关键词: 高光谱, 新疆南部, 地表覆盖物, 光谱特征, 反射率, 波谱曲线

Abstract: 【Objective】To provide convenience for the identification,monitoring and precise extraction of large-scale crops in the region by analyzing the spectral characteristics of major crops in southern Xinjiang.【Methods】Based on the remote sensing data of Zhuhai No.1 hyperspectral satellite,the spectral characteristics of land cover in reclamation area of Alar City,southern Xinjiang were analyzed. Two dimensional（wavelength-reflectance） spectral spatial models and three dimensional（phase-wavelength-reflectance） spectral spatial models were constructed by extracting information from analyzed end-member spectrum features,then analyzed the spectral characteristics of crops such as cotton and corn in the reclamation area from April to October.【Results】Based on the spectral curve characteristics of the same region at different times,the growth cycles of crops planted in the farmland of the reclamation area including the slow seedling stage,peak stage,and fruiting stage were determined. By calculating the mean value of land cover spectral curve,the average spectral curve was constructed to reflect its overall reflectance characteristics in a specific period of time. The overall reflectance of cotton was higher than that of corn and jujube trees. The absorption capacity of rice was noticeably stronger in the infrared band range. The spectral curves of sandy land and water body tend to be smooth and stable. Based on time,the maximum spectral reflectance curve could highlight the characteristics of crops,with cotton having higher reflectance,corn having lower reflectance,and rice having relatively stable reflectance. The spectral reflectance profile curves at a single time point during the vegetation growth cycle all followed the characteristics of vegetation spectral curves,with visible light range being valleys and peaks appearing in the near-infrared range. Major crops such as cotton,jujube,corn,and rice had similar overall spectral surface trends in the three dimensional spectral spatial model. The overall reflectance of sandy land and water body was not high,mostly concentrated below 25%,and their spectral reflectance curves had their own characteristics.【Conclusion】In different growth stages of crops in the reclamation area of Alar City in southern Xinjiang,the reflectance of different wavelengths was different. In the slow seedling stage,the light absorption capacity of visible light band was weak,and the reflectance was high. During the peak stage of vegetation,the light absorption capacity in the visible light band was relatively strong,and the reflectance was relatively low. Sandy land had relatively constant reflectance compared with that of crops. The overall variation range of water body reflectance was not large and the value was not high.

Key words: Hyperspectrum, Southern Xinjiang, Land cover, Spectral characteristics, Reflectivity, Spectral curve