ENCYCLOPEDIA ofREMOTE SENSING

Encyclopedia of Earth Sciences Series

ENCYCLOPEDIA OF REMOTE SENSING

Volume EditorEni G. Njoku is a Senior Research Scientist at the Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA. He hasa B.A. from the University of Cambridge, and S.M. and Ph.D. from the Massachusetts Institute of Technology. His research focuses on spacebornemicrowave sensing with application to land surface hydrology and the global water cycle. Amongst his awards are the NASA Exceptional ServiceMedal (1985) and Fellow of the Institute of Electrical and Electronics Engineers (1995).

Section EditorsMichael J. AbramsJet Propulsion LaboratoryCalifornia Institute of TechnologyPasadena, CA 91109USA

Ghassem R. AsrarWorld Climate Research ProgrammeWorld Meteorological Organization1211 GenevaSwitzerland

Frank S. MarzanoDepartment of Information EngineeringSapienza University of Rome00184 Rome, Italyand Centre of Excellence CETEMPSUniversity of L'Aquila67100 L'AquilaItaly

Peter J. MinnettMeteorology and Physical OceanographyRosenstiel School of Marine and Atmospheric ScienceUniversity of MiamiMiami, FL 33149USA

Vincent V. SalomonsonDepartment of GeographyUniversity of UtahSalt Lake City, UT 84112USA

Vernon H. SinghroyCanada Centre for Remote SensingOttawaOntario K1A 0Y7Canada

F. Joseph TurkJet Propulsion LaboratoryCalifornia Institute of TechnologyPasadena, CA 91109USA

Aims of the SeriesThe Encyclopedia of Earth Sciences Series provides comprehensive and authoritative coverage of all the main areas in the Earth Sciences. Eachvolume comprises a focused and carefully chosen collection of contributions from leading names in the subject, with copious illustrations andreference lists.These books represent one of the world’s leading resources for the Earth Sciences community. Previous volumes are being updated and new workspublished so that the volumes will continue to be essential reading for all professional earth scientists, geologists, geophysicists, climatologists, andoceanographers as well as for teachers and students. See the back of this volume for a current list of titles in the Encyclopedia of Earth SciencesSeries. Go to http://www.springerlink.com/reference-works/ and springerreference.com to visit the “Earth Sciences Series” on-line.

About the Series EditorProfessor Charles W. Finkl has edited and/or contributed to more than eight volumes in the Encyclopedia of Earth Sciences Series. For the past25 years he has been the Executive Director of the Coastal Education & Research Foundation and Editor-in-Chief of the international Journal ofCoastal Research. In addition to these duties, he is Professor at Florida Atlantic University in Boca Raton, Florida, USA. He is a graduate of theUniversity of Western Australia (Perth) and previously worked for a wholly owned Australian subsidiary of the International Nickel Company ofCanada (INCO). During his career, he acquired field experience in Australia; the Caribbean; South America; SW Pacific islands; southern Africa;Western Europe; and the Pacific Northwest, Midwest, and Southeast USA.

Founding Series EditorProfessor Rhodes W. Fairbridge (deceased) has edited more than 24 Encyclopedias in the Earth Sciences Series. During his career he has worked asa petroleum geologist in theMiddle East, been aWW II intelligence officer in the SWPacific and led expeditions to the Sahara, Arctic Canada, ArcticScandinavia, Brazil and New Guinea. He was Emeritus Professor of Geology at Columbia University and was affiliated with the Goddard Institutefor Space Studies.

ENCYCLOPEDIA OF EARTH SCIENCES SERIES

ENCYCLOPEDIA ofREMOTE SENSING

edited by

ENI G. NJOKUJet Propulsion Laboratory

California Institute of TechnologyPasadena, California

USA

Library of Congress Control Number: 2013953424

ISBN 978-0-387-36698-2This publication is available also as:Electronic publication under ISBN 978-0-387-36699-9 andPrint and electronic bundle under ISBN 978-0-387-36700-2

Springer New York, Heidelberg, Dordrecht, London

Printed on acid-free paper

Cover photo: Cloud formations over the western Aleuthian Islands, taken by Landsat 7, 1 June 2000.Credit: US Geological Survey, Earth Resources Observation and Science (EROS) Center.

Every effort has been made to contact the copyright holders of the figures and tables which have been reproducedfrom other sources. Anyone who has not been properly credited is requested to contact the publishers, so that dueacknowledgment may be made in subsequent editions.

All rights reserved for the contributionsAerosols;Air Pollution;AtmosphericGeneral CirculationModels;Calibration andValidation;Calibration, Optical/InfraredPassive Sensors;Calibration, Synthetic Aperture Radars;CloudProperties;DataProcessing, SAR Sensors; Earth System Models; Emerging Technologies; Emerging Technologies, Free-Space OpticalCommunications; Emerging Technologies, Radar; Emerging Technologies, Radiometer; Geodesy; Geomorphology;Geophysical Retrieval, Forward Models in Remote Sensing; Geophysical Retrieval, Inverse Problems in Remote Sensing;Geophysical Retrieval, Overview; GPS, Occultation Systems; Ionospheric Effects on the Propagation of ElectromagneticWaves; Irrigation Management; Land Surface Roughness; Land-Atmosphere Interactions, Evapotranspiration; LidarSystems; Limb Sounding, Atmospheric;Madden-Julian Oscillation (MJO);Mission Costs of Earth-Observing Satellite;Ocean Surface Topography; Ocean-Atmosphere Water Flux and Evaporation; Precision Agriculture; Reflected SolarRadiation Sensors, Multiangle Imaging; Reflected Solar Radiation Sensors, Polarimetric; Sea Level Rise; Sea SurfaceWind/Stress Vector; Solid Earth Mass Transport; Stratospheric Ozone; Terrestrial Snow; Thermal Radiation Sensors(Emitted); Trace Gases, Stratosphere, andMesosphere;Urban Environments, Beijing Case Study;Volcanism;Water Vapor

© Springer Science+Business Media New York 2014

No part of this work may be reproduced, stored in a retrieval system, or transmitted in any form or by any means,electronic, mechanical, photocopying, microfilming, recording or otherwise, without written permission from thePublisher, with the exception of any material supplied specifically for the purpose of being entered and executed ona computer system, for exclusive use by the purchaser of the work.

Contents

Contributors xi

Preface xxiii

Acknowledgments xxv

Acoustic Radiation 1Alain Weill

Acoustic Tomography, Ocean 4Brian Dushaw

Acoustic Waves, Propagation 11Alain Weill

Acoustic Waves, Scattering 13Alain Weill

Aerosols 16Ralph Kahn

Agricultural Expansion and Abandonment 20Jiaguo Qi

Agriculture and Remote Sensing 22Jerry Hatfield and Susan Moran

Air Pollution 32Annmarie Eldering

Atmospheric General Circulation Models 35Joao Teixeira, Mark Taylor, Anders Perssonand Georgios Matheou

Calibration and Validation 39Andreas Colliander

Calibration, Microwave Radiometers 46Christopher Ruf

Calibration, Optical/Infrared Passive Sensors 47Carol Bruegge

Calibration, Synthetic Aperture Radars 51Anthony Freeman

Calibration, Scatterometers 54David Long

Climate Data Records 58Eric F. Wood

Climate Monitoring and Prediction 58Mathew R. P. Sapiano

Cloud Liquid Water 68Fuzhong Weng

Cloud Properties 70Matthew Lebsock and Steve Cooper

Coastal Ecosystems 73Xiaojun Yang

Commercial Remote Sensing 78William Gail

Cosmic-Ray Hydrometeorology 83Darin Desilets and Marek Zreda

Cost Benefit Assessment 86Molly Macauley

Crop Stress 88Susan Moran

Cryosphere and Polar Region Observing System 91Mark Drinkwater

Cryosphere, Climate Change Effects 98Aixue Hu

Cryosphere, Climate Change Feedbacks 101Peter J. Minnett

Cryosphere, Measurements and Applications 104Roger Barry

Data Access 119Ron Weaver

Data Archival and Distribution 121Mark A. Parsons

Data Archives and Repositories 127Ruth Duerr

Data Assimilation 131Dennis McLaughlin

Data Policies 134Ray Harris

Data Processing, SAR Sensors 136Jakob van Zyl

Decision Fusion, Classificationof Multisource Data 140

Björn Waske and Jón Atli Benediktsson

Earth Radiation Budget, Top-of-AtmosphereRadiation 145

Bing Lin

Earth System Models 146Andrea Donnellan

Electromagnetic Theory and Wave Propagation 150Yang Du

Emerging Applications 159William Gail

Emerging Technologies 162Jason Hyon

Emerging Technologies, Free-Space OpticalCommunications 163

Hamid Hemmati

Emerging Technologies, Lidar 177David M. Tratt

Emerging Technologies, Radar 185Alina Moussessian

Emerging Technologies, Radiometer 186Todd Gaier

Emerging Technologies, Sensor Web 190Mahta Moghaddam, Agnelo Silvaand Mingyan Liu

Environmental Treaties 196Alexander de Sherbinin

Fields and Radiation 201Frank S. Marzano

Fisheries 202Cara Wilson

Forestry 210Dar Roberts

Gamma and X-Radiation 219Enrico Costa and Fabio Muleri

Geodesy 228Calvin Klatt

Geological Mapping Using Earth’sMagnetic Field 232

Vernon H. Singhroy and Mark Pilkington

Geomorphology 237David Pieri

Geophysical Retrieval, Forward Modelsin Remote Sensing 241

Eugene Ustinov

Geophysical Retrieval, Inverse Problemsin Remote Sensing 247

Eugene Ustinov

Geophysical Retrieval, Overview 251Eugene Ustinov

Global Climate Observing System 254Jean-Louis Fellous

Global Earth Observation Systemof Systems (GEOSS) 257

Steffen Fritz

Global Land Observing System 261Johannes A. Dolman

Global Programs, Operational Systems 263Mary Kicza

GPS, Occultation Systems 264Chi O. Ao

vi CONTENTS

Ice Sheets and Ice Volume 269Robert Thomas

Icebergs 281Donald L. Murphy

International Collaboration 284Lisa Robock Shaffer

Ionospheric Effects on the Propagationof Electromagnetic Waves 286

Attila Komjathy

Irrigation Management 291Steven R. Evett, Paul D. Colaizzi, Susan A.O’Shaughnessy, Douglas J. Hunsakerand Robert G. Evans

Land Surface Emissivity 303Alan Gillespie

Land Surface Roughness 311Thomas Farr

Land Surface Temperature 314Alan Gillespie

Land Surface Topography 320G. Bryan Bailey

Land-Atmosphere Interactions, Evapotranspiration 325Joshua B. Fisher

Landslides 328Vernon H. Singhroy

Law of Remote Sensing 332Joanne Irene Gabrynowicz

Lidar Systems 334Robert Menzies

Lightning 339Rachel I. Albrecht, Daniel J. Ceciland Steven J. Goodman

Limb Sounding, Atmospheric 344Nathaniel Livesey

Madden-Julian Oscillation (MJO) 349Baijun Tian and Duane Waliser

Magnetic Field 358Nils Olsen

Media, Electromagnetic Characteristics 362Yang Du

Microwave Dielectric Properties of Materials 364Martti Hallikainen

Microwave Horn Antennas 375Yahya Rahmat-Samii

Microwave Radiometers 382Niels Skou

Microwave Radiometers, Conventional 386Niels Skou

Microwave Radiometers, Correlation 389Christopher Ruf

Microwave Radiometers, Interferometers 390Manuel Martin-Neira

Microwave Radiometers, Polarimeters 395David Kunkee

Microwave Subsurface Propagation and Scattering 398Alexander Yarovoy

Microwave Surface Scattering and Emission 403David R. Lyzenga

Mission Costs of Earth-Observing Satellites 405Randall Friedl and Stacey Boland

Mission Operations, ScienceApplications/Requirements 407

David L. Glackin

Observational Platforms, Aircraft, and UAVs 409Jeffrey Myers

Observational Systems, Satellite 412David L. Glackin

Ocean Applications of Interferometric SAR 426Roland Romeiser

Ocean Data Telemetry 429Michael R. Prior-Jones

Ocean Internal Waves 433Werner Alpers

Ocean Measurements and Applications,Ocean Color 437

Samantha Lavender

Ocean Modeling and Data Assimilation 446Detlef Stammer

Ocean Surface Topography 455Lee-Lueng Fu

CONTENTS vii

Ocean Surface Velocity 461Bertrand Chapron, Johnny Johannessenand Fabrice Collard

Ocean, Measurements and Applications 469Ian Robinson

Ocean-Atmosphere Water Flux and Evaporation 480W. Timothy Liu and Xiaosu Xie

Operational Transition 489Richard Anthes

Optical/Infrared, Atmospheric Absorption/Transmission, and Media Spectral Properties 492

Gian Luigi Liberti

Optical/Infrared, Radiative Transfer 495Knut Stamnes

Optical/Infrared, Scattering by Aerosolsand Hydrometeors 498

Gian Luigi Liberti

Pattern Recognition and Classification 503Björn Waske and Jón Atli Benediktsson

Polar Ice Dynamics 509James Maslanik

Polar Ocean Navigation 512Lawson Brigham

Policies and Economics 515Roberta Balstad

Precision Agriculture 515Kelly Thorp

Processing Levels 517Ron Weaver

Public-Private Partnerships 520William Gail

Radar, Altimeters 525Keith Raney

Radar, Scatterometers 532David Long

Radar, Synthetic Aperture 536Keith Raney

Radars 547Keith Raney

Radiation (Natural) Within the Earth’sEnvironment 558

Anthony England

Radiation Sources (Natural) and Characteristics 574Anthony England

Radiation, Electromagnetic 576Frank S. Marzano

Radiation, Galactic, and Cosmic Background 581David M. Le Vine

Radiation, Multiple Scattering 585Frank S. Marzano

Radiation, Polarization, and Coherence 588Yang Du

Radiation, Solar and Lunar 591David M. Le Vine

Radiation, Volume Scattering 595Leung Tsang and Kung-Hau Ding

Radiative Transfer, Solution Techniques 606Rodolfo Guzzi

Radiative Transfer, Theory 624Frank S. Marzano

Radio-Frequency Interference (RFI) in PassiveMicrowave Sensing 634

David Kunkee

Rainfall 640Ralph Ferraro

Rangelands and Grazing 653Hunt E. Raymond, Jr.

Reflected Solar Radiation Sensors,Multiangle Imaging 658

David J. Diner

Reflected Solar Radiation Sensors, Polarimetric 663David J. Diner

Reflector Antennas 668Yahya Rahmat-Samii

Remote Sensing and Geologic Structure 681Vernon H. Singhroy and Paul Lowman

Remote Sensing, Historical Perspective 684Vincent V. Salomonson

viii CONTENTS

Remote Sensing, Physics and Techniques 691David L. Glackin

Resource Exploration 702Fred A. Kruse and Sandra L. Perry

SAR-Based Bathymetry 719Han Wensink and Werner Alpers

Sea Ice Albedo 722Donald Perovich

Sea Ice Concentration and Extent 727Josefino C. Comiso

Sea Level Rise 743Josh Willis

Sea Surface Salinity 747Gary Lagerloef

Sea Surface Temperature 754Peter J. Minnett

Sea Surface Wind/Stress Vector 759W. Timothy Liu and Xiaosu Xie

Severe Storms 767Charles A. III Doswell

Snowfall 780Ralf Bennartz

Soil Moisture 783Yann Kerr

Soil Properties 788Alfredo Huete

Solid Earth Mass Transport 791Erik Ivins

Stratospheric Ozone 796Michelle Santee

Subsidence 800Stuart Marsh and Martin Culshaw

Surface Radiative Fluxes 806Rachel T. Pinker

Surface Truth 815Christopher Ruf

Surface Water 816Michael Durand

Terrestrial Snow 821Son V. Nghiem, Dorothy K. Hall, James L. Fosterand Gregory Neumann

Thermal Radiation Sensors (Emitted) 830Simon Hook

Trace Gases, Stratosphere, and Mesosphere 834Nathaniel Livesey

Trace Gases, Troposphere - Detection from Space 838Pieternel F. Levelt, J. P. Veefkind and K. F. Boersma

Trafficability of Desert Terrains 846Charles Hibbitts

Tropospheric Winds 849Chris Velden

Ultraviolet Remote Sensing 853Arlin Krueger

Ultraviolet Sensors 860Arlin Krueger

Urban Environments, Beijing Case Study 869Son V. Nghiem, Alessandro Sorichetta, ChristopherD. Elvidge, Christopher Small, Deborah Balk,Uwe Deichmann and Gregory Neumann

Urban Heat Island 878Lela Prashad

Vegetation Indices 883Alfredo Huete

Vegetation Phenology 886John Kimball

Volcanism 890Michael J. Abrams

Water and Energy Cycles 895Taikan Oki and Pat J.-F. Yeh

Water Resources 903Taikan Oki and Pat J.-F. Yeh

Water Vapor 909Eric Fetzer

Weather Prediction 912Peter Bauer

Wetlands 921John Melack

Author Index 923

Subject Index 925

CONTENTS ix

Contributors

Michael J. AbramsJet Propulsion LaboratoryCalifornia Institute of TechnologyPasadena, CA 91109USAmichael.j.abrams@jpl.nasa.gov

Rachel I. AlbrechtDivisão de Satélites e Sistemas Ambientais(DSA/CPTEC), Instituto Nacional de PesquisasEspaciais (INPE)12630-000 Cachoeira Paulista, SPBrazilrachel.albrecht@cptec.inpe.br

Werner AlpersInstitute of OceanographyUniversity of Hamburg20146 HamburgGermanyalpers@ifm.uni-hamburg.de

Richard AnthesUniversity Corporation for Atmospheric ResearchBoulder, CO 80301USAanthes@ucar.edu

Chi O. AoJet Propulsion LaboratoryCalifornia Institute of TechnologyPasadena, CA 91109USAchi.o.ao@jpl.nasa.gov

G. Bryan BaileyUSGS Earth Resources Observation and Science CenterSioux Falls, SD 57198USAgbbailey@mchsi.com

Deborah BalkSchool of Public Affairs, Baruch CollegeCity University of New YorkNew York, NYUSAdeborah.balk@baruch.cuny.edu

Roberta BalstadCIESINColumbia UniversityPalisades, NY 10964USAroberta@ciesin.columbia.edu

Roger BarryNational Snow and Ice Data CenterNSIDC 449 UCBUniversity of ColoradoBoulder, CO 80309-0449USArbarry@nsidc.org

Peter BauerEuropean Centre for Medium-Range Weather Forecasts(ECMWF)Shinfield ParkReading RG2 9AXUKpeter.bauer@ecmwf.int

Jón Atli BenediktssonFaculty of Electrical and Computer EngineeringUniversity of Iceland107 ReykjavikIcelandbenedikt@hi.is

Ralf BennartzAtmospheric and Oceanic Sciences DepartmentUniversity of Wisconsin-MadisonMadison, WI 53706-1481USAbennartz@aos.wisc.edu

K. F. BoersmaKoninklijk Nederlands Meteorologisch Instituut (KNMI)3732 GK, De BiltThe NetherlandsandTechnical University Eindhoven (TUE)5612 AZ, EindhovenThe Netherlandsk.j.boersma@tu.nl

Stacey BolandJet Propulsion LaboratoryCalifornia Institute of TechnologyPasadena, CA 91109USA

Lawson BrighamUniversity of AlaskaFairbanks, AK 99775-5840USAlwb48@aol.com

Carol BrueggeJet Propulsion LaboratoryCalifornia Institute of TechnologyPasadena, CA 91109USAcarol.j.bruegge@jpl.nasa.gov

Daniel J. CecilMarshall Space Flight Center (MSFC), NationalAeronautics and Space Administration (NASA)Huntsville, AL 35805USAdaniel.j.cecil@nasa.gov

Bertrand ChapronSatellite Oceanography Laboratory, IFREMERPlouzané 29280Francebertrand.chapron@ifremer.fr

Paul D. ColaizziUSDA-ARS Conservation and Production ResearchLaboratoryBushland, TX 79012USApaul.colaizzi@ars.usda.gov

Fabrice CollardCLS, Division RadarPlouzané 29280Francedr.fab@cls.fr

Andreas CollianderJet Propulsion LaboratoryCalifornia Institute of TechnologyPasadena, CA 91109USAandreas.colliander@jpl.nasa.gov

Josefino C. ComisoCryospheric Sciences Laboratory, Code 615Earth Sciences Division, NASA Goddard SpaceFlight CenterGreenbelt, MD 20771USAjosefino.c.comiso@nasa.gov

Steve CooperJet Propulsion LaboratoryCalifornia Institute of TechnologyPasadena, CA 91109USA

Enrico CostaIstituto di Astrofisica e Planetologia Spaziali, INAF00133 RomeItalyenrico.costa@iasf-roma.inaf.it

Martin CulshawHonorary Research Associate, British Geological Survey,KeyworthNottingham NG12 1AEUKandHonorary Visiting Professor, School of Civil Engineering,University of Birmingham, EdgbastonBirmingham B15 2TTUK

Alexander de SherbininCenter for International Earth Science InformationNetwork (CIESIN)Columbia UniversityPalisades, NY 10964USAadesherbinin@ciesin.columbia.edu

xii CONTRIBUTORS

Uwe DeichmannDevelopment Research Group, The World BankWashington, DCUSAudeichmann@worldbank.org

Darin DesiletsHydroinnova LLCAlbuquerque, NM 87106USAdarin@hydroinnova.com

David J. DinerJet Propulsion LaboratoryCalifornia Institute of TechnologyPasadena, CA 91109USAdavid.j.diner@jpl.nasa.gov

Kung-Hau DingAir Force Research LaboratoryWright-Patterson AFBDayton, OH 45433USA

Johannes A. DolmanDepartment of Earth SciencesVU University Amsterdam1081 AmsterdamThe Netherlandshan.dolman@vu.nl

Andrea DonnellanScience DivisionJet Propulsion LaboratoryCalifornia Institute of TechnologyPasadena, CA 91109USAandrea.donnellan@jpl.nasa.gov

Charles A. III DoswellDoswell Scientific ConsultingNorman, OK 73071USAcdoswell@earthlink.net

Mark DrinkwaterMission Science DivisionEuropean Space Agency, ESA/ESTEC2201 AZ Noordwijk ZHThe Netherlandsmark.drinkwater@esa.int

Yang DuZhejiang University310027 HangzhouPeople’s Republic of Chinazjuydu03@zju.edu.cn

Ruth DuerrNational Snow and Ice Data Center, CIRES 449 UCB,University of ColoradoBoulder, CO 80309USArduerr@nsidc.org

Michael DurandSchool of Earth SciencesThe Ohio State University275 Mendenhall LaboratoryColumbus, OH 43210USAdurand.8@osu.edu

Brian DushawApplied Physics LaboratoryUniversity of WashingtonSeattle, WA 98105-6698USAdushaw@apl.washington.edu

Annmarie ElderingJet Propulsion LaboratoryCalifornia Institute of TechnologyPasadena, CA 91109USAannmarie.eldering@jpl.nasa.gov

Christopher D. ElvidgeEarth Observation Group, NOAA-NESDIS NationalGeophysical Data Center E/GC2Boulder, COUSAchris.elvidge@noaa.gov

Anthony EnglandCollege of EngineeringUniversity of MichiganAnn Arbor, MI 48109USAengland@umich.edu

Robert G. EvansUSDA-ARSSidney, MT 59270USArobert.evans@ars.usda.gov

Steven R. EvettUSDA-ARS Conservation and Production ResearchLaboratoryBushland, TX 79012USAsteve.evett@ars.usda.gov

CONTRIBUTORS xiii

Thomas FarrJet Propulsion LaboratoryCalifornia Institute of TechnologyPasadena, CA 91109USAthomas.g.farr@jpl.nasa.gov

Jean-Louis FellousCommittee on Space Research (COSPAR) Secretariatc/o CNES-2, place Maurice Quentin75039 ParisFrancejean-louis.fellous@cosparhq.cnes.fr

Ralph FerraroNOAA/NESDIS, ESSIC/CICSCollege Park, MD 20740USAralph.r.ferraro@noaa.gov

Eric FetzerJet Propulsion LaboratoryCalifornia Institute of TechnologyPasadena, CA 91109USAeric.j.fetzer@jpl.nasa.gov

Joshua B. FisherJet Propulsion LaboratoryCalifornia Institute of TechnologyPasadena, CA 91109USAjoshua.b.fisher@jpl.nasa.gov

James L. FosterHydrological Sciences Laboratory, Code 617National Aeronautics and Space AdministrationGoddard Space Flight CenterGreenbelt, MDUSAjames.l.foster@nasa.gov

Anthony FreemanJet Propulsion LaboratoryCalifornia Institute of TechnologyPasadena, CA 91109USAanthony.freeman@jpl.nasa.gov

Randall FriedlJet Propulsion LaboratoryCalifornia Institute of TechnologyPasadena, CA 91109USArandall.r.friedl@jpl.nasa.gov

Steffen FritzInternational Institute for Applied Systems Analysis2361 LaxenburgAustriafritz@iiasa.ac.at

Lee-Lueng FuJet Propulsion LaboratoryCalifornia Institute of TechnologyPasadena, CA 91109USAllf@jpl.nasa.gov

Joanne Irene GabrynowiczNational Center for Remote Sensing, Air, and Space LawThe University of Mississippi School of LawMissisippi, MS 38677-1848USAjgabryno@olemiss.edu

Todd GaierJet Propulsion LaboratoryCalifornia Institute of TechnologyPasadena, CA 91109USAtodd.c.gaier@jpl.nasa.gov

William GailGlobal Weather CorporationBoulder, CO 80303USAwb.gail@comcast.net

Alan GillespieDepartment of Earth and Space SciencesUniversity of WashingtonSeattle, WA 98195USAgillespie@ess.washington.edu

David L. GlackinLos Angeles, CAUSA

Steven J. GoodmanNational Environmental Satellite, Data, and InformationService (NESDIS), National Oceanic and AtmosphericAdministration (NOAA)Silver Spring, MD 20910USAsteven.j.goodman@noaa.gov

Rodolfo GuzziAgenzia Spaziale Italiana ASI00133 RomaItalyrodolfoguzzi@yahoo.it

xiv CONTRIBUTORS

Dorothy K. HallCryospheric Sciences Laboratory, Code 615NASA/Goddard Space Flight CenterGreenbelt, MD 20771USAdorothy.k.hall@nasa.gov

Martti HallikainenAalto University00076 Aalto EspooFinlandmartti.hallikainen@aalto.fi

Ray HarrisDepartment of GeographyUniversity College LondonLondon WC1E 6BTUKray.harris@ucl.ac.uk

Jerry HatfieldNational Laboratory for Agriculture and the EnvironmentAmes, IA 50011USAjerry.hatfield@ars.usda.gov

Hamid HemmatiJet Propulsion LaboratoryCalifornia Institute of TechnologyPasadena, CA 91109USAhamid.hemmati@jpl.nasa.gov

Charles HibbittsApplied Physics LaboratoryLaurel, MD 20723USAkarl.hibbitts@jhuapl.edu

Simon HookJet Propulsion LaboratoryCalifornia Institute of TechnologyPasadena, CA 91109USAsimon.j.hook@jpl.nasa.gov

Aixue HuClimate and Global Dynamics DivisionNational Center for Atmospheric ResearchBoulder, CO 80305USAahu@ucar.edu

Alfredo HuetePlant Functional Biology and Climate Change ClusterFaculty of ScienceUniversity of Technology2007 Sydney, NSWAustraliaalfredo.huete@uts.edu.au

Douglas J. HunsakerUSDA-ARSMaricopa, AZ 85138USAdoug.hunsaker@ars.usda.gov

E. Raymond Hunt, Jr.USDA-ARS Hydrology and Remote Sensing LaboratoryBeltsville, MD 20705USAraymond.hunt@ars.usda.gov

Jason HyonJet Propulsion LaboratoryCalifornia Institute of TechnologyPasadena, CA 91109USAjason.j.hyon@jpl.nasa.gov

Erik IvinsJet Propulsion LaboratoryCalifornia Institute of TechnologyPasadena, CA 9109USAerik.r.ivins@jpl.nasa.gov

Johnny JohannessenNansen Environmental and Remote Sensing Center5006 BergenNorwayjohnny.johannessen@nersc.no

Ralph KahnNASA Goddard Space Flight CenterGreenbelt, MD 20771USAralph.kahn@nasa.gov

Yann KerrCNES/CESBIO31401 ToulouseFranceyann.kerr@cesbio.cnes.fr

Mary KiczaNational Oceanic and Atmospheric Administration(NOAA)Washington, DC 20230USAnina.jackson@noaa.gov

CONTRIBUTORS xv

John KimballFlathead Lake Biological StationUniversity of MontanaPolson, MT 59860-6815USAjohnk@ntsg.umt.edu

Calvin KlattGeodetic Survey DivisionNatural Resources CanadaOttawa, ON K1A 0E9Canadacklatt@nrcan.gc.ca

Attila KomjathyJet Propulsion LaboratoryCalifornia Institute of TechnologyPasadena, CA 91109USAattila.komjathy@jpl.nasa.gov

Arlin KruegerAtmospheric Chemistry and Dynamics Laboratory(Code 614)NASA/Goddard Space Flight CenterGreenbelt, MD 20771USAakrueger3@verizon.net

Fred A. KrusePhysics Department and Remote Sensing CenterNaval Postgraduate SchoolMonterey, CA 93943USAfakruse@nps.edu

David KunkeeThe Aerospace CorporationLos Angeles, CA 90009USAdavid.b.kunkee@aero.org

Gary LagerloefESRSeattle, WA 98121USAlager@esr.org

Samantha LavenderPixalytics LtdPlymouth, Devon PL6 8BXUKslavender@pixalytics.com

David M. Le VineCode 615, Cryopsheric Sciences BranchNASA/Goddard Space Flight CenterGreenbelt, MD 20771USAdavid.m.levine@nasa.gov

Matthew LebsockJet Propulsion LaboratoryCalifornia Institute of TechnologyPasadena, CA 91109USAmatthew.d.lebsock@jpl.nasa.gov

Pieternel F. LeveltKoninklijk Nederlands Meteorologisch Instituut (KNMI)3730 AE De BiltThe NetherlandsandDelft University of Technology5612 AE EindhovenThe Netherlandspieternel.levelt@knmi.nl

Gian Luigi LibertiCNR/ISAC00133 RomeItalyg.liberti@isac.cnr.it

Bing LinNASA Langley Research Center, MS 420Hampton, VA 23681-2199USAbing.lin@nasa.gov

Mingyan LiuElectrical and Computer EngineeringUniversity of MichiganAnn Arbor, MI 48109USA

W. Timothy LiuJet Propulsion LaboratoryCalifornia Institute of TechnologyPasadena, CA 91109USAw.t.liu@jpl.nasa.gov

Nathaniel LiveseyJet Propulsion LaboratoryCalifornia Institute of TechnologyPasadena, CA 91109USAnathaniel.j.livesey@jpl.nasa.gov

xvi CONTRIBUTORS

David LongDepartment of Electrical and Computer EngineeringBYU Center for Remote SensingBrigham Young UniversityProvo, UT 84602USAlong@byu.edu

Paul LowmanNASA Goddard, Code 698.0Greenbelt, MD 20771USApaul.d.lowman@nasa.gov

David R. LyzengaCollege of Engineering, Naval Architecture and MarineEngineeringUniversity of MichiganAnn Arbor, MI 48109-2145USAlyzenga@umich.edu

Molly MacauleyResources for the FutureWashington, DC 202-328-5043USAmacauley@rff.org

Stuart MarshNottingham Geospatial InstituteThe University of NottinghamNottingham Geospatial Building, Triumph RoadNottingham NG7 2TUUKngi@nottingham.ac.uk

Manuel Martin-NeiraEuropean Space Agency (ESA-ESTEC)Keplerlaan 12200 NoordwijkThe Netherlandsmanuel.martin-neira@esa.int

Frank S. MarzanoDepartment of Information EngineeringSapienza University of Rome00184 RomeItalyandCentre of Excellence CETEMPSUniversity of L'Aquila67100 L'AquilaItalyfrank.marzano@uniroma1.it

James MaslanikDepartment of Aerospace Engineering SciencesUniversity of Colorado, CCARBoulder, CO 80309USAjimm@colorado.edu

Georgios MatheouJet Propulsion LaboratoryCalifornia Institute of TechnologyPasadena, CA 91109USAgeorgios.matheou@jpl.nasa.gov

Dennis McLaughlinDepartment of Civil and Environmental EngineeringMassachusetts Institute of TechnologyCambridge, MA 02139USAdennism@mit.edu

John MelackDepartment of Ecology, Evolution and Marine BiologyUniversity of CaliforniaSanta Barbara, CA 93106USAmelack@lifesci.ucsb.edu

Robert MenziesJet Propulsion LaboratoryCalifornia Institute of TechnologyPasadena, CA 91109USArobert.t.menzies@jpl.nasa.gov

Peter J. MinnettRosenstiel School of Marine and Atmospheric ScienceUniversity of MiamiMiami, FL 33149USApminnett@rsmas.miami.edu

Mahta MoghaddamElectrical Engineering – ElectrophysicsUniversity of Southern CaliforniaLos Angeles, CA 0089USAmahta@usc.edu

Susan MoranUSDA ARS Southwest Watershed Research CenterTuscon, AZ 85719USAsusan.moran@ars.usda.gov

CONTRIBUTORS xvii

Alina MoussessianJet Propulsion LaboratoryCalifornia Institute of TechnologyPasadena, CA 91109USAalina.moussessian@jpl.nasa.gov

Fabio MuleriIstituto di Astrofisica e Planetologia Spaziali, INAF00133 RomeItalyfabio.muleri@lasf-roma.inaf.it

Donald L. MurphyInternational Ice Patrol, US Coast GuardNew London, CT 06320USAiipcomms@uscg.mil

Jeffrey MyersNASA/Ames Research Center, Airborne Science andTechnology LaboratoryUniversity of California, Santa CruzMS244-15Moffett Field, CA 94035USAjmyers@mail.arc.nasa.gov

Gregory NeumannJet Propulsion LaboratoryCalifornia Institute of TechnologyPasadena, CA 91109USAgregory.neumann@jpl.nasa.gov

Son V. NghiemJet Propulsion LaboratoryCalifornia Institute of TechnologyPasadena, CA 91109USAson.v.nghiem@jpl.nasa.gov

Taikan OkiInstitute of Industrial Science, University of Tokyo153-8505 TokyoJapantaikan@iis.u-tokyo.ac.jp

Nils OlsenDTU SpaceTechnical University of Denmark2800 Kgs. LyngbyDenmarknio@space.dtu.dk

Susan A. O’ShaughnessyUSDA-ARS Conservation and Production ResearchLaboratoryBushland, TX 79012USAsusan.oshaughnessy@ars.usda.gov

Mark A. ParsonsCenter for a Digital SocietyRensselaer Polytechnic InstituteTroy, NY 12180USAparsonsm@nsidc.org

Donald PerovichUSACE Cold Regions Research and EngineeringLaboratoryHanover, NH 03755-1250USAdonald.k.perovich@erdc.usace.army.mil

Sandra L. PerryPerry Remote Sensing, LLCDenver, CO 80231USAsandyp@rm.incc.net

Anders PerssonUnited Kingdom Meteorological OfficeExeterDevon, EX1 3PBUK

David PieriJet Propulsion LaboratoryCalifornia Institute of TechnologyPasadena, CA 91109USAdave.pieri@jpl.nasa.gov

Mark PilkingtonGeological Survey of CanadaOttawa, ON K1A 0E9Canadamark.pilkington@nrcan-rncan.gc.ca

Rachel T. PinkerDepartment of Atmospheric and Oceanic ScienceUniversity of MarylandCollege Park, MD 20742USApinker@atmos.umd.edu

xviii CONTRIBUTORS

Lela PrashadSchool of Earth and Space Exploration, 100 Cities ProjectArizona State UniversityTempe, AZ 85287-1404USAlprashad@asu.edu

Michael R. Prior-JonesBritish Antarctic SurveyCambridge CB3 OETUKmichael@randominformation.co.uk

Jiaguo QiDepartment of Geography/CGCEOMichigan State UniversityEast Lansing, MI 48823USAqi@msu.edu

Yahya Rahmat-SamiiDepartment of Electrical EngineeringUniversity of California at Los AngelesLos Angeles, CA 90095USArahmat@ee.ucla.edu

Keith RaneyApplied Physics LaboratoryJohns Hopkins UniversityLaurel, MD 20723USAkeith.raney@jhuapl.edu

Dar RobertsDepartment of GeographyUniversity of CaliforniaSanta Barbara, CA 93106USAdar@geog.ucsb.edu

Ian RobinsonOcean and Earth ScienceUniversity of Southampton, at National OceanographyCentreSouthampton SO14 3ZHUKisr@noc.soton.ac.uk

Roland RomeiserRosenstiel School of Marine and Atmospheric ScienceUniversity of MiamiMiami, FL 33149-1031USArromeiser@rsmas.miami.edu

Christopher RufDepartment of Atmospheric, Oceanic and Space SciencesUniversity of MichiganAnn Arbor, MI 48109USAcruf@umich.edu

Vincent V. SalomonsonDepartment of Geography, University of UtahSouth Jordan, UT 84095USAvincent.v.salomonson@nasa.gov

Michelle SanteeJet Propulsion LaboratoryCalifornia Institute of TechnologyPasadena, CA 91109USAmichelle.l.santee@jpl.nasa.gov

Mathew R. P. SapianoUniversity of Maryland - College ParkCollege Park, MD 20742USAmsapiano@atmos.colostate.edu

Lisa Robock ShafferMC 0553 Rady School of ManagementUniversity of California, San DiegoLa Jolla, CA 92093-0553USAlshaffer@ucsd.edu

Agnelo SilvaElectrical Engineering – ElectrophysicsUniversity of Southern CaliforniaLos Angeles, CA 0089USA

Vernon H. SinghroyApplications Development SectionNatural Resources CanadaCanada Centre for Remote SensingOttawa, ON K1A 0Y7Canadavern.singhroy@nrcan-rncan.gc.ca

Niels SkouNational Space InstituteTechnical University of Denmark2800 LyngbyDenmarkns@space.dtu.dk

CONTRIBUTORS xix

Christopher SmallLamont Doherty Earth ObservatoryMarine Geology and GeophysicsColumbia UniversityPalisades, NYUSAcs184@columbia.edu

Alessandro SorichettaDipartimento di Scienze della Terra “A. Desio”Universita' degli Studi di Milano20122 MilanItalyalessandro.sorichetta@unimi.it

Detlef StammerInstitut für Meereskunde, Zentrum für Marine undAtmosphärische WissenschaftenUniversität Hamburg20146 HamburgGermanydetlef.stammer@zmaw.de

Knut StamnesStevens Institute of Technology, Castle Point on HudsonHoboken, NJ 07030-5991USAkstamnes@stevens.edu

Mark TaylorSandia National LaboratoryAlbuquerque, New Mexico 91109USAmataylor@sandia.gov

Joao TeixeiraJet Propulsion LaboratoryCalifornia Institute of TechnologyPasadena, CA 91109USAteixeira@jpl.nasa.gov

Robert ThomasSigma Space66-400 Gorzow WlkpPolandrobert_thomas@hotmail.com

Kelly ThorpUSDA-ARS U.S. Arid-Land Agricultural ResearchCenterMaricopa, AZ 85138USAkelly.thorp@ars.usda.gov

Baijun TianJet Propulsion LaboratoryCalifornia Institute of TechnologyPasadena, CA 91109USAbaijun.tian@jpl.nasa.gov

David M. TrattThe Aerospace CorporationLos Angeles, CA 90009-2957USAdtratt@aero.org

Leung TsangPaul Allen CenterDepartment of Electrical EngineeringUniversity of WashingtonSeattle, WA 98195-2500USAleung@ee.washington.edu

Eugene UstinovJet Propulsion LaboratoryCalifornia Institute of TechnologyPasadena, CA 91109USAeugene.a.ustinov@jpl.nasa.gov

Jakob van ZylJet Propulsion LaboratoryCalifornia Institute of TechnologyPasadena, CA 91109USAjakob.j.vanzyl@jpl.nasa.gov

J. P. VeefkindKoninklijk Nederlands Meteorologisch Instituut (KNMI)3732 GK, De BiltThe NetherlandsandEindhoven University of Technology5612 AE EindhovenThe Netherlandsveefkind@knmi.n

Chris VeldenUniversity of Wisconsin, CIMSSMadison, WI 53706USAchrisv@ssec.wisc.edu

Duane WaliserJet Propulsion LaboratoryCalifornia Institute of TechnologyPasadena, CA 9109USAduane.e.waliser@jpl.nasa.gov

xx CONTRIBUTORS

Björn WaskeInstitute of Geodesy and GeoinformationUniversity of Bonn53115 BonnGermanywf@ipb.uni-bonn.de

Ron WeaverNational Snow and Ice Data Center, Cooperative Institutefor Research in Environmental SciencesUniversity of ColoradoBoulder, CO 80309-0449USAweaverr@kryos.colorado.edu

Alain WeillBur. JussieuLATMOS, Laboratoire Atmosphere MilieuxObservations Spatiales75005 ParisFrancealain.weill@latmos.ipsl.fr

Fuzhong WengCenter for Satellite Applications and Research (STAR)National Oceanic and Atmospheric AdministrationCollege Park, MD 20740USAfuzhong.weng@noaa.gov

Han WensinkARGOSS BV8325ZH VollenhoveThe Netherlandswensink@argoss.nl

Josh WillisJet Propulsion LaboratoryCalifornia Institute of TechnologyPasadena, CA 91109USAjoshua.k.willis@jpl.nasa.gov

Cara WilsonSouthwest Fisheries Science CenterNOAA/NMFS, Environmental Research DivisionPacific Grove, CA 93950-2097USAcara.wilson@noaa.gov

Eric F. WoodDepartment of Civil and Environmental EngineeringPrinceton UniversityPrinceton, NJ 08544USAefwood@princeton.edu

Xiaosu XieJet Propulsion LaboratoryCalifornia Institute of TechnologyPasadena, CA 91109USAxiaosu.xie@jpl.nasa.gov

Xiaojun YangDepartment of GeographyFlorida State UniversityTallahassee, FL 32306-2190USAxyang@fsu.edu

Alexander YarovoyDelft University of Technology2628 CN DelftThe Netherlandsa.yarovoy@tudelft.nl

Pat J.-F. YehDepartment of Civil and Environmental EngineeringNational University of Singapore117576 SingaporeSingaporeceeyehj@nus.edu.sg

Marek ZredaDepartment of Hydrology and Water ResourcesUniversity of ArizonaTucson, AZ 85721USAmarek@hwr.arizona.edu

CONTRIBUTORS xxi

Preface

During the past few decades, the emergence of remotesensing as a discipline – its science, instruments, missions,and applications – has inspired new and comprehensivestudies of the Earth. Detailed observations of Earth’s land,ocean and atmospheric processes, and measurements ofhitherto unexplored geophysical phenomena have beenmade possible by remote sensing instruments on ground-based, airborne, and spaceborne platforms. In particular,the unique vantage point of space provides spatially exten-sive and global perspectives of Earth. Frequent measure-ments, made hourly, daily, or weekly, over extendedperiods of years to decades, depending on the observingsystem and its configuration, have enabled comprehensivestudies of Earth’s global system. Remote sensing has thusprofoundly altered our understanding of the world inwhich we live, and has revolutionized the approaches weuse to study our environment. Each year the growing num-ber of Earth observing satellites, and the increasingly hugeamounts of data and information provided, yield newknowledge and greater appreciation of the changes occur-ring on our planet, with important implications for futuregenerations of Earth inhabitants. This encyclopedia isa comprehensive reference work on Earth remote sensingthat presents the foundations, principles, and state of theart of remote sensing and describes the diverse applica-tions it serves. It covers the concepts, techniques, instru-mentation, data analysis, interpretation, and applicationsof remote sensing. This volume is part of the Encyclopediaof Earth Science series and is organized in the same styleas other volumes in the series. The scientific disciplinescovered by the series have all benefited in one way oranother from the new understanding and discoveriesafforded by remote sensing. It is thus timely for publica-tion of an encyclopedia that can link these disciplinesand the remote sensing techniques relevant to them in anintegrated framework.

The focus of the encyclopedia is on remote sensing ofEarth – its atmosphere, oceans, cryosphere, and land

surface and subsurface. Some of the techniques describedin this volume have their origins in the disciplines of astron-omy and astrophysics, and the study of the stars and planetsfor which, until recently, remote sensing was the onlymeans of obtaining observational scientific data. Whenapplied to Earth, these techniques have blossomed intoa remarkably diverse and increasingly sophisticated set ofscientific, technological, and computational approaches thatall fall under the umbrella of remote sensing. The rapidgrowth of remote sensing as a discipline is evidenced bythe large number of scientific journals now devoted to thisfield, and the number of courses and degree programsoffered at universities around the world. The measurementand interpretation of radiation scattered and emitted byEarth’s atmosphere, surface, and subsurface is what wegenerally mean when we speak of Earth remote sensing.Thesemeasurements are obtained by instruments on remoteplatforms that include satellites, aircraft, balloons, drones,trucks, and stationary towers. Remote sensing instrumentstake many forms and are designed to measure electromag-netic radiation in specific wavelength regions of the broadelectromagnetic spectrum; some instruments use otherforms of radiation such as acoustic radiation.Measurementsfrom the wide array of instruments, operating on the varietyof available platforms available, can be processed and ana-lyzed to extract characteristic information about Earth andits constituent biological, chemical, and physical structures,at resolutions from centimeters to thousands of kilometers.This remotely sensed information can be used on its ownor combined with direct or ‘in situ’measurements and geo-physical models to give a more comprehensive understand-ing of the diversity of Earth science phenomena, some ofwhichwould be very limitedwithout the unique perspectivebrought by remote sensing.

It is clear that an attempt to fully cover the breadth anddepth of topics in remote sensing is a daunting task. Never-theless, the need for a compendium that can be used asa reference work for this field, as a living document that

can be updated periodically to capture new advances, isa pressing one. It is with this aim in mind that the SpringerEncyclopedia of Remote Sensing was conceived. Both thisprint version of the encyclopedia, which can be updatedwith revisions once every several years, and an onlineversion, which can be updated on a more frequent basisby authors of individual entries, are provided. The onlineversion can accommodate introduction of new entriesas the need for new topics or treatments emerges.The encyclopedia entries cover topics that include broadintroductory surveys as well as more in-depth treatment ofsome subjects. The entries treat topics of the physical prin-ciples of remote sensing in different wavelength regimes,propagation and scattering of radiation, geophysicalmodels, remote sensing instrumentation, retrieval methods,remote sensing platforms and observational configurations.The models and retrieval methods are described withreference to specific applications in atmosphere, ocean,cryosphere, land, and solid earth geophysics. These applica-tions include human impacts of climate change, and theenabling interdisciplinary science, as well as applicationsof direct societal benefit such as human health, foodsecurity, and prediction and mitigation of natural hazards.Earth remote sensing from space has flourished in the pastfew decades, and has become a truly global enterprisethrough development of international collaborations andpartnerships, with investments from an increasing numberof countries in building and operating satellite observationalsystems. Several entries in this volume have been devotedto describing these programs, and associated internationalpolicies and principles.

This encyclopedia is designed to support the needs ofstudents, teachers, and professionals across a broad

spectrum of science, technology, and societal applica-tions related to Earth remote sensing. The intendedaudience includes those with observational interests inthe fields of oceanography, atmospheric sciences, meteo-rology, climate, cryospheric studies, hydrology, geology,solid earth geophysics, ecology, agronomy, forestry,environmental pollution, geography, land use and socialstudies, among others. The target audience also includesthose with interests in remote sensing theory andpractice, electromagnetic propagation, radiative transfermodeling, remote sensing instruments, spacecraftsystems and orbits, environmental policy and decision-making, resource planning, and monitoring and forecast-ing of extreme events and natural hazards. In thecommercial sector, economists, legal and insurancecompanies, and commercial and industrial concerns rely-ing on the production, marketing and availability ofvalue-added remote sensing products will also find theencyclopedia a valuable resource. The entries arepresented in alphabetical order with titles that aredesigned to aid searches for specific topics. Cross-referencing using keywords to related entries is alsoprovided to support efficient searches for information ofinterest to readers. The entries provide bibliographiesfor further in-depth reading. In summary, though itcannot be claimed that this encyclopedia represents anexhaustive treatment or complete coverage of the fieldof Earth remote sensing, it is hoped that the volume willserve as a comprehensive and dynamic introduction,and initial entry point, to inspire further reading andstudy of this exciting and rapidly developing field.

September 2013 Eni G. Njoku

xxiv PREFACE

Acknowledgments

A work the size of this encyclopedia inevitably relies onthe help and cooperation of a large number of people, onlysome of whom can be individually identified and thankedhere. My particular thanks go to the Board ofSection Editors, a group of diverse and highly respectedremote sensing scientists. To Mike Abrams, GhassemAsrar, Frank Marzano, Peter Minnett, Vince Salomonson,Vern Singhroy, and Joe Turk, thank you for keeping thisproject on course by helping to choose the topics that formthe entries, suggesting high-quality authors, reviewing theinitial manuscripts, and finally checking proofs with yourselected groups of authors as well as writing importantcontributions yourselves. I also wish to acknowledge thegreat help of Roberta Balstad, Farouk El-Baz, MoustafaChahine, Jean-Marie Dubois, A.J. Chen, Robert Gurney,Jim Smith, and Guido Visconti who contributed to theearly selection of topics and authors for the encyclopedia.My thanks are due also to Tom Farr who assisted me withthe editorial duties during a critical stage in the project.

This leads to the largest group I wish to acknowledge,the authors of the 170 entries that range in size fromseveral hundred words up to major contributions ofseveral thousand words. Many authors took on more thanone entry within their specialty area. Due to the length oftime required to produce a volume of this type many

authors who submitted entries early had to waita considerable amount of time before their entries werefinally published. To these authors I especially wish toexpress my thanks for their patience and dedication tothe completion of the project, and I hope they find the finalvolume worth the wait.

At the production end of the project has been the staff ofSpringer. Their help, understanding, and cooperation,especially when problems needed to be overcome, issomething that cannot be appreciated enough. Theirpatient discussions and exchanges with the authors andboard members did much to maintain the smooth progressof the project. Special acknowledgment should go to Petravan Steenbergen and Sylvia Blago who provided me withencouragement through many difficult periods, and toSimone Giesler, all of who were involved with theencyclopedia from start to finish. I must also acknowledgethe rewarding environment of my host institution andcolleagues, all of whom provided a rich source of motiva-tion and ideas in the field of remote sensing to inspirea publication of this type. My final appreciation goes tomy wife Mary whose patience and support over the yearshas been a major factor in my ability to undertake this task,and to my son Eni Jr. who reminds me constantly of thepower of positive thinking.