NASA CDDIS GNSS Broadcast Ephemeris: Daily Satellite Orbit Data

NASA's Crustal Dynamics Data Information System archives daily broadcast ephemeris files from a global network of ground receivers tracking multiple satellite constellations. Since 2011, the archive has expanded beyond GPS and GLONASS to include Europe's Galileo, China's Beidou, and other global navigation systems. Each daily file contains broadcast navigation data in the standard RINEX format for a single ground station.

Use Cases

• Precise point positioning calculations based on broadcast satellite orbit and clock parameters.
• Studying crustal motion and plate tectonics using derived geodetic coordinates from a global receiver network.
• Analyzing satellite constellation performance and signal structure across multiple GNSS systems.
• Calibrating satellite-based augmentation systems (SBAS) using ground-truth ephemeris data.

Strengths

• Data originates from the authoritative NASA CDDIS archive, a primary node for the International GNSS Service.
• Includes a multi-constellation record from 2011 onward, covering GPS, GLONASS, Galileo, Beidou, QZSS, IRNSS, and SBAS.
• Files are provided in the standardized, interoperable RINEX format, widely used in geodesy.

Limitations

• Critical metadata is missing: specific column names, row counts, and file sizes are not provided on any platform.
• A conflict exists between platform descriptions: one specifies 'GPS' data, while another specifies 'Galileo' data, creating ambiguity about the primary content.
• License is vaguely listed as 'other-license-specified' without explicit terms.

Provenance

Source

NASA Crustal Dynamics Data Information System (CDDIS)

Collection Method

Collected from a global permanent network of ground-based GNSS receivers.

Time Range

null

Freshness

Last updated metadata date is 2026-04-10, though this may refer to catalog refresh rather than data currency.

Geography

Global coverage from the permanent ground receiver network.