SLR Normal Points: Hourly and Monthly Satellite Laser Ranging Data

NASA CDDIS ground-based Satellite Laser Ranging data provides unambiguous range measurements with millimeter precision from a global network of stations. Analysis of these normal points contributes to the terrestrial reference frame, Earth's gravitational field modeling, and monitoring of the Earth's center of mass. The data supports precise orbit determination for altimeter missions and tests of General Relativity.

Use Cases

• Determining precise satellite orbits based on unambiguous range measurements.
• Modeling spatial and temporal variations in Earth's gravitational field using station position time series.
• Monitoring millimeter-level variations in Earth's center of mass location for geophysical studies.
• Contributing to the International Terrestrial Reference Frame (ITRF) using station position and velocity data.
• Performing sub-nanosecond global time transfer and tests of General Relativity.

Strengths

• Data provides unambiguous range measurements with millimeter precision, a unique capability among space geodetic techniques.
• Sourced from the authoritative NASA Crustal Dynamics Data Information System (CDDIS) and the International Laser Ranging Service network.
• Available in both hourly and monthly aggregated (normal point) files, offering different temporal resolutions.

Limitations

• Column names and specific data schema are not provided in the source metadata, limiting immediate understanding of the data structure.
• One source lists a last update date in the future (2026-04-10), indicating a potential metadata conflict or error.
• The license is vaguely specified as 'other-license-specified' without clear terms for reuse.

Provenance

Source

NASA Crustal Dynamics Data Information System (CDDIS), International Laser Ranging Service (ILRS) global network.

Collection Method

Ground-based Satellite Laser Ranging (SLR) observations aggregated into normal points.

Freshness

2026-04-10 02:15:28.554900 (Note: This is a future date, indicating a potential metadata error)

Geography

Global network of SLR stations.