Multiple GPS Measurements for Digital Elevation Model

Accurate representation of field topography is required for implementation of precision conservation management practices. Topographic data for the development of agricultural field digital elevation models (DEM) can be acquired using GPS-equipped farm vehicles during field operations. Repeated measurements of elevation data from multiple field operations may improve DEM accuracy over time. However, repeated topographic measurements would consequently increase the volume of data required to be stored, processed and manipulated unless the amount of data passed on between measurement intervals is reduced. For farmers to utilize topographic information effectively and efficiently, processes must be developed to analyze and manage topographic data collected during field operations and to generate DEMs with minimal user input and intervention. This paper presents an overview of the processes needed for utilizing multiple sets of topographic measurements acquired during field operations for the development of agriculture field DEMs. The procedures needed for DEM development include data preparation and cleaning, data reduction and geostatistical analysis with interpolation. Preliminary data analysis is conducted to extract useful information from GPS raw data set for preparation and cleaning prior to data combination process. The data combination and estimation technique presented is used to estimate elevation data without requiring new sets of measurements to be stored and reprocessed every time they are acquired. Finally, the elevation values at unmeasured locations can be predicted using geostatistical analysis and kriging interpolation method is used to predict the DEM surface