石榴树遥感辨识的最佳时相与方法  

The best phase and optimal identification method for identifying pomegranate trees

作　　者：邢东兴 焦俏 王明军[2] 封建民[1] 车自立 张文帅 XING Dongxing;JIAO Qiao;WANG Mingjun;FENG Jianmin;CHE Zili;ZHANG Wenshuai(College of Resources and Environment,Xianyang Normal University,Xianyang 712000,Shaanxi,China;College of Physics and Electronic Engineering,Xianyang Normal University,Xianyang 712000,Shaanxi,China;Shaanxi Natural Resources Survey Planning and Design Institute LTD,Xi’an 710077,Shaanxi,China)

机构地区：[1]咸阳师范学院资源环境学院,陕西咸阳712000 [2]咸阳师范学院物理与电子工程学院,陕西咸阳712000 [3]陕西自然资源勘测规划设计院股份有限公司,西安710077

出　　处：《果树学报》2020年第3期431-440,共10页Journal of Fruit Science

基　　金：国家自然科学基金(61771385);陕西省教育厅哲学社会科学重点研究基地项目(17JZ079)。

摘　　要：【目的】利用2015、2017与2018年逐月GF1-WFV影像(共42景),探寻石榴树遥感辨识的最佳时相与方法。【方法】首先对各景影像分别进行预处理;随后基于13种主要作物样地内的ROI(感兴趣区)数据对6类辨识方法(即反射光谱比较、波段差值或比值分析、光谱指数辨识分析、光谱指数变化追踪、影像复合与多指数联用分析)的辨识效能分别予以探试,以寻求最佳辨识时相与方法;最后采用全域影像对探寻结果加以验证。【结果】(1)4月中旬的石榴树具有相对较低的NDVI值,利用NDVI阈值可较好地将其与除葡萄、桃树外的其他9种果树以及小麦予以区分,但不可将其与葡萄、桃树以及许多城乡绿化植被、有草撂荒地、低龄果树等区分;(2)在5月中旬,正值盛花期的石榴树具有相对较高的1/Rb1-1/Rb3值,利用该指数阈值既可将石榴树与其他大多数果树树种及小麦予以较好地区分,也可将城乡绿化植被、有草撂荒地、低龄果树等予以正确辨别并大幅剔除。但受多种不利因素的影响,导致少数苹果、梨等果树以及一些非果树地物与石榴树混淆难辨。若继用此时期的NDVI阈值则可剔除部分非石榴树地物;(3)在上述两期影像复合、联用(1/Rb1-1/Rb3)5月中旬、NDVI5月中旬、NDVI4月中旬三重阈值的情形下,辨识精度更为理想,石榴树类的正确识别率可达86.28%,总体分类精度可达85.37%;(4)利用遥感影像辨识石榴树的最佳时相为5月中旬,4月中旬次之。【结论】复合4月中旬与5月中旬的两期影像并联用(1/Rb1-1/Rb3)5月中旬、NDVI5月中旬、NDVI_4月中旬三重阈值,可较好地辨识石榴树。【Objective】It is of great significance in production and management of fruit industry to quickly and accurately realize the planting information(i.e.planting region,planting area and planting structure)of various fruit trees in large areas by using the remote sensing technology.The present paper tries to find out the best phase and optimal method for identifying pomegranate trees by using monthly GF1-WFV images collected in 2015,2017 and 2018(a total of 42 images),in order to provide a theoretical basis for the remote sensing monitoring of pomegranate trees in Guanzhong and other fruit growing regions in China in the future.【Methods】Firstly,the images of each period were preprocessed(including image space clipping,image radiation calibration,image atmospheric radiation correction,image geometry correction,image mean filtering,etc).Then,in order to find out the best identification phase and method,the identification efficiencies of six methods(comparison of reflectance spectra of ground objects,bands difference or ratio analysis,analysis of spectral index identification,spectral index change tracking,image compound and analysis of multi-indices combined use)were tested separately by using ROI(Region of Interest)data,and these data were collected from the sample plots of 13 main crops(including pomegranate trees,grape vines,peach trees,cherry trees,mulberry trees,persimmon trees,apricot trees,pear trees,apple trees,walnut trees,plum trees,star fruit trees,winter wheat or summer maize).Finally,the identification efficiency of exploration results was verified in global image.【Results】(1)Because pomegranate trees were in the early stage of new shoot growth in mid-April,their leaves were small and narrow,and their canopy coverage and leaf area index were both small,the pomegranate trees had relatively low NDVI values during this period.The NDVI thresholds could be used to distinguish pomegranate trees from other 9 types of fruit trees and wheat.However,NDVI thresholds could not distinguish pomegranate trees

关 键 词：石榴树 GF1-WFV 果树树种辨识 最佳时相 光谱指数 

分 类 号：S665.4[农业科学—果树学]