This means that the pressure reading has to be slightly increased from the value read on a barometer situated above sea level (often know as the station pressure ).
(This; means; that the pressure reading has to be slightly increased from the value) (a barometer situated above sea level; know; as the station pressure; T:often) (the pressure reading; to be increased; from the value) (the value; read; L:on a barometer)
This a barometer situated above sea level the pressure reading the value
means know to be increased read
that the pressure reading has to be slightly increased from the value
as the station pressure T:often
from the value
L:on a barometer