自定义坐标系是共享资源，该资源定义默认情况下不包含在FME中的一个或多个坐标系。
FME is used in many different countries around the world, and it is also used with a variety of custom datasets within each country. However, sometimes FME’s Coordinate System Gallery doesn't include the coordinate systems that are being used. In these cases, you will have to define the coordinate systems before FME can use them.
Adding a Custom Coordinate System
要添加自定义坐标系，请创建一个新的.fme文件，该文件定义一个，将其保存到％user％\ document \ fme \ coordinateystems或共享文件夹（在工具中定义> fme选项>默认路径>共享fme文件夹）。
Often you are creating a coordinate system that is similar to an existing one. To use an existing coordinate system as a starting point:
- Open the coordinate system gallery (Tools > Browse Coordinate Systems).
- Select the Coordinate system you are using as a model.
- Click特性。
- 在坐标系的属性窗口中，在“坐标系参数”下复制文本，并在文本编辑器中粘贴。
- Format the definition to conform to the FME coordinate system syntax. For examples, refer to theMyCoordSysDefs.fme文件,位于Reprojectfolder of your FME install directory.
- Add, remove, and/or edit parameters to customize the coordinate system.
- Save the file as
.fme to %USER%\Documents\FME\CoordinateSystems, or a shared folder (defined in Tools > FME Options > Default Paths > Shared FME Folders).
You must restart Workbench before FME can recognize the custom coordinate system.
The custom coordinate system will appear in the columns of theCoordinate System Gallery。
源数据的投影和单位在FME中未预定义，因此，要定义它们，必须添加以下行：
| Coordinate System Definition Lines | 附加信息 |
|---|---|
表格投影类型 |
|
UNIT<单位的名字>\ |
|
表格预定义的论据和predefined ellipsoids。请注意，每个坐标系定义必须指定基准或椭圆形。 |
|
[ |
|
[GROUP <group_name>] \ |
Tip:Defining a unique group name allows you to sort coordinate systems by the "Group" column in the Coordinate System Gallery. |
Quadrant定义 |
|
This example of a custom coordinate system defines a NAD83-based UTM Zone 12 coordinate system:
conorde_system_def.UTM12N83 \
PROJ TM \
UNIT METER \
dt_name nad83 \
parm1 -111.0 \
组“自定义组”\
SCL_RED 0.9996 \
ORG_LAT 0.0 \
X_OFF 500000.0 \
Y_OFF 0.0 \
ZERO_X 0.001 \
ZERO_Y 0.001.
参数描述
The parameters above are described in坐标系参数。
Sharing Custom Coordinate Systems
可以从用户定义的文件夹（包括网络共享）读取坐标系。
This option is especially useful for groups who work together. For instance, if an entire workgroup uses just a few custom coordinate system definitions, keeping these definitions in one place means that everyone doesn't have to have a copy. Then, whenever any of the definitions are updated, the entire group automatically has access to the new version.
Coordinate Systems Files Reference
coordsys.db
Located directly under the root FME installation folder, this file contains the names and descriptions of all predefined coordinate systems. It is typically a subset of all the definitions that are known to FME. That is, there may be additional systems defined in the coordsys file that are not in coordsys.db because the systems have been deprecated, or for some other reason.
Note:任何定义的系统LocalCoordSysDefs.fme,MyCoordSysDefs.fmeor as an FME Shared Resource are automatically added to FME and do not need an entry in this file.
LocalCoordSysDefs.fme
To allow sites to add their own coordinate systems, a file of local coordinate system definitions is automatically loaded. This file is calledLocalCoordSysDefs.fme。
Located in the Reproject subfolder under the FME installation folder, this file contains overrides to the standard coordinate systems (and related parameters) defined by FME, and is made available to each FME session. It contains a series of COORDINATE_SYSTEM_DEF,DATUM_DEF, ELLIPSOID_DEF, and UNIT_DEF lines that define additional, site-specific coordinate systems.
The built-in definitions for any coordinate system/datum/ellipsoid may be overridden by this file. The structure of LocalCoordSysDefs.fme is the same as MyCoordSysDefs.fme, and its contents can be used as a template for new custom coordinate systems.
WARNING:You should NOT editLocalCoordSysDefs.fmebecause it is overwritten each time FME is installed.
MyCoordSysDefs.fme
Located in the Reproject folder, this file contains custom coordinate system definitions.
WARNING:Although FME does not overwriteMyCoordSysDefs.fmeduring installation, it is always good practice to back up this file. FME does overwriteLocalCoordSysDefs.fme和coordsys.dbduring installation. Although you should not need to edit these files, you should back them up if you did make any changes.