/* DATA DESCRIPTION:
Citation:	See, Linda (2017): A global reference database of crowdsourced cropland data collected using the Geo-Wiki platform. International Institute for Applied Systems Analysis, PANGAEA, https://doi.org/10.1594/PANGAEA.873912
Abstract:	A global reference dataset on cropland was collected through a crowdsourcing campaign implemented using Geo-Wiki. This reference dataset is based on a systematic sample at latitude and longitude intersections, enhanced in locations where the cropland probability varies between 25-75% for a better representation of cropland globally. Over a three week period, around 36K samples of cropland were collected. For the purpose of quality assessment, additional datasets are provided. One is a control dataset of 1793 sample locations that have been validated by students trained in image interpretation. This dataset was used to assess the quality of the crowd validations as the campaign progressed. Another set of data contains 60 expert or gold standard validations for additional evaluation of the quality of the participants. These three datasets have two parts, one showing cropland only and one where it is compiled per location and user. This reference dataset will be used to validate and compare medium and high resolution cropland maps that have been generated using remote sensing. The dataset can also be used to train classification algorithms in developing new maps of land cover and cropland extent.
Further details:	Further details on file structure and content (URI: http://store.pangaea.de/Publications/See_2017/See_2017_info.pdf)
Parameter(s):	File content (Content) * PI: See, Linda (see@iiasa.ac.at)
	File name (File name) * PI: See, Linda (see@iiasa.ac.at)
	File format (File format) * PI: See, Linda (see@iiasa.ac.at) * COMMENT: all files zipped
	File size [kByte] (File size) * PI: See, Linda (see@iiasa.ac.at) * COMMENT: zipped size
	Uniform resource locator/link to file (URL file) * PI: See, Linda (see@iiasa.ac.at)
License:	Creative Commons Attribution 3.0 Unported (CC-BY)
Size:	30 data points
*/
Content	File name	File format	File size [kByte]	URL file
Reference dataset of 35866 locations containing all grid cells marked as cropland as provided by participants	crop_all.zip	txt	7098.616	http://store.pangaea.de/Publications/See_2017/crop_all.zip
Control dataset of 1793 sample locations containing all grid cells marked as cropland as validated by students trained in image interpretation	crop_con.zip	txt	34.042	http://store.pangaea.de/Publications/See_2017/crop_con.zip
Expert validations of 60 sample locations containing all grid cells marked as cropland for additional evaluation of the quality of the participants	crop_exp.zip	txt	2.679	http://store.pangaea.de/Publications/See_2017/crop_exp.zip
Reference dataset of 35866 locations with mean cropland compiled per location and user as provided by participants	loc_all.zip	txt	1594.125	http://store.pangaea.de/Publications/See_2017/loc_all.zip
Control dataset of 1793 sample locations with mean cropland compiled per location validated by students trained in image interpretation	loc_con.zip	txt	13.533	http://store.pangaea.de/Publications/See_2017/loc_con.zip
Expert validations of 60 sample locations with mean cropland compiled per location for additional evaluation of the quality of the participants	loc_exp.zip	txt	0.885	http://store.pangaea.de/Publications/See_2017/loc_exp.zip