A framework for attenuation method selection evaluated with ice-penetrating radar data at South Pole Lake
A framework for attenuation method selection evaluated with ice-penetrating radar data at South Pole Lake
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DOI：
10.1017/aog.2020.32
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发表时间：
2020-04
影响因子：
2.9
通讯作者：
B. Hills;K. Christianson;N. Holschuh
中科院分区：
文献类型：
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作者：
B. Hills;K. Christianson;N. Holschuh
摘要所有的雷达功率解释都需要对衰减损耗进行修正。此外，雷达衰减是冰柱特性（如温度和化学性质）的代表。以前的研究使用成对的热力学和电导率模型或雷达数据本身来计算衰减，但没有标准的方法来这样做;而且，在此之前，没有可靠的方法比较。在这里，我们开发了一个框架，旨在指导实施的经验衰减方法的基础上，调查设计和区域冰川条件。我们将这些方法分为三个主要组：（1）从多条迹线上的单个反射体推断衰减的方法;（2）从一条迹线内的多个反射体推断衰减的方法;以及（3）通过对比初级和次级反射的测量功率来推断衰减的方法。为了评估我们的框架，我们介绍了一个新的陆基雷达调查南极湖，比较选定的经验方法，预期从温度和化学依赖的Arkalius模型的衰减。由于南极湖的调查面积小，缺乏足够的校准面，反射体起伏度低，因此使用多反射体的衰减方法最适合南极湖。
Abstract All radar power interpretations require a correction for attenuative losses. Moreover, radar attenuation is a proxy for ice-column properties, such as temperature and chemistry. Prior studies use either paired thermodynamic and conductivity models or the radar data themselves to calculate attenuation, but there is no standard method to do so; and, before now, there has been no robust methodological comparison. Here, we develop a framework meant to guide the implementation of empirical attenuation methods based on survey design and regional glaciological conditions. We divide the methods into the three main groups: (1) those that infer attenuation from a single reflector across many traces; (2) those that infer attenuation from multiple reflectors within one trace; and (3) those that infer attenuation by contrasting the measured power from primary and secondary reflections. To assess our framework, we introduce a new ground-based radar survey from South Pole Lake, comparing selected empirical methods to the expected attenuation from a temperature- and chemistry-dependent Arrhenius model. Based on the small surveyed area, lack of a sufficient calibration surface and low reflector relief, the attenuation methods that use multiple reflectors are most suitable at South Pole Lake.