Documentation | Help File | UI | 2D Mode | Menu | File | Coordinate Systems
Clicking on the File/Coordinate Systems
menu item provides the means for setting the coordinate system for the Map area, i.e., the coordinate system in which all layers of an open map project are displayed. This menu item invokes the Coordinate System
and Coordinate System Setup
dialog boxes (pictured below) with settings to select or custom define the map area coordinate system. Changes to the map area coordinate system settings are instantaneously reflected on the map display.
Before considering the Coordinate System
and Coordinate System Setup
dialog boxes, it is important to understand that in many situations the software intelligently anticipates the coordinate system. In these situations, the user need not use the map area coordinate system settings, because the program:
The incidence of the Coordinate System
and Coordinate System Setup
dialog boxes opened from the File/Coordinate Systems
menu relate only to the map area coordinate system. These same dialog boxes are also called by other functions elsewhere in the program that can require a coordinate system selection for another purpose:
For situations that do require the user to specify a coordinate system (for the map area or another purpose), there are two methods:
Coordinate System
dialog box. The coordinate systems are organized into two drop-down lists: Projected systems
reflecting linear units (meters, kilometers, miles, feet…) and Geographic systems
reflecting angular units (degrees, radians, grads). Because the lists are long, a handy search tool is built in. Type in the name of a coordinate system, or just a few letters of the name, and the coordinate system is quickly found. This method is easiest and recommended.Coordinate System Setup
dialog box, which is invoked by clicking on one of the …
buttons in the Coordinate system
dialog box. The Coordinate System Setup
dialog box provides settings to custom define a projected or geographic coordinate system, including 150+ projections, 900+ datums, linear and angular units, Easting, Northing, etc. (The built-in search tool also works for the projection and datum lists.) Manual coordinate system definition is more complicated and necessary only for unusual or advanced situations.
The program must know the coordinate system of each layer to properly display the layer in the map area coordinate system, with correct scale, rotation, and distance representations. If a layer without a recognized coordinate system (because information is missing, incomplete, or the layer does not reflect a coordinate system) is opened, the program notifies that the layer is without a coordinate system and presents the option to rectify (rotate, scale, skew, warp, and georeference) the layer to a coordinate system. (Refer to the Rectify help topic for more on rectification.) In the rare case that a layer reflects a coordinate system that is known to the user, but the coordinate system information is incomplete or missing from the layer, an advanced user can edit the layer coordinate system information within the Layer Properties dialog box (with changes saved to the project file) - instead of using the rectifying tools to georeference the layer to a coordinate system.
To choose a predefined projected (reflecting linear units) coordinate system
File/Coordinate Systems
menu item - this invokes the Coordinate System
dialog box.Coordinate System
dialog box, click on the Projected system
option.Projected system
list. (TIP: Use the built-in search tool by just entering in the field a few letters of the coordinate system name.)OK
button.To choose a predefined geographic (reflecting angular units) coordinate system
File/Coordinate Systems
menu item - this invokes the Coordinate System
dialog box.Coordinate System
dialog box, click on the Geographic system
option.Geographic system
list. (TIP: Use the handy search tool to quickly find a coordinate system from the list. Just type in the field a few letters of the coordinate system name.)OK
button.To custom define a projected coordinate system
File/Coordinate Systems
menu item - this invokes the Coordinate System
dialog box.Coordinate System
dialog box, click on the Projected system
option.…
button on the right hand side of the Projected system
option - this invokes the Coordinate System Setup
dialog box.Projection System
tab of the Coordinate System Setup
dialog box, define the coordinate system using the provided settings.OK
button.To custom define a geographic coordinate system
File/Coordinate Systems
menu item - this invokes the Coordinate System
dialog box.Coordinate System
dialog box, click on the Geographic system
option.…
button on the right hand side of the Geographic system
option - this invokes the Coordinate System Setup
dialog box.Geographic System
tab of the Coordinate System Setup
dialog box, define the geographic system using the provided settings.OK
button.To save a projected coordinate system to a file
File/Coordinate Systems
menu item - this invokes the Coordinate System
dialog box.Coordinate System
dialog box, click on the Projected system
option.…
button on the right hand side of the Projected system
option - this invokes the Coordinate System Setup
dialog box.WKT
tab of the Coordinate System Setup
dialog box, click on the Export
button - this invokes the Save As
dialog box.Save As
dialog box, go to the drive on which you want to save the file.File name
field.Save
button - this brings back the Coordinate System Setup
dialog box.Coordinate System Setup
dialog box, click on the OK
button - this brings back the Coordinate System
dialog box.Coordinate System
dialog box, click on the OK
button.To load a projected coordinate system from a file
File/Coordinate Systems
menu item - this invokes the Coordinate System
dialog box.Coordinate System
dialog box, click on the Projected system
option.…
button on the right hand side of the Projected system
option - this invokes the Coordinate System Setup
dialog box.WKT
tab of the Coordinate System Setup
dialog box, click on the Import
button - this invokes the Open
dialog box.Open
dialog box go to the drive on which the file is stored.Coordinate System Setup
dialog box.Coordinate System Setup
dialog box, click on the OK
button - this brings back the Coordinate System
dialog box.Coordinate System
dialog box, click on the OK
button.To save a geographic coordinate system to a file
File/Coordinate Systems
menu item - this invokes the Coordinate System
dialog box.Coordinate System
dialog box, click on the Geographic system
option.…
button on the right hand side of the Geographic system
option - this invokes the Coordinate System Setup
dialog box.WKT
tab of the Coordinate System Setup
dialog box, click on the Export
button - this invokes the Save As
dialog box.Save As
dialog box go to the drive on which you want to save the file.File name
field.Save
button - this brings back the Coordinate System Setup
dialog box.Coordinate System Setup
dialog box, click on the OK
button - this brings back the Coordinate System
dialog box.Coordinate System
dialog box, click on the OK
button.To load a geographic coordinate system from a file
File/Coordinate Systems
menu item - this invokes the Coordinate System
dialog box.Coordinate System
dialog box, click on the Geographic system
option.…
button on the right hand side of the Geographic system
option - this invokes the Coordinate System Setup
dialog box.WKT
tab of the Coordinate System Setup
dialog box, click on the Import
button - this invokes the Open
dialog box.Open
dialog box, go to the drive on which the file is stored.Coordinate System
dialog box.Coordinate System Setup
dialog box, click on the OK
button - this brings back the Coordinate System
dialog box.Coordinate System
dialog box, click on the OK
button.To turn off the map coordinate system
File/Coordinate Systems
menu item - this invokes the Coordinate System
dialog box.Coordinate System
dialog box, click on the Turn off (unknown system)
option.