In December 2023, a new message format appeared in GPS Subframe 4, Page 17 — one that starts with the ASCII string 'TEXT'. 26 unique examples later, here is what the byte structure reveals.
Read more →12 million observations, 3,994 unique payloads, two distinct operational regimes. A statistical breakdown of how the military GPS key distribution schedule has changed since 2007.
Read more →Every GPS satellite broadcasts a 22-byte field that civilian receivers silently discard. For nearly two decades, that field has carried encrypted military key material. Here is what the public data shows.
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