Directed EAM
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This subject of this article has no known official name. This article covers a subject which has not been named and/or discussed in unclassified military documents. Directed EAM is a theoretical or proposed name. |
Directed EAMs (also called FOR messages, directed messages, addressee messages, specifically addressed messages, or by other descriptors[Note 1]) are those EAMs that include explicit "FOR [CALLSIGN]" addressee designations announced by the operator during transmission. These messages constitute approximately 47% of Group 2 message traffic and represent the only message classification where intended recipients are explicitly identified during broadcast. The operator announces "FOR [CALLSIGN]" before transmitting the message content itself, making directed messages immediately identifiable from a monitoring perspective—unlike other message categories which require observing prefix behavioral patterns over extended monitoring periods to establish classification, directed messages effectively announce their own classification during transmission.
Structure and Transmission Format
directed messages adhere to the standard Emergency Action Message broadcast format employed across the HFGCS network but incorporate an addressee designation that the ground station operator announces before proceeding with the encrypted message content itself. The operator states "FOR [CALLSIGN]" when addressing a single recipient or employs the format "FOR [CALLSIGN], FOR [CALLSIGN]" when the message is intended for multiple designated recipients. The overwhelming majority of directed messages conform to the standard 30-character baseline length that represents the most common EAM format across all categories, though longer directed messages do occur as very rare exceptions. All documented directed messages have used Group 2 prefixes, while no instances of directed messages using Group 1, Group 3, or Group 4 prefixes have been observed.
Callsign Categories
directed messages can be further subcategorized according to their addressees.
ALPHABET FORCE Messages
ALPHABET FORCE Messages are directed to one or multiple [PHONETIC LETTER] FORCES. These callsigns have been documented consistently across the years, often during notable activity periods such as the annual Global Thunder exercises, suggesting the designations are persistent designators of standing organizational entities rather than tactical or mission-specific designations. Observed ALPHABET FORCE callsigns include ALPHA, BRAVO, CHARLIE, FOXTROT, GOLF, KILO, ROMEO, SIERRA, TANGO, UNIFORM, and VICTOR FORCE. During a particularly active period on the HFGCS in November 2023, numerous FORCE-directed messages were broadcast, including multiple transmissions to FOXTROT FORCE[1] as well as multi-addressee messages directed to GOLF, ROMEO, SIERRA, and VICTOR FORCE[2] and FOXTROT, GOLF, and ROMEO FORCE.[3]
ALPHABET REGION Messages
Similarly, ALPHABET REGION Messages are directed to one or multiple REGION [PHONETIC LETTER]S. Three REGION designations (ALPHA, BRAVO, CHARLIE) have been documented, with REGION CHARLIE being the most frequently documented. For example, messages to REGION ALPHA broadcast on November 06 2023,[4] and to REGION CHARLIE on December 07 and 12 2023.[5] There have also been messages directed to ALL REGIONS, such as on April 17 2023[6] and April 18 2023.[Reference needed] That these messages are for "regions" may suggest they are for geographic or operational areas of responsibility.
Directed EAMs for E-6B Mercurys
Messages for numbered callsigns ([WORD] [NUMBER]) are very strongly associated with E-6Bs. During a comprehensive monitoring period from June 23 2023 through February 01 2024, the majority of numbered callsign messages were readily identified as transmissions for E-6B aircraft based on identification of E-6Bs using the numbered callsign when searching for them on flight tracking sites such as ADSBExchange or Flightradar24. Examples include messages directed to TAMPA52 on June 26 2023[7] and WILE70 on June 29 2023.[8]
Directed EAMs for all other callsigns
Unnumbered callsigns not for FORCES or REGIONS represent the largest category of directed messages. Several hundred unique word-only callsigns have been observed across monitoring periods. Usage patterns vary considerably. Some word-only callsigns appear in concentrated bursts with multiple messages within hours. For example, on January 26 2022, multiple messages were directed to JITTER,[9] demonstrating the pattern of concentrated transmission bursts. Similarly, BUFFALO GAP received three consecutive transmissions on January 27 2022.[10] Other callsigns appear sporadically over multi-day periods. This variability could suggest usage for temporary operations, specific missions, exercises, deployed units, or other time-limited communication requirements.
Multi-addressee Messages
Approximately 8% of directed messages specify multiple recipients.
Multi-addressee messages can combine callsigns from the same category or mix different categories:
Same-category examples:
- FORCE+FORCE: ALPHA FORCE with CHARLIE FORCE (frequently paired);[Reference needed] FOXTROT FORCE with ROMEO FORCE and VICTOR FORCE;[Reference needed] GOLF FORCE with MIKE FORCE[Reference needed]
- REGION+REGION: REGION ALPHA with REGION BRAVO; a message on December 28 2023 was directed to both REGION BRAVO and REGION CHARLIE.[11]
- Others: PREXIE with APPOINT and VELLO[12]; TORCHBEARER with TURMOIL[13]; on January 26 2022, a multi-addressee message was directed to both JITTER and HUMID[14], followed hours later by transmissions to JITTER and HELM[15]
Mixed-category examples:
- FORCE + word-only: ALPHA FORCE with ERNIE; GOLF FORCE and MIKE FORCE with ERNIE
- FORCE + numbered: So far, there have been no messages documented that are addressed to a combination of FORCES and numbered callsigns.
- REGION + N/A: So far, there have been no messages documented that address REGIONS in combination with any other callsign types.
The largest documented multi-addressee message was directed to ten callsigns: UPSTAGE, NYLON TIRES, PARLOR, ASPHALT TILE, SNOBBY, ZIGZAG, BIG CROSS, WINKER, COTTON CANDY, and RICOTTA on October 24 2024.[Reference needed]
Relationship to non-directed Group 2 messages
directed messages share the same two-character prefix employed by non-directed Group 2 messages, with both message types utilizing identical prefixes during any given operational period. Any relationship beyond this immediately apparent point may not been investigated.
See also
Notes
- ↑ Need a section discussing the possible names of this thing, including mention that the hfgcs github documentation doesn't appear to have any internal name for them, maybe.
References
- ↑ HFGCS TIMECARD 231105, NEET INTEL DAILY TIMECARD PROJECT.
- ↑ HFGCS TIMECARD 231104, 14:52 UTC, NEET INTEL DAILY TIMECARD PROJECT.
- ↑ HFGCS TIMECARD 231104, NEET INTEL DAILY TIMECARD PROJECT.
- ↑ HFGCS TIMECARD 231106, 16:46 UTC, NEET INTEL DAILY TIMECARD PROJECT.
- ↑ HFGCS TIMECARD 231212, 17:16 UTC, NEET INTEL DAILY TIMECARD PROJECT.
- ↑ HFGCS EAM 230417 17:43 UTC, HFGCS INDIVIDUAL MESSAGE RECORDINGS.
- ↑ HFGCS TIMECARD 230626, 15:38 UTC, NEET INTEL DAILY TIMECARD PROJECT.
- ↑ HFGCS TIMECARD 230629, 21:53 UTC, NEET INTEL DAILY TIMECARD PROJECT.
- ↑ HFGCS EAM RECORDINGS 220126, HFGCS EAM DAILY COMPILATION RECORDING PROJECT.
- ↑ HFGCS EAM RECORDINGS 220127, HFGCS EAM DAILY COMPILATION RECORDING PROJECT.
- ↑ HFGCS TIMECARD 231228, 01:03 UTC, NEET INTEL DAILY TIMECARD PROJECT.
- ↑ HFGCS TIMECARD 240601, 15:02 UTC, NEET INTEL DAILY TIMECARD PROJECT.
- ↑ HFGCS TIMECARD 231014, 13:46 UTC, NEET INTEL DAILY TIMECARD PROJECT.
- ↑ HFGCS EAM RECORDINGS 220126, 15:24 UTC, HFGCS EAM DAILY COMPILATION RECORDING PROJECT.
- ↑ HFGCS EAM RECORDINGS 220126, 17:21, 17:24 UTC, HFGCS EAM DAILY COMPILATION RECORDING PROJECT.