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Global Navigation Satellite System (GNSS) Troposphere Zenith Path Delay (ZPD) product (Version 1) from NASA CDDIS

Metadata Updated: December 6, 2023

This derived product set consists of version 1 of the Global Navigation Satellite System Final Troposphere Zenith Path Delay (ZPD) Product (daily files by station) from the NASA Crustal Dynamics Data Information System (CDDIS). GNSS provide autonomous geo-spatial positioning with global coverage. GNSS data sets from ground receivers at the CDDIS consist primarily of the data from the U.S. Global Positioning System (GPS) and the Russian GLObal NAvigation Satellite System (GLONASS). Analysis Centers (ACs) of the International GNSS Service (IGS) retrieve GNSS data on regular schedules to produce troposphere ZPD estimates for stations of the IGS network. The primary troposphere products generated from ground-based GNSS data are estimates of total zenith path delay and north/east troposphere gradient. Ancillary measurements of surface pressure and temperature allow the extraction of precipitable water vapor from the total zenith path delay. The IGS Troposphere Analysis Center Coordinator (ACC) used these individual AC solutions to generate the official version 1 of the IGS troposphere ZPD estimates for many of the stations in the IGS network. The final products consisted of daily files containing data from each observing station. All ZPD solution files utilize the Solution INdependent EXchange format for combination of TROpospheric estimates (SINEX_TRO) and span 24 hours from 00:00 to 23:45 UTC. In late 2006, a new version of the troposphere combination has been generated by the IGS Troposphere Analysis Center Coordinator. More information about the new version can be found under collection CDDIS_GNSS_IGSTroposphereZPD_product.

Access & Use Information

Public: This dataset is intended for public access and use. License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

Downloads & Resources


Metadata Created Date November 12, 2020
Metadata Updated Date December 6, 2023

Metadata Source

Harvested from NASA Data.json

Additional Metadata

Resource Type Dataset
Metadata Created Date November 12, 2020
Metadata Updated Date December 6, 2023
Identifier C1708941255-CDDIS
Data First Published 2000-01-01
Language en-US
Data Last Modified 2023-03-18
Category IGS, geospatial
Public Access Level public
Bureau Code 026:00
Metadata Context
Metadata Catalog ID
Schema Version
Catalog Describedby
Citation Archived by National Aeronautics and Space Administration, U.S. Government, NASA/GSFC/SED/ESD/GGL/CDDIS.
Harvest Object Id 6c95e27e-f335-4c54-a4a8-fc527eb20451
Harvest Source Id 58f92550-7a01-4f00-b1b2-8dc953bd598f
Harvest Source Title NASA Data.json
Homepage URL
Metadata Type geospatial
Program Code 026:001
Source Datajson Identifier True
Source Hash 661ffe047d5e122231f2f3ee59ee0154528791d4a1dbdbafd8bf9576ca32ee01
Source Schema Version 1.1
Temporal 1997-01-01T00:00:00Z/2023-03-27T00:00:00Z

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