The Complete Nautical Dictionary

This book represents the ultimate nautical dictionary available in the world today. 10,000 words. The old and the modern are all here. achromatic lens. . See under ABERRATION, definition 2. aclinal. , adj. Without dip; horizontal. aclinic. , adj. Without magnetic dip. aclinic line. . The magnetic equator; the line on the surface of the earth connecting all points of zero magnetic dip. acoustic depth finder. . See ECHO SOUNDER. acoustic navigation. . See SONIC NAVIGATION. acoustics. , n. 1. That branch of physics dealing with sound. 2. The sound characteristics of a room, auditorium, etc., which determine its quality with respect to distinct hearing. acoustic sounding. . See ECHO SOUNDING. acquisition. , n. The selection of those targets or satellites requiring a tracking procedure and the initiation of their tracking. acre. , n. A unit of area equal to 43,560 square feet. across-the-scope echo. . See CLASSIFICATION OF RADAR ECHOES. active satellite. . 1. An artificial satellite which transmits an electromagnetic signal. A satellite with the capability to transmit, repeat, or retransmit electromagnetic information, as contrasted with PASSIVE SATELLITE. 2. As defined by International Telecommunications Union (ITU), an earth satellite carrying a station intended to transmit or re transmit radio communication signals.