Field evaluation of two machine navigation systems for variable rate application

Precision farming or spatially variable crop production (SVCP) aims to improve farm management efficiency by adjusting field/crop treatments to conditions existing at specific areas within fields. The implementation of map-based variable rate application in SVCP usually requires a navigation system for the application of production inputs. Positioning system requirements for application of farm inputs are different in terms of position resolution, reliability and dynamic performance. This paper describes the field performance of navigation tests of two DGPS receiver systems using the real-time differential correction signals from the US Coast Guard beacon signal and another from a commercial satellite- based wide area network. Tests were conducted in a citrus orchard located in the University of Florida, Gainesville, Florida. The dynamic repeatability performance of the two DGPS receivers was found not suitable as a stand alone system in the test site.