GPS-Based Wastewater Tracking System for Commercial Swine Production Facilities

The objectives of the project were to develop a system capable of tracking a traveling gun spray system using a DGPS unit and to determine its effectiveness. The GPS Wastewater Tracking System (GWTS) consisted of a roving unit that received DGPS signals and relayed them to a stationary decision center. Preliminary experimentation showed that the stationary unit could reliably relate the position of the rover to decision criteria to generate control output. Next, the usefulness of the system in locating thresholds between different management zones was investigated using a battery of 1-dimensional tests in which the rover was allowed to “find” pre-positioned lines of delineation. It was found that 95% of the observed discrepancy between the actual the position of the rover and the line the rover reported to have detected were less than 1.31 meters with satellite-based differential correction and less than 3.40 meters uncorrected. It was concluded that a system of this type would be more than adequate for tracking a slow-moving traveling gun using inexpensive, non-corrected, GPS units.