Abstract
Several global high-resolution built-up surface products have emerged over the last five years, taking full advantage of open sources of satellite data such as Landsat and Sentinel. However, these data sets require validation that is independent of the producers of these products. To fill this gap, we designed a validation sample set of 50 K locations using a stratified sampling approach independent of any existing global built-up surface products. We launched a crowdsourcing campaign using Geo-Wiki (https://www.geo-wiki.org/) to visually interpret this sample set for built-up surfaces using very high-resolution satellite images as a source of reference data for labelling the samples, with a minimum of five validations per sample location. Data were collected for 10 m sub-pixels in an 80 × 80 m grid to allow for geo-registration errors as well as the application of different validation modes including exact pixel matching to majority or percentage agreement. The data set presented in this paper is suitable for the validation and inter-comparison of multiple products of built-up areas.
Highlights
Background & SummaryAt present, around 55% of the world’s population lives in cities, which is predicted to increase to 68% by 20501
Mapping the location of urban areas is increasingly important for high resolution climate modelling[5], for climate change
More detailed urban mapping of urban structural types using remote sensing has been undertaken for numerous individual cities[13] or through initiatives such as the Urban Atlas, which has mapped all cities across the European Union (EU) with a population greater than 50K14, or the World Urban Database and Access Portal Tools (WUDAPT) project, which aims to map every city in the world using 10 detailed urban classes, mainly to improve urban climate modelling[5]
Summary
Around 55% of the world’s population lives in cities, which is predicted to increase to 68% by 20501. The Joint Research Center (JRC) of the European Commission, as part of the Group on Earth Observation’s (GEO) Human Planet Initiative, initially produced a series of built-up area grids for 1975, 1990, 2000 and 2014 available at a 30 m resolution based on multi-temporal Landsat imagery (R2018A)[15,16]. This was followed by built-up area grids derived from Sentinel-1 for 2016 (R2018A)[17,18] and from Sentinel-2 for 201819, as part of the Global Human Settlement Layer (GHSL) data package[20]. Change in built-up observed between pairs of images (from Google Maps and Microsoft Bing) was recorded along with the dates of the imagery
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
