1st Edition

Microwave Propagation and Remote Sensing Atmospheric Influences with Models and Applications

By Pranab Kumar Karmakar Copyright 2012
    258 Pages 113 B/W Illustrations
    by CRC Press

    258 Pages 113 B/W Illustrations
    by CRC Press

    Because prevailing atmospheric/troposcopic conditions greatly influence radio wave propagation above 10 GHz, the unguided propagation of microwaves in the neutral atmosphere can directly impact many vital applications in science and engineering. These include transmission of intelligence, and radar and radiometric applications used to probe the atmosphere, among others.

    Where most books address either one or the other, Microwave Propagation and Remote Sensing: Atmospheric Influences with Models and Applications melds coverage of these two subjects to help readers develop solutions to the problems they present. This reference offers a brief, elementary account of microwave propagation through the atmosphere and discusses radiometric applications in the microwave band used to characterize and model atmospheric constituents, which is also known as remote sensing.

    Summarizing the latest research results in the field, as well as radiometric models and measurement methods, this book covers topics including:

    • Free space propagation
    • Reflection, interference, polarization, and other key aspects of electromagnetic wave propagation
    • Radio refraction and its effects on propagation delay
    • Methodology of estimating water vapor attenuation using radiosonde data
    • Knowledge of rain structures and use of climatological patterns to estimate/measure attenuation of rain, snow, fog, and other prevalent atmospheric particles and human-made substances
    • Dual/multifrequency methodology to deal with the influence of clouds on radiometric attenuation
    • Deployment of microwaves to ascertain various tropospheric conditions
    • Composition and characteristics of the troposphere, to help readers fully understand microwave propagation
    • Derived parameters of water, free space propagation, and conditions and variable constituents such as water vapor and vapor pressure, density, and ray bending

    Outlines of Radio Waves and Troposphere
    General Perspective
    The Effective Earth’s Radius
    Radio Link
    Classification of Radio Waves according to Propagation Mechanism
    Radio Refractivity and Delay through the Atmosphere
    Tropospheric Aerosols
    Rain Characteristics

    Propagation of Radio Waves: An Outline
    Power Gain of Directional Aerial
    Free Space Field Due to Directional Transmitting Aerial
    Power at the Receiving Directional Aerial
    Free Space Transmission Loss
    Radio Waves in Neutral Atmosphere
    When Is a Medium a Conductor or Dielectric?
    Wave Polarization

    Reflection and Interference of Radio Waves
    Reflection of Radio Waves: An Outline
    Plane Wave at Dielectric Interface
    Reflection Coefficient for Flat Smooth Earth
    Field Strength Due to Reflection from Flat Earth
    Effect of the Earth’s Curvature: Spherical Earth
    Mechanism of Ground Wave Propagation

    Radio Refraction and Path Delay
    Radius of Curvature of the Ray Path
    Refractivity Is Complex and Frequency Dependent
    Turbulence-Induced Scintillation
    Microwave Propagation through Tropospheric Turbulence
    Propagation over Inhomogeneous Surface
    Tropospheric Ducting
    Propagation Delay through the Atmosphere

    Absorption of Microwaves
    Absorption Coefficient
    Microwave and Millimeter Wave Absorption in the Atmosphere
    Centrifugal Distortion
    Water Vapor Absorption at 22.235 GHz
    Water Vapor Absorption at 183.311 GHz
    Water Vapor and Microwave Attenuation
    Choice of Frequency
    Attenuation Studies in 50-70 GHz Band
    Attenuation Studies at 94 GHz

    Rain Attenuation and Its Application at Microwaves
    Radiometric Estimation of Rain Attenuation
    ITU-R Rain Attenuation Model and Its Applicability
    Raindrop Size Distribution in the Tropics

    Attenuation by Hydrometeors Other than Rain
    Clouds: Nonprecipitable Liquid Water
    Microwave Radiometric Estimation of Water Vapor and Cloud Liquid
    Effect of Water Vapor and Liquid Water on Microwave Spectra
    Cloud Radar

    Appendix: Mean Atmospheric Temperature at Microwaves and Millimeter Waves in Clear Air Environment


    Pranab Kumar Karmakar obtained his MSc in physics in 1979 and PhD in the area of microwave propagation and remote sensing in 1990 from the University of Calcutta, India. Associated with the Department of Radiophysics and Electronics at Calcutta University since 1988, he is involved in both teaching and research work. He has more than forty-five publications in national and international journals of repute. Karmakaralso has more than thirty conference articles to his credit. He was awarded the Young Scientist Award of URSI (International Union of Radio Science) in 1990. He has been a visiting scientist at the Remote Sensing Lab, University of Kansas; Centre for Space Science, China; and Satellite Division, National Institute for Space Research (INPE), Brazil. He has also been awarded the South-South fellowship of TWAS (The Academy of Sciences for the Developing World) in 1997.

    Karmakar’s current area of research includes microwave/millimeter wave propagation, microwave remote sensing, and atmospheric modeling.