Israeli Transverse Mercator
Encyclopedia
Israeli Transverse Mercator 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 ICS
. This coordinate system is sometimes also referred as the "New Israeli Grid". It is in use since January 1, 1994.
Additional information on the creation of the new grid is available in Hebrew
.
The ITM coordinate for the Western Wall
at Jerusalem is:
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 fact that the coordinate is in meters is indicated by the lowercase m.
The table below shows the same coordinate in 3 different grids:
Geographic coordinate system
A geographic coordinate system is a coordinate system that enables every location on the Earth to be specified by a set of numbers. The coordinates are often chosen such that one of the numbers represent vertical position, and two or three of the numbers represent horizontal position...
for Israel
Israel
The State of Israel is a parliamentary republic located in the Middle East, along the eastern shore of the Mediterranean Sea...
. 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 ICS
Israeli Cassini Soldner
Israeli Cassini Soldner is the old geographic coordinate system for Israel. The name is derived from the Cassini Soldner projection it uses and the fact that it is optimized for Israel. This coordinate system is sometimes also referred as the "Old Israeli Grid"...
. This coordinate system is sometimes also referred as the "New Israeli Grid". It is in use since January 1, 1994.
The need for a new grid
ITM replaced the old grid ICS which was based on the Cassini-Soldner projection. The central meridian in the new projection, as in the old one, crosses through Jerusalem. Replacing the projection eliminates two prominent drawbacks in the old network: assigning negative latitudinal values to the Southern Negev and the possibility of confusing coordinate values on the X and Y axes. The new system relocated the Y axis 50 km westward and the X axis 500 km southward so that now the entire country is covered by positive coordinate values.Additional information on the creation of the new grid is available in Hebrew
Examples
An ITM coordinate is generally given as a pair of two 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 originOrigin (mathematics)
In mathematics, the origin of a Euclidean space is a special point, usually denoted by the letter O, used as a fixed point of reference for the geometry of the surrounding space. In a Cartesian coordinate system, the origin is the point where the axes of the system intersect...
.
The ITM coordinate for the Western Wall
Western Wall
The Western Wall, Wailing Wall or Kotel is located in the Old City of Jerusalem at the foot of the western side of the Temple Mount...
at Jerusalem is:
- 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 fact that the coordinate is in meters is indicated by the lowercase m.
The table below shows the same coordinate in 3 different grids:
| Grid | Easting | Northing |
|---|---|---|
| ITM (Israeli Transverse Mercator) | 222286 | 631556 |
| ICS Israeli Cassini Soldner Israeli Cassini Soldner is the old geographic coordinate system for Israel. The name is derived from the Cassini Soldner projection it uses and the fact that it is optimized for Israel. This coordinate system is sometimes also referred as the "Old Israeli Grid"... (Israeli Cassini-Soldner) |
172249 | 1131586 |
| UTM (Universal Transverse Mercator) | 711563 | 3518045 |
Grid Parameters
The ITM coordinate system is defined by the following parameters:- ProjectionMap projectionA map projection is any method of representing the surface of a sphere or other three-dimensional body on a plane. Map projections are necessary for creating maps. All map projections distort the surface in some fashion...
: Transverse Mercator - Reference ellipsoidReference ellipsoidIn geodesy, a reference ellipsoid is a mathematically-defined surface that approximates the geoid, the truer figure of the Earth, or other planetary body....
: GRS80
- a(m): 6378137.000000000000000
- 1/f: 298.257222000000000
- Main datum point (central meridian) location:
- Latitude of origin (D-M-S): 31 44 3.816999999992845
- Longitude of origin (D-M-S): 35 12 16.260999999993260
- Main point grid values:
- False Easting (m): 219529.584000000000000
- False Northing(m): 626907.389999999900000
- Grid scale factor: 1.000006700000000
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.