An EPSG code is a unique identifier used to represent coordinate systems and other geodetic properties like datums, spheroids, and units. EPSG stands for European Petroleum Survey Group and is a scientific organization that maintains a geodetic parameter database with standard codes. Additionally, this database contains the parameters for these objects or at least references to where such parameters can be found (if they cannot easily be expressed as values). 


Currently, the Virtual Surveyor and Terrain Creator apps only support coordinate systems from the EPSG database.


Overview


EPSG Code Database

Every geographic object (coordinate system, spheroid, unit, etc.) gets assigned a unique number and the database is under continual active maintenance. An online database with all coordinate systems and the matching EPSG codes can be found online at EPSG.io: Coordinate Systems Worldwide. 


E.g. the EPSG code 3812 represents Belgian Lambert 2008, and EPSG code 6360 represents the North American Vertical Datum 1988 (NAVD88).


Where Can an EPSG Code Be Used in Virtual Surveyor?

The Virtual Surveyor and Terrain Creator apps allow four options for using an EPSG code:

  1. You can use it to Set the Project Coordinate System in Virtual Surveyor.
  2. You can use it to Set the Project Coordinate System in Terrain Creator for both horizontal and vertical coordinates.
  3. You can set the Data Coordinate System in a .csv file by adding specific tags:
    1. In a .csv file for survey or ground points
    2. In a .csv file for drone camera positions
  4. If you add data to a project that doesn't have a defined coordinate system, you can use an EPSG code to specify the Data Coordinate System.


The example image below shows what Project Coordinate System is applied to your project, in the Virtual Surveyor app. The referenced EPSG code is 31370, representing Belgian Lambert 72.