AARO GoFast Case Resolution and Methodology

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The UAP altitude was found to be ≈3,962 m (13,000 ft) above sea level. There is high
confidence in this result as it required only the sensor pointing angles and range to target. This
calculation does not depend on the absolute position of the F/A-18 or wind speed.
The speed and heading of the UAP varied based upon assumptions of the path of the F/A-18
relative to the winds at its operating altitude. In the case of the aircraft flying into a nominal
headwind, the UAP was determined to be heading within 5° of the wind direction at its altitude
and <2 m/s (4.5 mph, 3.9 kts) faster than the wind. At other angles of wind impacting flight of
the F/A-18, the UAP was as far as 27.0° from the wind direction and as much as 40 m/s (89 mph,
78 kts) faster (see Table III). With the uncertainty in the wind directions and speed and those
mentioned above, these quantitative results should not be used literally, but only to qualitatively
evaluate the UAP properties.
Considerations of Parallax Effect
When the F/A-18 is flying into a headwind as shown in Figure 16, it and the UAP would be
moving in opposite directions. In the case with no wind, the UAP is moving in the same
direction as the F/A-18 albeit much slower. This situation is illustrated in Figure 20. On the left
of Figure 20 shows a side view of the event with no wind and on the right the event considering a
headwind. For each, the dashed arrows show the UAP starting and stopping points projected to
the surface. The distance between these two points (red arrows) is the perceived distance the
UAP travelled due to parallax. The longer the projected distance (red arrow) compared to the
actual distance travelled (black arrow) at 3,962 m causes the perceived high speed of the UAP in
the video. With a headwind and the UAP going in the opposite direction of the F/A-18, this
affect is amplified and the UAP speed appears much faster leading to higher likelihood of
misinterpretation.