陆基散射计的水稻空间聚集特性分析

Analysis of spatial rice cluster characteristics based on ground-based scatterometer

地物的空间分布状态会影响微波后向散射特性,针对因生长特性而无明显行列向的水稻,该文利用L、C双频段全极化后向散射计对水稻整个生长季进行后向散射系数测量,提出了聚集度指数表征这类植被不同时相的空间特性。通过分析不同空间聚集度的水稻散射特性,研究了水稻后向散射系数在高低频的时空响应。实验结果表明,拔苗期至分蘖前期,下垫面土壤散射为主要散射分量时,C波段后向散射响应随着水稻聚集度变化而规律变化,从分蘖后期开始,随着生物量变大植被体散射增加,L波段后向散射相较C波段对空间聚集度响应更为明显。

The spatial distribution characteristics of land cover have influence on the backscattering properties.According to the implicit row characteristics of rice,we have measured the backscattering coefficients of rice in the entire growth season which obtained from full polarizations using scatter meter at L and C bands.This paper proposes kinds of cluster index to represent the spatial distribution characteristics of such type of vegetation at different times.Through comparing four paddies with diverse space cluster.The spatial and temporal responses of rice backscattering coefficients at high and low frequencies are studied with scattering characteristics of different spatial cluster.The experimental result shows when the soil surface scattering as the main scattering component from seedling to early tillering stage,C band backscatter responses regularly with the change of cluster.Meanwhile,when the volume scattering varies with the biomass increase from the beginning of the late tillering stage,L band backscatter is becoming more sensitive than C band to the response of spatial cluster.