USS Princeton AN/SPY-1 (Aegis) radar track data — 2004 Nimitz encounter.
documentedgovernment_studyScientific Instrumentation & Sensor Data
Aegis AN/SPY-1B radar tracks from USS Princeton, recalled via the Cooperative Engagement Capability (CEC) replay by Senior Chief Kevin Day, including the famous track of an object dropping from ~28,000 ft to near/below sea level in ~0.78 s.
The single most extreme data point in the case. Day (and CIC corroborator Gary Voorhis) reviewed the CEC replay the day after the encounter; Day described the descent track as looking 'more like a broken line than an actual track' because the radar couldn't update every second on so fast a target. The existence of the radar record and the operators' testimony is documented; whether the 0.78-s drop is a true measurement or a radar artifact is precisely what the skeptical critique contests, which is why the derived g-figure sits in the claim tier.