Other Allied Powers pilots and/or ground observers could independently confirm an enemy's destruction.

In addition, the translucent wings made it difficult for ground observers to detect a Taube at an altitude above 400 meters.

If the skies are clear, ground observers can see a Korolyov cross formed by the falling boosters.

When support was required it could be quickly summoned by a ground observer.

Pleiades'* was the term used by ground observers to describe a space fleet in planetary orbit.

"Signal Intelligence and ground observers, sensors, and after-action reports all agree," he added.

After the landing, naval gunfire directed by ground observers would target any enemy pillboxes that were still operational.

Such wonders were hidden from view until recently, when ground observers, aircraft and spacecraft managed to glimpse their ephemeral dance.

Initially, ground observers confirmed that pilots had rounded the turn-points.

Wake turbulence can occasionally, under the right conditions, be heard by ground observers.