Study On The Establishment Of High Precision DEM For Farmland In Mountainous Areas

The digital elevation model(DEM)is a set of solid models that represent the elevation of the ground using an ordered array of numerical values.It is a digital representation of the ground morphology.Due to the popularization of precision agriculture,digital terrain map DEM is required to level land in farmland,and high-precision DEM can provide a priori map for autopilot systems to improve autopilot accuracy.At present,for the production of high-precision DEMs,high-end instruments such as total stations,laser altimeters and other types of space interpolation methods are generally used.However,large-scale farms have already begun to gain a lot of popularity,and the existing ordinary farms are relatively large in size.However,for a modern farm,not much labor is required,and the amount of land owned by it can reach 100 mu.A few days ago,most farms have installed automatic steering systems for GPS-guided agricultural tractors.Therefore,in this study,in order to improve efficiency,save economic and learning costs,but also due to the popularity of self-driving agricultural machinery,it is proposed to use an automatic navigation and driving system of agricultural machinery with RTK-GPS technology to collect GPS point cloud data and use it together.A suitable spatial interpolation method is used to process the data to generate high-precision DEM in the hilly area of the mountainous area,and the method is studied in detail.The research work and conclusions of this paper are as follows:(1)Using RTK-GPS technology,agricultural tractors mount high-resolution GPS receivers and inertial measurement units(IMUs)as measurement tools for farming in the fields,and record GPS data and IMU data during farming and keep them simultaneously.The recorded GPS data and IMU data are filtered to retain only high-resolution data;the preserved high-resolution GPS data is projected to the ground to generate ground point cloud data as an interpolated sampling point(Ps).(2)For all sampling points(Ps)point cloud data gaps using dynamic,Cubic,Triangle Lineal,Natural,Nearlist spatial interpolation interpolation method to generate grid interpolation data(Pi),and use Pi as the original data to generate DEM.the(3)Proposed a Dynamic interpolation method,which has characteristics of wide search range and high flexibility.And the DEM generated by this method not only can meet the precision requirements in the DSP(double side pre-known)area and the SSP(single side pre-know)area,but also can meet the accuracy requirements in the NP(none pre-known)area generation.(5)The conclusion shows that using existing equipment:auch as tractors,GPS,IMU can also produce high-resolution DEM,this method can reduce costs and make farmers easy to learn.