A coordinate system is a way for determining where a point on the planet is located. To indicate the position of a point, most coordinate systems employ two integers, called coordinates.
Each of these values represents the distance between the point and the origin, which is a fixed reference point. The first number, the X value, specifies how far the point is from the origin to the left or right. The second number, the Y value, specifies how far the point is above or below the origin. 0, 0 is the coordinate of the origin.
Because they indicate locations on a sphere or globe, longitude and latitude constitute a specific type of coordinate system known as a spherical coordinate system.
However, hundreds of additional coordinate systems are used to locate locations on the planet in various parts of the world.
All of these coordinate systems overlay a flat map of a section of the world with a grid of vertical and horizontal lines.
The following is a thorough definition of a coordinate system:
a) The projection for drawing the earth on a flat map.
b) The originator’s location
c) The units of measurement for distances from the origin
Types of Coordinate system
Both horizontal and vertical coordinate systems are used to describe data. Vertical coordinate systems find the relative height or depth of data, while horizontal coordinate systems locate data over the earth’s surface.
There are three sorts of horizontal coordinate systems: global, projected, and local. Examining the attributes of the layer might help you figure out which sort of coordinate system your data utilizes.
Both horizontal and vertical coordinate systems are used to describe data. Vertical coordinate systems find the relative height or depth of data, while horizontal coordinate systems locate data over the earth’s surface.
A) Geographic Coordinate Systems
A geographic coordinate system is a method of identifying places on the earth’s curving surface. Locations on the earth’s surface are measured in angular units relative to two planes: the equator’s plane and the prime meridian’s plane (which crosses Greenwich England).
As a result, a place is characterized by two values: a latitudinal and a longitudinal value.
The angle between the equatorial plane and the point on the earth’s surface is measured by latitude.
The angle between the prime meridian plane and the north-south plane that intersects the point of interest is measured by longitude.
B) Projected Coordinate Systems
The earth’s surface is curved, yet maps appear flat. A projected coordinate system (PCS) is a method of recognizing and measuring features on a flat (map) surface. It is made up of lines that cross at right angles to form a grid.
An origin, an x axis, a y axis, and a linear unit of measure are all included in projected coordinate systems (which are based on Cartesian coordinates). Mathematical changes are required to convert a GCS to a PCS. Planar, cylindrical, and conical projections are the three forms of projections that may be found.
A) Planar Projections
B) Cylindrical Projection
C) Conical Projection
C) Geoid coordinate system
The nominal sea level is defined by the geoid. On the surface of the ellipsoid, latitude and longitude are utilized, as well as a height or Z value that determines the vertical displacement above or below the geoid.
The geoid is the earth’s gravitational field’s equipotential, or level, surface. Imagine the oceans settling only due to gravity, with no tidal or atmospheric influences. Tunnels are also used to link seas and allow water to flow freely.
The geoid is represented by the resultant surface. The geoid is about equal to MSL and varies by a meter or two from local MSL. It’s an intricate design.
The geoid’s slope may contain discontinuities due to the earth’s composition. This indicates that the surface is analytic rather than mathematical, as an ellipsoid is.
