Abstract. The global INTERMAGNET network provides the scientific community with geomagnetic time series data from its more than 100 member observatories. These time series include near real-time data (Reported) as well as delayed data products, such as Quasi-Definitive (QD) and Definitive (DD) data. QD data is published online with a delay of up to three months, while DD data become available on the INTERMAGNET website after the end of each calendar year. Additionally, the DD data and metadata are published with a unique identifier (DOI). DD data publications cover the records since 1991, and occasionally include updates of previously published DD datasets. All datasets are publicly accessible online.

QD and DD data allow the analysis of both short-term magnetic field variations and long-term secular variation. Monitoring these long-term changes distinguishes INTERMAGNET from other networks that focus primarily on short-term geomagnetic variations.

INTERMAGNET ensures high-quality DD geomagnetic data through a rigorous two-stage, peer-reviewed quality control process. Although this process delays publication, it guarantees the final DD datasets' highest possible accuracy and reliability.

This article discusses key aspects of the collection, processing, and publication of DD data within the INTERMAGNET network.