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EPSG:6668 — JGD2011

JGD2011 — Japan's current geodetic datum, revised after the 2011 Tōhoku earthquake to account for crustal deformation.

Code
EPSG:6668
Type
Geographic 2D
Area
Japan

PROJ definition

+proj=longlat +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +no_defs +type=crs

Geographic bounds

W 122.38°   S 17.09°   E 157.65°   N 46.05°

Convert coordinates with EPSG:6668

Official EPSG transformations for JGD2011

Datum transformations involving EPSG:6668 published in the EPSG dataset, with parameters, accuracy and area of use:

About EPSG:6668

EPSG:6668 is the Japanese Geodetic Datum 2011 (JGD2011), introduced by the Geospatial Information Authority of Japan (GSI) following the Mw 9.0 Tōhoku earthquake which produced metre-scale crustal displacements across eastern Japan. JGD2011 is aligned with ITRF2008 at epoch 2011.4 and provides a consistent reference frame for post-earthquake mapping and cadastre.

Japan uses 19 numbered Plane Rectangular Coordinate System zones (EPSG:6669-6687 on JGD2011, EPSG:2443-2461 on the older JGD2000) — each a Transverse Mercator projection covering one prefecture or region. JGD2000 (EPSG:4612) is the predecessor; conversion uses GSI-published grid files for high accuracy in the affected regions.

Common use cases

  • Japanese national and prefectural mapping
  • Cadastre and Land Registry in Japan
  • Post-2011 surveying and GNSS positioning
  • GSI Geographical Survey datasets

Common transformations from EPSG:6668

Frequently asked questions

Why was JGD2011 introduced after JGD2000?
The 2011 Tōhoku earthquake displaced parts of eastern Japan by up to 5 m horizontally — too large to leave the official datum unchanged. JGD2011 re-aligns the national network to post-earthquake reality.
What is the proj4 string for EPSG:6668?
The proj4 definition for EPSG:6668 is: +proj=longlat +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +no_defs +type=crs
Where is EPSG:6668 used?
EPSG:6668 (JGD2011) is defined for the area: Japan.