The Empty Field That Wasn't: GPS, OTAD and Two Decades of Encrypted Broadcasts (pipeline, analysis, figures, and verifiers for the GPS L1 C/A Subframe 4 Page 17 corpus, 2007–2026)

Code, data pipeline, analysis scripts, article figures, and claim-level verifiers accompanying Murdoch (2026), "The Empty Field That Wasn't: GPS, OTAD, and Two Decades of Encrypted Broadcasts" (Inside GNSS, May/June 2026). Reproduces 12,163,006 special-message observations across 3,994 unique payloads from the GFZ Potsdam navigation-bit archive, 2007-06-19 to 2026-01-23.