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Real-time national GPS networks: Opportunities for atmospheric sensing

  • The Correction to this article has been published in Earth, Planets and Space 2019 71:46


Real-time national Global Positioning System (GPS) networks are being established in a number of countries for atmospheric sensing. UCAR, in collaboration with participating universities, is developing one of these networks in the United States. The network, named “SuomiNet” to honor meteorological satellite pioneer Verner Suomi, is funded by the U.S. National Science Foundation. SuomiNet will exploit the recently-shown ability of ground-based GPS receivers to make thousands of accurate upper and lower atmospheric measurements per day. Phase delays induced in GPS signals by the ionosphere and neutral atmosphere can be measured with high precision simultaneously along up to a dozen GPS ray paths in the field of view. These delays can be converted into total electron content (TEC), and integrated water vapor (if surface pressure data or estimates are available), along each GPS ray path. The resulting continuous, accurate, all-weather, real-time upper and lower atmospheric data create a variety of opportunities for atmospheric research. In this letter we describe SuomiNet, its applications, and the opportunity to coordinate national real-time GPS networks to create a global network with larger scientific and operational potential.


  1. Alber, C., R. Ware, C. Rocken, and J. Braun, Obtaining single path phase delays from GPS double differences, Geophys. Res. Lett., 27, 2661–2664, 2000.

  2. Bevis, M., S. Businger, T. Herring, C. Rocken, R. Anthes, and R. Ware, GPS meteorology: Remote sensing of atmospheric water vapor using the global positioning system, J. Geophys. Res., 97, 15,787–15,801, 1992.

  3. Bevis, M., S. Businger, S. Chiswell, T. Herring, R. Anthes, C. Rocken, and R. Ware, GPS meteorology: Mapping zenith wet delays onto precipitable water, J. Appl. Meteor., 33, 379–386, 1994.

  4. Braun, J., C. Rocken, and R. Ware, Validation of single slant water vapor measurements with GPS, Radio Sci., 2000 (in press).

  5. Brooks, I., D. Rogers, and L. Regier, The Scripps Institution of Oceanography Marine Observatory: A Platform for Real-Time Measurements of the Coastal Ocean and Atmosphere, 16th International Conference on Interactive Information and Processing Systems (IIPS) for Meteorology, Oceanography, and Hydrology, Long Beach, CA, Jan. 9–14, 2000.

  6. Chen, G. and T. Herring, Effects of atmospheric azimuthal asymmetry on the analysis of space geodetic data, J. Geophys. Res., 102, 20,489–20,502, 1996.

  7. Dodson, A., C. Wu, N. Penna, and H. Baker, GPS Estimation of Atmospheric Water Vapour from a Moving Platform, IUGG99, Birmingham, U.K., July 18–30, 1999.

  8. Domenico, B., S. Bates, and D. Fulker, Unidata Internet Data Distribution (IDD), Proceedings, Tenth International Conference on Interactive Information and Processing Systems for Meteorology, Oceanography and Hydrology, Am. Met. Soc., J15–J20, 1994.

  9. Duan, J., M. Bevis, P. Fang, Y. Bock, S. Chiswell, S. Businger, C. Rocken, F. Solheim, T. Van Hove, R. Ware, S. McClusky, T. Herring, and R. King, GPS meteorology: Direct estimation of the absolute value of precipitable water vapor, J. Appl. Meteor., 35, 830–838, 1996.

  10. Flores, A., G. Ruffini, and A. Rius, 4D tropospheric tomography using GPS slant wet delays, Ann. Geophysicae, 18, 223–234, 2000.

  11. Haines, B. J. and Y. E. Bar-Sever, Monitoring the TOPEX microwave radiometer with GPS: Stability of columnar water vapor measurements, Geophys. Res. Lett., 25, 3563–3566, 1998.

  12. Hanssen, R., T. Weckworth, H. Zebker, and R. Klees, High-resolution water vapor mapping from interferometric radar measurements, Science, 283, 1297–1299, 1999.

  13. Hirahara, K., Local GPS tropospheric tomography, Earth Planets Space, 52, this issue, 935–939, 2000.

  14. Ho, C., A. Mannucci, U. Lindqwister, S. Pi, and B. Tsuritani, Global ionosphere perturbations monitored by the worldwide GPS network, Geophys. Res. Lett., 23, 3219–3222, 1996.

  15. Howe, B., K. Runciman, and J. Secan, Tomography of the ionosphere: Four-dimensional simulations, Radio Sci., 33, 109–128, 1998.

  16. Juan, J. M., A. Rius, M. Hernandes-Pajares, and J. Sanz, A two-layer model of the ionosphere using Global Positioning System data, Geophys. Res. Lett., 24, 393–396, 1997.

  17. MacDonald, A. and Y. Xie, On the Use of Slant Observations from GPS to Diagnose Three Dimensional Water Vapor Using 3DVAR, Proc. 4th Integrated Observing Systems Symp. (Amer. Met. Soc.), Long Beach CA, 62–73, 2000.

  18. MacDonald, A., Y. Xie, and R. Ware, Diagnosis of three dimensional water vapor using slant observations from a GPS network, Bull. Am. Meteor. Soc., 2000 (in preparation).

  19. Niell, A., Global mapping functions for the atmosphere delay at radio wavelengths, J. Geophys. Res., 101, 3227–3246, 1996.

  20. Roads, J., S.-C. Chen, A. Guetter, and K. Georgakakos, Large-scale aspects of the united states hydrological cycle, Bull. Am. Meteor. Soc., 75, 1589–1610, 1994.

  21. Rocken, C., R. Ware, T. Van Hove, F. Solheim, C. Alber, and J. Johnson, Sensing atmospheric water vapor with the global positioning system, Geophys. Res. Lett., 20, 2631–2634, 1993.

  22. Rocken, C., T. Van Hove, and R. Ware, Near real-time sensing of atmospheric water vapor, Geophys. Res. Lett., 24, 3221–3224, 1997.

  23. Seko, H., H. Nakamura, T. Kato, and S. Shimada, Estimation of three dimensional distribution of moisture based on GPS precipitable water in meso-scale system in baiu season, Earth Planets Space, 52, this issue, 927–933, 2000.

  24. Segall, P. and J. Davis, GPS applications for geodynamics and earthquake studies, Annu. Rev. Earth Planet. Sci., 25, 301–336, 1997.

  25. Stevens, M., Optimal climate signal detection in four dimensions, J. Geophys. Res., 104, 4089–4099, 1999.

  26. Stokes, G. and S. Schwartz, The Atmospheric Radiation Measurement (ARM) program: Programmatic background and design of the cloud and radiation test bed, Bull. Am. Meteor. Soc., 119, 153–186, 1994.

  27. Trenberth, K. and C. Guillemot, Evaluation of the Atmospheric Moisture and Hydrological Cycle in the NCEP Reanalyses, NCAR Technical Note TN-430, December, 1996.

  28. Ware, R., M. Exner, D. Feng, M. Gorbunov, K. Hardy, B. Herman, H. K. Kuo, T. Meehan, W. Melbourne, C. Rocken, W. Schreiner, S. Sokolovskiy, F. Solheim, X. Zou, R. Anthes, S. Businger, and K. Trenberth, GPS sounding the atmosphere from low Earth orbit, preliminary results, Bull. Am. Meteor. Soc., 77, 19–40, 1996.

  29. Ware, R., C. Alber, C. Rocken, and F. Solheim, Sensing integrated water vapor along GPS ray paths, Geophys. Res. Lett., 24, 417–420, 1997.

  30. Ware, R., D. Fulker, S. Stein, D. Anderson, S. Avery, R. Clark, K. Droegemeier, J. Kuettner, J. Minster, and S. Sorooshian, SuomiNet: A real-time national GPS network for atmospheric research and education, Bull. Am. Meteor. Soc., 81, 677–694, 2000.

  31. Yuan, L., R. Anthes, R. Ware, C. Rocken, W. Bonner, M. Bevis, and S. Businger, Sensing climate change using the global positioning system, J. Geophys. Res., 98, 14,925–14,937, 1993.

  32. Zebker, H., P. Rosen, and S. Hensley, Atmospheric effects in interferometric synthetic radar surface deformation and topographic maps, J. Geophys. Res., 102, 7547–7563, 1997.

  33. Zumberge, J., D. Fulton, and R. Neilan, editors, International GPS Service 1996 Annual Report, IGS Central Bureau, Jet Propulsion Laboratory, Pasadena, CA, 1997.

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Correspondence to Randolph H. Ware.

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Ware, R.H., Fulker, D.W., Stein, S.A. et al. Real-time national GPS networks: Opportunities for atmospheric sensing. Earth Planet Sp 52, 901–905 (2000).

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  • Global Position System
  • Total Electron Content
  • Synthetic Aperture Radar Image
  • Global Position System Data
  • Global Position System Receiver