Ground Cover Reference Sites Database of Northern Territory

The Ground Cover Reference Sites Database of Northern Territory has been collected by Department of Natural Resources, Environment, The Arts and Sport, Northern Territory as 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 every 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北领地地表覆盖参考站点数据库由北领地自然资源、环境、艺术与体育部（Department of Natural Resources, Environment, The Arts and Sport, Northern Territory）作为澳大利亚地表覆盖监测项目（Ground Cover Monitoring for Australia project）的一部分采集构建。该数据集被用于校准、验证并改进由遥感手段反演得到的植被分数覆盖度（vegetation fractional cover）产品，特别是基于MODIS与Landsat卫星传感器的反演产品。其被用于改进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）的全国植被分数覆盖度产品。本算法针对每8天生成的16天合成光谱反射率数据应用线性解混方法（linear unmixing methodology），可在全国尺度上按月区分光合与非光合组分的地表覆盖。为保障地表覆盖估算结果的可靠性，研究团队在澳大利亚全境选定站点开展野外验证，以更全面地校准、验证遥感反演方法的精度并完成准确性核查。北领地地表覆盖参考站点数据库记录了通过沿测点交点开展覆盖度观测得到的野外验证结果，共包含300个测点（农田站点则包含200个测点），以此获取遥感反演的地表覆盖测量值。该数据库还包含额外的观测与测量项，涵盖景观特征、火灾痕迹、侵蚀痕迹、生物干扰证据、生物量估算值、基径测量值、土壤特征与优势植被物种，以及站点实拍照片。北领地地表覆盖参考站点数据库主要覆盖稀树草原牧区的大面积放牧系统，仅少量覆盖混合农业或集约土地利用区域。野外验证工作以实现站点的广域空间覆盖为目标，通过有限的站点重访来获取时间序列覆盖数据。请通过以下链接获取该数据集：http://aekos.org.au/collection/gov.au/abares/gcrs_NT