Definition

(U.S. terminology). A BOAT SHEET or a SMOOTH SHEET on which intersecting systems of curves are drawn, each curve corresponding to the LOCUS of some angle between two STATIONS. POSITIONS are plotted on circle sheets at the intersection of the LOCI of two observed angles, each LOCUS being found by INTERPOLATION between the curves drawn on the sheet. Circle sheets are prepared and employed in HYDROGRAPHIC SURVEYS for plotting FIXES without the use of PROTRACTOR. Also calledstandard circle sheet; formerly calledsextant chart. See also FIXED ANGLE PLOT, and LATTICE.