Convert coordinates from RGF93 v2 (EPSG:9777) to NTF (EPSG:4275) — official EPSG transformation parameters, accuracy and area of use, with a free in-browser converter.
The EPSG Geodetic Parameter Dataset defines 1 transformation between RGF93 v2 (EPSG:9777) and NTF (EPSG:4275). Its parameters, accuracy and area of use are listed below.
Grid file: rgf93_ntf.gsb
Emulation of transformation NTF to RGF93 v2 (1), code 9888. Note that grid file parameters are of opposite sign. Parameter file is from RGF93 v1 to NTF (code 15958), assuming that RGF93 v1 is equivalent to RGF93 v2 within the accuracy of the CT.
The same transformation with common GIS tools and libraries:
from pyproj import Transformer
transformer = Transformer.from_crs("EPSG:9777", "EPSG:4275", 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: France
+proj=longlat +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +no_defs +type=crsMore about EPSG:9777 →
geographic system using latitude and longitude on an ellipsoid · Area of use: France - onshore - mainland and Corsica
+proj=longlat +ellps=clrk80ign +towgs84=-168,-60,320,0,0,0,0 +no_defs +type=crsMore about EPSG:4275 →