Radio Echo Sounding of Horizontal Layers in Ice
Radio Echo Sounding of Horizontal Layers in Ice
复制标题
DOI：
10.3189/s0022143000031804
复制
发表时间：
1973
影响因子：
3.4
通讯作者：
C. Harrison
中科院分区：
文献类型：
--
作者：
C. Harrison
对南极洲和格陵兰岛的无线电回声探测揭示了冰层内部的广泛分层。在脉冲雷达的观测下，导出了隔离层或多个随机间隔层的有效反射系数公式。在后一种情况下，介电常数随深度的变化由垂直自相关函数和标准偏差来描述。给出了各层反射系数和冰的介电吸收的测量结果。讨论了层回波衰减的意义和介电常数变化的可能原因，并提出了进一步研究的建议。结果表明，在南极发现的回波强度可以用多层来解释，并且介电常数的必要分数变化可能小到10−4。这种介电常数的变化可能是由于各向异性冰晶取向的不同。
Radio echo-sounding surveys of Antarctica and Greenland have revealed extensive layering within the ice. Formulae for the effective reflection coefficient, when viewed by a pulsed radar, are derived for isolated or multiple randomly spaced layers. In the latter case the variation in dielectric constant with depth is described by a vertical autocorrelation function and a standard deviation. Some measurements of the reflection coefficient of layers, and the dielectric absorption of ice are given. The significance of the fading of layer echoes and the possible causes of variations in the dielectric constant are considered and some further investigations are suggested. It is concluded that the echo strengths found in the Antarctic may be explained by multiple layering, and that the necessary fractional change in the dielectric constant may be as small as 10−4. It is suggested that this change in dielectric constant may be due to differences in orientation of anisotropic ice crystals.