RTK Mobile Machine Control--Assessing Partial Sky Blockage with GIS

Effective Real Time Kinematic (RTK) mobile machine control requires a sufficient number of global positioning system (GPS) satellites that are both visible and suitably positioned. Reliably obtaining the highest degree of accuracy and precision afforded by RTK technology requires the initial acquiring of a solution (i.e., obtaining an RTK "fix" solution), the maintaining of the RTK fix solution, and if it is lost, rapidly reestablishing the RTK fix solution. Losing the RTK fix solution is a common occurrence when operating near trees, tall landforms, and large structures that can cause significant sky blockage. Operators can increase the likelihood of acquiring and maintaining an RTK fix solution by incorporating more satellites from multi-national Global Navigation Satellite System (GNSS) constellations. However, this added capability is only of practical economic benefit when and if operating near sky blockages. Due to the additional expense in upgrading mobile machine control to full GNSS coverage capabilities, upgrade considerations should include the impact of sky blockages surrounding production fields caused by the rolling terrain, nearby landforms, and most importantly, field-surrounding tree canopies.