Ian Yule

Ian Yule’s 1999 paper on precision farming in New Zealand described sub-metre differential receivers as capable of meeting the needs of precision agriculture, but the correction signal was a significant part of the cost. A user could establish a local base station, use a commercial UHF correction service where coverage existed, or buy corrections delivered through satellite services. Yule described Satlink coverage in Canterbury at NZ$3,600 a year and satellite-delivered correction services through Omnistar and Racal at about NZ$4,000 a year. His worked example allowed NZ$8,000 for the DGPS receiver itself.