Geodata - What are Geodata?

What is GIS data or geodata?

Geodata is information with a spatial reference that can be used, among other data, in a Geographic Information System (GIS).

They are divided into several categories. Basically there are primary data and secondary data.

  • Primary data: Primary data is raw data, i.e. data that comes directly from a data acquisition and is created, for example, when measuring a property.
  • Secondary data: Secondary data are revised primary data. They were calculated, modeled or otherwise processed.

All geodata consist of object attributes and object geometries. The attributes describe the object and the geometry determines the position and shape of the object. Objects can be represented as points, lines, surfaces or bodies.

Let's come back to Google Maps, for example. For example, if you search there for petrol stations in Honolulu, all the petrol stations nearby recorded are shown on a map.

Object attributes would be here, for example:

  • Gas station
  • Brand
  • Address
  • Reviews

In this case, the object geometry is a point with the corresponding coordinates. Google has chosen a "red, upside down raindrop" for this point for a nice display.

Furthermore, a distinction is now made between geodata.

Geospatial base data: Geospatial base data means basic official data. They serve as the basis for specialist cards and thematic cards. For example, landscape (topography), properties, data from Alkis or the surface of the earth. They are data from the surveying administration and are created by public bodies. The use of this commercial data is restricted by law.

Geo-technical data: Geo-technical data are data from various specialist areas and are shown on the corresponding maps. They are used in: urban planning, demography, environmental protection, education, social affairs, supply and disposal, disaster protection, real estate management, geomarketing

There are various ways of storing geographic information. Amongst other things:

  • in a database e.g. PostgreSQL
  • as shapefile
  • in a geodatabase
  • as a raster image
  • as table data

Geodata can be obtained from public and private providers. The State Office for Digitization, Broadband and Surveying offers, for example, aerial photos and topographic maps, which are subject to legal restrictions. The costs for this are very different.

Depending on the area of ​​application, geodata must have certain quality features in order to fulfill its purpose. With underground lines, for example, it is not enough if they are accurate to a few meters, otherwise you would have to look for the line if repairs are required. When determining the position of the petrol station, it would theoretically not matter whether the point was now shifted by one or two meters, since a petrol station is normally larger than two meters. In principle, one can say that the measurement accuracy can be directly proportional to the dimension of an object.

In addition, geodata must also be logical, i.e. when collecting data for population mapping, no negative values ​​may occur. Time often plays an important role. In the following, objects with an exact location and time are four-dimensional. This is important, for example, for historical data or when analyzing population structures over a certain period of time.


Geodata is spatial data that represents a real object. They include attributes that describe the object and a geometry that determines the position of the object. Geodata is divided into primary and secondary data and saved in databases, tabular data, as images or shapefiles. They are the medium for maps, which are represented in a geographic information system, in order to analyze complex topics and to make a decision.

About The Author

Max Dietrich
Max Dietrich

Geospatial Developer

Hi, I'm Max (he/him). I am a geospatial developer, author and cyclist from Rosenheim, Germany.

0 Webmentions

Have you published a response to this? Send me a webmention by letting me know the URL.

Found no Webmentions yet. Be the first!


Continue Reading

  • How to create a Mapnik stylesheet for displaying any data from PostgreSQL/PostGIS

    In this article i want to show you how you can build your own Mapnik stylesheet for displaying any data from PostgreSQL/PostGIS. The Mapnik Stylesheet XML can be used for a tile-server with your custom style. Continue reading...
  • How i constantly track my location and display a web-map with all the locations

    Inspired by Aaron Parecki and who he has been tracking his location since 2008 with an iPhone app and a server side tracking API i decided to go for a similar approach. I wanted to track my position constantly with my Android smartphone and use the data to display a map with all locations i have ever been to. Continue reading...
  • Fetching and storing activities from Garmin Connect with Strapi and visualizing them with NextJS

    Step-by-step guide explaining how to fetch data from Garmin Connect, store it in Strapi and visualize it with NextJS and React-Leaflet. Continue reading...