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NISAR:TheNASA-ISROSARMission
MonitoringForestDisturbanceOptimal forestmanagementrequiresknowledgeofhowforests change over time in response to naturaldisturbances and management activities, includinginvasive species; diseases; plant and animal pests; fire;
changes in climate and serious weather events such astornadoes,hurricanesandicestorms;pollutionoftheair,water,andsoil;realestatedevelopmentofforest lands;andtimberharvest.
MonitoringGlobalForestResources
Theworld’spopulationsrelyonforestsforsustaininglifeandbiodiversity,andasaresourceforavastnumberofproductsandservices.MappingandmonitoringthechangesintheUnitedStates’andinternationalforestresourcesbenefitsthetimberindustry,forestservices,andnaturalresourcemanagersalike.
Forests as a Multi-Faceted Resource
Forestshave apivotal role asa renewablenatural resource. Asdemandforforestproductsandthecompetitionforforestlandisincreasing, modern timber management is committed tosustainableforestmanagement.Currently,timberhasmorethan30,000 applications worldwide. Also, non-timber products areharvestedinforests,suchasplantsforfoodandmedicines,fishandgame.Inadditiontotheproductivefunctionofforests,theyhaveacentralroleintheprotectionandstabilizationofthenaturalenvironment and real estate. Forests protect water resources,provide air purification, and reduce erosion. They are key tosustaining crucial biodiversity and enhance conditions foragricultural production.Forests alsoserve asocial function asarecreationalresource,animportantlabormarket,livingspace,andtheyenhancenationaldefense.
TheNISARMission–Reliable,ConsistentObservations
The NASA–ISRO Synthetic Aperture Radar (NISAR) mission, a collaborationbetween the National Aeronautics and Space Administration (NASA) and theIndianSpace ResearchOrganization (ISRO),will provideall-weather,day/nightimagingofnearlytheentirelandandicemassesoftheEarthrepeated4-6timespermonth.NISAR’sorbitingradarswill imageatresolutionsof5-10meterstoidentifyandtracksubtlemovementoftheEarth’slandanditsseaice,andevenprovideinformationaboutwhatishappeningbelowthesurface.NISARwillalsoprovideforestvolumeandbiomassovertimeandwithenoughdetailtorevealchangesonhumanscales.Productsareexpectedtobeavailable1-2daysafterobservation, and within hours in response to disasters, providing actionable,timelydataformanyapplications.
Imagecredits:U.S.DepartmentofAgricultureandNationalParkService
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Withtheworld’spopulationcriticallydependentonsustainably managed and utilized forest resources,the need is greater now than ever before for theapplicationofmoderntechnologytoprovidedetailedand timely informational map data to the timberindustry, resource managers and forest policymakers. Satellite sensors provide synoptic views oftheglobefromspace. This information isroutinelyused to guide policy both decision-makers andcommercial interests. Examples include planningforest management activities, supportingpreparation of information for forest real estatetransactions domestically and in foreign countries,andmonitoringtheeffectsofforestpolicychanges,such as logging concessions or illegal loggingactivities.The upcoming NISAR mission will address theseneedsthroughadependableobservingstrategythatwillcollecthighresolution imageryover90%ofthe
Earth’slandsurfaces.Theuseofactivelygeneratedmicrowavesignals(L-andS-band,orequivalently,24cm and 10 cm wavelength) on board the satellitemeans that the observations will be able to bereliably planned, collected and distributed at timescalesthatarecommensuratewiththesatellite’s12-repeat cycle of the full set of orbits,which imageseachforestatleastonceevery6days.Radarimagesfrom satellites, such as NISAR, are known for theirability to penetrate through clouds and theirday/night imaging capability. Hence, even undernear-perpetualdensetropicalorfrequenttemperatecloud cover that are characteristicsof global forestecosystems, NISAR will provide bi-weeklyobservations that complement optical data andprovideindependentinformationthatissensitivetothemappingofforestdisturbance,includingbelow-canopy inundation from natural and catastrophicfloodingevents.
NationalAeronauticsandSpaceAdministration Formoreinformation,visithttp://nisar.jpl.nasa.gov/applications
JetPropulsionLaboratory/CaliforniaInstituteofTechnology/Pasadena,California/www.jpl.nasa.gov
ImageData©JAXA/METI2007-2009.ImageProcessing:EarthBigData,LLC.
Observations of the Earth’s land surfaces from space using activemicrowavesensorsallowsforreliableandrepeatedmeasurementstobemadeevenunderdensecloudcover.Whenforestscanopiesaredisturbed,suchthatstandingtreesarepartiallyorwhollyfelledorremoved,orsignificantfractionsoftheuppercanopyarelost,e.g.in a forest fire, thechanges arereflected in a richvarietyof radarsignals thatcanbemeasured. Thetimehistoryofchanges showswhen,where,andbyhowmuchthewoodswerealtered.Shown at right are data collected by the Japanese ALOS satellitemissionoperatingfrom2006to2011.Theimageisathree-datecolorcomposite,whereradarsignaturesresultincolorcombinationsthatare directly related to various types of forest disturbance andregrowth.TheNISARmissionwillprovidedataofsimilarquality,yetatgreaterobservation frequency and with easy data access by U.S. timberindustry,naturalresourcemanagers,naturaldisasterpreventionandresponseteams,researchers,anddecisionmakers.Thedatawillbea critical complement to theU.S. global landobserving system byprovidingroutine,global,cloud-freeforestmonitoringcapacity.
Three-date (2007, 2008, 2009) L-Band radar image of timberproduction land in southern Louisiana, one of themost intensivetimberproductionareasoftheUnitedStates.Redandyellowcolorsreadily show various dates and intensities of forestmanagementactivities (clear-cut and selective logging). Blue and purple colorsshowareasandstageofre-growingforestplantations.
Radar Imaging of Forest Disturbance
