Geodesy is the mathematical science of describing the shape of the earth. Though land surveying and topography could be considered part of geodesy, the latter is often understood as ‘higher’ geodesy, that is describing the larger shape of the earth. Geodesy provides the framework for all global positioning systems such as GNSS.  

Geodesy is not only concerned with horizontal coordinate reference systems on the surface of the earth but also about defining vertical reference levels or chart datums such as those derived from water levels.  

Iranian Permanent GPS Network

Lying in one of the most tectonically active zones in the Alpine-Himalayan belt, Iran frequently suffers from heavy and disastrous earthquakes. To monitor surface displacement and measure velocity and...

Geospatial Data in Support of 3D Cadastre

Geospatial Data in Support of 3D Cadastre

The urbanization trend is leading to an increasing number of people living in cities, thus also placing new demands on cadastral registration. To be able to register the complex infrastructures and bu...

Struve Geodetic Arc Joins World Heritage List

15th July, Durban, South Africa The World Heritage Committee chaired by Themba Wakashe, South Africa’s deputy director-general for Heritage and National Archives has inscribed seventeen cultural si...

Surveying in the land of fire and ice

Surveying in the land of fire and ice

Geodesists and surveyors in Iceland face considerable challenges due to the deformation effects of earthquakes, volcanic eruptions and glaciers on the geodetic networks. This article provides insight ...

500 Years of Mercator

500 Years of Mercator

Gerard de Kremer was born on 5 March 1512 in the small town of Rupelmonde, situated in the heart of what is now the Flemish region of Belgium. In his mid-teens, whilst studying in ‘s-Hertogenbosch, ...

The Gauss Heritage

The astronomer, mathematician and geodesist Carl Friedrich Gauss died 150 years ago. He is famous for his contributions to mathematics, but more directly of interest in a GIS context is his work to de...

Geodetic control networks: challenges and solutions

Geodetic control networks: challenges and solutions

What are the key challenges in establishing precise geodetic control networks? This is one of the most important tasks of geodesists and land surveyors, since geodetic control networks are essential f...

Modern Geodesy: Formula 1 Geospatial

Modern Geodesy: Formula 1 Geospatial

Chris Rizos, new president of the International Association of Geodesy (IAG), is advocating ‘modern geodesy' and a stronger, more visible role for the IAG. GIM International met Rizos in an early Ju...

The African Geodetic Reference Frame

The African Geodetic Reference Frame

The African Geodetic Reference Frame (AFREF) was conceived to unify the patchwork of geodetic reference frames and vertical datums in the 54 countries in Africa. A common reference frame is intended t...

Comparing 3D-Earth Viewers

A 3D-Earth viewer enables navigating through the virtual environment and can be easily downloaded from the internet. How might this rapid development support steady, long-term development of instituti...

The Fierce Rise of Airborne Lidar

The Fierce Rise of Airborne Lidar

Today, automatic matching of overlapping aerial imagery and airborne Lidar are the main geodata technologies for capturing dense point clouds of the Earth’s surface. The sampled points are used for ...

Accuracy of Geodetic GNSS Antennas

During the last decade, GNSS (Global Navigation Satellite System) technologies experienced an accelerated growth, both in terms of quantity in use and quality. The accuracy achieved by technology prov...