Ground Cover Reference Sites Database of Northern Territory

The Ground Cover Reference Sites Database of Northern Territoryhas been collected by Department of Natural Resources, Environment, The Arts and Sport, Northern Territoryas part of the Ground Cover Monitoring for Australia project. The data is being used to calibrate, validate and improve vegetation fractional cover products derived from remote sensing, in particular the satellite sensors MODIS and Landsat. The data is being used to improve the national fractional vegetation cover product of Guerschman et al. (2009) derived from the Moderate Resolution Imaging Spectroradiometer (MODIS). This algorithm enables national, monthly identification of ground cover separating the photosynthetic and non-photosynthetic components by applying a linear unmixing methodology for spectral reflectance evey 8 days as 16-day composites. For confidence in its ground cover estimates, the results were verified in the field at selected sites across Australia to allow more extensive calibration, validation and verification of accuracy of the remote sensing method. The Ground Cover Reference Sites Database represents the results of the field validation of remotely determined cover measurements by observing cover along point intersects with a total of 300 points (or 200 points with crops). It also has additional observations and measures such as landscape features, fire evidence, erosion evidence, biotic disturbance evidence, biomass estimates, basal area measurements, soil features and dominant vegetation species, as well as site photographs. The Ground Cover Reference Sites Database focuses on sites in extensive grazing systems of the rangelands and, to a lesser extent, in the mixed farming or intensive land use zone. Field validation aims at obtaining a wide spatial coverage of sites, with limited site revisits for temporal coverage. Please use the following URL to access the dataset: http://aekos.org.au/collection/gov.au/abares/gcrs_NT

北领地地被参考位点数据库（Ground Cover Reference Sites Database）由北领地自然资源、环境、艺术与体育部（Department of Natural Resources, Environment, The Arts and Sport, Northern Territory）为澳大利亚地被监测项目（Ground Cover Monitoring for Australia project）采集建立。
本数据集被用于校准、验证并优化遥感反演得到的植被覆盖度（vegetation fractional cover）产品，尤其是基于MODIS与Landsat卫星传感器反演的相关产品。
该数据还被用于优化Guerschman等人2009年提出的基于中分辨率成像光谱辐射计（Moderate Resolution Imaging Spectroradiometer, MODIS）反演的全国植被覆盖度产品。
该算法通过对每8天的光谱反射率数据采用线性解混方法生成16天合成产品，以此实现全国尺度下每月对光合与非光合地被组分的分离识别。
为保障地被估算结果的可靠性，相关团队在澳大利亚全境选取样地开展野外验证，以实现遥感反演方法的更广泛校准、验证与精度核查。
北领地地被参考位点数据库包含了通过点截法沿样线开展盖度观测的野外验证结果，总计包含300个测点（其中农作物样地为200个测点）的遥感反演地被测量值。
该数据库还涵盖了额外的观测与测量数据，包括景观特征、火烧痕迹、侵蚀痕迹、生物干扰痕迹、生物量估算值、基径测量值、土壤特征与优势植被物种，以及样地照片。
本数据库主要聚焦于牧场牧区的大面积放牧系统样地，仅少量覆盖混合农业或集约土地利用区域。
野外验证工作旨在实现样地的广域空间覆盖，并通过有限的样地重访获取时间序列覆盖数据。
请通过以下链接获取本数据集：http://aekos.org.au/collection/gov.au/abares/gcrs_NT