美国俄亥俄州克利夫兰市的North Coast Tool和Mold公司的加工设计理念，有助于Lockheed Martin Aeronautics公司采用树脂传递模塑法（RTM）开发制造全复合材料垂直机尾结构。该机尾结构长13英尺，宽5英尺，还包括机尾外部蒙皮，结构中...美国俄亥俄州克利夫兰市的North Coast Tool和Mold公司的加工设计理念，有助于Lockheed Martin Aeronautics公司采用树脂传递模塑法（RTM）开发制造全复合材料垂直机尾结构。该机尾结构长13英尺，宽5英尺，还包括机尾外部蒙皮，结构中采用一系列14根空芯转矩管作为承重结构。所用的纤维增强材料有纤维编织物、织物及单向带，采用的树脂为双马来酰胺树脂（BMI）。据说，采用此法可降低成本且可自动化生产。展开更多
The visible and infrared bands of Landsat Thematic Mapper （TM） can be used for inland water studies. A method of retrieving water-leaving radiance from TM image over Taihu Lake in Jiangsu Province of China was inves...The visible and infrared bands of Landsat Thematic Mapper （TM） can be used for inland water studies. A method of retrieving water-leaving radiance from TM image over Taihu Lake in Jiangsu Province of China was investigated in this article. To estimate water-leaving radiance, atmospheric correction was performed in three visible bands of 485nm, 560nm and 660rim. Rayleigh scattering was computed precisely, and the aerosol contribution was estimated by adopting the clear-water-pixels approach. The clear waters were identified by using the Landsat TM middle-infrared band （2.1 μm）, and the water-leaving radiance of clear water pixels in the green band was estimated by using field data. Aerosol scattering at green band was derived for six points, and interpolated to match the TM image. Assuming the atmospheric correction coefficient was 1.0, the aerosol scattering image at blue and red bands were derived. Based on a simplified atmospheric radiation transfer model, the water-leaving radiance for three visible bands was retrieved. The water-leaving radiance was normalized to make it comparable with that estimated from other remotely sensed data acquired at different times, and under different atmospheric conditions. Additionally, remotely sensed reflectance of water was computed. To evaluate the atmospheric correction method presented in this article, the correlation was analyzed between the corrected remotely sensed data and the measured water parameters based on the retrieval model. The results show that the atmospheric correction method based on the image itself is more effective for the retrieval of water parameters from Landsat TM data than 6S （Second Simulation of the Satellite Signal in the Solar Spectrum） code based on standard atmospheric and aerosol models.展开更多
文摘美国俄亥俄州克利夫兰市的North Coast Tool和Mold公司的加工设计理念，有助于Lockheed Martin Aeronautics公司采用树脂传递模塑法（RTM）开发制造全复合材料垂直机尾结构。该机尾结构长13英尺，宽5英尺，还包括机尾外部蒙皮，结构中采用一系列14根空芯转矩管作为承重结构。所用的纤维增强材料有纤维编织物、织物及单向带，采用的树脂为双马来酰胺树脂（BMI）。据说，采用此法可降低成本且可自动化生产。
基金Under the auspices of National Natural Science Foundation of China (No. 40671138)
文摘The visible and infrared bands of Landsat Thematic Mapper （TM） can be used for inland water studies. A method of retrieving water-leaving radiance from TM image over Taihu Lake in Jiangsu Province of China was investigated in this article. To estimate water-leaving radiance, atmospheric correction was performed in three visible bands of 485nm, 560nm and 660rim. Rayleigh scattering was computed precisely, and the aerosol contribution was estimated by adopting the clear-water-pixels approach. The clear waters were identified by using the Landsat TM middle-infrared band （2.1 μm）, and the water-leaving radiance of clear water pixels in the green band was estimated by using field data. Aerosol scattering at green band was derived for six points, and interpolated to match the TM image. Assuming the atmospheric correction coefficient was 1.0, the aerosol scattering image at blue and red bands were derived. Based on a simplified atmospheric radiation transfer model, the water-leaving radiance for three visible bands was retrieved. The water-leaving radiance was normalized to make it comparable with that estimated from other remotely sensed data acquired at different times, and under different atmospheric conditions. Additionally, remotely sensed reflectance of water was computed. To evaluate the atmospheric correction method presented in this article, the correlation was analyzed between the corrected remotely sensed data and the measured water parameters based on the retrieval model. The results show that the atmospheric correction method based on the image itself is more effective for the retrieval of water parameters from Landsat TM data than 6S （Second Simulation of the Satellite Signal in the Solar Spectrum） code based on standard atmospheric and aerosol models.
