• Beutler, G., and Coauthors, 1996: Bernese GPS Software Version 4.0. University of Berne, 418 pp.

  • Bevis, M., S. Businger, T. A. Herring, C. Rocken, R. A. Anthes, and R. H. Ware, 1992: GPS meteorology: Remote sensing of atmospheric water vapor using the Global Positioning System. J. Geophys. Res.,97, 15 784–15 801.

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

  • Businger, S., and Coauthors, 1996: The promise of GPS in atmospheric monitoring. Bull. Amer. Meteor. Soc.,77, 5–18.

  • Duan, J., and Coauthors, 1996: GPS meteorology: Direct estimation of the absolute value of precipitable water. J. Appl. Meteor.,35, 830–838.

  • Elgered, G., J. L. Davis, T. A. Herring, and I. I. Shapiro, 1991: Geodesy by radio interferometry: Water vapor radiometry for estimation of the wet delay. J. Geophys. Res.,96, 6541–6555.

  • Emardson, T. R., G. Elgered, and J. Johansson, 1998: Three months of continuous monitoring of atmospheric water vapor with a network of GPS receivers. J. Geophys. Res.,103, 1807–1820.

  • Han, Y., and E. R. Westwater, 2000: Analysis and improvement of tipping calibration for ground-based microwave radiometers. IEEE Trans. Geosci. Remote Sens.,38, 1260–1276.

  • Leick, A., 1995: GPS Satellite Surveying. John Wiley and Sons, 560 pp.

  • Lesht, B., 1997: An internal analysis of SGP/CART radiosonde performance during WVIPO-96. Sixth Atmospheric Radiation Measurement Program Science Team Meeting, San Antonio, TX, U.S. Department of Energy, 59–62.

  • Liljegren, J., 1999: Automatic self-calibration of ARM microwave radiometers. Microwave Radiometry and Remote Sensing of the Earth’s Surface and Atmosphere, P. Pampaloni and S. Paloscia, Eds., VSP, 552 pp.

  • Liljegren, J., B. Lesht, E. Westwater, and Y. Han, 1997: A comparison of integrated water vapor sensors: WVIOP-96. Sixth Atmospheric Radiation Measurement Program Science Team Meeting, San Antonio, TX, U.S. Department of Energy, 1–4.

  • Liljegren, J., B. Lesht, T. Van Hove, and C. Rocken, 1999: A comparison of integrated water vapor from microwave radiometer, balloon-borne sounding system and Global Positioning System. Ninth Atmospheric Radiation Measurement Program Science Team Meeting, San Antonio, TX, U.S. Department of Energy, 1–8.

  • Liou, Y.-A., 1999: Ground-based radiometric sensing of atmospheric dynamics in precipitable water vapor. Atmos. Sci.,27, 141–158.

  • Liou, Y.-A., C.-Y. Huang, and Y.-T. Teng, 2000: Precipitable water observed by ground-based GPS receivers and microwave radiometry. Earth Planets Space,52, 445–450.

  • Plana-Fattori, A., M. Legrand, D. Tanre, C. Devaux, and A. Vermeulen, 1998: Estimating the atmospheric water vapor content from sun photometer measurements. J. Appl. Meteor.,37, 790–804.

  • Radiometrics, 1997: WVR-1100 Water Vapor and Liquid Water Radiometer. Radiometrics Corporation, 30 pp. [Available from Radiometrics Corporation, 2840 Wilderness Place, Unit G, Boulder, CO 80301-5414.].

  • Rocken, C., R. Ware, T. Van Hove, F. Solheim, C. Alber, J. Johnson, M. Bevis, and S. Businger, 1993: Sensing atmospheric water vapor with the Global Positioning System. Geophys. Res. Lett.,20, 2631–2634.

  • Rocken, C., T. Van Hove, J. Johnson, F. Solheim, R. Ware, M. Bevis, S. Businger, and S. Chiswell, 1995: GPS/STORM—GPS sensing of atmospheric water vapor for meteorology. J. Atmos. Oceanic Technol.,12, 468–478.

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

  • Ross, R. J., and S. Rosenfeld, 1997: Estimating mean weighted temperature of the atmosphere for Global Positioning System applications. J. Geophys. Res.,102, 21 719–21 730.

  • Schroeder, J. A., and E. R. Westwater, 1991: Users’ guide to WPL microwave radiative transfer software. NOAA Tech. Memo. ERL WPL-213, 84 pp.

  • Sierk, B., B. Burki, H. Becker-Ross, S. Florek, R. Neubert, L. P. Kruse, and H. Kahle, 1997: Tropospheric water vapor derived from solar spectrometer, radiometer, and GPS measurements. J. Geophys. Res.,102, 22 411–22 424.

  • Solheim, F., 1993: Use of pointed water vapor radiometer observations to improve vertical GPS surveying accuracy. Ph.D. dissertation, University of Colorado, 128 pp. [Available from Radiometrics Corporation, 2840 Wilderness Place, Unit G, Boulder, CO 80301-5414.].

  • Solheim, F., J. R. Godwin, E. R. Westwater, Y. Han, S. J. Keihm, K. Marsh, and R. Ware, 1998: Radiometric profiling of temperature, water vapor and cloud liquid water using various inversion methods. Radio Sci.,33, 393–404.

  • Stokes, G. M., and S. E. Schwartz, 1994: The Atmospheric Radiation Measurement (ARM) Program: Programmatic background and design of the Cloud and Radiation Testbed. Bull. Amer. Meteor. Soc.,75, 1201–1221.

  • Tregoning, P., R. Boers, D. O’Brien, and M. Hendy, 1998: Accuracy of absolute precipitable water vapor estimates from GPS observations. J. Geophys. Res.,103, 28 701–28 710.

  • Westwater, E. R., 1978: The accuracy of water vapor and cloud liquid determinations by dual-frequency ground-based microwave radiometry. Radio Sci.,13, 677–685.

  • Westwater, E. R., and Coauthors, 1999: Ground-based remote sensor observations during PROBE in the tropical western Pacific. Bull. Amer. Meteor. Soc.,80, 257–270.

  • Zhang, G., J. Vivekanandan, and M. K. Politovich, 1999: Scattering effects on microwave passive remote sensing of cloud parameters. Preprints, Eighth Conf. on Aviation, Range, and Aerospace Meteorology, Dallas, TX, Amer. Meteor. Soc., 497–501.

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Comparison of Precipitable Water Observations in the Near Tropics by GPS, Microwave Radiometer, and Radiosondes

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  • a Center for Space and Remote Sensing Research, and Institute of Space Sciences, National Central University, Chungli, Taiwan
  • | b GPS Science and Technology, University Corporation for Atmospheric Research, Boulder, Colorado
  • | c Environmental Research Division, Argonne National Laboratory, Argonne, Illinois
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Abstract

The sensing of precipitable water (PW) using the Global Positioning System (GPS) in the near Tropics is investigated. GPS data acquired from the Central Weather Bureau’s Taipei weather station in Banchao (Taipei), Taiwan, and each of nine International GPS Service (IGS) stations were utilized to determine independently the PW at the Taipei site from 18 to 24 March 1998. Baselines between Taipei and the other nine stations range from 676 to 3009 km. The PW determined from GPS observations for the nine baseline cases are compared with measurements by a dual-channel water vapor radiometer (WVR) and radiosondes at the Taipei site. Although previous results from other locations show that the variability in the rms difference between GPS- and WVR-observed PW ranges from 1 to 2 mm, a variability of 2.2 mm is found. The increase is consistent with scaling of the variability with the total water vapor burden (PW). In addition, accurate absolute PW estimates from GPS data for baseline lengths between 1500 and 3000 km were obtained. Previously, 500 and 2000 km have been recommended in the literature as the minimum baseline length needed for accurate absolute PW estimation. An exception occurs when GPS data acquired in Guam, one of the nine IGS stations, were utilized. This result is a possible further indication that the rms difference between GPS- and WVR-measured PW is dependent on the total water vapor burden, because both Taipei and Guam are located in more humid regions than the other stations.

Corresponding author address: Dr. Yuei-An Lou, Center for Space and Remote Sensing Research, National Central University, Chungli 320, Taiwan.

yueian@csrsr.ncu.tw

Abstract

The sensing of precipitable water (PW) using the Global Positioning System (GPS) in the near Tropics is investigated. GPS data acquired from the Central Weather Bureau’s Taipei weather station in Banchao (Taipei), Taiwan, and each of nine International GPS Service (IGS) stations were utilized to determine independently the PW at the Taipei site from 18 to 24 March 1998. Baselines between Taipei and the other nine stations range from 676 to 3009 km. The PW determined from GPS observations for the nine baseline cases are compared with measurements by a dual-channel water vapor radiometer (WVR) and radiosondes at the Taipei site. Although previous results from other locations show that the variability in the rms difference between GPS- and WVR-observed PW ranges from 1 to 2 mm, a variability of 2.2 mm is found. The increase is consistent with scaling of the variability with the total water vapor burden (PW). In addition, accurate absolute PW estimates from GPS data for baseline lengths between 1500 and 3000 km were obtained. Previously, 500 and 2000 km have been recommended in the literature as the minimum baseline length needed for accurate absolute PW estimation. An exception occurs when GPS data acquired in Guam, one of the nine IGS stations, were utilized. This result is a possible further indication that the rms difference between GPS- and WVR-measured PW is dependent on the total water vapor burden, because both Taipei and Guam are located in more humid regions than the other stations.

Corresponding author address: Dr. Yuei-An Lou, Center for Space and Remote Sensing Research, National Central University, Chungli 320, Taiwan.

yueian@csrsr.ncu.tw

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