偏振光谱的土壤湿度遥感方法实验研究

Experimental Study on Soil Moisture Remote Sensing Based on Polarization Spectrum

偏振探测作为一种新型遥感技术,是对传统光谱遥感探测的有益补充,为目标遥感探测提供更丰富的信息。用地物偏振光谱仪实验测量,分析土壤湿度与偏振光谱的相关性,同时研究不同观测角下的土壤表面反射光偏振光谱特性。结果表明：在土壤湿度较高的情况下,偏振光谱与土壤湿度具有一定的相关性,尤其在500~700nm波段,湿度与偏振度呈正比关系;低湿度的情况下,偏振光谱与土壤湿度相关性不明显;此外,不同观测角对偏振光谱也有影响,如入射角固定为50°,观测角在20°~60°区间测量时,偏振度随观测角增大而增大,且观测角愈大,偏振度随湿度的变化愈显著。

As a novel remote sensing technique,polarimetric detecting technology is a useful supplement to traditional hyperspectral remote sensing technology,which provides more information for remote sensing.By taking advantage of the polarization characteristics of the surface reflecting light of soil with different moisture,the polarization spectral method is applied to measure soil moisture.The spectropolarimeter was used to measure the polarized reflectance spectrum of different soil moisture.The correlation between soil moisture and polarization spectrum was analyzed.The polarization characteristics of soil surface reflecting light in different viewing angles were surveyed by experiments.The experimental results show that：in the higher soil moisture conditions,the polarization spectrum and soil moisture have a certain connection,especially in the 500~700nm band and soil moisture is directly proportional to the degree of polarization;but in low soil moisture conditions,the correlation of polarization spectrum and soil moisture is not obvious;in addition,the polarization spectrum are influenced by viewing angles,for example,when the incident angle of source light is fixed at 50°,while the viewing angle of instrument is between 20°and 60°,the degree of polarization increases with the viewing angle.When the viewing angle becomes wider,,the degree of polarization changed more significantly with the soil moisture.