Land surface phenology based crop maps for Continental United States 2000-2018

This data collection contains annual maps of crop types for Continental United States for the period 2000-2018 at spatial resolution of ~231m derived using MODIS Land Surface Phenology. This data collection is a companion to the paper <strong><em>Konduri, V., Kumar, J., Hargrove, W. W., Hoffman, F. M., Ganguly, A. R. (2020) Mapping Crops Within the Growing Season Across the United States. Remote Sensing of Environment, Vol 251, 2020 </em></strong>https://doi.org/10.1016/j.rse.2020.112048, which describes the methodology for development of these datasets, validation metrics and analysis. <strong><strong>Files in collection (28): </strong></strong> <strong><em>crop_map_predicted_[YEAR].nc</em>: </strong>Annual crop type maps for YEAR = 2000-2018 <strong><em>Crop_map_legend.csv</em>: </strong>Legend for crop type categories in the maps (Category numbers and legends for crop types are consistent with those used by USDA Crop Data Layer) Maps of earliest date (Day of Year) of classification for eight dominant crop types for year 2015: <strong>earliest_classification_date_corn_CONUS.nc</strong> : Earliest date of classification for corn <strong>earliest_classification_date_soybeans_CONUS.nc</strong> : Earliest date of classification for soybeans <strong>earliest_classification_date_winter_wheat_CONUS.nc</strong> : Earliest date of classification for winter wheat <strong>earliest_classification_date_fallow_CONUS.nc</strong> : Earliest date of classification for fallow <strong>earliest_classification_date_other_hay_non_alfalfa_CONUS.nc</strong> : Earliest date of classification for other hay/non-alfalfa <strong>earliest_classification_date_alfalfa_CONUS.nc</strong> : Earliest date of classification for alfalfa <strong>earliest_classification_date_sorghum_CONUS.nc</strong> : Earliest date of classification for sorghum <strong>earliest_classification_date_rice_CONUS.nc</strong> : Earliest date of classification for rice <strong><strong>Data formats:</strong></strong> All map products are in gridded NetCDF format. Annual crop type maps use category types described in Crop_map_legend.csv. Earliest date of classification maps are encoded as Day of the Year. <strong><strong>Projection for geospatial data</strong> (in PROJ4 format):</strong> <pre><code class="language-bash">PROJCS["US_National_Atlas_Equal_Area", GEOGCS["sphere", DATUM["unknown", SPHEROID["Spherical_Earth",6370997,"inf"]], PRIMEM["Greenwich",0], UNIT["degree",0.0174532925199433]], PROJECTION["Lambert_Azimuthal_Equal_Area"], PARAMETER["latitude_of_center",45], PARAMETER["longitude_of_center",-100], PARAMETER["false_easting",0], PARAMETER["false_northing",0], UNIT["Meter",1]]</code></pre> <strong>Paper Citation:</strong> <strong><em>Konduri, V., Kumar, J., Hargrove, W. W., Hoffman, F. M., Ganguly, A. R. (2020) Mapping Crops Within the Growing Season Across the United States. Remote Sensing of Environment (in revision)</em></strong>本数据集收录了2000-2018年美国本土大陆（Continental United States）的年度作物类型栅格制图数据，空间分辨率约231米，基于MODIS地表物候（Land Surface Phenology）产品生成。本数据集为以下研究论文的配套数据：Konduri, V., Kumar, J., Hargrove, W. W., Hoffman, F. M., Ganguly, A. R. (2020) 《美国本土生长季内作物制图》（*Mapping Crops Within the Growing Season Across the United States*），发表于《Remote Sensing of Environment》2020年第251卷，DOI链接：https://doi.org/10.1016/j.rse.2020.112048，该论文详细阐述了本数据集的开发方法、验证指标与分析流程。 数据集文件共28个： 1. `crop_map_predicted_[YEAR].nc`：对应年份为2000-2018的年度作物类型栅格制图文件 2. `Crop_map_legend.csv`：作物类型分类图例文件（作物类型的类别编号与图例与美国农业部作物数据层（USDA Crop Data Layer）保持一致） 以下为2015年8种优势作物类型的最早分类日期（以年积日（Day of Year，DOY）标注）制图文件： - `earliest_classification_date_corn_CONUS.nc`：玉米最早分类日期制图 - `earliest_classification_date_soybeans_CONUS.nc`：大豆最早分类日期制图 - `earliest_classification_date_winter_wheat_CONUS.nc`：冬小麦最早分类日期制图 - `earliest_classification_date_fallow_CONUS.nc`：休耕地最早分类日期制图 - `earliest_classification_date_other_hay_non_alfalfa_CONUS.nc`：其他干草/非紫花苜蓿最早分类日期制图 - `earliest_classification_date_alfalfa_CONUS.nc`：紫花苜蓿最早分类日期制图 - `earliest_classification_date_sorghum_CONUS.nc`：高粱最早分类日期制图 - `earliest_classification_date_rice_CONUS.nc`：水稻最早分类日期制图 数据格式： 所有制图产品均采用网格化NetCDF（网络通用数据格式）格式。年度作物类型制图采用`Crop_map_legend.csv`中定义的分类类别。最早分类日期制图以年积日编码。 地理空间数据投影（采用PROJ4格式）： <pre><code class="language-bash">PROJCS["US_National_Atlas_Equal_Area", GEOGCS["sphere", DATUM["unknown", SPHEROID["Spherical_Earth",6370997,"inf"]], PRIMEM["Greenwich",0], UNIT["degree",0.0174532925199433]], PROJECTION["Lambert_Azimuthal_Equal_Area"], PARAMETER["latitude_of_center",45], PARAMETER["longitude_of_center",-100], PARAMETER["false_easting",0], PARAMETER["false_northing",0], UNIT["Meter",1]]</code></pre> 论文引用： Konduri, V., Kumar, J., Hargrove, W. W., Hoffman, F. M., Ganguly, A. R. (2020) 《美国本土生长季内作物制图》（*Mapping Crops Within the Growing Season Across the United States*），《Remote Sensing of Environment》（已修回）