Wenting Han, Jiangtao Yang, Zhitao Zhang, Chengfeng Cui

　　Institute of Soil and Water Conservation, Northwest A&F University, Yangling, China

　　Institute of Water-saving Agriculture in Arid Areas of China, Northwest A&F University, Yangling, China

　　Remote sensing technology has been used for determining crop water requirements and irrigation scheduling in recent 20 years. Efficient irrigation scheduling tools and management are based on high spatially and temporally resolution images obtained by remote sensing platforms. Unmanned Aircraft Vehicle (UAV) sensing systems with RGB, multiple-spectral and thermal cameras to obtain high quality images were developed. Two fixed wing and 1 4-rotors UAVs were developed using open source pilot software. The control system was designed to trigger the camera independent of the pilot system of UAV. The GPS coordinates were obtained and saved in the log file of the camera. The ground resolution can be calculated based on the parameters of camera and the height of UAV. The UAV remote sensing systems were used to obtain the images of crops in 2013, 2014 and 2015 with the combination of ground data collection like soil and leaf water contents. Soil water content models were developed using linear regression methods based on the UAV remote sensing images and ground measurements.