Garmin GPSMAP 96 Owner's Manual - Page 133
What are Map Datums?, What is Position Format?, coordinate systems. UTM/UPS Universal Transverse
View all Garmin GPSMAP 96 manuals
Add to My Manuals
Save this manual to your list of manuals |
Page 133 highlights
What are Map Datums? A datum is a mathematical model of the Earth which approximates the shape of the Earth and enables calculations to be carried out in a consistent and accurate manner. The datum is physically represented by a framework of ground monuments (i.e. trig. stations) whose positions have been accurately measured and calculated on this reference surface. Lines of latitude and longitude on a map or chart are referenced to a specific map datum. Every chart has a map datum reference and the GPSMAP 96/96C can be set to match most of those commonly used. If you are navigating and comparing the GPS coordinates to a map, chart or other reference, the map datum in the GPS unit should be set to the same datum as the map or chart to ensure the most accurate navigation. Appendix > What is Position Format? Your current location can be viewed on the GPS in the form of coordinates. Since different maps and charts use different location formats, Garmin GPS units allow you to choose the correct coordinate system for the type of map you are using. The most common format is latitude and longitude, which is utilized by all Garmin units. On most models, you can choose to change the position format to use with other coordinate systems. UTM/UPS (Universal Transverse Mercator/Universal Polar Stereographic) are easyto-use metric grids that are found on most USGS topographic quadrangle maps. Several other grids, including a user-definable grid (for the advanced user), can also be selected. 96/96C Owner's Manual 125