Radar for Meteorological and AtmosphericObservations

Shoichiro Fukao • Kyosuke Hamazu

Radar for Meteorological andAtmospheric Observations

Consulted by Richard J. Doviak

123

Shoichiro FukaoProfessor EmeritusKyoto University, Kyoto, Japan

Consulted By:Richard J. DoviakNational Severe Storms Laboratory, NOAAAffiliated ProfessorThe School of Meteorology and

the Department of Electricaland Computer Engineering

The University of Oklahoma

Kyosuke HamazuMitsubishi Electric Corporation and

Mitsubishi Electric Tokki SystemsCorporation

Iga, Japan

ISBN 978-4-431-54333-6 ISBN 978-4-431-54334-3 (eBook)DOI 10.1007/978-4-431-54334-3Springer Tokyo Heidelberg New York Dordrecht London

Library of Congress Control Number: 2013943813

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Foreword

During the past several decades an appreciable amount of research and developmenthas been focused on the use of remote sensing techniques to better our understand-ing of weather and the atmosphere. Radar has the obvious advantage of providingobservations with temporal and/or spatial continuity which is leading to improvedforecasts of weather.

Observations and interpretation of Doppler and polarimetric weather radar data,combined with in situ observations, have led to giant leaps in our understandingof the dynamics and microphysics of weather systems. Complementary to weatherradar observations are those obtained with typically longer wavelength radars (i.e.,wavelengths from meters to centimeters versus centimeters to millimeters used toobserve precipitation and clouds), observing the precipitation-free atmosphere. Theechoing mechanism at these longer wavelengths is typically Bragg scatter fromrefractive index perturbations caused by turbulent mixing, or reflection from sharpgradients in refractive index. These long-wavelength and super-powerful radars,referred to as atmospheric radars, have mapped the vertical structure of reflectivityand radial winds in the clear atmosphere from below a kilometer to well above100 km, whereas meteorological radars map the reflectivity and radial velocitiesof precipitation and cloud particles on horizontal surfaces at various heights inthe troposphere. Weather and cloud radar research has attracted the attention ofmeteorologists whereas atmospheric radar research has primarily attracted theattention of atmospheric physicists.

The authors have done a remarkable job of combing the results of research inthese two disciplines to provide readers with a comprehensive overview of theoutstanding observations that have been made with radar used as a remote sensorof weather and atmospheric phenomena. This book has a generous amount offigures that display many of the remote sensing facilities to give the reader aquick appreciation for the variety of atmospheric and meteorological radar typesaround the world, many of which are unique and interesting. Furthermore, liberalreference to publications provides readers a vast reservoir for further pursuit oftheir preferred topics of interest. In addition this book presents the fundamentalsof remote sensing so that students and professors, with a minimal background in

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vi Foreword

physics and electromagnetic theory, and engineers in the field can better understandthe potential and limitations of radar in observing weather and the atmosphere whilelearning about the various instruments and techniques used in remote sensing. Theauthors plan to maintain a Website where comments from readers can be addressedand where supplements to the book can be found; this will help to keep the bookcurrent and up-to-date.

Norman, OK Richard J. Doviak

Preface

With the application of radar to observations of the atmosphere, various weatherphenomena and winds in the clear atmosphere can be monitored and mappedin real time. Great progress in understanding weather and the dynamics of theatmosphere has been made using radar, which brings new observational discoveriesand promotes further understanding of our environment.

Remote sensing with radar has been developed in the interdisciplinary domainsof physical science and engineering. In the past, advances in weather and the atmo-spheric sciences have developed independently because the respective engineeringefforts and scientific studies were conducted within relatively separate communities.However, the scientific and technical bases for atmospheric observations with radarcan be treated in common. We worked in academia (Fukao) and industry (Hamazu)and have collaborated to develop various types of weather and atmospheric radars.Routine discussion with our colleagues convinced us that understanding of weatherand atmospheric radars can be deepened if they are described comprehensively andsystematically in one volume using common approaches whenever possible.

This book is written for scientists, engineers, students, and other interestedmeteorological and atmospheric personnel. In this book, we try to bridge the gapin our understanding of weather and atmospheric radar. The book consists of twoparts. The first half, Chaps. 1–7, mainly discusses the theoretical bases of weatherand atmospheric radar, and the last half, Chaps. 8–12, describes actual systems andobservations with these radars. This interdisciplinary book was first published inJapanese by the Kyoto University Press in 2005. In the English version, all chaptersincluding those dealing with recent developments contain more in-depth coveragethan does the original.

Kyoto, Japan Shoichiro FukaoIga, Japan Kyosuke Hamazu

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Acknowledgements

We are indebted to many people in bringing this book to publication in this form.First and foremost, we wish to express our deepest gratitude to Dr. Richard J. Doviakof the National Severe Storms Laboratory of the National Oceanic and AtmosphericAdministration (NOAA) and the University of Oklahoma who has long been a closefriend of one of the authors (Fukao) and has been looked upon as mentor for theother (Hamazu). All chapters have been reviewed and edited by him. We wereable to complete the work because of his continuous suggestions and stimulatingencouragement.

We would like to express our deep gratitude to our colleagues, Drs. ToruSato, Toshitaka Tsuda, Mamoru Yamamoto, and Hiroyuki Hashiguchi of KyotoUniversity; Dr. Takuji Nakamura of the National Institute of Polar Research, Japan;Dr. Manabu D. Yamanaka of the Japan Agency for Marine-Earth Science andTechnology (JAMSTEC) and Kobe University; and Drs. Hiroaki Miyasita, AtsushiOkamura, Toshio Wakayama, and Shoji Matsuda of Mitsubishi Electric Corporationfor various suggestions through discussions. Many of them provided us with theoriginal figures that are included in the book. It is a great pleasure for us toacknowledge the valuable advice and suggestions of Emeritus Professor HisanaoOgura of Kyoto University; Dr. Hubert Luce of the Universite de Toulon et du Var;Drs. Yasushi Fujiyoshi and Takeshi Horinouchi of Hokkaido University; Dr. ToshioIguchi of the National Institute of Information and Communication Technology(NICT), Japan; Dr. Hiroshi Uyeda of Nagoya University; Dr. Masahiro Ishiharaof Kyoto University; Dr. Masayuki Maki of Kagoshima University; Dr. KoyuruIwanami of the National Research Institute for Earth Science and Disaster Prevision(NIED), Japan; and Drs. Ahoro Adachi and Hiroshi Yamauchi of the MeteorologicalResearch Institute, Japan Meteorological Agency. We would like to express our spe-cial thanks to Dr. Yoshiaki Shibagaki of Osaka Electro-Communication University;Seiji Kawamura of the NICT; Drs. Masayuki Yamamoto, Tomohiko Mitani, JunichiFurumoto, and Tatsuhiro Yokoyama of Kyoto University; and Drs. NobukyukiKawano and Akihisa Uematsu of the Japan Aerospace Exploration Agency (JAXA).In writing this book, we received warm encouragement from emeritus professorsSusumu Kato and Isamu Hirota of Kyoto University.

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x Acknowledgements

Finally, we are especially grateful for the support of our respective spouses,Keiko Fukao and Masuni Hamazu, during the writing of this book.

Kyoto, Japan Shoichiro FukaoIga, Japan Kyosuke Hamazu

Contents

1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.1 Principle of Radar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.2 History of Meteorological and Atmospheric Radars . . . . . . . . . . . . . . . 21.3 Radar Frequency Bands and Usage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2 Electromagnetic Waves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72.1 Characteristics of Electromagnetic Waves . . . . . . . . . . . . . . . . . . . . . . . . . . 7

2.1.1 Basic Equations .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72.1.2 Polarization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122.1.3 Reflection and Refraction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142.1.4 Radiation .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

2.2 Electromagnetic Wave Propagation in the Atmosphere . . . . . . . . . . . . 232.2.1 Physical Property of the Atmosphere . . . . . . . . . . . . . . . . . . . . . . 232.2.2 Propagation of Electromagnetic Wave. . . . . . . . . . . . . . . . . . . . . 262.2.3 Wave Path in the Spherically Stratified Atmosphere .. . . . . 272.2.4 The Profile of the Standard Atmosphere . . . . . . . . . . . . . . . . . . 30

3 Radar Measurements and Scatterer Parameters . . . . . . . . . . . . . . . . . . . . . . . 333.1 Basics of Radar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

3.1.1 System Parameters of Pulse Radars . . . . . . . . . . . . . . . . . . . . . . . 333.1.2 Characteristics of Scatter and Scatterers. . . . . . . . . . . . . . . . . . . 36

3.2 Radar Observation of Isolated Scatterers. . . . . . . . . . . . . . . . . . . . . . . . . . . . 383.2.1 Radar Equation for an Isolated Scatterer . . . . . . . . . . . . . . . . . . 383.2.2 Characteristics of Scattering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

3.3 Radar Theory for Hard Scatterers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 423.3.1 Scattering by Dielectric Spheres . . . . . . . . . . . . . . . . . . . . . . . . . . . 423.3.2 Radar Equation for Distributed Hard Scatterers . . . . . . . . . . 463.3.3 Mie Scattering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 493.3.4 The Rayleigh Approximation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 523.3.5 Radar Reflectivity Factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

3.4 Radar Theory for Soft Scatterers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 573.4.1 Backscattering Mechanisms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 573.4.2 Bragg Scatter due to Refractive Index Perturbations . . . . . 59

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3.4.3 Partial Reflection from a Stratified Atmosphere . . . . . . . . . . 683.4.4 Scattering by Linear Scatterers . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

4 Principle of Doppler Velocity Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 754.1 Doppler Velocity Measurements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

4.1.1 Principles of Doppler Radar. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 754.1.2 Measurable Limit of Doppler Velocity . . . . . . . . . . . . . . . . . . . . 794.1.3 Expansion of Doppler Velocity Measurement Range . . . . . 81

4.2 Methods of Applying Doppler Radar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 814.2.1 Volume Velocity Processing (VVP) Method . . . . . . . . . . . . . . 824.2.2 Velocity Azimuth Display (VAD) Method . . . . . . . . . . . . . . . . 864.2.3 Wind Observations with Bistatic Doppler Radar. . . . . . . . . . 89

4.3 Multiple Monostatic Doppler Radars. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 954.3.1 Independent Scanning Method .. . . . . . . . . . . . . . . . . . . . . . . . . . . . 964.3.2 COPLAN. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 994.3.3 Distance of Two Doppler Radars . . . . . . . . . . . . . . . . . . . . . . . . . . 1014.3.4 Wind Velocity Observations with Three or

More Radars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103

5 Reception and Processing of Signals. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1055.1 Receiver Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105

5.1.1 Noise Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1055.1.2 Receiver Noise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111

5.2 Receiver System .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1155.2.1 Matched Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1155.2.2 Frequency Conversion and Phase Measurement . . . . . . . . . . 118

5.3 Characteristics of Received Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1205.3.1 Signals Received from Precipitation Particles

and the Atmosphere . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1205.3.2 Probability Density Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122

5.4 Fundamentals of Radar Signal Processing . . . . . . . . . . . . . . . . . . . . . . . . . . 1245.4.1 Fourier Transform and Its Characteristics . . . . . . . . . . . . . . . . . 1255.4.2 Signals in a Linear System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1275.4.3 Power Spectral Moments and Basic Radar Parameters . . . 130

5.5 Processing of Sampled Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1335.5.1 Waveform of Transmitted Pulse and Series

of Signal Waves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1335.5.2 Sampling of a Received Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1375.5.3 Processing of Discrete Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1395.5.4 Estimation of Mean Doppler Frequency.. . . . . . . . . . . . . . . . . . 1435.5.5 Estimation of Spectrum Width . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1455.5.6 Estimation of Spectral Parameter by Fitting . . . . . . . . . . . . . . 1465.5.7 Estimation Based on Prediction Theory . . . . . . . . . . . . . . . . . . . 149

5.6 Correlation and Accuracy of Sampled Signal . . . . . . . . . . . . . . . . . . . . . . . 1505.6.1 Correlation Function and Correlation Time . . . . . . . . . . . . . . . 1505.6.2 Coherent Integration .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154

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5.6.3 Incoherent Integration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1555.6.4 Standard Deviation of Radar Reflectivity Factor . . . . . . . . . . 1595.6.5 Standard Deviation of Mean Doppler Velocity. . . . . . . . . . . . 1625.6.6 Standard Deviation of Spectrum Width . . . . . . . . . . . . . . . . . . . 164

6 Radar Observations of Precipitation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1676.1 Parameters of Precipitation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168

6.1.1 Parameters of Drop Size. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1686.1.2 Relations Between Basic Radar Parameters

and DSD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1716.1.3 Physical Quantities Concerned with Precipitation . . . . . . . . 1736.1.4 Radar Reflectivity Factor and Rainfall Rate . . . . . . . . . . . . . . . 176

6.2 Estimation of DSD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1796.3 Attenuation of Radio Waves in the Atmosphere .. . . . . . . . . . . . . . . . . . . 182

6.3.1 Attenuation Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1836.3.2 Attenuation by the Atmosphere .. . . . . . . . . . . . . . . . . . . . . . . . . . . 1846.3.3 Attenuation by Water Particle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186

6.4 Polarimetric Radar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1896.4.1 Generation of Dual Polarized Wave . . . . . . . . . . . . . . . . . . . . . . . 1906.4.2 Characteristics of Polarization Parameter . . . . . . . . . . . . . . . . . 1956.4.3 Shapes of Precipitation Particles and

Polarization Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2006.4.4 Attenuation Correction Using KDP . . . . . . . . . . . . . . . . . . . . . . . . . 2046.4.5 Estimates and Variances of Polarization Parameters . . . . . . 2076.4.6 Radar Rainfall Estimation Using Polarization

Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2166.4.7 Estimation of Cloud Water Content . . . . . . . . . . . . . . . . . . . . . . . 2186.4.8 Hydrometeor Classification with Polarization

Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219

7 Radar Observations of the Clear Atmosphere . . . . . . . . . . . . . . . . . . . . . . . . . . 2237.1 Detectability of Atmospheric Radar Signals . . . . . . . . . . . . . . . . . . . . . . . . 223

7.1.1 Received Power and Radar Reflectivity . . . . . . . . . . . . . . . . . . . 2237.1.2 Coherent Integration in Atmospheric Radar. . . . . . . . . . . . . . . 2247.1.3 Detection of Signal in Noise Background .. . . . . . . . . . . . . . . . 226

7.2 Wind Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2277.2.1 DBS/VAD Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2277.2.2 Wind Velocity Measurements from Spaced

Antenna Methods .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2307.3 Turbulence Observations .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234

7.3.1 Measurement of Momentum Flux . . . . . . . . . . . . . . . . . . . . . . . . . 2357.3.2 Estimation of the Turbulence Contribution

to Spectrum Width . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2377.3.3 Estimation of Turbulence Parameters. . . . . . . . . . . . . . . . . . . . . . 2427.3.4 Relation Between Refractive Index and

Structure Constant for Refractivity Turbulence . . . . . . . . . . . 245

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7.4 Observations of Temperature Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2477.4.1 Measurement of Atmospheric Temperature

with RASS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2477.4.2 Change of Refractive Index and Radar

Equation for RASS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2497.4.3 Bragg Condition and Background Wind . . . . . . . . . . . . . . . . . . 251

7.5 Estimation of Water Vapor Profiles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2557.6 Radar Interferometry Techniques .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257

7.6.1 SDI and FDI Techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2577.6.2 Radar Imaging Techniques .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262

8 Overview of Radar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2698.1 Brief Discussion on Two Types of Radar . . . . . . . . . . . . . . . . . . . . . . . . . . . 269

8.1.1 FMCW Radar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2698.1.2 Pulse Radar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2728.1.3 Echo Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2738.1.4 Scanning Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274

8.2 Radar Antenna .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2778.2.1 Radar Antenna Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2778.2.2 Parabolic Antenna . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2808.2.3 Radome . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2838.2.4 Array Antenna . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2858.2.5 Measurement of Antenna Radiation Pattern. . . . . . . . . . . . . . . 295

8.3 Transmitters and Receivers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2978.3.1 Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2988.3.2 Transmitter Used for Meteorological Doppler Radar . . . . . 2998.3.3 Transmitter of Atmospheric Radar. . . . . . . . . . . . . . . . . . . . . . . . . 3078.3.4 Pulse Compression . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3088.3.5 Receiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 317

8.4 Digital Signal Processing System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3218.4.1 Signal Processing .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3218.4.2 Removal of Unwanted Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3248.4.3 Analog to Digital Conversion .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3298.4.4 Spectral Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3328.4.5 Window Function .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3338.4.6 Parameters for the DFT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 338

9 Practical Meteorological Radars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3419.1 Meteorological Radars of Various Frequency Bands . . . . . . . . . . . . . . . 3419.2 Precipitation Observation Radar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 344

9.2.1 2.8-GHz Band Radars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3449.2.2 NEXRAD: WSR-88D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3449.2.3 5.6-GHz Band Radar: The Terminal Doppler

Weather Radar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3479.2.4 5.3-GHz Band Radar: The Doppler Radar for

Airport Weather in Japan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 352

Contents xv

9.2.5 5.3-GHz Band Meteorological Radars in Japan . . . . . . . . . . . 3539.2.6 Radar Raingauge.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3569.2.7 9.5-GHz Band Radars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 357

9.3 Cloud and Fog Observation Radar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3619.3.1 35-GHz Band Radar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3619.3.2 35/95-GHz Multiple Radar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 364

9.4 Satellite-Borne Radar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3669.4.1 Tropical Rainfall Measuring Satellite . . . . . . . . . . . . . . . . . . . . . 3669.4.2 Global Precipitation Measurement Program . . . . . . . . . . . . . . 368

10 Practical Atmospheric Radars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36910.1 Characteristics of Atmospheric Radar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36910.2 Large-Scale Atmospheric Radars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 370

10.2.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37010.2.2 Radars with COCO Array Antenna . . . . . . . . . . . . . . . . . . . . . . . . 37210.2.3 The MU Radar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37410.2.4 Equatorial Atmospheric Radar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38010.2.5 The Antarctic Syowa MST/IS Radar: PANSY . . . . . . . . . . . . 384

10.3 Wind Profiler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38410.3.1 The NOAA Profiler Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38410.3.2 Wind Profiler Network in Europe .. . . . . . . . . . . . . . . . . . . . . . . . . 387

10.4 Lower Troposphere Radar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38710.4.1 Boundary Layer Radar (BLR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38810.4.2 Turbulent Eddy Profiler (TEP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38910.4.3 Lower Troposphere Radar (LTR) . . . . . . . . . . . . . . . . . . . . . . . . . . 39110.4.4 WINDAS of Japan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 393

11 Observations by Meteorological Radar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39511.1 Precipitation Observation by Meteorological Radar . . . . . . . . . . . . . . . . 39511.2 Mesoscale Rain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 397

11.2.1 Structure of Extratropical Cyclone and Front . . . . . . . . . . . . . 39711.2.2 Horizontal Structure of Precipitation . . . . . . . . . . . . . . . . . . . . . . 40111.2.3 Vertical Structure of Precipitation . . . . . . . . . . . . . . . . . . . . . . . . . 402

11.3 Typhoon.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40511.3.1 Horizontal Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40511.3.2 Spatial Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 408

11.4 Cumulus Convection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40911.4.1 Multicell Thunderstorms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40911.4.2 Ordinary Thunderstorms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41011.4.3 Tornado . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41111.4.4 Downburst . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 413

11.5 Polarimetric Radar Observations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41711.5.1 Polarimetric Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41711.5.2 Attenuation Correction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41911.5.3 Radar Rainfall Estimation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42211.5.4 Hydrometeor Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 424

xvi Contents

11.6 Clear Air Observations .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42611.6.1 High Power Large Radar Observation .. . . . . . . . . . . . . . . . . . . . 42611.6.2 FMCW Radar Observation .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 427

11.7 Cloud and Fog Observations .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42811.7.1 Cloud . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42811.7.2 Fog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 429

11.8 Retrieval of Heating Distribution in a Cloud . . . . . . . . . . . . . . . . . . . . . . . . 430

12 Observations by Atmospheric Radar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43512.1 Wind Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43512.2 Mesoscale Convective System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 437

12.2.1 Cold Vortex . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43812.2.2 Tropical Cyclone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44112.2.3 Convection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44412.2.4 Precipitating Cloud . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44612.2.5 Orographic Rainfall . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44812.2.6 Echoes from Precipitation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 449

12.3 Atmospheric Gravity Waves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45112.3.1 Wave Propagation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45212.3.2 Dispersion Equation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45312.3.3 Critical Layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45512.3.4 Gravity Wave Spectra . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45612.3.5 Momentum Flux . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45812.3.6 Turbulence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46012.3.7 Wave Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 461

12.4 Boundary Layer and Equatorial Atmosphere . . . . . . . . . . . . . . . . . . . . . . . 46312.4.1 Boundary Layer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46312.4.2 Equatorial Atmosphere .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46512.4.3 Atmospheric Temperature and Water Vapor Content . . . . . 467

12.5 Beam Swinging and Radar Imaging Techniques . . . . . . . . . . . . . . . . . . . 46912.5.1 Scattering Layer Observations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 470

12.6 Wind Profiler Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48212.6.1 Quality Control and Actual Operation .. . . . . . . . . . . . . . . . . . . . 48212.6.2 Application for Short-Term Forecasting .. . . . . . . . . . . . . . . . . . 483

A Mie Coefficients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 487

B Autocovariance Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 493B.1 Mean Doppler Frequency .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 493B.2 Doppler Frequency Spectrum Width . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 494

Errata E-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . .

Contents xvii

C The Fast Fourier Transform (FFT) Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . 497C.1 Decimation-in-Time (DIT) FFT Algorithm .. . . . . . . . . . . . . . . . . . . . . . . . 497C.2 Decimation-in-Frequency (DIF) FFT Algorithm . . . . . . . . . . . . . . . . . . . 499

D Radar Equation for RASS Echo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 503

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 507

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 529

List of Symbols

a Attenuation rate [m−1], mean radius of the Earth (6370 km), semi-majoraxis diameter of spheroid rain drop

ae Effective Earth radiusaT Temperature lapse rateA Attenuation coefficient [dB km−1], physical antenna apertureA Vector potentialAe Effective antenna apertureb Semi-minor axis diameter of spheroid rain dropB Frequency bandwidth of the receiverB Magnetic flux densityBf Filter bandwidthBn Noise bandwidthc Speed of light (in vacuum) [m s−1]ca Sound velocityca Apparent sound velocitycs True sound velocityC2

n Refractive index structure constant [m−2/3]Cp Specific heat capacity at constant pressure (� 1004) [J K−1 kg−1]d Distance between successive element antennasD Detectability of radar signal, diameter of raindrop, wind direction,D Electric flux densityD0 Median volume diameterDa Antenna diameter, distance of two separated antennasDm Mass weighted mean drop diameterDr Dynamic range of A/D conversionDrmax Maximum dynamic rangee Partial pressure of water vapor [hPa]E Total energy of a receiver input signal, withstand voltage [V mm−1]E Electric field strengthE0 Incident electric fieldEa Array factor

xix

xx List of Symbols

Es Scattered electric fieldf Radar frequency (transmitted frequency) [Hz]f0 Carrier frequency [Hz]fc Frequency of coherent oscillator (COHO)fd Doppler frequency (Doppler shift)fdmax Maximum measurable Doppler frequencyfi Inertial frequencyfN Nyquist frequencyfp Pulse repetition frequencyfs Frequency of stabilized local oscillator (STALO), sampling frequencyF Noise figureFr Froude Numberg Antenna gain at the direction of the maximum radiation pattern (main lobe)

in linear unit, radiation pattern of the element antenna (or element pattern),gravitational acceleration

gat Transmission gain of the RASSgD Directivity of antennaG Antenna gain in decibelh Altitude (height from sea level), beam height, mountain heightH Magnetic field strengthH1 Scale height (7.3 km)ii Unit vector along the radar beam directionI Electric current, in-phase component of the complex signalIa Acoustic intensity [W m−2]j Imaginary unit ( j2 =−1)J Electric current densityk Boltzmann constant (= 1.38× 10−23 J K−1), radar wave number

(= ω√εμ = 2π/λ )ka Imaginary part of the complex refractive index, wave number of acoustic

waveks Scattering vector wave numberK Thermodynamic temperature measured in kelvins, vertical eddy diffusivityKDP Specific differential phase [deg km−1]l Autocorrelation time lag, length of short dipole (differential antenna), loss

value in a true numberl Separation of the scatterer from the volume centerl0 Inner scale of turbulencelK Kolmogoroff microscaleL Loss value in decibelLB Maximum scale of eddy in the inertial subrange (or buoyancy lengthscale)Ldr Linear depolarization ratio in linear unitLDR Linear depolarization ratio in decibelm Complex refractive index of drop (or particle), modified refractive index,

vertical wavenumbermn The nth moment of drop size distribution

List of Symbols xxi

M Mean molecular weight of the atmosphere, number of DFT or FFTpoints, number of signal samples along sample time axis (total numberof samples), refractive modulus,

MB Total number of points of periodogram (FFT points)Mcoh Number of coherent integrationMI Number of independent samplesMinc Number of incoherent integrationMn Refractive index gradient (=dn/dz)Ms Total number of actual signal samplesMv Total water vapor content [kg mm−3]n Refractive indexnr Real part of the complex refractive indexN Bit length, Brunt Vaisala frequency, number of element antenna, number

of raindrops, number of range samples, Nyquist numberN0 Parameter of drop size distribution (intercept parameter)N(D) Drop size distribution (DSD)Ne Density of free electron [m−3]NT Total number of raindropsp Atmospheric pressure [hPa]P Breakdown power, total electric powerP Dielectric polarizationPa Transmitted power from sound wave sourcePar Received power backscattered from sound wave surfacePr Received signal powerPs Scattered powerPt Transmitted power, peak transmitted powerPV Dipole momentq Humidity mixing ratio [kg kg−1]qe Linear density of meteor trail [m−1]Q Quadrature phase component of the complex signalr Distance between the radar and the scatterer, rangera Maximum observable rangerR Distance between bistatic scatterer and receiverrT Distance between transmitter and bistatic scattererR Gas constant, rainfall rate,Rd Transmitter’s duty cycleRf Flux Richardson numberRi Richardson numberRR Radiation resistance of short dipoleRsp Specific constant of drying air (= 287 J K−1 kg−1)s f Frequency stabilitys Backscattering matrix of the linear polarization waveS Power density, signal powerS Complex Poynting vectorSi Incident power density

xxii List of Symbols

SN Power spectral density of noiseSs Scattered power densitySS Power spectral density of signalSw Vertical shear [s−1]SNR Signal-to-noise ratiot TimeT Atmospheric temperature [K], noise temperature [K], period of gravity

wave, pulse repetition time (PRT) [s], time periodT0 Room temperature (290 K)Tc Correlation timeTe Equivalent input noise temperatureTi Input noise temperature, independent sample timeTs Sample time interval (sampling interval), sky noise temperatureTsys System noise temperatureTv Temperature of moist atmosphereTW Window widthu East-west (zonal) windu Mean zonal windu′ Horizontal IGW perturbation from turbulenceU Horizontal wind speedv Phase velocity of electromagnetic wavev′ Fluctuation component of wind perpendicular to the direction of wave

travelv Wind vector (vx, vy, vz)vd Doppler velocityvd Mean Doppler velocityvh Horizontal wind velocityvN Nyquist velocity (Nyquist limit)vr Radial velocityV Radar resolution volumeV6 Resolution volume circumscribed by the 6 dB contour of radar parametersVD Volume of raindropw Vertical wind velocity (or vertical component of wind velocity; vz)w′ Vertical IGW perturbation from turbulencewT Terminal velocity of precipitation (fall speed)W Cloud water content (or water content in unit volume) [g m−3]WB Bandwidth of the signalz Altitude, height from sea level [km]Z Radar reflectivity factorZdr Differential reflectivity in linear unitZDR Differential reflectivity in decibelZe Equivalent radar reflectivity factorZi Radar reflectivity factor for ice particlesα Azimuth angle of the baseline formed between two antennas in SDIβ Bistatic angle

List of Symbols xxiii

γ Specific heat ratio of ideal gas (� 1.4 for dry air)Γ Dry adiabatic lapse rate (= g/Cp � 9.80) [K km−1]δ Differential scattering phase, direction of horizontal wind, phase difference

between successive element antennasΔ Resolution of the A/D converterε Turbulent energy dissipation rateε Permittivity [F m−1]ε0 Permittivity in vacuum [F m−1]ζ Axis ratio b/a, where a is the semi-major axis diameter and b the semi-

minor axis diameter of a flat raindropη Radar reflectivityη1 Efficiency of antennaηa Antenna aperture efficiencyηi Intrinsic impedance (or wave impedance) (=

√μ/ε)

θ Zenith angle of radar beamθ1 One-way beamwidth between half-power points (or beam width)θe Elevation angle of radar beamϑB One way half-power beamwidth in the E-plane [rad]Θ Potential temperatureκ Wave number for Bragg scatteringκ Wave number vector for Bragg scatteringκa Wave number vector for acoustic waveκb Wave number corresponding to the Bragg scaleκB Wave number corresponding to buoyancy lengthscale (= 2π/LB)λ Radar wavelength [m]Λ Parameter of drop size distribution (or slope parameter)Λs Structure wavelength of perturbations within inertial subrangeμ Permeability [H m−1]μ0 Permeability in vacuum [H m−1]ν Kinematic viscosity (dynamic viscosity divided by the fluid density)ρ Electric charge density [C m−1], radar cross section [m2]|ρ |2 Partial reflection coefficientρa Atmospheric density [kg m−3]ρhv Correlation coefficient between horizontally and vertically polarized wavesρv Water vapor density [g m−3]ρw Density of precipitation particles [g m−3](= 106 for water)σ Electric conductivity [S m−1]σa Absorption cross sectionσb Backscattering cross sectionσ f Doppler frequency spectrum width [Hz]σs Scattering cross sectionσt Extinction (or attenuation) cross sectionσv Doppler velocity spectrum width [m s−1]σvn Doppler velocity spectrum width normalized with the Nyquist widthτ Transmitted pules width [s], time lag

xxiv List of Symbols

τi Independent sample timeτc Correlation timeφ Angular distance from the beam axis in the H-planeφh Phase delay per unit distance (one way) for horizontally polarized wave

[rad]φv Phase delay per unit distance (one way) for vertically polarized wave [rad]ΦDP Differential phase in two-way (ΦDP =Φhh −Φhh) [deg]Φhh Phase shift in round trip between radar and scatterer for horizontally

polarized wave [deg]Φvv Phase shift in round trip between radar and scatterer for vertically polarized

wave [deg]ϕ Phase of received echo signal, zenith angle in the H-plane based on radar

beam axisϕB One way half-power beamwidth in the H-plane [rad]χ Angle between the direction of polarization of the incident electric field

and the direction of scattering vector (= π/2 for backscatteringΨ Differential phase of measured signals between horizontally and vertically

polarized waves [deg], scalar potentialω Angular frequency [rad s−1]ωd Doppler angular frequencyωi Intrinsic frequencyΩ Angular velocity of the Earth’s rotation (= 7.292× 10−5 s−1)

List of Abbreviations

A/D Analog to digitalAFWS Air Force Weather ServiceAGC Automatic gain controlAGL Above ground levelAMeDAS Automated Meteorological Rata Acquisition SystemAMS American Meteorological SocietyARM Atmospheric Research Measurement programATC Air traffic controlATSR Alternate transmission and simultaneous receptionBL Boundary layerBLR Boundary layer radarCAP Cooperative Agency ProfilerCAT Clear air turbulenceCCIR International Radio Consultative CommitteeCDL Coherent Doppler lidarCIRA Committee on Space Research (COSPA) International Reference

AtmosphereCOCO Coaxial-collinearCOHO Coherent oscillatorCOST European Cooperation in Science and TechnologyCRI Coherent radar imagingCST Central Standard TimeCSU Colorado State UniversityDBS Doppler beam swingingDFT Discrete Fourier transformDIF Decimation-in-frequencyDIT Decimation-in-timeDOA Direction of arrivalDPR Dual-frequency Precipitation RadarDRAW Doppler Radar for Airport WeatherDSD Drop size distribution

xxv

xxvi List of Abbreviations

EAR Equatorial Atmospheric RadarECCD Electromagnetically coupled coaxial dipoleEIK Extended interaction amplifierEST Eastern Standard TimeFAA Federal Aviation AdministrationFCA Full correlation analysisFDI Frequency domain interferometryFET Field effect transistorFFT First Fourier transformFII Frequency domain interferometric imagingFIR Finite impulse responseFMCW Frequency-modulated continuous wavesFRP Fiber-reinforced plasticFSA Full spectral analysisFWHM Full width at half maximumGMAP Gaussian model adaptive processingGMS Geostationary meteorological satelliteGMT Greenwich mean timeGPM Global Precipitation MeasurementGPS Global positioning systemGTS Global Telecommunication SystemHEMT High electric mobility transistorHS Hail signalHVPS High-Volume Particle SpectrometerI In-phaseIDFT Inverse discrete Fourier transformIF Intermediate frequencyIFFT Inverse fast Fourier transformIGW Inertia-gravity waveIIR Infinite impulse responseIR Infrared radiationIS Incoherent scatterITU International Telecommunication UnionJAFNA Joint Air Force and NASAJAXA Japan Aerospace Exploration AgencyJMA Japan Meteorological AgencyJST Japan Standard TimeKH Kelvin–HelmholtzKIX Kansai International AirportLAN Local area networkLDR Linear depolarization ratioLEO Low Earth orbitLHC Left-hand circularLLJ Low-level jetLNA Low noise amplifier

List of Abbreviations xxvii

LO Local frequencyLT Local timeLTR Lower Troposphere RadarM-P Marshall–PalmerMEM Maximum entropy methodMESFET Metal-semiconductor FETML Multi-lagMLIT Ministry of Land, Infrastructure, Transport and TourismMLM Maximum likelihood methodMMIC Monolithic microwave integrated circuitMOPA Master oscillator and power amplifierMP Multi-parameterMPIfR Max-Planck-Institut fur RadioastronomieMPM Millimeter-wavelength propagation modelMRI Meteorological Research instituteMSM Mesoscale numerical modelMST Mesospheric-stratospheric-troposphericMU Middle and Upper atmosphereMUSIC Multiple signal classificationNASA National Aeronautics and Space AdministrationNCAR National Center for Atmospheric ResearchNIED National Research Institute for Earth Science and Disaster Pre-

ventionNOAA National Oceanic and Atmospheric AdministrationNPN NOAA Profiler NetworkNSSL National Severe Storms LaboratoryNWS National Weather ServiceORDA Open radar data acquisitionOTH Over the horizonPA Power-aperturePANSY Program of the Antarctic Syowa MST/IS RadarPBL Planetary boundary layerPBS Post beam steeringPHS Personal Handy-phone SystemPOS PositioningPPI Plan position indicatorPR Precipitation radarPRF Pulse repetition frequencyPRT Pulse repetition timePSS Post static steeringPUP Principal user processorQ Quadrature-phaseRASS Radio acoustic sounding systemRCS Radar cross sectionRDA Radar data acquisition

xxviii List of Abbreviations

rf Radio frequencyRHC Right-hand circularRHI Range height indicatorRIM Range imagingROPS Radar Observation data Processing SystemRPG Radar product generatorRPM Rotation per minuteRX ReceiverSA Spaced antennaSAD Spaced antenna driftSCSI Small Computer System InterfaceSDI Spatial domain interferometrySI Le Systeme InternationalSNR Signal-to-noise ratioSPBS Sequential post beam steeringSSPA Solid state power amplifierST Stratospheric-troposphericSTALO Stabilized local oscillatorSTC Sensitivity time controlSTSR Simultaneous transmission and simultaneous receptionSVD Singular value decompositionT TroposphericTAI Temps Atomique InternationalTC Tropical cycloneTDWR Terminal Doppler Weather RadarTEP Turbulent eddy profilerTOGA-COARE Tropical Ocean Global Atmosphere–Coupled Ocean Atmosphere

Research ExperimentTPPN Trans-Pacific Profiler NetworkTR Transmitter/receiverTRMM Tropical Rainfall Measurement MissionTWT Traveling wave tubeTX TransmitterUHF Ultrahigh frequencyUTC Coordinated Universal TimeVAD Velocity azimuth displayVCP Volume coverage patternVHF Very high frequencyVIL Vertical integrated liquidVVP Volume velocity processingWCB Warm conveyor beltWCRP World Climate Research ProgramWINDAS Wind Profiler Data Acquisition SystemWRC World Telecommunication ConferenceWMO World Meteorological Organization