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GPS Coordinate System

Latitude-Longitude page is additional help for understanding the GEO locating coordinate system used by this website. If you have a good understand of the GPS system then you can stop reading. This page is a short tutorial for those that might not understand or have a full appreciation of the world's geographical coordinate system.


Latitude, Longitude vs X,Y,Z

Navigators and chartist notate coordinates differently. The geographic coordinate system was Invented thousands of years ago and was first used for ship navigation. For their purpose latitude (North and South) is most important. In notation, It is the first number in the coordinate set. Chartest and mathematicians came along much later and used a system where vertical lines X (East-West) numbers are first. This is confusing because for navigation systems latitude comes first and for chartist (X,Y,Z) longitude comes first. This website uses navigation coordinates. Latitude comes first. For sake of charting and plotting points X = longitude, Y = latitude and Z = elevation and you will see notation Y,X on plotted charts.

Decimal Coordinates

Geographic coordinates can be represented in different ways. The notation N (North) or S (South) to denote latitude and E (East) or W (West) to denote longitude is used in navigational notation, then they usually show degrees in minutes and seconds. If N, S, E and W is not shown, N and E are positive values and S and W negative values. The notations are: ° the degrees symbol, ' the minutes symbol and '' the seconds symbol. There are 60 minutes in one degree and 60 seconds in one minute. This notation system makes it easy for humans to read and understand coordinates like a dial on a clock. This is all good except databases, websites and servers are on computers which are mathematical machines. For this purpose the website uses decimal coordinates where the number is shown as degrees and decimal minutes. Latitude can be - 90 degrees (S) to + 90 degrees (N) and -180 degrees (W) to +180 degrees (E). 0,0 is on the equator at the prime meridian which is physically in the Atlantic Ocean in the Gulf of Guinea just below Accra. Ghana on the African continent.

Wikipedia

Geographic coordinate system A geographic coordinate system is a coordinate system used in geography that enables every location on Earth to be specified by a set of numbers, letters or symbols.[n 1] The coordinates are often chosen such that one of the numbers represents a vertical position, and two or three of the numbers represent a horizontal position. A common choice of coordinates is latitude, longitude and elevation. ... more


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