EPSG:8991 — ITRF91

Geographic 2D · World

Export Formats

OGC WKT

GEOGCS[
    "ITRF91",
    DATUM[
        "International_Terrestrial_Reference_Frame_1991",
        SPHEROID["GRS 1980",6378137,298.257222101,AUTHORITY["EPSG","7019"]],
        AUTHORITY["EPSG","6650"]
    ],
    PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],
    UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],
    AUTHORITY["EPSG","8991"]
]

WKT2

GEOGCRS[
    "ITRF91",
    DYNAMIC[FRAMEEPOCH[1988.0]],
    DATUM[
        "International Terrestrial Reference Frame 1991",
        ELLIPSOID[
            "GRS 1980",
            6378137,
            298.257222101,
            LENGTHUNIT["metre",1,ID["EPSG",9001]],
            ID["EPSG",7019]
        ],
        ID["EPSG",6650]
    ],
    CS[ellipsoidal,2,ID["EPSG",6422]],
    AXIS["Geodetic latitude (Lat)",north],
    AXIS["Geodetic longitude (Lon)",east],
    ANGLEUNIT["degree",0.0174532925199433,ID["EPSG",9102]],
    ID["EPSG",8991]
]

PROJ.4

+proj=longlat +ellps=GRS80 +no_defs +type=crs

Proj4js

How to add a projection to Proj4js? →

proj4.defs("EPSG:8991", "+proj=longlat +ellps=GRS80 +no_defs +type=crs");

JSON

{
  "type": "CoordinateReferenceSystem",
  "code": 8991,
  "name": "ITRF91",
  "kind": "geographic 2D",
  "area": "World",
  "unit": "degree (supplier to define representation)",
  "bbox": [
    -90,
    -180,
    90,
    180
  ],
  "proj4": "+proj=longlat +ellps=GRS80 +no_defs +type=crs"
}

PostGIS

How to add a projection to PostGIS? →

INSERT INTO spatial_ref_sys (srid, auth_name, auth_srid, proj4text, srtext)
VALUES (8991, 'EPSG', 8991, '+proj=longlat +ellps=GRS80 +no_defs +type=crs', 'GEOGCS["ITRF91",DATUM["International_Terrestrial_Reference_Frame_1991",SPHEROID["GRS 1980",6378137,298.257222101,AUTHORITY["EPSG","7019"]],AUTHORITY["EPSG","6650"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","8991"]]');

MapServer

How to add a projection to MapServer? →

PROJECTION
  "+proj=longlat"
  "+ellps=GRS80"
  "+no_defs"
  "+type=crs"
END

GeoServer

How to add a projection to GeoServer? →

8991=GEOGCS["ITRF91",DATUM["International_Terrestrial_Reference_Frame_1991",SPHEROID["GRS 1980",6378137,298.257222101,AUTHORITY["EPSG","7019"]],AUTHORITY["EPSG","6650"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","8991"]]

Related Coordinate Systems

Available Transformations (15)

Transformations inherited from base CRS: EPSG:4913 (ITRF91)

Transformation	Source → Target	Accuracy (m)
ITRF91 to ETRF91 (1)	4913 → 7918	0
ITRF91 to ITRF92 (1)	4913 → 4914	0.005
ITRF91 to ITRF92 (2)	4913 → 4914	0.005
ITRF90 to ITRF91 (1)	4912 → 4913	0.007
ITRF90 to ITRF91 (2)	4912 → 4913	0.007
ITRF91 to ITRF2000 (1)	4913 → 4919	0.01
ITRF91 to ITRF2008 (1)	4913 → 5332	0.01
ITRF91 to ETRF2000 (1)	4913 → 7930	0.01
ITRF91 to ITRF2014 (1)	4913 → 7789	0.01
ITRF91 to ETRF2014 (1)	4913 → 8401	0.01

Other CRS using International Terrestrial Reference Frame 1991

Frequently Asked Questions

How do I add EPSG:8991 to GeoServer?

Add the following definition to your GeoServer configuration:

8991=GEOGCS["ITRF91",DATUM["International_Terrestrial_Reference_Frame_1991",SPHEROID["GRS 1980",6378137,298.257222101,AUTHORITY["EPSG","7019"]],AUTHORITY["EPSG","6650"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","8991"]]

Read the full GeoServer guide →

How do I add EPSG:8991 to PostGIS?

Add the following definition to your PostGIS configuration:

INSERT INTO spatial_ref_sys (srid, auth_name, auth_srid, proj4text, srtext)
VALUES (8991, 'EPSG', 8991, '+proj=longlat +ellps=GRS80 +no_defs +type=crs', 'GEOGCS["ITRF91",DATUM["International_Terrestrial_Reference_Frame_1991",SPHEROID["GRS 1980",6378137,298.257222101,AUTHORITY["EPSG","7019"]],AUTHORITY["EPSG","6650"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","8991"]]');

Read the full PostGIS guide →

How do I add EPSG:8991 to MapServer?

Add the following definition to your MapServer configuration:

PROJECTION
  "+proj=longlat"
  "+ellps=GRS80"
  "+no_defs"
  "+type=crs"
END

Read the full MapServer guide →

How do I use EPSG:8991 with Proj4js?

Add the following definition to your Proj4js configuration:

proj4.defs("EPSG:8991", "+proj=longlat +ellps=GRS80 +no_defs +type=crs");

Read the full Proj4js guide →