基于双粗糙界面数值仿真模型的机载雷达山岳冰川介电虚部反演OA

As a key indicator of global climate change and an essential freshwater resource,the accu-rate acquisition of multiple physical parameters of glaciers holds significant importance for global cli-mate change research,ecological conservation,and water resource planning.In China,glaciers are pre-dominantly mountain glaciers distributed in high-altitude regions.Constrained by harsh environments and complex terrain,traditional in-situ detection methods fail to achieve large-scale continuous monitor-ing of internal glacier parameters.Satellite-borne glacier remote sensing,meanwhile,faces limitations in resolution and interference from complex ground clutter in mountainous glacier regions,and thus has yet to be operationalized.Airborne radar,with its superior spatial resolution and flexible detection capabili-ties,has become a critical technical tool for glacier monitoring and research.However,airborne detec-tion of mountain glaciers still confronts challenges posed by undulating ice surfaces and complex sub-glacial topography:scattering clutter from the uneven ice surface interferes with radar signal interpreta-tion and precise inversion of key parameters,while the intricate subglacial structure and scattering loss-es caused by ice surface topography interact with dielectric losses within the ice,impeding accurate in-version of glacier dielectric constants.To address these challenges,this study integrates airborne ultra-wideband radar detection data from mountain glaciers with the Pseudo-Spectral Time Domain(PSTD)numerical simulation method.A coupled model of ice surface-subglacial dual interface topography and dielectric parameters is established.Through two-dimensional PSTD electromagnetic simulations,the in-teraction mechanism between topographic scattering and ice dielectric loss is elucidated.Furthermore,an inversion method for the imaginary part of the ice layer dielectric constant in measured regions is pro-posed based on dynamic range analysis.For the measured data from Laohugou Glacier No.12,iterative optimization converges the estimated imaginary part value to 6.0×10-4.The relative error between the estimated imaginary part and the theoretical mean is 21%.Cross-validation between simulation results and theoretical models demonstrates that this method effectively improves the inversion accuracy of glacier dielectric parameters in complex terrain by decoupling the synergistic interference between topo-graphic relief and dielectric parameters,thereby offering a viable solution for studying internal dielectric properties of glaciers.