Abstract Recent advancement in the understanding of snow-microwave interactions has helped to isolate the considerable potential for radar-based retrieval of snow water equivalent (SWE). There are however, few datasets available to address spatial uncertainties, such as the influence of snow microstructure, at scales relevant to space-borne application. In this study we introduce measurements from SnowSAR, an airborne, dual-frequency (9.6 and 17.2 GHz) synthetic aperture radar (SAR), to evaluate high resolution (10 m) backscatter within a snow-covered tundra basin. Coincident in situ surveys at two sites characterize a generally thin snowpack (50 cm) interspersed with deeper drift features. Structure of the snowpack is found to be predominantly wind slab (65%) with smaller proportions of depth hoar underlain (35%). Objective estimates of snow microstructure (exponential correlation length; lex), show the slab layers to be 2.8 times smaller than the basal depth hoar. In situ measurements are used to parametrize the Microwave Emission Model of Layered Snowpacks (MEMLS3&a) and compare against collocated SnowSAR backscatter. The evaluation shows a scaling factor (ϕ) between 1.37 and 1.08, when applied to input of lex, minimizes MEMLS root mean squared error to

中文翻译：

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苔原环境下雪微结构对双频雷达测量的影响

摘要 对雪-微波相互作用理解的最新进展有助于隔离基于雷达的雪水当量 (SWE) 反演的巨大潜力。然而，在与星载应用相关的尺度上，很少有数据集可用于解决空间不确定性，例如雪微结构的影响。在本研究中，我们介绍了来自机载双频（9.6 和 17.2 GHz）合成孔径雷达 (SAR) SnowSAR 的测量结果，以评估积雪覆盖的苔原盆地内的高分辨率 (10 m) 反向散射。在两个地点同时进行的原位调查显示，一般较薄的积雪（50 厘米）散布着较深的漂移特征。发现积雪的结构主要是风板（65%）和较小比例的深灰白底（35%）。雪微结构的客观估计（指数相关长度；lex）显示，板层比基础深度白板小 2.8 倍。原位测量用于参数化分层积雪的微波发射模型 (MEMLS3&a) 并与并置的 SnowSAR 反向散射进行比较。评估显示 1.37 和 1.08 之间的比例因子 (ϕ)，当应用于 lex 的输入时，将 MEMLS 均方根误差最小化为