Monitoring winter wheat in ShanDong province using Sentinel data and Google Earth Engine platform

Using remote sensing technology to extract winter wheat planting area can provide an effective way and reliable data for macroeconomic decision-making of agricultural economy. The cooperation of Sentinel-2A and Sentinel-2B can achieve a five-day visit cycle, and more phenology information can be obtained when monitoring winter wheat. However, at present, Chinese users can only download Sentinel Level-1C data, Level-2 data need to be produced and processed by users themselves. The data downloading and processing is more troublesome. Google Earth Engine (GEE) is a cloud platform provided by Google for online visual calculation and analysis of a large number of global-scale geoscientific data. The platform can not only access the data from satellite images and other earth observation databases, including the level-2 products of Sentinel data, but also provide enough computing power to process these data, which greatly simplifies the time of data downloading and processing, and improves the efficiency of winter wheat area monitoring. Based on GEE platform and Sentinel 2 data, the time series of winter wheat in growing season was constructed. The winter wheat planting area in Shandong Province from 2018 to 2019 was monitored through the characteristics of the actual phenology period in the time series. The monitoring results were verified by more than 6000 ground sample zones collected in 2018 distributed throughout the province. The results showed that the extraction technology of winter wheat planting area in this paper could be achieved to 92.45%.