Firn-line detection on Austre Okstindbreen, Norway, with airborne multipolarization SAR
Firn-line detection on Austre Okstindbreen, Norway, with airborne multipolarization SAR
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DOI：
10.3189/172756501781832241
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发表时间：
2001
影响因子：
3.4
通讯作者：
M. König;J. Winther;N. Knudsen;T. Guneriussen
中科院分区：
文献类型：
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作者：
M. König;J. Winther;N. Knudsen;T. Guneriussen
翻译后摘要我们研究的能力，合成孔径雷达（SAR）检测的冰川南极Okstindbreen，挪威的平衡线，使用多极化SAR图像在C-和L-波段获得的电磁研究所的技术大学的丹麦的机载EMISAR传感器在欧洲多传感器机载运动EMAC '95。在合成孔径雷达图像上看不到接近平衡线的夏末雪线。相反，来自Austre Okstind-breen的照片显示，在C波段合成孔径雷达图像上可见的明显边界对应于多年前积雪形成的雪线。这在交叉极化SAR图像（HV和VH）上可以更好地看到，其通常比HH和VV极化图像显示更多细节。我们从净平衡和冰川速度数据来模拟地层，以计算雪线高度（弗拉）。模拟的弗拉和观测到的边界在海拔高度上相隔50米，但考虑到在配准和建模过程中的误差，我们得出结论，在Austre Okstindbreen观测到的边界是雪线。因此，建议用遥感监测弗拉而不是平衡线高度（ELA）进行质量平衡研究。
Abstract We examine the ability of synthetic aperture radar (SAR) to detect the equilibrium line on the glacier Austre Okstindbreen, Norway, using multipolarization SAR images in C- and L-band acquired with the Electromagnetic Institute of the Technical University of Denmark’s airborne EMISAR sensor during the European Multisensor Airborne Campaign EMAC ’95. The late-summer snowline, approximating the equilibrium line, cannot be seen on the SAR images. Instead, photographs from Austre Okstind-breen show that a distinct boundary visible on the C-band SAR images corresponds to the firn line created by old snow from many previous years. This is better seen on the cross-polarized SAR images (HV and VH), which in general reveal more detail than the HH- and VV-polarized images. We model the stratigraphy from net balance and glacier velocity data to calculate the firn-line altitude (FLA). Modelled FLA and the observed boundary are separated by 50 m in elevation, but considering errors during co-registration and modelling we conclude that the observed boundary on Austre Okstindbreen is the firn line. Monitoring FLA rather than equilibrium-line altitude (ELA) for mass-balance studies with remote sensing is therefore suggested.