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.
Sight for that which is on the outside; the ability or capacity to perceive or anticipate external things; view; outlook; perspective; power of observation.
Movable goods kept out of doors, such as animals, ploughs, carts, and other implements of husbandry.
Expectation; prospect.