• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>IEEE Transactions on Geoscience and Remote Sensing >Differences Between the HUT Snow Emission Model and MEMLS and Their Effects on Brightness Temperature Simulation
【24h】

Differences Between the HUT Snow Emission Model and MEMLS and Their Effects on Brightness Temperature Simulation

机译：HUT雪排放模型与MEMLS的差异及其对亮度温度模拟的影响

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Microwave emission models are a critical component of snow water equivalent retrieval algorithms applied to passive microwave measurements. Several such emission models exist, but their differences need to be systematically compared. This paper compares the basic theories of two models: the multiple-layer Helsinki University of Technology (HUT) model and the microwave emission model of layered snowpacks (MEMLS). By comparing the mathematical formulation side by side, three major differences were identified: 1) by assuming that the scattered intensity is mostly (96%) in the forward direction, the HUT model simplifies the radiative transfer equation in space into two one-flux equations, whereas MEMLS uses a two-flux theory; 2) the HUT scattering coefficient is much larger than the one of MEMLS; and 3) MEMLS considers the trapped radiation inside snow due to internal reflection by a six-flux model, which is not included in HUT. Simulation experiments indicate that the large scattering coefficient of the HUT model compensates for its large forward scattering ratio to some extent, but the effects of one-flux simplification and the trapped radiation still result in different simulations between the HUT model and MEMLS. The models were compared with observations of natural snow cover at Sodankylä, Finland; Churchill, Canada; and Colorado, USA. No optimization of the snow grain size was performed. It shows that the HUT model tends to underestimate for deep snow. MEMLS with the physically based improved Born approximation performed best among the models, with a bias of −1.4 K and a root-mean-square error of 11.0 K.
机译：微波发射模型是应用于被动微波测量的雪水当量检索算法的重要组成部分。存在几种这样的排放模型，但是需要系统地比较它们之间的差异。本文比较了两种模型的基本理论：多层赫尔辛基工业大学（HUT）模型和分层积雪的微波发射模型（MEMLS）。通过并排比较数学公式，确定了三个主要差异：1）通过假设散射强度在正向方向上大部分为（96％），HUT模型将空间中的辐射传递方程简化为两个单通量方程，而MEMLS使用双通量理论； 2）HUT散射系数远大于MEMLS之一。 3）MEMLS通过六通量模型考虑了由于内部反射而在雪中捕获的辐射，该模型未包含在HUT中。仿真实验表明，HUT模型的较大散射系数在一定程度上补偿了其较大的前向散射比，但单通量简化和被俘获辐射的影响仍然导致HUT模型与MEMLS之间的模拟不同。将模型与芬兰Sodankylä的自然积雪观测值进行了比较；加拿大丘吉尔；和美国科罗拉多州。没有对雪粒大小进行优化。它表明，HUT模型倾向于低估深雪。在模型中，基于物理的改进的Born近似的MEMLS表现最佳，偏差为-1.4 K，均方根误差为11.0K。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号