You might have come across these terms in may be your 8th grade science class or sometimes even earlier. If you are looking for some short refreshment course then go ahead.
Any location on Earth can be described by two numbers, its latitude and its longitude. These are two angles, measured in degrees, minutes and seconds. These are denoted by the symbols ( °, ', " ) e.g. 33° 21' 16" means an angle of 33 degrees, 21 minutes and 16 seconds. A degree contains 60 minutes of arc and a minute contains 60 seconds of arc. You may omit the words "of arc" where the context makes it absolutely clear that these are not units of time. Now lets see how these values are measured.
Latitude
Imagine the Earth as a sphere (actually it is slightly oval but it doesn't matter here). The center of the sphere will be the center of the earth. The horizontal plane that passes through the center is called the equatorial plane. This plain splits earth into two halves, the Northern Hemisphere and the Southern Hemisphere. So, the ring that splits Earth in to two halves is called the equator.
To specify the latitude of some point on the surface, draw draw a line from center of Earth to that point. Then the elevation angle of that point above the equator is its latitude. So the equator will be at 0°. A point with latitude 45°N will be somewhere between equator and the North pole. Similarly a point with latitude 45°S will be a somewhere between equator and South pole. The North pole will be having a Latitude of 90°N and the South pole will have a latitude of 90°S.
Instead of using 'N' or 'S', it can be written as positive or negative numbers. For eg 45°N can be written as just 45° and 45°S can be written as -45°.
Longitude
On the globe, lines of constant longitude (also called as meridians) extend from pole to pole, like the segment boundaries on a peeled orange. Every meridian crosses the equator at a point. Since the equator is a circle, we can divide it, like any circle, into 360 degrees, and the longitude of a point is then the marked value of that division where its meridian meets the equator. What that value is depends of course on where we begin to count or where zero longitude is. For historical reasons, the meridian passing the old Royal Astronomical Observatory in Greenwich, England, is the one chosen as zero longitude. This meridian is called the Prime Meridian and has a longitude of 0°. So a meridian at 10° East of Prime Meridian has a longitude 10°E and similar is the case for 10°W. The maximum value for longitude is 180°. 180°E and 180°W represents the same meridian which is located exactly at the opposite side of the Prime Meridian.
Well, these are the basic information required to identify Latitudes and Longitudes on a map and to decode them. The latitudes and longitudes might be represented as decimal values also. To convert Latitudes and Longitudes from one format to another, consider reading this post : DMS to Decimal Conversion
Any location on Earth can be described by two numbers, its latitude and its longitude. These are two angles, measured in degrees, minutes and seconds. These are denoted by the symbols ( °, ', " ) e.g. 33° 21' 16" means an angle of 33 degrees, 21 minutes and 16 seconds. A degree contains 60 minutes of arc and a minute contains 60 seconds of arc. You may omit the words "of arc" where the context makes it absolutely clear that these are not units of time. Now lets see how these values are measured.
Latitude
Imagine the Earth as a sphere (actually it is slightly oval but it doesn't matter here). The center of the sphere will be the center of the earth. The horizontal plane that passes through the center is called the equatorial plane. This plain splits earth into two halves, the Northern Hemisphere and the Southern Hemisphere. So, the ring that splits Earth in to two halves is called the equator.
To specify the latitude of some point on the surface, draw draw a line from center of Earth to that point. Then the elevation angle of that point above the equator is its latitude. So the equator will be at 0°. A point with latitude 45°N will be somewhere between equator and the North pole. Similarly a point with latitude 45°S will be a somewhere between equator and South pole. The North pole will be having a Latitude of 90°N and the South pole will have a latitude of 90°S.
Instead of using 'N' or 'S', it can be written as positive or negative numbers. For eg 45°N can be written as just 45° and 45°S can be written as -45°.
Longitude
On the globe, lines of constant longitude (also called as meridians) extend from pole to pole, like the segment boundaries on a peeled orange. Every meridian crosses the equator at a point. Since the equator is a circle, we can divide it, like any circle, into 360 degrees, and the longitude of a point is then the marked value of that division where its meridian meets the equator. What that value is depends of course on where we begin to count or where zero longitude is. For historical reasons, the meridian passing the old Royal Astronomical Observatory in Greenwich, England, is the one chosen as zero longitude. This meridian is called the Prime Meridian and has a longitude of 0°. So a meridian at 10° East of Prime Meridian has a longitude 10°E and similar is the case for 10°W. The maximum value for longitude is 180°. 180°E and 180°W represents the same meridian which is located exactly at the opposite side of the Prime Meridian.
Well, these are the basic information required to identify Latitudes and Longitudes on a map and to decode them. The latitudes and longitudes might be represented as decimal values also. To convert Latitudes and Longitudes from one format to another, consider reading this post : DMS to Decimal Conversion
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