TOPOGRAPHIC MAPPING THROUGH MEASUREMENT OF VEHICLE ATTITUDE AND ELEVATION

Abstract

A self-propelled agricultural sprayer was equipped with four RTK DGPS receivers and an inertial measurementunit (IMU) to measure vehicle attitude and field elevation as the vehicle was driven across a field. Data were collected ina stop-and-go fashion at 3.05 m (10 ft) intervals, as well as in a continuous fashion at three different speed levels on a 2.3 hafield area with varying topography. Pitch and roll offset angles were estimated to within 95% confidence intervals that rangedfrom 0.01 to 0.10. Using ordinary kriging, digital elevation models (DEMs) were interpolated using only elevationmeasurements, as well as a combination of elevation and vehicle attitude measurements. The resulting DEMs were comparedwith each other to evaluate the effect of including attitude measurement on DEM accuracy. At the widest measurement swathwidth, the DEMs generated with attitude measurements had RMSE values of 10 to 11 cm, which was significantly lower thanthe RMSE of 15 cm associated with the DEMs generated without attitude measurements. Vehicle speed affected DEM error,but no discernable trends were detected. These results provide evidence supporting the feasibility of using vehicle-basedmeasurements collected during typical field operation for accurate DEM development.