Garmin GPSMAP 76Cx Owner's Manual

Also see for GPSMAP 76Cx: Owner's manual Declaration of conformity Quick reference guide Guide de l'utilisateur

Contents

Garmin GPSMAP 76Cx Owner's Manual Manual pdf 90 page image

80 GPSMAP 76Cx Owner’s ManualAPPENDIX > M AP DATUMS AND LOCATION FORMATSMap Datums and LocationFormatsWhat Are Map Datums?A datum is a mathematical model of the Earth thatapproximates the shape of the Earth and enablescalculations to be carried out in a consistent andaccurate manner. The datum is physically representedby a framework of ground monuments whosepositions have been accurately measured andcalculated on this reference surface. Lines of latitudeand longitude on a map or chart are referenced to aspecific map datum. Every chart has a map datumreference and the GPSMAP 76Cx can be set to matchmost of those commonly used.If you are navigating and comparing the GPScoordinates to a map, chart, or other reference, set themap datum in the GPS unit to the same datum as themap to insure the most accurate navigation. .What is a Location Format?Your current location can be viewed on the GPS inthe form of coordinates. Because different maps andcharts use different location formats, Garmin GPSunits allow you to choose the correct coordinatesystem for the type of map you are using. The mostcommon format is latitude and longitude, which isused by all Garmin units.You can choose to change the location format to usewith other coordinate systems. UTM/UPS (UniversalTransverse Mercator/Universal Polar Stereographic)are easy-to-use metric grids that are found on mostUSGS topographic quadrangle maps. You can alsoselect one of several other grids, including a user-definable grid (for the advanced user).