Purpose

• Validate EUREF combined Zenith Path Delay (ZPD) parameters with ZPD derived from radiosonde (RS) data at co-located sites
• Variations and differences are influenced by the horizontal distance between the two stations
• Time series of differences reflect changes in analysis strategy

Procedure

• Download of RS data provided by EUMETNET, based on the EUREF-EUMETNET MoU
• Processing ZPD parameters (software provided by H. Vedel, Danish Meteorological Institute (DMI))
• Geoid undulations at co-located sites are taken into account
• Differences at co-located sites for identical points in time

GNSS Solutions

• Results from GPS weeks 834 (1996) until 1824 (2014) are based on EPN-repro2 results.
• Results from GPS weeks 1825 (2015) until present are coming from the routine data analysis