Lambert 72 vs. Lambert 2008: What’s the difference?

If you work with GIS, cartography, or geospatial data in Belgium, understanding the differences between Lambert 72 and Lambert 2008 is crucial. In this article we explain why.

Understanding coordinate systems and map projections

When mapping the Earth or any part of it, a three-dimensional spherical surface must be transformed into a two-dimensional flat map. This process inevitably introduces distortions. To minimize these distortions, various coordinate systems have been developed.

For example, WGS 84 (World Geodetic System 1984) is commonly used for global maps. However, for more accurate representation of specific countries or regions, specialized coordinate systems exist. Belgium used the Lambert 72 coordinate system for decades. However, with advancements in Global Navigation Satellite System (GNSS) technology, a new coordinate system Lambert 2008 was introduced to simplify data transformations.

Why was Lambert 2008 introduced?

Lambert 72, officially known as Belge Lambert 1972 (EPSG:31370), was widely used for mapping all kind of data in Belgium. However, it had a significant drawback: data from GNSS systems (such as GPS) couldn’t be directly projected onto Lambert 72. This required complex transformations, increasing the risk of errors and inconsistencies.

To address this issue, the Lambert 2008 coordinate system (EPSG:3812) was introduced. The key differences between Lambert 72 and Lambert 2008 include:

1. Different Geodetic Date and Reference Ellipsoid: Lambert 2008 is based on ETRS89 (European Terrestrial Reference System 1989), which aligns with the INSPIRE directive, a European standard for geospatial data.

2. Better Compatibility with GNSS: Unlike Lambert 72, Lambert 2008 allows for direct integration of satellite positioning data, making it more efficient for modern geospatial applications.

3. Improved Accuracy: The transformation between Lambert 72 and Lambert 2008 introduces only minimal shifts, improving precision for high-resolution mapping.

Adoption of Lambert 2008 in Belgium

The transition from Lambert 72 to Lambert 2008 has been a gradual but significant process. Key organizations have already made the switch:

– Belgian Land Registry (Kadaster): Adopted Lambert 2008 in 2017.

– Walloon Region: Began migrating all spatial data to Lambert 2008 in 2021.

– National Geographic Institute (NGI): Announced that it would no longer support Lambert 72 and has fully transitioned to Lambert 2008

– Flemish Region: Currently undergoing migration, coordinated by Digitaal Vlaanderen.

How do Lambert 72 and Lambert 2008 differ in practice?

When using GIS software, you can view the coordinates of each location on the map. The zero point (origin) of Lambert 72 is located near Beauvais, France. As a result, all coordinates in Belgium appear as positive values.

For example, the coordinates of the Grand Place in Brussels in Lambert 72 are: 📍 X = 148850, Y = 170705

To avoid confusion with the new system, the zero point in Lambert 2008 has been shifted 500000 meters south and west. This means that in Lambert 2008, the same location has the following coordinates: 📍 X = 648850, Y = 670705

Is it as simple as adding 500000 meters?

Not quite… While adding 500000 meters to both X and Y coordinates provides a general transformation, minor variations still exist. These small differences become especially noticeable in precision measurements.

Tests have shown that the average shift per point is around 0,5 mm. While negligible for large-scale mapping, this slight shift matters for high-accuracy datasets like surveying and engineering applications.

Why should you care about Lambert 2008?

If you work with GIS, cartography, or geospatial data in Belgium, understanding the differences between Lambert 72 and Lambert 2008 is crucial. Using outdated coordinate systems can lead to errors in spatial data, inaccurate measurements, and compatibility issues with modern GNSS-based mapping tools.

By transitioning to Lambert 2008, Belgium ensures that its geospatial data is:

✅ More accurate

✅ Compatible with GNSS and European standards

✅ Easier to integrate into international projects

Conclusion: The future of mapping in Belgium

The switch from Lambert 72 to Lambert 2008 reflects Belgium’s commitment to modernizing its geospatial infrastructure. While Lambert 72 served well for decades, new technologies demand better compatibility which Lambert 2008 delivers.

As more regions and institutions complete their migration, Lambert 72 will gradually be phased out. If you haven’t already, now is the time to update your GIS datasets and workflows to ensure seamless integration with Lambert 2008.

Need more information?

If you have questions about Lambert 2008 or need assistance with coordinate transformations, feel free to reach out to us.