How John Deere developed one of the best GPS locators in the world

One of the most accurate GPS-based location systems in the world isn’t a hyper-secret military technology or a top-of-the-line scientific device – it’s John Deere’s worldwide correction network, a dual-band GPS system that lets farmers track their planting, harvesting and more to an accuracy of less than an inch. “It’s one of the most difficult and exciting programs that Deere’s ever done,” according to Terry Pickett, manager of advanced engineering at the company’s Intelligent Solutions Group.The technology is important because everything from tilling to planting to irrigation to harvesting is better and easier when farmers have a more precise way to track their position – crops can be distributed more evenly across a field, seeds planted at exactly the correct depth and position to maximize yield.Dual-frequency GPS makes for greater accuracy, thanks to a better ability to correct errors introduced by atmospheric interference. Monitoring the difference between delays in the two frequencies lets operators “calculate out” the interference for a much more accurate positional reading.