Limits on Velocity Recovery from the PURSUE Sensor Videos

Abstract

This paper analyzes the 112 sensor videos released by the U.S. Department of War under the PURSUE (Presidential Unsealing and Reporting System for UAP Encounters) initiative. Redactions to the on-screen displays limit the information available for identifying the nature of the reported unidentified anomalous phenomena (UAP). The rate at which any object transits across part or all of a frame can be measured in pixels per frame; however, converting this to a physical velocity also requires (1) the range to the object, (2) the velocity of the observing aircraft, (3) the aspect angle between the object's path and the observer, and (4) the field angle of the camera sensor. No sensor video in the PURSUE corpus provides this complete set of information. In one clip (DOW-UAP-PR113), the object crosses visible depression-angle markings, allowing the camera's field of view to be reconstructed. Even this clip does not provide sufficient information to distinguish between a bird flying past the sensor at close range and a large craft traveling at Mach 5 a kilometer away. A second clip (DOW-UAP-PR149) includes a vessel of known size in the frame, which can be used as a reference to calculate an upper bound of Mach 0.4 on the object's relative velocity. Without further information, the PURSUE sensor videos in their present form cannot fully resolve unidentified cases or conclusively indicate anomalous velocities.