Basic Mapping Concepts

What is WGS84?
WGS84 is an extensively used term in mapping. There are different situations when WGS84 is used, and people often get confused. Does WGS84 means the same th...
Mon, 26 Mar, 2018 at 2:13 PM
What is an ellipsoid?
Our earth isn't perfectly spherical. So when we try to approximate the shape of earth, we need to choose an appropriate reference model. An ellipsoid i...
Mon, 26 Mar, 2018 at 2:13 PM
What is a horizontal datum?
In surveying and geodesy, a datum is a reference system or an approximation of the Earth's surface against which positional measurements are made for c...
Mon, 26 Mar, 2018 at 2:13 PM
What is the difference between a geographic and a projected coordinate system?
Geographic coordinate system A geographic coordinate system (GCS) is a coordinate system which uses a three-dimensional spherical surface (ellipsoid) to...
Mon, 26 Mar, 2018 at 2:13 PM
What is the geoid?
The shape of our earth is not perfectly spherical. So when we try to approximate the shape of it, we have to find a appropriateĀ model. We've seen earli...
Mon, 26 Mar, 2018 at 2:13 PM
What is the difference between ellipsoidal and orthometric elevation?
The Orthometric Height or Geodetic Height is the vertical distance from a location on the Earth's Surface distance to the geoid (blue surface in the il...
Thu, 29 Mar, 2018 at 11:05 AM
What is an EPSG code?
EPSGĀ stands for European Petroleum Survey Group and is an organization that maintains a geodetic parameter database with standard codes, the EPSG codes, for...
Mon, 26 Mar, 2018 at 2:14 PM