Coordinate transformation between space rectangular coordinate of different datum plane.

Hi Xinxin (@smilevigood)

FME's CsmapReprojector transformer can use custom datum transformations when reprojecting between coordinate system in different datums. To define your custom datum transformation, please see the following page:

https://docs.safe.com/fme/html/FME_Desktop_Documentation/FME_Coordinate_Systems/CoordSys/coord_sys_custom_transformation.htm

Hi Dave, I tried CsmapReprojector, some questions:

 

1. The definition of custom transformation for CsmapReprojector are used for the parameter "Transformation" , but there are another two parameters should be set: "Source Coordinate System" and "Destination Coordinate System". If they are not set corret, the "Transformation" can not load the custom transformation. I don't very clear about their relationship.

 

2. In the link you give to me said as follows

 

"this transformation proceeds in three phases. First, the geographic coordinates are converted to three-dimensional Cartesian, geocentric coordinates using the ellipsoid of the original datum. Second, the three-dimensional transformation defined by the seven parameters is applied producing a modified set of geocentric Cartesian coordinates. Third, the resulting geocentric coordinates are converted back to geographic form using the target ellipsoid."

 

So this step are all coordinate transformation in FME? If I only want to translate three-dimensional Cartesian of two different coordinate system, how to define the custom coordinate transformation?