EPSG:24821 — PSAD56 / UTM zone 21N

PROJCRS[
    "PSAD56 / UTM zone 21N",
    BASEGEOGCRS[
        "PSAD56",
        DATUM[
            "Provisional South American Datum 1956",
            ELLIPSOID[
                "International 1924",
                6378388,
                297,
                LENGTHUNIT["metre",1,ID["EPSG",9001]],
                ID["EPSG",7022]
            ],
            ID["EPSG",6248]
        ],
        ID["EPSG",4248]
    ],
    CONVERSION[
        "UTM zone 21N",
        METHOD["Transverse Mercator",ID["EPSG",9807]],
        PARAMETER[
            "Latitude of natural origin",
            0,
            ANGLEUNIT["degree",0.0174532925199433,ID["EPSG",9102]],
            ID["EPSG",8801]
        ],
        PARAMETER[
            "Longitude of natural origin",
            -57,
            ANGLEUNIT["degree",0.0174532925199433,ID["EPSG",9102]],
            ID["EPSG",8802]
        ],
        PARAMETER[
            "Scale factor at natural origin",
            0.9996,
            SCALEUNIT["unity",1,ID["EPSG",9201]],
            ID["EPSG",8805]
        ],
        PARAMETER[
            "False easting",
            500000,
            LENGTHUNIT["metre",1,ID["EPSG",9001]],
            ID["EPSG",8806]
        ],
        PARAMETER[
            "False northing",
            0,
            LENGTHUNIT["metre",1,ID["EPSG",9001]],
            ID["EPSG",8807]
        ],
        ID["EPSG",16021]
    ],
    CS[Cartesian,2,ID["EPSG",4400]],
    AXIS["Easting (E)",east],
    AXIS["Northing (N)",north],
    LENGTHUNIT["metre",1,ID["EPSG",9001]],
    ID["EPSG",24821]
]

+proj=utm +zone=21 +ellps=intl +towgs84=-288,175,-376,0,0,0,0 +units=m +no_defs +type=crs

proj4.defs("EPSG:24821", "+proj=utm +zone=21 +ellps=intl +towgs84=-288,175,-376,0,0,0,0 +units=m +no_defs +type=crs");

{
  "type": "CoordinateReferenceSystem",
  "code": 24821,
  "name": "PSAD56 / UTM zone 21N",
  "kind": "projected",
  "area": "South America - 60°W to 54°W, N hemisphere and PSAD56 by country",
  "unit": "metre",
  "bbox": [
    1.18,
    -60,
    8.58,
    -56.47
  ],
  "proj4": "+proj=utm +zone=21 +ellps=intl +towgs84=-288,175,-376,0,0,0,0 +units=m +no_defs +type=crs"
}

INSERT INTO spatial_ref_sys (srid, auth_name, auth_srid, proj4text, srtext)
VALUES (24821, 'EPSG', 24821, '+proj=utm +zone=21 +ellps=intl +towgs84=-288,175,-376,0,0,0,0 +units=m +no_defs +type=crs', 'PROJCS["PSAD56 / UTM zone 21N",GEOGCS["PSAD56",DATUM["Provisional_South_American_Datum_1956",SPHEROID["International 1924",6378388,297],TOWGS84[-288,175,-376,0,0,0,0]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4248"]],PROJECTION["Transverse_Mercator"],PARAMETER["latitude_of_origin",0],PARAMETER["central_meridian",-57],PARAMETER["scale_factor",0.9996],PARAMETER["false_easting",500000],PARAMETER["false_northing",0],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["Easting",EAST],AXIS["Northing",NORTH],AUTHORITY["EPSG","24821"]]');

PROJECTION
  "+proj=utm"
  "+zone=21"
  "+ellps=intl"
  "+towgs84=-288,175,-376,0,0,0,0"
  "+units=m"
  "+no_defs"
  "+type=crs"
END

24821=PROJCS["PSAD56 / UTM zone 21N",GEOGCS["PSAD56",DATUM["Provisional_South_American_Datum_1956",SPHEROID["International 1924",6378388,297],TOWGS84[-288,175,-376,0,0,0,0]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4248"]],PROJECTION["Transverse_Mercator"],PARAMETER["latitude_of_origin",0],PARAMETER["central_meridian",-57],PARAMETER["scale_factor",0.9996],PARAMETER["false_easting",500000],PARAMETER["false_northing",0],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["Easting",EAST],AXIS["Northing",NORTH],AUTHORITY["EPSG","24821"]]