PRODUCTS & SERVICES > TROPOSPHERIC DELAYS
New results including EPN-REPRO1 available!!

Introduction

Since June 2001 (GPS week 1110) Zenith Path Delay (ZPD) parameters are estimated for all EPN stations as part of the routine EPN operation. A combined EPN solution is produced on a weekly basis using the daily SINEX TRO files of the EPN Local Analysis Centres (LACs).
As the result of the combination two files for each week 'wwww' are produced:

The troposphere files from routine operation for the LACs as well as for the combined solution, starting with GPS week 1110, can be downloaded from the EUREF product directory at BKG data centre.
Since 2011, the first EPN reprocessing (EPN REPRO 1) is completed. The reprocessing covers the years 1996 until end of 2006. Similar to the operational products, two files from weekly combination are available: EU0wwww7.TRO and EU0wwww7.TSU. Note that the number and composition of the LACs in the reprocessing for each EPN station may differ from the routine operation.
The troposphere files from EPN REPRO 1 for the LACs as well as for the combined solution, covering the GPS weeks 0834 to 1407 (up to week 1585 for few individual solutions), can be downloaded from BKG data centre as well, using the EUREF repro1 directory.

Products

ZPD time series / monthly mean

ZPD biases time series

ZPD radiosonde time series

Zenith Path Delay time series extracted from weekly EPN troposphere combined solution.

Time series of Zenith Path Delay biases for the participating LACs.

Zenith Path Delay differences radiosonde data minus EUREF combination.
Updated weekly Updated weekly Updated weekly

Purpose :

  • Show time series of ZPD parameters derived from the EPN combined solution

Purpose :

  • Show the agreement of the individual EPN LACs ZPD solutions

  • Visualize potential periodic signals

  • Reflect changes in, e.g. used options, analysis procedures etc

Purpose :

  • Validate EUREF combined Zenith Path Delay (ZPD) parameters with ZPD derived from radiosonde (RS) data at co-located stations

  • Variations and differences are influenced by the horizontal distance between the two stations

  • Time series of differences reflect changes in analysis strategy

Procedure :

  • Combination of daily SINEX TRO files of the individual LACs solutions on a weekly basis

  • Weak ZPD estimates of the individual LACs solutions are excluded beforehand because of a standard deviation exceeding 15 mm

  • Outliers of the individual LACs solutions are excluded before the combination

  • Site-specific solutions of a particular LAC are eliminated for single days if the standard deviation of the series exceeds 20 mm

  • Single ZPD values of the combined solution exceeding a standard deviation of 20 mm are investigated for potential outliers

Procedure :

  • EPN LACs are delivering estimated ZPD parameters on a daily basis

  • These solutions are combined to the EPN combined (mean) solution considering the biases between the individual solutions (this way jumps will be avoided if single observations of the individual solutions are missing)

  • The resulting daily biases show the agreement of the LACs individual solutions to each other and to the mean

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 stations are taken into account

  • Differences at co-located stations for identical points in time

envel  EPN Central Bureau - Royal Observatory of Belgium Disclaimer and Copyright Jan 21, 2013