受风灾影响后的农作物冠层反射信息测量与分析

Measurement and Analysis of Reflected Information from Crops Canopy Suffering from Wind Disaster Influence

受到台风"布拉万"的影响,吉林中部地区大范围处于灌浆期的玉米倒伏。为了确定倒伏后玉米冠层对反射信息的影响,从不同角度对其高光谱反射信息进行了测量与分析;与此同时,对偏振反射信息也进行了测量,将反射与偏振信息结合起来分析了受风灾影响后农作物冠层反射特征的变化。结果表明,风灾过后倒伏玉米的反射信息在可见光波段降低,而在近红外波段范围增大,与正常直立生长的玉米反射信息比较,具有非常明显的各项异性特征;同时,倒伏玉米的反射光中包含丰富的偏振信息,利用偏振信息可以为区分倒伏区域提供依据。这为利用遥感技术确定受灾范围与计算损失产量提供了依据。

The corn in the grain filling stage fell over in the central region of Jilin province by the Typhoon Bolaven influence.In order to determine the impact of falling over corn canopy on the reflected information,the hyperspectral reflectance was detected at different viewing zenith angles,at the same time,the polarized reflection was also measured.The results from the analysis by combining the reflection and polarization from corn canopy showed that the reflection of falling over corn is low in visible,while increases in the near infrared wavelength.The reflection from falling over corn canopy was more anisotropic than stand-up corn canopy.The reflected light was highly polarized,the polarization of corn canopy provided the probability for distinguishing between falling over corn and stand-up corn.This research provides a basis for estimating the disaster area and lost units.