Georeferencing is the process of geographically locating a spatial object, in a reference system, through the assignment of coordinates. It is the action of measuring any point or demarcating any polygon of the Earth's surface through topographic, geodetic or geographic mechanisms, using one of the various reference or coordinate systems available for the purpose, depending on the objective to be achieved.
The computerisation of these data, through computational tools called Geographic Information Systems (GIS), began in Canada in the 1960s. However, it was in the 1990s that georeferencing and GIS became popular as an indispensable support tool for surveying and other areas.
Currently the Official Reference System for:
Mainland Portugal is the:
PT-TM06/ETRS89 – European Terrestrial Reference System 1989
Autonomous Region of Madeira and Autonomous Region of Açores is the:
PTRA08-UTM/ITRF93
For more official information see https://www.dgterritorio.gov.pt
What is Georeferencing?
