Accession Number : AD0781840

Title :   An Analysis of the Positioning Accuracy of Horizontal Sextant Angles

Descriptive Note : Final rept. Oct 1973-Mar 1974

Corporate Author : COAST GUARD WASHINGTON DC OFFICE OF RESEARCH AND DEVELOPMENT

Personal Author(s) : Tozzi, John T ; Millan, Harold E

PDF Url : AD0781840

Report Date : Jun 1974

Pagination or Media Count : 104

Abstract : The paper presents a method for determining the positioning accuracy which may be obtained from horizontal sextant angle fixes. A system model for a three-object, two-line-of-position (LOP) fix is developed from which the independent and dependent component instrument and human factors errors for both the sextant and the three-arm protractor can be identified and analyzed. The conversion of these angular measurement errors into distance units is accomplished by a function termed the Geometric Multiplication of Precision (GMOP) which is derived from the gradient of beta (beta is defined as the exact angular measurement of a horizontal sextant angle). The LOP errors in distance units are used with the LOP crossing angle to determine the positioning accuracy, expressed as the radius from the exact position within which the actual position may be expected to lie for a particular accuracy probability.

Descriptors :   *POSITION FINDING, *SEXTANTS, ACCURACY, ANGLES, BUOYS, ERRORS, HORIZONTAL ORIENTATION, MEASUREMENT, TRIANGULATION

Subject Categories : Target Direction, Range and Position Finding

Distribution Statement : APPROVED FOR PUBLIC RELEASE