衰减作用 meaning in Chinese
attenuation
damping action
Examples
- Based on the vector radiative transfer theory and the characteristics of the sar technology , several sub - models for rice backscattering are constructed , including the leaf scattering model , the leaf extinction model , the trunk scattering model , the trunk extinction model and the water reflection model . then an integrated model for the first - order scattering mechanisms of rice , including all the main physical processes , is achieved
针对合成孔径雷达sar的技术特点，以水稻为研究对象，从矢量辐射传输理论vrt出发，通过模拟水稻主要器官稻叶和稻杆对电磁波的散射衰减作用等物理过程，建立了一套完整的水稻一次后向散射作用的物理模型，用以模拟水稻层的后向散射系数 - The results show that these algorithms for attenuation correction can work well in the valid range and their effects on attenuation correction are almost identical . when attenuation is strong or measurement error of real echo is large , however , the result from the h - b algorithm for attenuation correction is not good
结果表明：在有效的订正范围内，几种订正方法均能得到很好的订正，并且订正效果几乎保持一致，但h - b算法在衰减作用很强或实际回波测量值误差很大时，其订正结果就变得不可靠了，从而造成订正能力下降。 - Main conclusions drawn from the analyses of calculating results are as follows : ( 1 ) the microwave absorption of atmosphere gas have obvious attenuation at the wavelengths for cloud detection , thereinto , the water attenuation effect changes greatly , so the 94ghz cloud detecting radar should have water vapor attenuation correction scheme . ( 2 ) when 37ghz and 94ghz radars detect clouds , the difference between the atmosphere and cloud attenuation and the large variety of radar reflectivity conduce the intension of the radar backscatter signals change . ( 3 ) for the thin cloud layer and low water content of cloud , 37 - ghz radar backscatter signals are not as good as 94 - ghz radar , that is to say that the 94ghz radar has better capability in thin clouds detection
本工作得出如下结论： ( 1 )大气气体的微波吸收在测云波段产生明显的衰减，其中水汽衰减效应变化很大；即将上天的空间94ghz测云雷达必须有水汽衰减订正方案； ( 2 ) 37ghz和94ghz雷达测云，由于大气和云衰减不同和雷达反射率的很大差异，导致雷达回波信号强弱不同； ( 3 )对云层较薄、含水量较少的云，在不计雷达参数的情况下， 37ghz雷达回波信号不如94ghz测云雷达，也就是说94ghz对薄云有更强的探测能力；对云层较厚、含水量大的云，由于强衰减的作用， 94ghz雷达回波信号小于37ghz雷达； ( 4 )从大气衰减的不利因素方面考虑，空间94ghz雷达测高层薄云的效果最好；测低层薄云时需要考虑气体衰减订正；因浓厚云的强衰减作用，探测其中下部的能力大大减弱，不仅要进行衰减订正，而且要借助其他信息来反演整个云层的含水量垂直分布； （ 5 ）为了获得从极薄到极浓厚云的垂直分布探测能力，未来测云雷达系统最好采用双波长甚至三波长（如94 、 37和13ghz ） 。