A fact known from direct observation.
A premise from which conclusions are drawn.
A floating reference point, or SLDMB, used to evaluate surface currents in a body of water. Often employed by coastal search and rescue.
A fixed reference point or set of reference points which precisely define a system of measurement or a coordinate system.
To provide missing data points by using a mathematical model to extrapolate values that are outside the range of a measuring device.
The act of observing; perception.
A published critical review of a play or the like.
A written or printed announcement.
Advance notification of termination of employment, given by an employer to an employee or vice versa.
A formal notification or warning.
Prior notification.
To be noticeable; to show.
To become aware of; to observe.