GNSS IGS Ionosphere VTEC Maps: Global 2-Hour Resolution

NASA CDDIS provides daily Vertical Total Electron Content (VTEC) maps derived from multiple Global Navigation Satellite Systems, including GPS, GLONASS, Galileo, and Beidou. Analysis Centers compute these maps with a spatial resolution of 5 degrees in longitude and 2.5 degrees in latitude, and a temporal resolution of 2 hours in Universal Time. The final IGS product has a latency of 3-7 days, while a rapid version is available within 1-2 days.

Use Cases

• Modeling ionospheric disturbances for satellite signal correction based on VTEC maps.
• Analyzing global electron density variations over time using the 2-hour resolution data.
• Calibrating GNSS receiver and satellite hardware biases using the included Delay Code Bias (DCB) values.
• Validating space weather forecast models against observed VTEC from a multi-constellation GNSS network.

Strengths

• Data incorporates observations from a global multi-constellation GNSS network, including systems operational since 2011.
• Products have defined spatial (5° lon, 2.5° lat) and temporal (2-hour) resolutions.
• Cross-platform presence on NASA and government portals indicates established importance and reliability.

Limitations

• Specific column names and dataset size (row count, file size) are not provided by any source.
• Sources conflict on product latency: one describes a 3-7 day latency for the final product, another a 1-2 day latency for a rapid product.
• License is ambiguously listed as 'other-license-specified' without explicit terms.

Provenance

Source

NASA Crustal Dynamics Data Information System (CDDIS), generated by International GNSS Service (IGS) Analysis Centers.

Collection Method

Derived from GNSS observations retrieved from a global ground receiver network and processed by IGS Analysis Centers to produce VTEC maps.

Time Range

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Freshness

Last updated on 2026-04-10 according to datagov.

Geography

Global coverage.