黑河中游试验区不同分辨率LAI数据处理、分析和尺度转换

LAI Measuring Data Processing,Analysis and Spatial Scaling in the Middle Reaches of Heihe Experimental Research Region

2008年开展的黑河综合遥感联合试验获取了大量野外实测叶面积指数(LAI)数据以及遥感LAI产品。在利用LAI地面点观测数据对遥感影像进行验证或者不同分辨率遥感产品相互比较的过程中存在由于地表异质性引起的尺度效应,导致无法直接进行验证、比较,需要进行尺度转换。以基于泰勒级数展开的尺度转换模型为基础,研究不同源LAI之间的尺度转换方法。包括两部分内容:①以高分辨率影像为辅助数据将地面实测点尺度的LAI转换到中、低分辨率遥感像元尺度;②利用高分辨率影像作为亚像元信息对低分辨率LAI产品进行尺度纠正。结果表明,利用泰勒级数展开模型进行尺度转换是一种简单可行的方法,经尺度转换的地面实测点尺度LAI可用作像元尺度数据比较验证的参考。

Watershed Allied Telemetry Experimental Research was hold in Heihe experimental research region in the summer of 2008.During that period,a number of ground LAI measurements and remote sensing LAI products were collected.When validating remote sensing LAI products with ground measurements or matching of LAI products derived from different resolution remote sensing images,scaling issue caused by surface heterogeneity cannot be ignored.So different measured and estimated LAI data can＇t be directly compared to each other without spatial scaling.In this paper,we developed a spatial scaling method based on Taylor series expansion model.This study mainly included two parts.① Setting high-resolution image as auxiliary data,ground LAI measurements were converted into middle-resolution and low-resolution.② LAI products of low-resolution were scale transferred with high-resolution image as sub-pixel information.based on these results,we find that,scaling method based on Taylor series expansion model is simple and effective.After spatial scaling process,the ground LAI measurements can be consider as reference to validate estimated LAI from remote sensing data.