You really don't have to be a GPS expert to use this site to its fullest. A very basic understanding of how coordinates are represented, and the ability to get coordinates for a location is all that is needed.
You can get coordinates either from your GPS/SatNav unit, or simply clicking on a map when you upload your photograph.
I'm sure you're familiar with the lines drawn round the globe as shown here.
Using this grid system, the world is divided into vertical lines (latitude), and horizontal lines (longitude).
How far round the world (longitude), and the vertical point (latitude) is expressed in Degrees, using the sign: "°". More exact locations are expressed using either fractions of degrees, or (in one system), smaller units of Minutes and Seconds.
Using the combination of Latitude and Longitude, any point on earth can be accurately pinpointed.
The starting point for longitude (0°) is set as the Prime Meridian, which runs vertically through a point at the Royal Observatory in London, England.
The starting point for latitude (0°) is set as the equator  the line which runs horizontally round the globe in the exact middle.
Points West of the Prime Meridian are either expressed as negative numbers (83.9383° lat), or, sometimes simply by adding "W" after the amount (83.9383° W).
Points South of the equator are either expressed as negative numbers (10.5625° lng), or, sometimes by adding "S" after the amount (10.5625° S).

There are three main systems in use to specify coordinates. They all express the position with equal precision:
 Decimal (83.9383°)
 GPS (83° 56.2980')
 DMS (83° 56' 17")
Internally, this site stores all coordinates using the decimal system. You can, however enter them in any system you like. This site will convert automatically for you, and present them to you in your preferred system.
Most GPS units allow for you to select the system you prefer. As does Google Earth if you are using that to find your coordinates.
We do not use compass points to specify coordinates. If a point is West of 0° lat, it is expressed as a negative number. If a point is South of the equator (0° lng), it is expressed as a negative number.
You do not have to remember the allowable ranges of coordinates, as the system will alert you if you try to enter an invalid value.
Please note: Most of the issues with coordinates are with the wrong polarity. This site does not use 'N', 'S', 'E' or 'W' designators.
If you have a coordinate that is followed by either the letter "W" or the letter "S", remove the letter and make the degrees part negative. (80° 20' 13" W = 80° 20' 13").
(83° 58.049' W = 83° 58.049').
