If the specified source coordinate system is “Read from feature” or blank, the input feature’s coordinate system is used as the source. In this case, if the input feature doesn’t have a coordinate system, this transformer only sets the coordinate system of the feature to the destination coordinate system, and the coordinates of the feature remain unchanged.
This parameter specifies what geographic transformation will be used to convert points from the source datum to the destination. If set to <Auto>or left blank, FME will attempt to choose an appropriate transformation. If set to <None>, the NULL_FME transformation will be used which does not alter the value of any coordinates.
Note: <Auto> and <None> are GUI only values. Use the alternative blank string and NULL_FME respectively when passing in as an attribute.
This parameter determines how Z values will be handled:
Geocentric or ellipsoid height -> Orthometric height: Z values will be converted from ellipsoid height to orthometric (sea level) height given the specified geoid height grid. Z units will be the same as the horizontal units (or meters, for geographic coordinate systems). If the source coordinate system is geocentric, coordinates will be converted to geographic+ellipsoid height before being processed.
Example: [Geocentric (datum A) ->] LL + ellipsoid height (datum A) -> LL + ellipsoid height (datum B) -> LL + orthometric height (datum B)
Orthometric height -> Geocentric or ellipsoid height: Z values will be converted from orthometric (sea level) height to ellipsoid height given the specified geoid height grid. Z units will be the same as the horizontal units (or meters, for geographic coordinate systems). If the destination coordinate system is geocentric, coordinates will be converted to geocentric after being processed.
Example: LL + orthometric height (datum A) -> LL + ellipsoid height (datum A) -> LL + ellipsoid height (datum B) [-> Geocentric (datum B)]
Note: Note that rasters can only be reprojected in 2D (that is, with Ignore heights and leave them unchanged).
This parameter determines which geoid height grid will be applied to the Z values of coordinates.
FME supports the following vertical grid formats:
The CsmapReprojector can apply grids in any of these formats via a .gdc file, which is a text file that list one or more grid files in the formats listed above. Grids will be tried in order until one is found that provides coverage for the point being transformed. Grid files may be listed with absolute paths, or by paths relative to the .gdc file.
Example .gdc file contents for a grid file in the same folder as the .gdc:
# comments start with '#' ./CGG2000.byn
Some of the .gdc files shipped with FME reference grid files that are not included in the Desktop installer. You can download those grid files from at http://www.safe.com/support/support-resources/fme-downloads/beta/.
See Vertical Grids for more information.
The Interpolation Type affects only raster data. Cell values are interpolated in order to change the raster to the specified size.
The Cell Size applies only to raster features.
If the destination coordinate system is specified as "_AZMEA_" or "_AZMED_", each input feature is reprojected to either an equal area or equal distance projection appropriate for that feature, respectively. In general, this causes a new coordinate system to be defined for each input feature.
Each feature remembers which specific equal distance or equal area coordinate system it has, and can be safely reprojected back to a normal (non-dynamic) coordinate system.
For example:
There is an input feature representing a point on the earth in LL-WGS84 (normal lat/long).
You have now changed the point into a line extending 1km east of the original point, in lat/long.
Dynamic coordinate systems have the following limitation:
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.
Associated FME function or factory: @Reproject
Search for samples and information about this transformer on the FME Knowledge Center.