The goal of this site is to provide GNSS Vertical Land Motion (VLM) data in the Netherlands for in-situ studies of ground heave and subsidence, calibration and verification of space based InSAR observations, and training of vertical land motion models. The focus is on vertical motion of the top soil layer, using GNSS receivers founded in the top layer, though sometimes additional receivers at a site may be founded in other soil layers to provide information on the relative motion of soil layers (geodetic extensometer).
On Wednesday 8 October, 2025, a new station and extensometer were installed in Moordrecht. The GNSS antenna is mounted on the extensometer and moves along with the top soil plate of the extensometer. The extensometer is operated by Deltares. [8 October 2025]
Conversion and quality checking of data collected from before the station redesign is complete. All available data is now ingested into the system. Station statistics and performance charts are complete, but processing for land motion is pending. Land motion series before the October 2024 station redesign are not yet available. [14 December 2024]
Alpha release of the data portal with provisional land motion time series. Data analysis procedures are not (yet) optimized for handling atmospheric and antenna delays and should be used with caution. Land motion time series, starting October 2024, are updated every Tuesday morning at around 8:00 UTC. [19 November 2024]
The data loggers at Ilperveld were updated and reinstalled on Friday 25 October and Saturday 26 October 2024 All three u-blox GNSS receivers at Ilperveld resumed observations. [26 October 2024]
The receivers and data logger at Zegveld station were reinstalled and switched to AC mains on Tuesday 22 October 2024. Both u-blox GNSS receivers at Zegveld resumed observations. [22 October 2024]
Monday 14 October 2024 the receiver and data logger at Weerribben were upgraded and the station resumed observations. [14 October 2024]
Release 1.0 of the TU Delft ubxlogger software, with hard and software design notes, on Github. [14 October 2024]
TU Delft took over operations of three GNSS vertical land motion sites in the framework of the "Nationaal Onderzoeksprogramma Broeikasgassen Veenweiden" (NOBV). All three sites were deployed by Shore Monitoring and Research; Zegveld in May 2020 with two GNSS receivers, Ilperveld in June 2023 with three receivers, and Weerribben in July 2023 with one receiver. To improve the availability of the stations TU Delft redesigned the receiver data logger hard and software, but without any changes the antenna installation. [2 October 2024]
Information on the stations, availability, latency, completeness, gnss data quality, gnns data and land motion timeseries can be obtained from the following links
or by clicking on one of the stations on the map to the left.
Daily RINEX observation file with 10 second data interval are available through the calendar download button above, directory tree http://gnss1.tudelft.nl/sumo/rinex and anonymous ftp ftp://gnss1.tudelft.nl.
The land motion series is updated every Tuesday morning at 8:00 UTC. Land motion series are only available as graphs. The data analysis procedures are not (yet) optimized for handling atmospheric and antenna delays and should therefore be considered provisional and should be used with caution, especially for longer baselines. More information on the available data products and processing can be found on the data products info page.The stations in Zegveld, Ilperveld en Weerribben use all similar GNSS hardware, with a U-blox ZED-F9P ArduSimple simpleRTK2B board and a U-blox ANN-MB-00 GNSS dualband antenna. The hard and software design is available from Github ubxlogger under an Apache version 2.0 licence.
The data analysis and portal is hardware agnostic. It is not necessary to follow the station hardware design on Github ubxlogger. Any GNSS sensor that provides
Except where otherwise noted, the GNSS station data, land motion timeseries are other content provided on this site
http://dx.oii.org/10.xxx is provided under a
Creative Commons Attribution 4.0 International License (CC-BY 4.0).
Your attribution should include both this site http://dx.oii.org/10.xxx and station owner(s)
given on the station information pages.
ALL DATA IS PROVIDED BY THIS SITE IS "AS IS" WITHOUT WARRANTY OF ANY KIND.
