Effect of Forced Perspective and Parallax View on UAP Observations

All-domain Anomaly Resolution Office (AARO)
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Parallax
Parallax view, or the parallax effect, is a phenomenon that can distort an object’s actual position
when viewed against a background from different angles. A simple demonstration of the parallax
effect is to hold a thumb out at arm’s length and close one eye. Note the location of your thumb
relative to an object in the background. Now, without moving your thumb, close the first eye and
open your other eye. Again, note the position of the thumb relative to the background. Though
your thumb did not move, it appears to have changed locations due to the distance between your
eyes. Moving your thumb closer to your eyes and repeating the process gives the impression that
the thumb moved further relative to the background. Your thumb appears to move because each
eye provides a different parallax view.
Another way to experience multiple parallax views of a stationary object is for the observer to be
in motion. As the observer moves, the parallax view changes. This change in perspective can
cause a stationary object to appear to be in motion. The faster the observer moves, the more
dramatic this effect can be. Electronic sensors can also be susceptible to these effects. Unlike in
the thumb example, when an electronic sensor on an airborne platform moves relative to an
object, it can be too far away to estimate an exact range, leading to misinterpretation of true size
and speed.
Consider the example shown in Figure 3. An observer in an airborne platform moves over the
earth’s surface which features a river running through the surrounding area. A stationary object is
suspended directly above the river. As the airborne observer moves from position 1 to 2 to 3 in
the air, they view the object from different angles. Parallax effects cause the object to be
“projected” against three different points in the background. From position one, the object
appears projected against the right bank of the river, from position two against the river1, and
from position three against the left bank of the river. This projection illusion creates a perception
of motion as the object appears to move across the river in the opposite direction of the observer.
The faster the airborne sensor moves, the higher the perceived speed of the object. Because of
parallax, stationary objects can appear to have motion, and slow-moving objects can appear to
move very fast.
1 The parallax angle is zero if the observer is directly above the object. This allows the observer to perceive the
object’s location against the background accurately.