As a consequence of population aging and shrinkage in China, the trend of labor shortage for agricultural production has grown and will continue in future. Acceleration of agricultural mechanization has been proposed as a developmental strategy in support of steady and sustainable development of agriculture in China. In alignment with this national developmental plan, the use of unmanned aerial vehicle (UAV) for pesticide application contributes to the advancement of plant protection mechanization by providing improved ability to apply pesticide in a time sensitive manner with enhanced safety and efficiency.The flight parameter of UAV was one kind of the most important indices affecting the quality of aerial pesticide application. To explore the distribution characteristics of pesticide spraying droplets deposition of UAV and the effect of flight parameters (flight altitude and velocity) and parameter accuracy on the deposition distribution characteristics, the spraying droplets depositions of 4 models of typical Chinese domestic UAVs (3WQF120-12, MercuryⅠ, 3WCJ8-10 and 3WQFTX-10) were tested in the wheat field in Xinxiang City, Henan Province in April, 2017. The high-precision Beidou navigation satellite system was used for recording the accurate working altitude, velocity and track of UAV, and the tartrazine tracer water solution of 0.5％ was adopted to replace pesticide liquid for spraying. The filter paper with the diameter of 7 mm was used for collecting spraying droplets from UAV at the height of 0.7 m on the top of the wheat canopy, and the sensor of Zeno-3200 weather station was set at the height of 6 m to record the environmental parameters at test site. The size of the testing field was 50 m × 100 m and there were 15 sampling points in a straight line with 3 duplications for longitudinal droplet deposition distribution and 11 sampling points also with 3 duplications for crosswise one. During every test, the operator controlled the UAV remotely to take off, when the UAV reached the required height, then open the spraying system and make the unmanned aircraft fly over the experimental area according to the planned flight. After tests, the eluent from the filter paper was used to measure the absorbance of the tracer tartrazine by the 722 type spectrophotometer and the droplet deposition in every test was figured out. Combining the flight parameters with their coefficient of variation (CV) and root mean square error (RMSE), the impact factors on deposition distribution characteristics were studied and the results were analyzed by significance and regression analysis via SPSS 20 software. The results showed: The deposition in the area of both ends of flight route varied violently (30％展开▼
