EAM Overnight Livestream – 231204 – HFGCS (8992 kHz)

** NEW DESCRIPTION FOR DECEMBER 2023 **

I. Introduction

Follow me on Twitter for HFGCS news and updates: https://www.twitter.com/neetintel

I take time out of every day to monitor the HFGCS for EAMs and transcribe the messages to post to both YouTube and Twitter. If you're interested in the work I'm doing and are able to contribute, you can support this project via my Patreon and BuyMeACoffee. Funds will be invested into equipment upgrades for improving future stream quality;
https://buymeacoffee.com/metalenergy
https://www.patreon.com/internetfriend

II. Overview

This is a livestream of frequencies known to be used by the US military as part of their High Frequency Global Communications System (HFGCS), which is used by the US military to communicate with various assets (including nuclear-capable aircraft and submarines) in a variety of ways. One of the more interesting methods of communication that can be heard over the HFGCS is Emergency Action Messages (EAMs) and Force Direction Messages (FDMs).

III. Stream Source

This series is overwhelmingly a livestream using the UTwente WebSDR;
Stream url: http://websdr.ewi.utwente.nl:8901/

Incidentally, other SDRs are streamed and I endeavour to show the source on-screen. Some of the ones I've streamed in the past include;
Utah – http://websdr3.sdrutah.org:8903/index1a.html
Alberta, Canada – 209.115.233.71:8073
Montana, USA – http://kiwi.foxgulch.net

IV. FAQ

𝑸. How long do streams last?
𝑨. As long as I don't forget to reset them, they run for about 12 hours – if they run much longer YouTube won't archive them. This is done manually because the streams run off of a 2009 iMac which can't support stream automation very well. (Streams will continue to run off this device until it burns out or I find a good deal on a newer model, with funds from the above used to subsidize the purchase.)

𝑸. What's an EAM?
𝑨. From a recent document published by the Department of Defense; "Emergency Action Messages (EAMs) are highly structured, authenticated messages primarily used in the command and control of nuclear forces. They are disseminated over numerous survivable and non-survivable communication systems including terrestrial and space systems."

The typical EAM is 30 characters, but it can vary. Some messages are slightly shorter, at only 27 characters. As well, sometimes messages over 200 characters long are broadcast*.

𝑸. What's an FDM?
𝑨. Some of what we refer to as 'EAMs' are actually FDMs. It seems likely that the first 2 characters of a message distinguish an EAM from an FDM.

𝑸. Why are you streaming an antenna in Europe? Wouldn't it make more sense to stream an antenna in North America?
𝑨. Yes, but the impact isn't as great as you might think. The HFGCS has ground stations across the world, and these stations have a relay system set up so that all ground stations simulcast the same messages at the same time. UTwente WebSDR's antenna is located in the Netherlands, and most likely picking up these broadcasts from (at least) HFGCS transmitters at RAF Croughton (UK) and/or NAS Sigonella (Italy). As far as ground station transmissions go, there's essentially no difference.

However, there are also broadcasts by airborne "relay stations", which are transmitted by (at least) E6s flying about the US. While "relay station" is my own terminology as far as I'm aware and the actual term is probably TACAMO**, "relay station" captures something the more obtuse term doesn't – the majority of messages broadcast by these aircraft are repeats of those broadcast by ground stations.

𝑸. How many structured messages are broadcast on any given day?
𝑨. The 'typical' amount of daily messages is around 10-15, but the range is quite wide;
- Occasionally, there are days with 0 messages; recent examples include Sept 30 2023, Nov 23 2023. This will often line up with holidays – Nov 23 2023 was Thanksgiving.
- Alternatively, there can be many more messages; Nov 30 2022 had over 50 messages, Sept 5 2023 had over 40. Attempts made to correlate these days with real-world events are usually only circumstantial at best.

𝑸. Are these messages cause for concern?
𝑨. No. (Probably not.)

𝑸. Why did you stop contributing to eam.watch?
𝑨. I stopped contributing to that website's database after multiple significant differences with the website's Discord community. An example of one is thus; I was made a moderator of the community early in 2023 and became aware of one of the site's senior staff falsely representing themselves as having "insider knowledge" about the HFGCS as well as impersonating other members of the SWL community. When I brought this to the attention of other moderators, evidence was deleted and no action was taken. After contributing over 4500 entries to the site database and actively promoting the site throughout 2023, I quit in Nov 2023.

* Rcordings are available; see https://www.youtube.com/playlist?list=PLVmgc_OQTMfyAICaD4N_S_TpMMOX7Qdos
** https://en.wikipedia.org/wiki/TACAMO