(This comment is assuming you mean airplane pilots, as marine pilots
would not be on board a ship in the middle of the ocean).
FIRST PART:
Voice communication is used for contact between Aeradio Stations and
aircraft flying over the Atlantic, Pacific and Indian Oceans. It is
in use 24 hours a day, every day of the year; so, yes, you could say
it is reliable. However, it is HF radio, and it is SSB (Single Side
Band), so it is not as clear as VHF, and it can be subject to radio
interference occasionally. However, if it is difficult to hear on one
frequency, it should be possible to change to a better frequency.
For the Atlantic Ocean, there are aeronautical communications stations
in: GANDER, Canada; SHANNON, Ireland; REYKJAVIK, Iceland; NEW YORK;
and SANTA MARIA, Azores.
There are also stations for the Pacific and Indian Oceans, and the
Caribbean; such as SAN FRANCISCO, HONOLULU, MUMBAI, SEYCHELLES, SAN
JUAN, PIARCO, etc, etc.
These stations use "H.F." (Short Wave) Radio to keep in contact with
the aircraft right across the oceans, to relay messages to and from
Oceanic ATC controllers.
(By the way, VHF radio communication would be used over land, but
aircaft over the oceans would be out of VHF coverage).
In future years, HF voice communications may be replaced by HF data
communications, and/or satellite communications. Satellite systems
are in use in parts of the Pacific Ocean and are on trial in the
Atlantic Ocean.
Airline companies also use HF voice communications to communicate with
their own planes. Some airlines have their own company frequencies,
and others use a
commercial station such as Stockholm Radio.
SECOND PART:
In my opinion, "GPS Satellites" would NOT allow voice communications.
They are just navigation satellites. For voice and data
communications, "Communications Satellites" such as Inmarsat would be
used.
NOTE:
The above comment is just for guidance, and is open to correction.
Some of my facts from memory may already be out of date.
A researcher may be able to give you a more technical answer.
RELEVANT LINKS:
Gander Aeradio http://www.navcanada.ca/NavCanada.asp?language=en&Content=ContentDefinitionFiles%5CNewsroom%5CBackgrounders%5Cgander.xml
Iceland Radio http://www.iceradio.is/html/icelandradio.htm
Shannon Aeradio http://www.iaa.ie/air_traf/sha_map.asp
Stockholm Radio http://www.stockholmradio.com/aero/show.php/25932.html
FREQUENCIES
HF radio frequencies used by the North Atlantic Ocean stations:
3016, 5598, 8906, 13306, 17946,
2899, 5616, 8864, 13291,
2872, 5649, 8879, 11336,
2971, 4675, 8891, 11279,
2962, 6628, 8825, 11309, 13354,
3476, 6622, 8831 kHz.
I hope this helps. |
