The network of overlapping real-time kinematic (RTK) correction systems continues to grow, now offering growers in a sweet spot over the central Corn Belt a half-dozen or more options for acquiring correction signals for their navigation systems.

The sweet spot — Illinois, Indiana, Iowa, Ohio and southern Minnesota — highlights a big leap in the number of correction signal networks that have begun offering their services in recent years. Even in less-well-served geographies flanking this area, multiple RTK network options are becoming the status quo.

A decade ago, whether there was an RTK network covering your farming operation depended on whether a radio-based system had been deployed by your local John Deere, Trimble or AutoFarm dealer. Then, beginning in 2000, a third correction signal option gradually became available as state departments of transportation (DOT) began building RTK base station networks. By 2009, DOT networks, which deliver correction signals via cellular modems, had been deployed in Iowa, Indiana, Ohio, Michigan, Minnesota, Missouri and Wisconsin.

In the past two years, new commercial ag-only cellular RTK systems — plus a new satellite-delivered option — have doubled RTK correction signal options in many areas. Trimble, MyWay RTK and Raven Slingshot have built, or are planning to build, statewide and regional networks from Ohio on the east and Kansas and Nebraska on the west.

Here’s a look at what’s new on the RTK correction network horizon for 2012.