sight-reduction tables
sight-reduction tables
[′sīt ri¦dək·shən ‚tā·bəlz] (navigation)
Tables for performing sight reduction obtained by the use of a sextant or octant, particularly those sights for determining computed altitude for comparison with the observed altitude of a celestial body to determine the altitude difference for establishing a line of position.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.