Global Ground-Based GPS Precipitable Water Measurements at 2-Hour Intervals

NCAR global, 2-hourly GPS precipitable water data are derived from ground-based GPS measurements of zenith path delay. The dataset combines measurements from the International GNSS Service (since 1995), U.S. SuomiNet (since 2002), and the Japanese GEONET network (approximately 1100 stations from 1997 to 2005). The data are provided by SCIOPS, with the last known update in December 2012.

Use Cases

• Analyze long-term trends in atmospheric precipitable water from the IGS tropospheric product time series starting in 1995.
• Validate satellite-derived water vapor estimates using ground-based GPS zenith path delay measurements from the GEONET network's ~1100 stations.
• Study regional water vapor variability by comparing data from the SuomiNet network with the combined IGS and SuomiNet product.
• Assimilate 2-hourly precipitable water observations from multiple GPS networks into numerical weather prediction models.

Strengths

• Long temporal coverage, with some data streams beginning in 1995.
• Combines data from three major GPS networks, including the dense Japanese GEONET network of approximately 1100 stations.
• Provides high temporal resolution data at 2-hour intervals.

Limitations

• Data freshness is limited, with the last known update in December 2012.
• The GEONET component has a restricted time range, covering only 1997 to 2005.
• Specific details on data volume (rows, size) and column structure are unavailable.

Provenance

Source

National Center for Atmospheric Research (NCAR).

Collection Method

Derived from ground-based GPS measurements of zenith path delay from the IGS, SuomiNet (UCAR/COSMIC), and GEONET networks.

Time Range

1995 to approximately 2012 (IGS/SuomiNet); 1997 to 2005 (GEONET).

Freshness

Planned to be updated yearly, but last known update was in 2012.

Geography

Global, with stations from the IGS, U.S. SuomiNet, and Japanese GEONET networks.