Atmospheric water vapor measurements: Comparison of microwave radiometry and lidar

The NASA/GSFC Crustal Dynamics Project microwave water vapor radiometer (J03) is evaluated in terms of measurements of the integrated precipitable water vapor content of a particular column of the troposphere. The measurements were taken during the Atmospheric Moisture Intercomparison Study (ATMIS) held at Wallops Island, Virginia, during April 1989. Various water vapor sensing instruments were used during ATMIS, including radiometers, radiosondes, and the NASA/GSFC Raman lidar. Comparisons between water vapor measurements by the radiometer and the lidar yielded a correlation coefficient of 0.998 and rms differences for three nights of −0.2±0.2mm (April 11–12, 1989), −0.8±0.5 mm (April 16–17, 1989), and −0.4±0.3 mm (April 17–18, 1989). The integrated precipitable water vapor measurements for these three nights were approximately 5, 10, and 21 mm, respectively. The first two periods had clear meteorological conditions, while clouds were present during the third period. The lidar results during the third period are augmented with radiosonde measurements above the cloud base. This study shows that the radiometer provides accurate, continuous measurements of the water vapor integrated through the depth of the atmosphere.

[1]  G. Resch,et al.  Water vapor radiometry research and development phase , 1985 .

[2]  Frederick J. Brousaides.  the radiosonde hygristor and low relative humidity measurements , 1975 .

[3]  G. J. Haltiner,et al.  Dynamical and physical meteorology , 1957 .

[4]  J. Kaiser,et al.  Data smoothing using low‐pass digital filters , 1977 .

[5]  S H Melfi,et al.  Remote measurements of the atmosphere using Raman scattering. , 1972, Applied optics.

[6]  Ed R. Westwater,et al.  Ground-Based Microwave Radiometric Observations of Precipitable Water Vapor: A Comparison with Ground Truth from Two Radiosonde Observing Systems , 1989 .

[7]  Gunnar Elgered,et al.  The ONSAM Experiment: Remote Sensing Techniques for Vertical Sounding of the Atmosphere , 1987 .

[8]  P. Rosenkranz,et al.  Interference coefficients for overlapping oxygen lines in air , 1988 .

[9]  S. H. Melfi,et al.  Observation of Lower-Atmospheric Moisture Structure and Its Evolution Using a Raman Lidar , 1985 .

[10]  Hans J. Liebe,et al.  Millimeter-wave properties of the atmosphere: Laboratory studies and propagation modeling , 1987 .

[11]  S. H. Melfi,et al.  Raman lidar system for the measurement of water vapor and aerosols in the Earth's atmosphere. , 1992, Applied optics.

[12]  J. Johansson,et al.  Geodesy by radio interferometry: Optimization of wet path delay algorithms using microwave radiometer data , 1987 .

[13]  Hans J. Liebe.  Millimeter–Wave Properties of the Atmosphere , 1987 .

[14]  G. Resch.  Water vapor - The wet blanket of microwave interferometry , 1980 .

[15]  Robert M. Rauber,et al.  Field Evaluation of a Dual-Channel Microwave Radiometer Designed for Measurements of Integrated Water Vapor and Cloud Liquid Water in the Atmosphere , 1987 .

[16]  Ed R. Westwater,et al.  The accuracy of water vapor and cloud liquid determination by dual‐frequency ground‐based microwave radiometry , 1978 .

[17]  Thomas D. Wilkerson,et al.  Atmospheric Water Vapor , 1980 .

[18]  David N. Whiteman,et al.  Observation of atmospheric fronts using Raman lidar moisture measurements , 1989 .

[19]  G. E. Becker,et al.  Water Vapor Absorption of Electromagnetic Radiation in the Centimeter Wave-Length Range , 1946 .

[20]  Gunnar Elgered,et al.  Measurements of atmospheric water vapor with microwave radiometry , 1982 .

[21]  Gunnar Elgered,et al.  Geodesy by radio interferometry - Water vapor radiometry for estimation of the wet delay , 1991 .

[22]  Van Vleck,et al.  The Absorption of Microwaves by Uncondensed Water Vapor , 1947 .

[23]  G. M. Resch,et al.  Inversion Algorithms for Water Vapor Radiometers Operating at 20.7 and 31.4 Ghz , 1984 .

[24]  I. Shapiro,et al.  Geodesy by radio interferometry: Effects of atmospheric modeling errors on estimates of baseline length , 1985 .

[25]  Steven E. Robinson,et al.  The profile algorithm for microwave delay estimation from water vapor radiometer data , 1988 .

[26]  Alan Whitney,et al.  Precision Geodesy Using the Mark-III Very-Long-Baseline Interferometer System , 1985, IEEE Transactions on Geoscience and Remote Sensing.

[27]  A. B. Vane,et al.  Atmospheric Absorption Measurements with a Microwave Radiometer , 1946 .

[28]  Michael Janssen,et al.  A New Instrument for the Determination of Radio Path Delay due to Atmospheric Water Vapor , 1985, IEEE Transactions on Geoscience and Remote Sensing.

[29]  E. Westwater.  Ground-Based Determination of Low Altitude Temperature Profiles by Microwaves , 1972 .

[30]  Ed R. Westwater,et al.  A Steerable Dual-Channel Microwave Radiometer for Measurement of Water Vapor and Liquid in the Troposphere , 1983 .

[31]  Stephen Keihm,et al.  Optimum Strategies and Performance for the Remote Sensing of Path-Delay using Ground-Based Microwave Radiometers , 1985, IEEE Transactions on Geoscience and Remote Sensing.

[32]  Irwin I. Shapiro,et al.  5.6. Estimation of Astrometric and Geodetic Parameters , 1976 .