ISO Standard 19111, Geographic information - Spatial referencing by coordinates, defines the conceptual scheme for the description of spatial referencing through coordinates. Describes the necessary data to define the reference systems of one, two- and three-dimensional coordinates as well as the information needed to convert coordinates from one system to another.
According to this Standard, a coordinate reference system is composed of a coordinate system and a datum. Of the different types of datums that distinguish the Standard, the Geodetic Datums and the Vertical Datums are the ones that will be used in this module. The former requires the description of an Ellipsoid and the latter do not.
Based on this classification, two groups of coordinate reference systems have been created: Geodetic SRC and the Vertical SRC.
The Geodetic SRCs are divided into different types. Based on the classification of ISO 19111 and the classification made by the EPSG (European Petroleum Survey Group, www.epsg.org,http://www.epsg.org/now the OGP, International Association of Oil & Gas Producers) in its database, we will distinguish: the SRC Geographical, the SRC Geocentric and the SRC Projected.
To start working on a project, it is essential to define in which coordinate system the points and geographic data will be represented.
Clicking on the button displays a list of coordinate systems that have previously been configured in the application in other projects (Figure 19).
If you want to add a new one, click on .
Once the coordinate system is selected from the list, it will be assigned to the project by clicking on the button .
The coordinate system could be also deleted using the button .
If you use a coordinate system frequently, it can be set as your default coordinate system of your new projects by selecting it from the list and pressing the button .
Aplitop is continuously improving its applications and service. One of them is the coordinate system service. By pressing the button the user can check if new updates of the coordinate system database are available to always have the latest versions and systems[2].
When a new coordinate system is created, the continent and the country in which it will be worked will be established, and then the coordinate systems, datumtransformations and available geoids (Figure 20) in that region will be listed in this region:
·Coordinate systems: List of projected coordinate systems used in the selected country.
·Datum transformations: List of datum transformations for the area that has been selected in the coordinate system.
·Geoids: List of geoids that can be used to calculate orthometric heights.
The contents of:4.3 Selection of coordinate system
displays a list of coordinate systems that have previously been configured in the application in other projects (Figure 19).
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the user can check if new updates of the coordinate system database are available to always have the latest versions and systems