• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文会议>Conference on Applications with Weather Satellites Oct 24, 2002 Hangzhou, China >MODIS Cloud Mask: Current situation and its improvements
【24h】

MODIS Cloud Mask: Current situation and its improvements

机译：MODIS Cloud Mask：现状及其改进

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

The 36 channel Moderate Resolution Imaging Spectroradiometer (MODIS) offers the opportunity for multispectral approaches to cloud detection. The MODIS cloud mask developed at the Cooperative Institute for Meteorological Satellite Studies (CIMSS) uses several cloud detection tests to indicate a level of confidence that the MODIS is observing clear skies. The MODIS cloud mask algorithm identifies several conceptual domains according to surface type and solar illumination, including land, water, snow/ice, desert, and coast for both day and night. The updated cloud mask has many improvements, such as improved cloud/surface discrimination over desert regions, sun glint processing and thin cirrus detection. For non-snow-covered land areas, a clear sky confidence of 0.96 (probably clear) will be assigned if thresholds are met for three tests: 3.9-11 μm and 3.75-3.9 μm brightness temperature differences and a 1.24/0.55 μm reflectance ratio test. Values of these must be <15K, <11K and >2.0, respectively. A change has been made to the NIR (band 2) reflectance test for sun glint processing. The updated method is to calculate a cloud threshold as a linear function of sun-glint angle in three separate ranges. A new clear-sky restoral test was added where the ratio of band 17/18 reflectance is utilized to discriminate between low clouds and water surfaces. The thin cirrus thresholds using corrected band 26 (1.38 μm) reflectances were also modified.
机译：36通道中分辨率成像光谱仪（MODIS）为云探测的多光谱方法提供了机会。由气象卫星研究合作研究所（CIMSS）开发的MODIS云遮罩使用几种云探测测试来表明MODIS观测晴朗天空的置信度。 MODIS云遮罩算法根据表面类型和太阳光照识别几个概念领域，包括白天和黑夜的土地，水，雪/冰，沙漠和海岸。更新的云遮罩具有许多改进，例如，改善了沙漠地区的云/表面辨别力，阳光闪烁处理和细卷云检测。对于未被雪覆盖的陆地区域，如果满足以下三个测试的阈值，则将分配0.96（可能是晴朗）的晴朗天空置信度：3.9-11μm和3.75-3.9μm亮度温度差以及1.24 / 0.55μm反射率测试。这些值必须分别为<15K，<11K和> 2.0。对NIR（波段2）反射率测试进行了更改，以进行日照处理。更新的方法是在三个单独的范围内将云阈值计算为太阳闪角的线性函数。添加了新的晴空恢复测试，其中波段17/18反射率的比率用于区分低云和水面。还修改了使用校正带26（1.38μm）反射率的薄卷云阈值。

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