Deformation, Ecosystem Structure, and Dynamics of Ice(DESDynI)

摘要

The National Research Council’s DecadalSurvey for Earth Science identified the Deformation,Ecosystem Structure, and Dynamics of Ice (DESDynI)mission among the highest priorities for new NASA Earthmissions. DESDynI consists of an L-band SyntheticAperture Radar configured for repeat-pass interferometricobservations (InSAR), and a nadir pointing lidar suitable forvegetation canopy structure characterization. In response,analyses are underway to evaluate efficient combinations ofscience objectives and mission/instrument scenarios. TheInSAR component can be satisfied by a traditional phasedarray deployable aperture as flown in space on SeaSAT,JERS-1, and ALOS. Alternatively, the SAR can bedesigned as an offset-fed reflector, capitalizing on largecommercial mesh reflector antenna and transmit/receivemodules developed for the NASA UAVSAR airborne radar.This InSAR system satisfies key science objectives andaddresses several shortcomings of existing InSAR capablesatellites. To reduce temporal decorrelation, L-band (24 cmwavelength) is used. A 340 km wide-swath scanSAR modewith 8 (or 12) day repeat enhances study of ice dynamics,pre/post earthquake deformation, volcano monitoring, andother dynamic phenomena. Fully polarimetric capabilityallows wide-area extension of key parameters of thevegetation canopy, such as biomass and land cover change,firmly anchored through the fine detail provided by the lidarin globally distributed profiles. Similarly polarimetricInSAR measurements allow further refinement of canopystructure in appropriate canopies. Key challenges involvescheduling and observational strategy to optimizeoverlapping observational requirements of various sciencecommunities served. This paper focuses on the InSARtechnology and observational trades that affect the sciencereturn, in combination with and distinct from the lidar.