The two frequencies are coherent in the ratio 8:3. Both the Soviet Union and the USA chose these frequency pairings for their navigation satellites, driven partly by space available in the worldwide radio spectrum. Both nations (the Soviet programmes having been taken over by Russia) and others now have satellites that transmit in this fashion.
The USA's Transit navigation satellites and their derivatives found their way here. The Transit system no longer operates but some of the later, Transit-O (OSCAR) vehicles still transmit, though their function has changed to ionospheric monitoring under the US Navy's Ionospheric Monitoring System (NIMS).
A coherent pair also exists for use by the US military for Doppler tracking and orbit measurement.
The Soviet Union's 'Tsikada' navigation satellites, later 'Nadezhda', also operated here also but the system was switched off when GPS-style navigation satellites took over.
Another former Soviet system currently operated by Russia also transmits here. The 'Parus' transmissions are Tsikada-like in content but they hide another purpose. They may have included a navigation function originally but they carry a second, clandestine, payload for communications. The 'navigation' transmissions are probably more about allowing the user to calculate where to point the transmitting aerial rather than working out their location on the Earth's surface.
Occasional launches of 'Cometa' recoverable spacecraft can be found using coherent frequencies at 150/400 MHz.
Many of the PRC's early launches used coherent frequency pairs at 180 and 480 MHz for orbit determination, still in the ratio 8:3. Currently, only CBERS and Fengyun satellites can be detected at these frequencies.
In 2006, the Cosmic/Formosat satellites arrived on orbit, using coherent frequencies in the 150/400 MHz bands but adding another one near 1066 MHz. This higher frequency is, as before an 8:3 relationship but with 400 MHz as the lower frequency. These satellites, like the Oscar/NIMS are used for ionospheric measurements.
| Freq (MHz) |
Satellite |
Payload |
Signal Type |
Notes |
| 149.910 |
Cosmos 2341 (Parus)
1997-017A 24772 |
Comms |
FM time and position information - sidebands at 3 kHz, 5 kHz and 7 kHz |
Transmission contains an almanac for all active satellites in the constellation - Use for navigation has probably ceased but is still supporting whatever other system requires reasonably precise positional information for the satellites - Coherent transmission at 399.920 MHz |
| 149.910 |
Cosmos 2398 (Parus)
2003-023A 27818 |
Comms |
FM time and position information - sidebands at 3 kHz, 5 kHz and 7 kHz |
Transmission contains an almanac for all active satellites in the constellation - Use for navigation has probably ceased but is still supporting whatever other system requires reasonably precise positional information for the satellites - Coherent transmission at 399.760 MHz |
| 149.940 |
Cosmos 2378 (Parus)
2001-023A 26818 |
Comms |
FM time and position information - sidebands at 3 kHz, 5 kHz and 7 kHz |
Transmission contains an almanac for all active satellites in the constellation - Use for navigation has probably ceased but is still supporting whatever other system requires reasonably precise positional information for the satellites - Coherent transmission at 399.840 MHz |
| 149.940 |
Cosmos 2454 (Parus)
2009-039A 35635 |
Comms |
FM time and position information - sidebands at 3 kHz, 5 kHz and 7 kHz |
Transmission contains an almanac for all active satellites in the constellation - Use for navigation has probably ceased but is still supporting whatever other system requires reasonably precise positional information for the satellites - Coherent transmission at 399.840 MHz |
| 149.970 |
Cosmos 2336 (Parus)
1996-071A 24677 |
Comms |
FM time and position information - sidebands at 3 kHz, 5 kHz and 7 kHz |
Transmission contains an almanac for all active satellites in the constellation - Use for navigation has probably ceased but is still supporting whatever other system requires reasonably precise positional information for the satellites - Coherent transmission at 399.840 MHz |
| 149.970 |
Cosmos 2389 (Parus)
2002-026A 27436 |
Comms |
FM time and position information - sidebands at 3 kHz, 5 kHz and 7 kHz |
Transmission contains an almanac for all active satellites in the constellation - Use for navigation has probably ceased but is still supporting whatever other system requires reasonably precise positional information for the satellites - Coherent transmission at 399.920 MHz |
| 149.979 |
Oscar 29 (Transit/NIMS)
1987-080B 18362 |
Ionospheric modelling for US military (NIMS) |
Modulated CW carrier |
Maintenance frequency - Coherent transmission at 399.944 MHz (has been heard to transmit tones similar to the other OSCAR satellite but 2003 December 28 - this frequency was occupied by a modulated 'buzzing' signal - No longer transmitting as of 2008 Feb 1 |
| 149.979 |
Oscar 31 (Transit/NIMS)
1988-074B 19420 |
Ionospheric modelling for US military (NIMS) |
FM telemetry (tones) +/- 2.4 kHz from carrier |
Maintenance frequency - Coherent transmission at 399.944 MHz - Occasionally changes between this frequency and the operational one - Sometime between 2007 Dec 21 and 2008 Feb 7, the normal transmissions at both frequencies were replaced with a highly unstable CW carrier (wandering frequency + variations in strength) |
| 149.988 |
Oscar 27 (Transit/NIMS)
1987-080A 18361 |
Ionospheric modelling for US military (NIMS) |
FM telemetry (tones) +/- 2.4 kHz from carrier |
Operational frequency - Coherent transmission at 399.968 MHz - Occasionally changes between this frequency and the maintenance one) - No longer transmitting as of 2008 Jan 1 |
| 149.988 |
Oscar 23 (Transit/NIMS)
1988-033A 19070 |
Ionospheric modelling for US military (NIMS) |
FM telemetry (tones) +/- 2.4 kHz from carrier |
Operational frequency - Coherent transmission at 399.968 MHz - Occasionally changes between this frequency and the maintenance one) |
| 149.988 |
Oscar 32 (Transit/NIMS)
1988-033B 19071 |
Ionospheric modelling for US military (NIMS) |
FM telemetry (tones) +/- 2.4 kHz from carrier |
Operational frequency - Coherent transmission at 399.968 MHz - Occasionally changes between this frequency and the maintenance one) |
| 149.988 |
Oscar 25 (Transit/NIMS)
1988-074A 19419 |
Ionospheric modelling for US military (NIMS) |
FM telemetry (tones) +/- 2.4 kHz from carrier |
Operational frequency - Coherent transmission at 399.968 MHz - Occasionally changes between this frequency and the maintenance one) |
| 150.000 |
Nadezhda |
Navigation - plus Search and Rescue monitoring |
FM time and position information - sidebands at 3 kHz, 5 kHz and 7 kHz |
Several satellites - the system is no longer operational, has been silent since 2003 November 26 - Coherent transmission at 400.000 MHz |
| 150.000 |
Tsikada |
Navigation - plus Search and Rescue monitoring |
FM time and position information - sidebands at 3 kHz, 5 kHz and 7 kHz |
Several satellites - the system is no longer operational, has been silent since 2003 November 26 - Coherent transmission at 400.000 MHz |
| 150.012 |
Unknown |
Not known |
'Wandering' CW |
Satellite in GEO, possibly graveyard orbit, also transmits 400.032 MHz |
| 150.012 |
Geosat
1985-021A 15595 |
Oceanography - wave height measurement |
CW - Doppler tracking beacon |
Detected being switched on and off over Europe, not continuously active. Sometime around 2007, transmissions ceased to be detected but Geosat was subsequently determined to be transmitting continuously while in sunlight. Coherent transmission at 400.032 MHz |
| 150.012 |
RADCAL (STEP P92-1)
1993-041A 22698 |
Radar calibration |
CW - Doppler tracking beacon |
Radar Calibration satellite - Coherent transmission at 400.032 MHz, operation is intermittent |
| 150.012 |
GFO
1998-007A 25157 |
Oceanography - wave height measurement |
CW - Doppler tracking beacon |
Geosat Follow On satellite - Coherent transmission at 400.032 MHz and also transmitted at 2207.5 MHz. Ceased to transmit 2208 November. |
| 150.012 |
ARGOS (STEP P91-1)
1999-008A 25634 |
USAF space experiments |
CW - Doppler tracking beacon |
Coherent transmission at 400.032 MHz - Ceased to transmit 2003 |
| 150.012 |
USA 147 (DMSP F-15)
1999-067A 25991 |
RADCAL secondary payload aboard US military metsat |
CW - Doppler tracking beacon |
Defense Meteorological Satellite Program - Also transmits at 2237.5 MHz and 2252.5 MHz, and 400.032 MHz - Post-launch testing revealed interference with other equipment from the 150/400 MHz transmitters so they remained inactive (apart from further testing) until 2006 Aug 14 |
| 150.012 |
Picosat 9 (STEP P97-1)
2001-043B 26930 |
USAF Space Test Program (STEP) |
CW - Doppler tracking beacon |
Coherent transmission at 400.032 MHz - Ceased to transmit late-2004 |
| 150.012 |
Formosat 3A (Cosmic FM-6)
2006-011A 29047 |
Atmospheric studies using CW beacons at coherent frequencies |
CW |
Switched on when observation required, European observations usuall 08:00-17:00 UTC Mon-Fri, also transmits 400.032 MHz and 1066.752 MHz |
| 150.012 |
Formosat 3B (Cosmic FM-1)
2006-011B 29048 |
Atmospheric studies using CW beacons at coherent frequencies |
CW |
Switched on when observation required, European observations usuall 08:00-17:00 UTC Mon-Fri, also transmits 400.032 MHz and 1066.752 MHz |
| 150.012 |
Formosat 3C (Cosmic FM-5)
2006-011C 29049 |
Atmospheric studies using CW beacons at coherent frequencies |
CW |
Switched on when observation required, European observations usuall 08:00-17:00 UTC Mon-Fri, also transmits 400.032MHz and 1066.752 MHz |
| 150.012 |
Formosat 3D (Cosmic FM-3)
2006-011D 29050 |
Atmospheric studies using CW beacons at coherent frequencies |
CW |
Switched on when observation required, European observations usuall 08:00-17:00 UTC Mon-Fri, also transmits 400.032 MHz and 1066.752 MHz |
| 150.012 |
Formosat 3E (Cosmic FM-4)
2006-011E 29051 |
Atmospheric studies using CW beacons at coherent frequencies |
CW |
Switched on when observation required, European observations usuall 08:00-17:00 UTC Mon-Fri, also transmits 400.032 MHz and 1066.752 MHz |
| 150.012 |
Formosat 3F (Cosmic FM-2)
2006-011F 29052 |
Atmospheric studies using CW beacons at coherent frequencies |
CW |
Switched on when observation required, European observations usuall 08:00-17:00 UTC Mon-Fri, also transmits 400.032 MHz and 1066.752 MHz |
| 150.030 |
Cosmos 2361 (Parus)
1998-076A 25590 |
Navigation (+ comms?) |
FM time and position information - sidebands at 3 kHz, 5 kHz and 7 kHz |
Coherent transmission at 400.080 MHz |
| 150.300 |
Cosmos 2373 (Yantar-1KFT11Ф660 №20, Kometa)
2000-058A 26552 |
Yantar/Cometa' recoverable satellite - photographic mapping |
AM telemetry - wide bandwidth |
Coherent transmission at 400.800 MHz - Cameras and film recovered after mission running between 2000 September 29 and 2000 November 14 - no longer in orbit |
| 150.300 |
Cosmos 2415 (Yantar-1KFT11Ф660 №21, Kometa)
2005-034A 28841 |
Yantar/Cometa' recoverable satellite - wide-area photographic reconnaissance |
CW - Doppler tracking beacon |
Coherent transmission at 400.800 MHz - Cameras and film recovered after mission mission running between 2005 September 2 and 2005 October 14 - transmissions heard over the USA - no longer in orbit |
| 179.951 |
Zi Yuan 2 (Jiang Bing 3A)
2000-050A 26481 |
Remote Sensing |
CW carrier on centre frequency plus telemetry sidebands at +/- 20 kHz- and further carriers at +/- 40 kHz |
Coherent transmission at 479.865 MHz |
| 180.006 |
Fengyun 1C
1999-025A 25730 |
Meteorological imaging |
CW carrier on centre frequency plus telemetry sidebands at +/- 5 kHz- and further carriers at +/- 10 kHz |
Active transmitter until 2007 February when attacked in ground-based interceptor test - Coherent transmission at 480.017 MHz |
| 180.007 |
Fengyun 1D
2002-024B 27431 |
Meteorological Imaging |
CW carrier on centre frequency plus telemetry sidebands at +/- 5 kHz- and further carriers at +/- 10 kHz |
Coherent transmission at 480.017 MHz |
| 180.011 |
CBERS 1
1999-057A 25940 |
Remote sensing |
CW carrier on centre frequency plus telemetry sidebands at +/- 20 kHz - and further carriers at +/- 40 kHz |
China Brasil Earth Resources Satellite - Coherent transmission at 480.025 MHz - Silent since mid 2003, the last public report being 2003 Jun 6 by Maik Hermenau of www.satellitenwelt.de |
| 180.013 |
CBERS 2B
2007-042A 32062 |
Remote sensing |
CW carrier on centre frequency plus telemetry sidebands at +/- 20 kHz- and further carriers at +/- 40 kHz |
China Brazil Earth Resources Satellite - Coherent transmission at 480.033 MHz, also transmits 2204.400 MHz |
| 180.014 |
CBERS 2
2003-049A 28057 |
Remote sensing |
CW carrier on centre frequency plus telemetry sidebands at +/- 20 kHz- and further carriers at +/- 40 kHz |
China Brazil Earth Resources Satellite - Coherent transmission at 480.037 MHz, ceased to transmit 2007 |
| 399.760 |
Cosmos 2341 (Parus)
1997-017A 24772 |
Comms |
CW - Doppler tracking beacon |
Coherent transmission at 149.910 MHz |
| 399.760 |
Cosmos 2398 (Parus)
2003-023A 27818 |
Comms |
CW - Doppler tracking beacon |
Coherent transmission at 149.910 MHz |
| 399.840 |
Cosmos 2378 (Parus)
2001-023A 26818 |
Comms |
CW - Doppler tracking beacon |
Coherent transmisiion at 149.940 MHz |
| 399.840 |
Cosmos 2389 (Parus)
2002-026A 27436 |
Comms |
CW - Doppler tracking beacon |
Coherent transmisiion at 149.940 MHz |
| 399.840 |
Cosmos 2454 (Parus)
2009-039A 35635 |
Comms |
CW - Doppler tracking beacon |
Coherent transmisiion at 149.940 MHz |
| 399.920 |
Cosmos 2336 (Parus)
1996-071A 24677 |
Navigation |
CW - Doppler tracking beacon |
Coherent transmission at 149.970 MHz |
| 399.944 |
Oscar 29 (Transit/NIMS)
1987-080B 18362 |
Ionospheric modelling for US military (NIMS) |
Modulated CW carrier |
Maintenance frequency - Coherent transmission at 149.979 MHz (known to change between this frequency and the operational one) - No longer transmitting as of 2008 Jan 1 |
| 399.944 |
Oscar 31 (Transit/NIMS)
1988-074B 19420 |
Ionospheric modelling for US military (NIMS) |
Modulated CW carrier |
Maintenance frequency - Coherent transmission at 149.979 MHz (known to change between this frequency and the operational one) - Sometime between 2007 Dec 21 and 2008 Feb 7, the normal transmissions at both frequencies were replaced with a highly unstable CW carrier (wandering frequency + variations in strength) |
| 399.968 |
Oscar 27 (Transit/NIMS)
1987-080A 18361 |
Ionospheric modelling for US military (NIMS) |
Modulated CW carrier |
Operational frequency - Coherent transmission at 149.988 MHz (known to change between this frequency and the maintenance one) - No longer transmitting as of 2008 Feb 1 |
| 399.968 |
Oscar 23 (Transit/NIMS)
1988-033A 19070 |
Ionospheric modelling for US military (NIMS) |
Modulated CW carrier |
Operational frequency - Coherent transmission at 149.988 MHz (known to change between this frequency and the maintenance one) |
| 399.968 |
Oscar 32 (Transit/NIMS)
1988-033B 19071 |
Ionospheric modelling for US military (NIMS) |
Modulated CW carrier |
Operational frequency - Coherent transmission at 149.988 MHz (known to change between this frequency and the maintenance one) |
| 399.968 |
Oscar 25 (Transit/NIMS)
1988-074A 19419 |
Ionospheric modelling for US military (NIMS) |
Modulated CW carrier |
Operational frequency - Coherent transmission at 149.988 MHz (known to change between this frequency and the maintenance one) |
| 400.000 |
Nadezhda |
Navigation - plus Search and Rescue monitoring |
CW - Doppler tracking beacon |
Coherent transmission at 150.000 MHz - no longer active (see 150 MHz note) |
| 400.000 |
Tsikada |
Navigation - plus Search and Rescue monitoring |
CW - Doppler tracking beacon |
Coherent transmission at 150.000 MHz - no longer active (see 150 MHz note) |
| 400.032 |
Unknown |
Not known |
'Wandering' CW |
Satellite in GEO, possibly graveyard orbit, also transmits 150.012 MHz |
| 400.032 |
Geosat
1985-021A 15595 |
Oceanography - wave height measurement |
CW - Doppler tracking beacon |
Detected being switched on and off over Europe, not continuously active. Sometime around 2007, transmissions ceased to be detected but Geosat was subsequently determined to be transmitting continuously while in sunlight. Coherent transmission at 150.012 MHz |
| 400.032 |
RADCAL (STEP P92-1)
1993-041A 22698 |
Radar calibration |
CW - Doppler tracking beacon |
Radar Calibration satellite - Coherent transmission at 150.012 MHz, operation is intermittent |
| 400.032 |
GFO
1998-007A 25157 |
Oceanography - wave height measurement |
CW - Doppler tracking beacon |
Geosat Follow On - Coherent transmission at 150.012 MHz and also transmittedat 2207.5 MHz. Ceased to transmit 2208 November. |
| 400.032 |
ARGOS (STEP P91-1)
1999-008A 25634 |
USAF space experiments |
CW - Doppler tracking beacon |
Coherent transmission at 150.012 MHz - Ceased to transmit 2003 |
| 400.032 |
USA 147 (DMSP F-15)
1999-067A 25991 |
RADCAL secondary payload aboard US military metsat |
CW - Doppler tracking beacon |
Defense Meteorological Satellite Program - also transmits at 2237.5 MHz, and 150.012 MHz - Post-launch testing revealed interference with other equipment from the 150/400 MHz transmitters so they remained inactive (apart from further testing) until 2006 Aug 14 . |
| 400.032 |
Picosat 9 (STEP P97-1)
2001-043B 26930 |
USAF Space Test Program (STEP) |
CW - Doppler tracking beacon |
Detected being switched on and off over Europe, not continuously active - Coherent transmission at 150.012 MHz - Ceased to transmit late-2004 |
| 400.032 |
Formosat 3A (Cosmic FM-6)
2006-011A 29047 |
Atmospheric studies using CW beacons at coherent frequencies |
CW |
Switched on when observation required, European observations usuall 08:00-17:00 UTC Mon-Fri, also transmits 150.012 MHz and 1066.752 MHz |
| 400.032 |
Formosat 3B (Cosmic FM-1)
2006-011B 29048 |
Atmospheric studies using CW beacons at coherent frequencies |
CW |
Switched on when observation required, European observations usuall 08:00-17:00 UTC Mon-Fri, also transmits 150.012 MHz and 1066.752 MHz |
| 400.032 |
Formosat 3C (Cosmic FM-5)
2006-011C 29049 |
Atmospheric studies using CW beacons at coherent frequencies |
CW |
Switched on when observation required, European observations usuall 08:00-17:00 UTC Mon-Fri, also transmits 150.012 MHz and 1066.752 MHz, during 2007 December, Formosat 3C appeared to be about 5 kHz lower than the nominal frequency - the other frequencies may be shifted pro-rata
|
| 400.032 |
Formosat 3D (Cosmic FM-3)
2006-011D 29050 |
Atmospheric studies using CW beacons at coherent frequencies |
CW |
Switched on when observation required, European observations usuall 08:00-17:00 UTC Mon-Fri, also transmits 150.012 MHz and 1066.752 MHz |
| 400.032 |
Formosat 3E (Cosmic FM-4)
2006-011E 29051 |
Atmospheric studies using CW beacons at coherent frequencies |
CW |
Switched on when observation required, European observations usuall 08:00-17:00 UTC Mon-Fri, also transmits 150.012 MHz and 1066.752 MHz |
| 400.032 |
Formosat 3F (Cosmic FM-2)
2006-011F 29052 |
Atmospheric studies using CW beacons at coherent frequencies |
CW |
Switched on when observation required, European observations usuall 08:00-17:00 UTC Mon-Fri, also transmits 150.012 MHz and 1066.752 MHz |
| 400.080 |
Cosmos 2361 (Parus)
1998-076A 25590 |
Navigation |
CW - Doppler tracking beacon |
Non operational but still transmitting 2000 December 13 - Coherent transmission at 150.030 MHz |
| 400.800 |
Cosmos 2373 (Yantar-1KFT11Ф660 №20, Kometa)
2000-058A 26552 |
'Yantar/Cometa' recoverable satellite - photographic mapping |
CW - Doppler tracking beacon |
Coherent transmission at 150.300 MHz - Cameras and film recovered after mission running between 2000 September 29 and 2000 November 14 - no longer active |
| 400.800 |
Cosmos 2415 (Yantar-1KFT11Ф660 №21, Kometa)
2005-034A 28841 |
Yantar/Cometa' recoverable satellite - wide-area photographic reconnaissance |
CW - Doppler tracking beacon |
Coherent transmission at 150.300 MHz - Cameras and film recovered after mission running between 2005 September 2 and 2005 October 14? - no longer active |
| 479.865 |
Zi Yuan 2 (Jiang Bing 3A)
2000-050A 26481 |
Remote sensing |
CW - Doppler tracking beacon |
Coherent transmission at at 179.951 MHz |
| 480.017 |
Fengyun 1D
2002-024B 27431 |
Meteorological Imaging |
CW - Doppler tracking beacon |
Coherent transmission at 180.007 MHz |
| 480.019 |
Fengyun 1C
1999-025A 25730 |
Remote sensing |
CW - Doppler tracking beacon |
Active transmitter until 2007 February when attacked in ground-based interceptor test - Coherent transmission at 180.007 MHz |
| 480.025 |
CBERS 1
1999-057A 25940 |
Remote sensing |
CW - Doppler tracking beacon |
China Brasil Earth Resources Satellite - Coherent transmission at 180.011 MHz - silent since mid-2003 |
| 480.033 |
CBERS 2B
2007-042A 32062 |
Remote sensing |
CW - Doppler tracking beacon |
China Brazil Earth Resources Satellite - Coherent transmission at 180.013 MHz, also transmits at 2204.400 MHz |
| 480.037 |
CBERS 2
2003-049A 28057 |
Remote sensing |
CW - Doppler tracking beacon |
China Brazil Earth Resources Satellite - Coherent transmission at 180.014 MHz, ceased to transmit 2007 |
| 1066.752 |
Formosat 3A (Cosmic FM-6)
2006-011A 29047 |
Atmospheric studies using CW beacons at coherent frequencies |
CW |
Switched on when observation required, European observations usuall 08:00-17:00 UTC Mon-Fri, also transmits 150.012 MHz and 400.032 MHz |
| 1066.752 |
Formosat 3B (Cosmic FM-1)
2006-011B 29048 |
Atmospheric studies using CW beacons at coherent frequencies |
CW |
Switched on when observation required, European observations usuall 08:00-17:00 UTC Mon-Fri, also transmits 150.012 MHz and 400.032 MHz |
| 1066.752 |
Formosat 3C (Cosmic FM-5)
2006-011C 29049 |
Atmospheric studies using CW beacons at coherent frequencies |
CW |
Switched on when observation required, European observations usually 08:00-17:00 UTC Mon-Fri, also transmits 150.012 MHz and 400.032 MHz |
| 1066.752 |
Formosat 3D (Cosmic FM-3)
2006-011D 29050 |
Atmospheric studies using CW beacons at coherent frequencies |
CW |
Switched on when observation required, European observations usuall 08:00-17:00 UTC Mon-Fri, also transmits 150.012 MHz and 400.032 MHz |
| 1066.752 |
Formosat 3E (Cosmic FM-4)
2006-011E 29051 |
Atmospheric studies using CW beacons at coherent frequencies |
CW |
Switched on when observation required, European observations usuall 08:00-17:00 UTC Mon-Fri, also transmits 150.012 MHz and 400.032 MHz |
| 1066.752 |
Formosat 3F (Cosmic FM-2)
2006-011F 29052 |
Atmospheric studies using CW beacons at coherent frequencies |
CW |
Switched on when observation required, European observations usuall 08:00-17:00 UTC Mon-Fri, also transmits 150.012 MHz and 400.032 MHz |