Working with coordinate systems, Displaying coordinates, Elements of a coordinate system – Pitney Bowes MapInfo Professional User Manual
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Working with Coordinate Systems
The terms "projection" and "coordinate system" are often used interchangeably, however they do not
mean the same thing.
Projection - An equation or set of equations that contain mathematical parameters for a map. The exact
number and nature of the parameters depends upon the type of projection. You can think of a projection
as a method of reducing a map's distortion caused by the curvature of the Earth, or more precisely, a
projection compensates for the shortcomings of depicting maps in two dimensions when the coordinates
exist in three dimensions.
Coordinate System - When parameters of a projection are assigned specific values, they become a
coordinate system. A coordinate system is a collection of parameters that describe coordinates, one of
which is a projection.
Displaying Coordinates
There are two places where coordinates display:
• In the Status Bar by cursor location (set in the Map Options dialog box or by clicking on the Status
Bar).
• In dialog boxes that display area measurements, such as a Point Object, Region Object etc.
Coordinates can only be entered in the Object Info dialog boxes when a layer is editable.
Note:
You can display coordinates in one of the following formats:
• Decimal degrees (for example -97.90052°, 42.85732°)
• Degrees, minutes, seconds (for example -97° 54' 1.908", 42° 51' 26.28")
• Military Grid Reference (WGS 1984 datum) (for example 14TNN8982545555)
• US National Grid Reference (NAD 83/WGS 84) (for example 14TNN8982545555)
• US National Grid Reference (NAD 27) (for example 14TNN8985745342 (NAD 27))
The default is Decimal degrees.
Elements of a Coordinate System
A coordinate system in MapInfo Professional is made up of many elements which need to be specified
in advance. Once these elements are in place, you can be sure that your maps are as accurate as
possible. These are the projection elements you need to set in the MAPINFOW.PRJ file:
•
•
•
•
•
Standard Parallels (Conic Projections)
•
Oblique Azimuth (Hotine Oblique Mercator)
•
Scale Factor (Transverse Mercator)
•
False Easting and False Northing
•
For datum and unit tables, see
and
.
Note:
MapInfo Professional 12.5
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Working with Coordinate Systems