Office of the Secretary of Defense: 016_Parallax_Paper

All-domain Anomaly Resolution Office (AARO)
Figure 3: Parallax causes the position of an object to be projected at different points
against a background. As the observer moves, the changes in background projections
cause the object to have an apparent motion.
Summary
Not all reports of fast-moving UAP are attributable to the effects of forced perspective or
parallax. However, in some cases, the effects of these phenomena are known to cause inaccurate
estimations of a UAP’s size, speed, and direction of travel. These phenomena consequently affect
data derived from a single sensor moving very fast relative to the target object. Despite this
susceptibility, single-observer reports are critical to consider in AARO analyses. These reports
can supplement additional sensor data to help create a more holistic picture of an object’s size
and speed. Observers submitting a UAP report should still estimate range, size, and speed as part
of a complete description of their observation. Observers with a more robust understanding of
forced perspective and parallax are better equipped to assess a UAP’s characteristics and provide
more context to these details in their reporting.016
Page determined to be Unclassified
Reviewed by Chief of Staff, AARO
IAW FY24 NDAA, Section 1841(a)(1)(C)
Date: 2/6/2025