noun
apparent horizon
Astronomical term for the visible horizon where the sky appears to meet the Earth's surface, as opposed to the true horizon.
視地平は大気差の影響で真地平よりわずかに高い位置に見える。
The apparent horizon appears slightly higher than the true horizon due to atmospheric refraction.
The true horizon, the astronomical horizon at 90° from the zenith; 視地平 is the visible, apparent horizon.
Compound of 視 (shi, 'visual') and 地平 (chihei, 'horizon'), literally 'visual horizon'. The exact historical derivation is uncertain; the spelling is conventionally associated with the astronomical meaning.