Israeli Cassini Soldner
Encyclopedia
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". ICS has been mostly replaced by the new coordinate system Israeli Transverse Mercator
(ITM), but still referenced by older books and navigation software.
, the False Northing of ICS was increased by 1000000. As a result, coordinates in the south of Israel are higher than 800000.
. The easting is always a 6 digit number while the northing has 6 or 7 digits.
The ICS coordinate for the Western Wall
at Jerusalem is:
The first figure is the easting and means that the location is 172,249 meters east from the false origin (along the X axis). The second figure is the northing and puts the location 1,131,586 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 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". ICS has been mostly replaced by the new coordinate system Israeli Transverse Mercator
Israeli Transverse Mercator
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...
(ITM), but still referenced by older books and navigation software.
History
The Cassini Soldner projection was used by the British Mandate of Palestine. The British grid reached as south as Beer-Sheba. To avoid the existence of negative coordinates in the southern NegevNegev
The Negev is a desert and semidesert region of southern Israel. The Arabs, including the native Bedouin population of the region, refer to the desert as al-Naqab. The origin of the word Neghebh is from the Hebrew root denoting 'dry'...
, the False Northing of ICS was increased by 1000000. As a result, coordinates in the south of Israel are higher than 800000.
Examples
An ICS coordinate is generally given as a pair of two 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 easting is always a 6 digit number while the northing has 6 or 7 digits.
The ICS 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 172249 m
- N 1131586 m
The first figure is the easting and means that the location is 172,249 meters east from the false origin (along the X axis). The second figure is the northing and puts the location 1,131,586 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 |
|---|---|---|
| ICS (Israeli Cassini Soldner) | 172249 | 1131586 |
| ITM Israeli Transverse Mercator 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... (Israeli Transverse Mercator) |
222286 | 631556 |
| UTM (Universal Transverse Mercator) | 711563 | 518045 |
Grid parameters
The ICS 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...
: Cassini Soldner - 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....
: Clarke 80 ModifiedFigure of the EarthThe expression figure of the Earth has various meanings in geodesy according to the way it is used and the precision with which the Earth's size and shape is to be defined. The actual topographic surface is most apparent with its variety of land forms and water areas. This is, in fact, the surface...
- a(m): 6378300.789000000000000
- 1/f: 293.466000000000000
- Main datum point values:
- Latitude of origin (D-M-S): 31 44 2.748999999990644
- Longitude of origin (D-M-S): 35 12 43.490000000012970
- Main point grid values:
- False Easting (m): 170251.554999999900000
- False Northing(m): 1126867.909000000000000
- Grid scale factor: 1.000000000000000
Sources
- Official ICS Grid Definition
- MAPI (Mapping Center of Israel) official website (Hebrew).
- Geography educational website of Haifa's university.
External links
- MAPI (Mapping Center of Israel) official website (Hebrew).
- Geography educational website of Haifa's university.