Reprojects feature coordinates from one coordinate system to another using the Grid InQuestII engine from Ordnance Survey, for use in Great Britain, Ireland, and Northern Ireland.
Typical Uses
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Reprojecting features when explicitly using the Grid InQuestII engine is desired
How does it work?
The GridInquestIIReprojector receives raster, vector, or point cloud features and reprojects their coordinates from one coordinate system to another, using Ordnance Survey’s Grid InQuestII engine.
Its library allows you to transform coordinates between ETRS89 (WGS84) and the national coordinate systems of Great Britain, Northern Ireland and the Republic of Ireland.
The following coordinate systems are supported:
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ETRS89 (WGS84)
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UTM Zone 29N
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UTM Zone 30N
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UTM Zone 31N
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Cartesian
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Geodetic
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OSGB36 British National Grid
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Irish Grid
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Irish Transverse Mercator
Two vertical datums are available, for Irish systems only:
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Malin Head
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Belfast
This transformer always reprojects from the source coordinate system to the destination coordinate system, tagging the features with the destination coordinate system on output.
Any coordinate system set on the input features is ignored - it is not able to read coordinate systems from incoming features.
Usage Notes
- FME has a Workspace Parameter, Reprojection Engine, that may be set to either FME (CS-Map) or Esri. This transformer will override this parameter setting.
- The Reprojector provides similar functionality, and will use the default library (CS-Map or Esri) set in FME. It supports some of the same coordinate systems, but will not use the Grid InQuestII library.
Working With Coordinate System Transformers
FME inherently supports coordinate system transformations and reprojections.
Coordinate System Support and Reprojection
Coordinate systems generally have a name and a definition, and the syntax of that definition can vary greatly between both spatial data formats and other coordinate system libraries. Custom and local coordinate systems can also be defined in FME, further complicating matters. For in-depth information, see the Working With Coordinate Systems documentation.
Reprojections are generally done with the FME Reprojection Engine, which is based on the CS-Map coordinate system library. This default can be overridden on a per-workspace basis, using the Workspace Parameters > Translation > Reprojection Engine parameter, and set to Esri. Where appropriate, FME will use the Esri Reprojection Engine if it is selected there, with or without an Esri product being installed.
Coordinate System Support
These transformers perform various coordinate system-related tasks, but do not reproject the data.
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Looks up coordinate system names and definitions between FME’s internal format and common third-party and open source representations, storing the results as an attribute. |
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Retrieves the name of the feature's assigned FME coordinate system into an attribute. |
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Removes the coordinate system from features, without modifying geometry or coordinates. |
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Assigns a specified coordinate system to features, without modifying geometry or coordinates. |
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Assigns a specified local coordinate system to features, without modifying geometry or coordinates. |
Coordinate System Reprojection
Different coordinate system libraries (engines) not only contain coordinate system definitions, they also have unique reprojection algorithms. FME’s generic reprojection transformers, in the first table below, default to using the FME (CS-Map) library.
A selection of other libraries is also available, some of which are specific to certain areas of the world or software platforms.
Inherent reprojections, as in a workspace with different input and output coordinate systems selected, default to using the FME (CS-Map) library.
If you are reprojecting explicitly with a transformer in the workspace, using library-specific transformers is recommended. In the case of CsmapReprojector versus the Reprojector (with default engine), the library may be identical, but the CSMapReprojector handles vertical coordinate calculations whereas the Reprojector does not.
Generic Reprojection Transformers
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Library |
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Reprojects x and y coordinates stored as attributes from one coordinate system to another. |
FME (default) or Esri |
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Reprojects one or more features to a local coordinate system centered on the bounding box containing all features. |
FME (default) or Esri |
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Converts a given angle from one coordinate system to another. |
FME (default) or Esri |
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Converts a given length from one coordinate system to another. |
FME (default) or Esri |
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Reprojects feature x and y coordinates from one coordinate system to another. |
FME (default) or Esri |
Library-Specific Reprojection Transformers (Recommended)
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Library (External Links) |
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Reprojects x, y, and optionally z coordinates stored as attributes from one coordinate system to another using the CS-MAP library. |
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Reprojects feature x, y, and optionally z coordinates from one coordinate system to another using the CS-Map library. |
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Reprojects feature coordinates from one coordinate system to another using the Esri reprojection library. |
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Great Britain Northern Ireland Republic of Ireland |
Reprojects feature coordinates from one coordinate system to another using the Grid InQuestII engine from Ordnance Survey, for use in Great Britain, Ireland, and Northern Ireland. |
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Sweden |
Reprojects coordinates stored as attributes from one coordinate system to another using the Gtrans reprojection engine from the National Land Survey of Sweden (Lantmäteriet). |
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Sweden |
Reprojects feature coordinates from one coordinate system to another using the Gtrans reprojection engine from the National Land Survey of Sweden (Lantmäteriet). |
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Reprojects coordinates stored as attributes from one coordinate system to another using the PROJ library. |
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Reprojects feature coordinates from one coordinate system to another using the PROJ library. |
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Switzerland |
Reprojects feature coordinates from one coordinate system to another in Switzerland, using the Reframe library from the Federal Office of Topography (swisstopo). |
Configuration
Input Ports
Input
Features with geometry to be reprojected.
Output Ports
Reprojected
Features reprojected as specified in parameters.
Parameters
Coordinate Systems
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Source Coordinate System |
Specify the coordinate system of the input features. Choices include:
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Source Coordinate System Version |
When Source Coordinate System is one of the following:
specify the version, either:
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Destination Coordinate System |
Select the coordinate system for the output features. Choices include:
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Destination Coordinate System Version |
When Destination Coordinate System is one of the following:
specify the version, either:
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Vertical Datum (Irish systems only) |
If required, select a vertical datum. Choices include:
This parameter is for the regions between Northern Ireland and the Republic of Ireland. |
Raster Parameters
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Interpolation Type |
Select a method for interpolating reprojected cell values:
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Cell Size |
Select a method for resizing cells:
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Tolerance (cells) |
Sets the tolerance, in cells, for approximating reprojected cell locations. Using the default value of 0.0, every cell will be reprojected. If a value greater than 0.0 is specified, some cell locations will be approximated. The difference between an approximated cell location and the true cell location should be at most the tolerance value. For example, if a value of 0.5 is specified, each approximated cell location should be maximum one-half of a pixel away from its true location. Increasing the Tolerance value may improve performance. |
Editing Transformer Parameters
Using a set of menu options, transformer parameters can be assigned by referencing other elements in the workspace. More advanced functions, such as an advanced editor and an arithmetic editor, are also available in some transformers. To access a menu of these options, click 
beside the applicable parameter. For more information, see Transformer Parameter Menu Options.
Defining Values
There are several ways to define a value for use in a Transformer. The simplest is to simply type in a value or string, which can include functions of various types such as attribute references, math and string functions, and workspace parameters. There are a number of tools and shortcuts that can assist in constructing values, generally available from the drop-down context menu adjacent to the value field.
How to Set Parameter Values
Using the Text Editor
The Text Editor provides a convenient way to construct text strings (including regular expressions) from various data sources, such as attributes, parameters, and constants, where the result is used directly inside a parameter.
Using the Arithmetic Editor
The Arithmetic Editor provides a convenient way to construct math expressions from various data sources, such as attributes, parameters, and feature functions, where the result is used directly inside a parameter.
Conditional Values
Set values depending on one or more test conditions that either pass or fail.
Parameter Condition Definition Dialog
Content
Expressions and strings can include a number of functions, characters, parameters, and more.
When setting values - whether entered directly in a parameter or constructed using one of the editors - strings and expressions containing String, Math, Date/Time or FME Feature Functions will have those functions evaluated. Therefore, the names of these functions (in the form @<function_name>) should not be used as literal string values.
Content Types
| These functions manipulate and format strings. | |
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Special Characters |
A set of control characters is available in the Text Editor. |
| Math functions are available in both editors. | |
| Date/Time Functions | Date and time functions are available in the Text Editor. |
| These operators are available in the Arithmetic Editor. | |
| These return primarily feature-specific values. | |
| FME and workspace-specific parameters may be used. | |
| Creating and Modifying User Parameters | Create your own editable parameters. |
Dialog Options - Tables
Transformers with table-style parameters have additional tools for populating and manipulating values.
Table Tools
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Row Reordering
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Enabled once you have clicked on a row item. Choices include:
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Cut, Copy, and Paste
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Enabled once you have clicked on a row item. Choices include:
Cut, copy, and paste may be used within a transformer, or between transformers. |
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Filter
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Start typing a string, and the matrix will only display rows matching those characters. Searches all columns. This only affects the display of attributes within the transformer - it does not alter which attributes are output. |
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Import
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Import populates the table with a set of new attributes read from a dataset. Specific application varies between transformers. |
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Reset/Refresh
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Generally resets the table to its initial state, and may provide additional options to remove invalid entries. Behavior varies between transformers. |
Note: Not all tools are available in all transformers.
Reference
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Processing Behavior |
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Feature Holding |
No |
| Dependencies | Ordnance Survey Grid InQuestII engine, provided with FME |
| Operating System Restrictions | Windows only |
| Aliases | |
| History |
FME Community
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Examples may contain information licensed under the Open Government Licence – Vancouver and/or the Open Government Licence – Canada.