Comparison of the Characteristics of Precipitable Water Vapor Measured by Global Positioning System and Microwave Radiometer

  • Sohn, Dong-Hyo ;
  • Park, Kwan-Dong ;
  • Won, Ji-Hye ;
  • Cho, Jung-Ho ;
  • Roh, Kyoung-Min
  • Received : 2011.12.02
  • Accepted : 2012.02.14
  • Published : 2012.03.15


In this study, global positioning system (GPS)-derived precipitable water vapor (PWV) and microwave radiometer (MWR)-measured integrated water vapor (IWV) were compared and their characteristics were analyzed. Comparing those two quantities for two years from August 2009, we found that GPS PWV estimates were larger than MWR IWV. The average difference over the entire test period was 1.1 mm and the standard deviation was 1.2 mm. When the discrepancies between GPS PWV and MWR IWV were analyzed depending on season, the average difference was 0.7 mm and 1.9 mm in the winter and summer months, respectively. Thus, the average difference was about 2.5 times larger in summer than that in winter. However, MWR IWV measurements in the winter months were over-estimated than those in the summer months as the water vapor content got larger. The results of the diurnal analysis showed that MWR IWV was underestimated in the daytime, showing a difference of 0.8 mm. In the early morning hours, MWR IWV has a tendency to be over-estimated, with a difference of 1.3 mm with respect to GPS PWV.


global positioning system;microwave radiometer;precipitable water vapor;diurnal variation


  1. Basili P, Bonafoni S, Mattioli V, Ciotti P, Fionda E, A ground-based microwave radiometer and a GPS network for the remote sensing of atmospheric water vapour content: a year of experimental results, in Workshop on COST Action 720, L'Aquila, Italy, 19-21 Jun 2002.
  2. Bevis M, Businger S, Herring TA, Rocken C, Anthes RA, et al., GPS meteorology: remote sensing of atmospheric water vapor using the global positioning system, JGR, 97, 15787-15801 (1992).
  3. Birkenheuer D, Gutman S, A comparison of GOES moisture-derived product and GPS-IPW data during IHOP-2002, JAtOT, 22, 1838-1845 (2006).
  4. Elliott WP, Gaffen DJ, On the utility of radiosonde humidity archives for climate studies, BAMS, 72, 1507-1520 (1991).<1507:OTUORH>2.0.CO;2<1507:OTUORH>2.0.CO;2
  5. Ha J, Park K-D, Chang K-H, Yang H-Y, Precision validation of GPS precipitable water vapor via comparison with MWR measurements, Atmosphere, 17, 291-298 (2007).
  6. Ha J, Park K-D, Heo B-H, Development of a local mean temperature equation for GPS-based precipitable water vapor over the Korean peninsula, JASS, 23, 373-384 (2006).
  7. Janes HW, Lagley RB, Newby SP, Analysis of tropospheric delay prediction models: comparisons with ray-tracing and implications for GPS relative positioning, BGeod, 65, 151-161 (1991).
  8. Jeon E-H, Kim Y-H, Kim K-H, Lee H-S, Operation and application guidance for the ground based dual-band radiometer, Atmosphere, 18, 441-458 (2008).
  9. Jones J, Nowcasting applications of GPS water vapour networks, in E-GVAP Workshop, Denmark Meteorological Institute, Copenhagen, Denmark, 6 Nov 2008.
  10. Kwon H-T, Iwabuchi T, Lim G-H, Comparison of precipitable water derived from ground-based GPS measurements with radiosonde observations over the Korean Peninsula, J Meteor Soc Jpn, 85, 733-746 (2007). 10.2151/jmsj.85.733
  11. Liou Y-A, Teng Y-T, Hove TV, Liljegren JC, Comparison of precipitable water observations in the near tropics by GPS, microwave radiometer, and radiosondes, JApMe, 40, 5-15 (2001).<0005:COPWOI>2.0.CO;2<0005:COPWOI>2.0.CO;2
  12. Moon Y-J, Choi K-H, Park P-H, Estimation of precipitable water vapor using the GPS, JASS, 16, 61-68 (1999).
  13. Morland J, Collaud Coen M, Hocke K, Jeannet P, Maetzler C, Tropospheric water vapour above Switzerland over the last 12 years, ACP, 9, 5975-5988 (2009).
  14. Motell C, Porter J, Foster J, Bevis M, Businger S, Comparison of precipitable water over Hawaii using AVHRR-based split-window techniques, GPS and radiosondes, IJRS, 23, 2335-2339 (2002). 01431160110069944
  15. Ninomiya K, Dynamic meteorology essence (Sigma Press, Seoul, 2003), 130-132.
  16. Pacione R, Fionda E, Ferrara R, Lanotte R, Sciarretta C, et al., Comparison of atmospheric parameters derived from GPS, VLBI and a ground-based microwave radiometer in Italy, PCE, 27, 309-316 (2002). 10.1016/S1474-7065(02)00005-0
  17. Park C-G, Baek J, Cho, J, Analysis on characteristics of radiosonde bias using GPS precipitable water vapor, JASS, 27, 213-220 (2010).
  18. Prasad AK, Singh RP, Validation of MODIS Terra, AIRS, NCEP/DOE AMIP-II Reanalysis-2, and AERONET Sun photometer derived integrated precipitable water vapor using ground-based GPS receivers over India, JGR, 114, D05107 (2009).
  19. Richardson SJ, Guichard F, Lesht BM, The radiative impact of the radiosonde relative humidity bias, in 10th ARM Science Team Meeting Proceedings, San Antonio, TX, 13-17 Mar 2000.
  20. Rose T, Crewell S, Loehnert U, Simmer C, A network suitable microwave radiometer for operational monitoring of the cloudy atmosphere, AtmRe, 75, 183-200 (2005).
  21. Rose T, Czekala H, RPG-HATPRO operating manual version 7.88 (Printing Radiometer Physics Gmbh, Meckenheim, Germany, 2009), 1-239.
  22. Turner DD, Lesht BM, Clought SA, Liljegren JC, Revercomb HE, et al., Dry bias and variability in Vaisala RS80-H radiosondes: the ARM experience, JAtOT, 20, 117-132 (2003).< 0117:DBAVIV>2.0.CO;2<0117:DBAVIV>2.0.CO;2
  23. Wang J, Cole HL, Carlson DJ, Miller ER, Beierle K, et al., Corrections of humidity measurement errors from the Vaisala RS80 radiosonde-application to TOGA COARE data, JAtOT, 19, 981-1002 (2002). 1520-0426(2002)019<0981:COHMEF>2.0.CO;2<0981:COHMEF>2.0.CO;2
  24. Wang J, Zhang L, Systematic errors in global radiosonde precipitable water data from comparisons with ground-based GPS measurements, JCli, 21, 2218-2238 (2008).
  25. Webb FH, Zumberge JF, An introduction to the GIPSY/OASIS II (Jet Propulsion Laboratory, Pasadena, 1993), D-11088.
  26. Westwater ER, Falls MJ, Popa Fotino IA, Ground-based microwave radiometric observations of precipitable water vapor: a comparison with ground truth from two radiosonde observing systems, JAtOT, 6, 724-730 (1989).<0724:GBMROO>2.0.CO;2<0724:GBMROO>2.0.CO;2
  27. Won J, Park K-D, Ha J, Cho J, Effects of tropospheric mapping functions on GPS data processing, JASS, 27, 21-30 (2010).

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Supported by : National Research Foundation of Korea (NRF)