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    EPSG reference

    EPSG:22991 — Egypt 1907 / Blue Belt

    Egypt 1907 / Blue Belt (EPSG:22991) — a Projected (metres) system on the helmert datum, used in Egypt. Parameters, proj4, WKT, accuracy ±4.3 m, plus a free converter to…

    At a glance

    EPSG
    22991
    Name
    Egypt 1907 / Blue Belt
    Kind
    Projected (metres)
    Family
    Transverse Mercator (belt)
    Ellipsoid
    helmert
    Accuracy
    ±4.3 m (vs PROJ)
    Countries
    Egypt
    Convert from this system now

    Area of use

    West33.00°
    South21.97°
    East36.95°
    North31.36°

    Projection parameters

    Projectiontmerc
    Latitude of origin30
    Central meridian35
    Scale factor1
    False easting300000
    False northing1100000
    Ellipsoidhelmert
    Unitsm
    Helmert shift to WGS84-130,110,-13,0,0,0,0
    proj4
    +proj=tmerc +lat_0=30 +lon_0=35 +k=1 +x_0=300000 +y_0=1100000 +ellps=helmert +units=m +no_defs +towgs84=-130,110,-13,0,0,0,0
    WKT (ESRI)
    PROJCS["Egypt 1907 / Blue Belt",GEOGCS["GCS_Egypt 1907 / Blue Belt",DATUM["D_Helmert_1906",SPHEROID["Helmert_1906",6378200,298.3],TOWGS84[-130,110,-13,0,0,0,0]],PRIMEM["Greenwich",0],UNIT["Degree",0.0174532925199433]],PROJECTION["Transverse_Mercator"],PARAMETER["False_Easting",300000],PARAMETER["False_Northing",1100000],PARAMETER["Central_Meridian",35],PARAMETER["Scale_Factor",1],PARAMETER["Latitude_Of_Origin",30],UNIT["Meter",1],AUTHORITY["EPSG","22991"]]

    Sample conversion

    Centre of the area of use: WGS84 34.97500, 26.66500 → EPSG:22991 297346.638, 730384.811

    Values are within ±4.3 m at the test point.

    About the Transverse Mercator (belt) family

    Egypt 1907 / Blue Belt is a Transverse Mercator belt — a national or cadastral grid in metres, conformal (angles are preserved), with its own central meridian and scale factor. Egypt's Red/Purple/Blue belts, the Levant grids, and many Gulf cadastral systems are of this kind.

    Two things decide whether your coordinates land correctly: the exact belt (central meridian) and the datum. Mixing a coordinate from one belt into another, or ignoring the datum shift to WGS 84, is the usual cause of a systematic offset in imported survey data.

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    FAQ

    It is the coordinate system “Egypt 1907 / Blue Belt”, a Projected (metres) system in the Transverse Mercator (belt) family, identified worldwide by the code EPSG:22991.

    You may also need: Arab-world coordinate converter · Surveying file format converter · Batch coordinate file converter