Re:Cave-Link: Underground text communication system
by cmurf on Wednesday November 10, 2021 @08:51AM
(#29174595)
There's a huge antenna in Colorado, I think managed by the Denver Air Route Traffic Control Center which is located in Longmont, that's used as a backup for transatlantic flights communications.
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Re:Cave-Link: Underground text communication system
by tomfanning on Wednesday November 10, 2021 @09:42AM
(#29175104)
Trans-oceanic flights go far beyond the VHF radio horizon to land so routinely use HF radio. It's not a backup, it's the norm.
Example: https://www.iaa.ie/air-traffic-management/north-atlantic-com...
"Huge" is probably not that big vs VLF. Maybe on the order of ~50m width (~3MHz / ~100m wavelength for ~50m half-wave antennas). VLF is more like wires across entire valleys - kilometres.
Re:Cave-Link: Underground text communication system
by ale42 on Wednesday November 10, 2021 @09:17AM
(#29174854)
How huge? Aviation uses HF (shortwaves) and not VLF as a backup for translatlantic flights (see for example https://thepointsguy.com/guide/how-pilots-communicate-with-a...). HF antennas can already look huge ;-)