Convert coordinates from Greek (EPSG:4120) to GGRS87 (EPSG:4121) — official EPSG transformation parameters, accuracy and area of use, with a free in-browser converter.
The EPSG Geodetic Parameter Dataset defines 1 transformation between Greek (EPSG:4120) and GGRS87 (EPSG:4121). Its parameters, accuracy and area of use are listed below.
| Parameter | Value | Unit |
|---|---|---|
| Latitude offset | -5.86 | arc-second |
| Longitude offset | 0.28 | arc-second |
More accurate polynomial transformations between Greek / Hatt projection zones and GGRS87 / Greek Grid are available from the Military Geographic Service.
The same transformation with common GIS tools and libraries:
from pyproj import Transformer
transformer = Transformer.from_crs("EPSG:4120", "EPSG:4121", always_xy=True)
x, y = transformer.transform(-73.9857, 40.7484)
print(x, y)geographic system using latitude and longitude on an ellipsoid · Area of use: Greece - onshore
+proj=longlat +ellps=bessel +no_defs +type=crsMore about EPSG:4120 →
geographic system using latitude and longitude on an ellipsoid · Area of use: Greece - onshore
+proj=longlat +ellps=GRS80 +towgs84=-199.87,74.79,246.62,0,0,0,0 +no_defs +type=crsMore about EPSG:4121 →