A geographic coordinate is nothing else than a defined point on the suface of the earth. Each waypoint, each track point and each GPS online position refers to a coordinate. In other words: when talking about GPS navigation we always refer to coordinates.
In the simplest way, a coordinate refers to two angular values, the lattitude and the longitude. However, in reality, things are a littel more complex because many different coordinate systems are existing which vary bothh in the units used and also in the map reference system (map datum). In any case, they are all use to define points on the surface of the earth.
The common units are degrees, meters and - less common - gons. The map reference system (map datum) is a mathematical model to describe the spheric surface of the earth which is not a perfect ball but a rather irregular speroid. Thus, depending on the area to be described, different values for the radius, geometric flattening, etc. are use in order to increase the accuracy of the model.
A good explanation on the basics can be found under this link http://en.wikipedia.org/wiki/Geographic_coordinate_system.
The good news about it: You don not have to worry too much about it because QV does the job for you: Internally, it will always work in the standard lattitude and longitude system using the global reference system WGS84. However, you can use for display or data input any other unit or map datum. Just click the icon Units in the standard symbol bar, see chapter Units.
The presently selected map datum will be displayed in the map window on the righthand side of the status line at the lower map window margin but also in the status line of the QV Xplorer, in this case on the lefthand side:
In the example shown, the selected map reference system is WGS 84, and the unit chosen is decimal degrees, so DD.DDDDD .
Please note that the map datum and units setting selected are always valid system wide, so the settings will be applied to all map and Xplorer windows.
You can enter and/or modify coordinates in QV at various instances:
During coordinate input, please follow these guidlines:
Following a couple of examples for valid entries:
|Unit setting||coordinates||Alternative entries||Invalid entries||Comments|
|DD.DDDDD||N 48,12° O 8,53°|| 48.12 8,53|
|DD MM.MMM||N 48° 7,2' O 8° 31,8'|| 48 7.2 8 31,8|
+48 7.2; e8 31,8
|48 7.2 8.5|
|DD MM SS.S|| S 22° 38' 1“|
O 14° 0' 0”
| -22 38 1 14 0 0|
s22 38 1, 14 0 0
|-22 38 1; 14|
|UTM|| N/S Northing Zone Easting|
N 5.329.745 32 465.022
|5329745 32 465022||N is default and can be skipped, S or - codes the southern hemisphere|
|National meter grid|| Prefix Northing Easting|
GK3 5.331.439 3.465.084
|5331439 3465084||It is not essential to enter the prefex as this is already specified with the unit setting|