为了有效的利用高光谱卫星数据获取植被信息,Furumi等在模式分解方法(PDM)的基础上,建立了一种新的植被指数(VIPD)。根据地面实验建立的相应光合成曲线植被净初级生产力(NPP)遥感估算模型,利用2001年前后多个月份的MODIS影像数据,对日本纪伊半岛地区的植被净初级生产力进行了估算。研究表明,根据地面实验建立估算模型估算得到的温带常绿植被净初级生产力年均值,与2001年IPCC调查报告上的估算值,在误差范围内一致。地面实验结果证明该光合成曲线NPP估算模型能够较好的应用于温带植被研究。在北纬32°30′—36°24′,东经134°30′—137°06′,面积3.94×104km2研究区域内,2001年NPP约为6.11kg CO2/a。从NPP的空间分布上而言,纪伊半岛范围内单位面积NPP以三重和奈良县山地林地带最高,达2.56kg CO2/m2/a。在纪伊半岛植被分类中,温带落叶植被的年均NPP最大,约为2.23 kg CO2/m2/a,水田的年均NPP最小,仅约为1.42 kg CO2/m2/a。
High-resolution hyper-spectral image (HHR) provides both detailed structural and spectral information for urban study. However, due to the inherent correlation between spectral bands and within-class variability in the data, the data processing of HHR is a challenging work. In this paper, based on spectral mixture analysis theory, a new stack of parts description features were extracted, and then incorporated with a stack of morphology based spatial features. Partially supervised constrained energy minimization (CEM) and unsupervised nonnegative matrix factorization (NMF) were used to extract the part-features. The joint features were then integrated by SVM classifier. The advantages of this method are the representation of physical composition of the urban area by the parts-features and the show of multi-scale structure information by morphology profiles. Experiments with an airborne hyper-spectral data flightline over the Washington DC Mall were performed, and the performance of the proposed algorithm was evaluated in comparison with well-known nonparametric weighted feature extraction (NWFE) and feature selection method. The results shown that the proposed features-joint scheme consistently outperforms the traditional methods, and so can provide an effective option for processing HHR data in urban area.
HUANG Yuancheng ZHANG Liangpei LI Pingxiang ZHONG Yanfei
