false horizon

American  

noun

1. a line or plane that simulates the horizon, used in altitude-measuring devices or the like.

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Etymology

Origin of false horizon

First recorded in 1805–15

Example Sentences

Its upper limit is very distinct, as seen by the “false” horizon.

From Project Gutenberg

They ranged southward to the point where vision failed against the false horizon of dull amber haze.

From Project Gutenberg

On holidays, when the sun was up in the sky, the Captain delighted to accompany his pupils to some open space, where, with the aid of a false horizon, he could teach them practically how to take an observation or to “shoot the sun,” as he called it.

From Project Gutenberg

The sky was losing its burnished copper hue and becoming blue again, and, on the false horizon supplied by the crest of the fog-bank, stood a brilliantly vivid panorama.

From Project Gutenberg

One of the officers of Admiral Rodgers' expedition climbed to near the top of Herald Island, at a time of great refraction, when probably a false horizon existed, and hence did not see Plover Island, although Wrangell Land was in sight.

From Project Gutenberg