Israeli Transverse Mercator - ITM

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Concepts Geographical distance Geoid Figure of the Earth (radius and circumference) Geodetic coordinates Geodetic datum Geodesic Horizontal position representation Latitude / Longitude Map projection Reference ellipsoid Satellite geodesy Spatial reference system Spatial relations Vertical positions
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Standards (history) NGVD 29 Sea Level Datum 1929 OSGB36 Ordnance Survey Great Britain 1936 SK-42 Systema Koordinat 1942 goda ED50 European Datum 1950 SAD69 South American Datum 1969 GRS 80 Geodetic Reference System 1980 ISO 6709 Geographic point coord. 1983 NAD 83 North American Datum 1983 WGS 84 World Geodetic System 1984 NAVD 88 N. American Vertical Datum 1988 ETRS89 European Terrestrial Ref. Sys. 1989 GCJ-02 Chinese obfuscated datum 2002 Geo URI Internet link to a point 2010 International Terrestrial Reference System Spatial Reference System Identifier (SRID) Universal Transverse Mercator (UTM)

Israeli Transverse Mercator (ITM), also known as the New Israel Grid (NIG; Hebrew: רשת ישראל חדשה, רשת ישראל החדשה Reshet Yisra'el Ha-Ḥadasha) is the new geographic coordinate system for Israel. The name is derived from the transverse Mercator projection it uses and the fact that it is optimized for Israel. ITM has replaced the old coordinate system Israeli Cassini Soldner (ICS), also known as the Old Israel Grid (OIG). It became the official grid for Israel in 1998.^[1]

The need for a new grid

ITM replaced the Old Israel Grid (OIG) (Hebrew: רשת ישראל ישנה), also known as the Israel Cassini Soldner (ICS), which was based on the Cassini-Soldner projection. ICS in turn was a simple modification of the Palestine grid used during the British mandate. The central meridian in the new projection, as in the old one, crosses through Jerusalem. The new grid has two main advantages. One is that the Transverse Mercator projection is better for navigation than Cassini-Soldner. The other is that ICS was based on a 19th-century reference ellipsoid (approximation of the shape of the Earth) and this was replaced by a more accurate approximation.

Additional information on the creation of the new grid is available in Hebrew.^[2]

Examples

An ITM coordinate is generally given as a pair of six digit numbers (excluding any digits behind a decimal point which may be used in very precise surveying). The first number is always the Easting and the second is the Northing. The easting and northing are in metres from the false origin.

The ITM coordinate for the Western Wall at Jerusalem is 222286 632556, which means

E 222286 m

N 631556 m

The first figure is the easting and means that the location is 222,286 meters east from the false origin (along the X axis). The second figure is the northing and puts the location 631,556 meters north of the false origin (along the Y axis). Also notice how the easting in this example is indicated with an “E” and likewise an “N” for the northing.

The table below shows the same coordinate in 3 different grids:

Grid Parameters

The ITM coordinate system is defined^[3] by the following parameters:

Projection

Transverse Mercator

Reference ellipsoid

Origin Point

False Origin

See also

• ICS
• GRS80
• Transverse Mercator

References

External links

• MAPI (Mapping Center of Israel) official website (Hebrew).
• Converting latitude and longitude to ITM coordinates (free and open source software).
• Geography educational website of Haifa's university.