Projection problem from WGS84 Web Mercator (102100) to RD New (28992)

Question

I have been trying to reproject the geometry from wgs84 (102100) to RD New(28992). Its working fine but there is an offset of 200 meters from the original location. I am using geometryService.ProjectAsync method for the re-projection. I tried using both WKID and WKT. Also there is 'TOWGS84' parameter missing in the projection definition.But unfortunately I could not find the right parameters for 'TOWGS84' in WKT String.
Any suggestions/Help would be great. Thanks.

WKT string:

PROJCS["RD_New",GEOGCS["GCS_Amersfoort",DATUM["D_Amersfoort",SPHEROID["Bessel_1841",6377397.155,299.1528128]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Double_Stereographic"],PARAMETER["False_Easting",155000.0],PARAMETER["False_Northing",463000.0],PARAMETER["Central_Meridian",5.38763888888889],PARAMETER["Scale_Factor",0.9999079],PARAMETER["Latitude_Of_Origin",52.15616055555555],UNIT["Meter",1.0]]

DominiqueBroux · Answer

It seems you are right. There is a shift due to the datum transformation.
 
Unfortunately, at this time, the geometry service project REST API doesn't support explicitely specifying a datum for transformation.
AFAIK it's planned for version 10.1.
 So my conclusion is that 'TOWGS84' parameter is missing in WKT string of 28992.

I don't think that the project REST API takes in care the TOWGS84 parameter. So it would be useless to initialize it.
But I am not sure, you should get better answers to REST API forum

MahenderRajendran · Answer

Are you sure that the result is incorrect?

I tried with a coordinates converter which is not using the ESRI library and I got the same result.
See attached screenshot:
[ATTACH=CONFIG]7816[/ATTACH]

That being said, it doesn't prove that both are right. Where are your results coming from?

I checked the results in ArcGIS desktop. Check the screenshots attached.
In the image '102100_point' ,I have added input XY coordinates with base map having epsg 102100.

In the image '28992_projected_point_without_transformations' , I have added base map having EPSG 102100 without applying transformations to my RD New Data and then added the result XY coordintes (from projectAsync method) . RD New data is not projected properly.Added point is in the correct place based on map data but displaced based on my RD New data.

In the image '28992_projected_point_with_transformations', you can see that my rdnew data has been properly projected with the base map after applying transformations,but added point has been displaced. Check the attachment 'transformation_parameters' for the transformation parameters applied before projection.

Apart from ArcGIS desktop i also checked in an external site. Check the attachment 'external_check'

So my conclusion is that 'TOWGS84' parameter is missing in WKT string of 28992. I tried the parameters used in desktop and did not work neither.

102100_to_28992.pdf

DominiqueBroux · Answer

Are you sure that the result is incorrect?

I tried with a coordinates converter which is not using the ESRI library and I got the same result.
See attached screenshot:
[ATTACH=CONFIG]7816[/ATTACH]

That being said, it doesn't prove that both are right. Where are your results coming from?

Projection.jpg