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Contact Information Regarding Products

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Help with and information about our products is available for each of the topical areas served by this portal.  Please select the topical area to get to a information request form for that class of products.


Time Products

GPS timing, Loran-C, Two-Way Satellite Time Transfer (TWSTT), Network Time Protocol (NTP), and technical information about USNO timing products.

Earth Orientation Products

Polar motion, UT1-UTC, celestial pole offsets, long-term Delta T, 24-hour and 48-hour sets of GPS satellite orbits, satellite and receiver clock solutions, earth orientation parameters, and UTGPS (GPS-based UT1-like quantity).

Astronomy Products

Astronomical phenomena, astronomical data services, astronomical software products, almanacs, astrometric catalogs (NOMAD/UCAC/USNO-B1), imaging data (PMM/RRFID), double star catalogs (WDS), reference frames (CRF/TRF).

Meteorology Products

Meteorology product help.

Oceanography Products

Oceanography product help.

Ice Products

National Ice Center for links to product help.