## 2 Materials
### Remote Sensing Data  
Photosynthetically active radiation (PAR) data from the Himawari-8 satellite, reflectance, land surface temperature (LST), and the FPAR datasets from the MODIS sensors were employed during the winter wheat growth period, from March to June 2017. The Himawari-8 spacecraft was launched  
Figure 1: The location of the Yucheng experimental station, study area, and experimental plots in the study area as follows: (**a**) the map of the Yucheng experimental station and study area; (**b**) experimental plots in study area (exp2); and (**c**) the scheme of the sub-plots.  
on 7 October 2014 from the Tangeashima Space Center (TNSC) of JAXA, Japan. The Himawari standard data included the visible to infrared radiances (Band 1 to 16) of the three regions of the Full Disk (global), Japan Area, and Target Area. The Himawari-8 data were released to research communities for creating the products. The products included short wave radiation, PAR, chlorophyll-a, sea surface temperature, aerosol optical thickness, and wild fire. All of the data were in the NetCDF format. With 5 km of spatial resolution and 30 min of temporal resolution, the PAR data were of level 3 and were downloaded with a JAXA Himawari Monitor ([[http://www.eorc.jaxa.jp/ptree/userguide.html](http://www.eorc.jaxa.jp/ptree/userguide.html)]([http://www.eorc.jaxa.jp/ptree/userguide.html](http://www.eorc.jaxa.jp/ptree/userguide.html))). The downloaded PAR data were geometrically corrected using the ENVI (The Environment for Visualizing Images) software. Then, the PAR data were integrated into 8-day composite products and resampled to 1 km.  
The MODIS images provided a low spatial resolution but a high temporal resolution and wide coverage areas. This study used an 8-day composite time-series dataset of the MODIS surface reflectance (MOD09A1), LST (MOD11A2), and FPAR (MCD15A2H), from 20 March to 31 May 2017. The MODIS dataset were downloaded from EARTHDATA ([[https://search.earthdata.nasa.gov](https://search.earthdata.nasa.gov)]([https://search.earthdata.nasa.gov](https://search.earthdata.nasa.gov))) with a tile of h27v05. The MOD11A2 MODIS images were of a level 3 product with 1 km pixel size. The MOD09A1 MODIS images were of level 3 product with 500 m pixel size. The MCD15A2H MODIS images were of a level 4 product with a 500 m pixel size. MOD09A1 and MCD15A2H data were resampled to 1 km. Atmospheric, geometric, and radiometric corrections were not required for the MODIS level 3 and 4 data, facilitating the user to popularize and spread the data. However, all of the MODIS images were re-projected from Sinusoidal to the World Geodetic System 1984 projection.  
The study used Sentinel-2 time-series data to identify the winter wheat area in Hengshui City. Eight images with 10 m of spatial resolution were captured on 29 March and 7 June 2017, corresponding to the Tillering and Harvest stages of the winter wheat. Atmospheric correction were then performed on the Sentinel-2 images.  
The one Worldview2 image that was acquired on 13 March 2017 was used to verify the accuracy of Sentinel-2 classification. The radiometric correction and atmospheric correction were performed on the Worldview2 image. Using a false color composite, the winter wheat distribution map covering part of Shenzhou County was obtained.