use |
|---|---|
| 406.028 MHz | Primary LEO and MEO satellite detection — all modern beacons |
| 121.500 MHz | Legacy homing frequency — SAR aircraft direction finding |
| 406.037 MHz | Second COSPAS-SARSAT channel (some beacon types) |