EPSG:4122 — ATS77

Geographic 2D · Canada - Maritime Provinces

Export Formats

OGC WKT

GEOGCS[
    "ATS77",
    DATUM[
        "Average_Terrestrial_System_1977",
        SPHEROID["Average Terrestrial System 1977",6378135,298.257],
        EXTENSION["PROJ4_GRIDS","NB7783v2.gsb"]
    ],
    PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],
    UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],
    AUTHORITY["EPSG","4122"]
]

WKT2

GEOGCRS[
    "ATS77",
    DATUM[
        "Average Terrestrial System 1977",
        ELLIPSOID[
            "Average Terrestrial System 1977",
            6378135,
            298.257,
            LENGTHUNIT["metre",1,ID["EPSG",9001]],
            ID["EPSG",7041]
        ],
        ID["EPSG",6122]
    ],
    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",4122]
]

PROJ.4

+proj=longlat +a=6378135 +rf=298.257 +nadgrids=NB7783v2.gsb +no_defs +type=crs

Proj4js

How to add a projection to Proj4js? →

proj4.defs("EPSG:4122", "+proj=longlat +a=6378135 +rf=298.257 +nadgrids=NB7783v2.gsb +no_defs +type=crs");

JSON

{
  "type": "CoordinateReferenceSystem",
  "code": 4122,
  "name": "ATS77",
  "kind": "geographic 2D",
  "area": "Canada - Maritime Provinces",
  "unit": "degree (supplier to define representation)",
  "bbox": [
    43.41,
    -69.05,
    48.07,
    -59.73
  ],
  "proj4": "+proj=longlat +a=6378135 +rf=298.257 +nadgrids=NB7783v2.gsb +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 (4122, 'EPSG', 4122, '+proj=longlat +a=6378135 +rf=298.257 +nadgrids=NB7783v2.gsb +no_defs +type=crs', 'GEOGCS["ATS77",DATUM["Average_Terrestrial_System_1977",SPHEROID["Average Terrestrial System 1977",6378135,298.257],EXTENSION["PROJ4_GRIDS","NB7783v2.gsb"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4122"]]');

MapServer

How to add a projection to MapServer? →

PROJECTION
  "+proj=longlat"
  "+a=6378135"
  "+rf=298.257"
  "+nadgrids=NB7783v2.gsb"
  "+no_defs"
  "+type=crs"
END

GeoServer

How to add a projection to GeoServer? →

4122=GEOGCS["ATS77",DATUM["Average_Terrestrial_System_1977",SPHEROID["Average Terrestrial System 1977",6378135,298.257],EXTENSION["PROJ4_GRIDS","NB7783v2.gsb"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4122"]]

Related Coordinate Systems

Available Transformations (24)

Transformation	Source → Target	Accuracy (m)
ATS77 to NAD83(CSRS)v6 (4)	4122 → 8252	0.06
ATS77 to NAD83 (1)	4122 → 4269	0.5
ATS77 to WGS 84 (1)	4122 → 4326	1.5
ATS77 to WGS 84 (2)	4122 → 4326	1.5
ATS77 to WGS 84 (3)	4122 → 4326	1.5
ATS77 to NAD27 (1)	4122 → 4267	1.5
ATS77 to NAD27 (2)	4122 → 4267	1.5
ATS77 to NAD27 (3)	4122 → 4267	1.5
ATS77 to NAD83(CSRS)v3 (3)	4122 → 8240	1.5
ATS77 to NAD83(CSRS)v2 (2)	4122 → 8237	1.5

Other CRS using Average Terrestrial System 1977

Frequently Asked Questions

How do I add EPSG:4122 to GeoServer?

Add the following definition to your GeoServer configuration:

4122=GEOGCS["ATS77",DATUM["Average_Terrestrial_System_1977",SPHEROID["Average Terrestrial System 1977",6378135,298.257],EXTENSION["PROJ4_GRIDS","NB7783v2.gsb"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4122"]]

Read the full GeoServer guide →

How do I add EPSG:4122 to PostGIS?

Add the following definition to your PostGIS configuration:

INSERT INTO spatial_ref_sys (srid, auth_name, auth_srid, proj4text, srtext)
VALUES (4122, 'EPSG', 4122, '+proj=longlat +a=6378135 +rf=298.257 +nadgrids=NB7783v2.gsb +no_defs +type=crs', 'GEOGCS["ATS77",DATUM["Average_Terrestrial_System_1977",SPHEROID["Average Terrestrial System 1977",6378135,298.257],EXTENSION["PROJ4_GRIDS","NB7783v2.gsb"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4122"]]');

Read the full PostGIS guide →

How do I add EPSG:4122 to MapServer?

Add the following definition to your MapServer configuration:

PROJECTION
  "+proj=longlat"
  "+a=6378135"
  "+rf=298.257"
  "+nadgrids=NB7783v2.gsb"
  "+no_defs"
  "+type=crs"
END

Read the full MapServer guide →

How do I use EPSG:4122 with Proj4js?

Add the following definition to your Proj4js configuration:

proj4.defs("EPSG:4122", "+proj=longlat +a=6378135 +rf=298.257 +nadgrids=NB7783v2.gsb +no_defs +type=crs");

Read the full Proj4js guide →