*2.2. Data*

The GF-1 satellite was launched in April 2013 and obtained a large amount of data since then. It carries two panchromatic/multi-spectral (P/MS) and four wide-field of view (WFV) cameras. Within the spectral range of the GF-1 WFV sensor (450–890 nm), there are four spectral channels to observe the reflected solar radiation from the earth. It has a spatial resolution of 16 m, a stripe width of 800 km, and consists of four cameras. The temporal resolution is four days. Therefore, it has the characteristics of high frequency revisit time, high spatial resolution and wide coverage, and is an ideal data for large-scale land surface monitoring.

The GF-1 satellite images are provided by the China Resource Satellite Application Center (http://www.cresda.com/CN/). In this study, our model also increases the input channels compared with the conventional neural network, and all the four spectral channels of GF-1 images are used.
