I have some projects where I work with this coordinate system:
DHDN_3_Degree_Gauss_Zone_4
WKID: 31468 Authority: EPSG
Projection: Gauss_Kruger
False_Easting: 4500000.0
False_Northing: 0.0
Central_Meridian: 12.0
Scale_Factor: 1.0
Latitude_Of_Origin: 0.0
Linear Unit: Meter (1.0)
I usually get my data in ETRS89:
ETRS_1989_ETRS-TM32
WKID: 3044 Authority: EPSG
Projection: Transverse_Mercator
False_Easting: 500000.0
False_Northing: 0.0
Central_Meridian: 9.0
Scale_Factor: 0.9996
Latitude_Of_Origin: 0.0
Linear Unit: Meter (1.0)
Or WGS84:
GCS_WGS_1984
WKID: 4326 Authority: EPSG
Angular Unit: Degree (0.0174532925199433)
Prime Meridian: Greenwich (0.0)
Datum: D_WGS_1984
Spheroid: WGS_1984
Semimajor Axis: 6378137.0
Semiminor Axis: 6356752.314245179
Inverse Flattening: 298.257223563
Now I realised, that when I load my data into a ETSR89-project and to a Gauss-Krüger-project I have an offset of approximately 200 m between the two points. I used the transformation "DHDN_To_WGS_1984_5x" and "ETRS_1989_To_WGS_1984", respectively. (The "DHDN_To_WGS_1984_4_NTv2" does not give better results.) I found out about this using the calculate geometry function, which unfortunately calculates different WGS84 coordinates depending on the project coordinate system.
How can I make sure my data is on the right spot?
Best Answer
Depends where is located the data. Check Geographic (datum) transformations, parameters and areas of use and select which is more accurate to your data. They have small differences in dy and dz translation.
Conversions are:
Diferences are:
Also check Geographic and Vertical Transformation Tables. This document recommends min/max latitude/longitude to select the right transformation between datums. Both sources of information belongs to ESRI: