The Slingshot system from Raven Industries, which was introduced in early 2010, provides cellular-delivered RTK correction signals, plus high-speed communications and data transfer capabilities through the Slingshot Field Hub cellular modem/router. The Field Hub works with all major cellular-capable guidance products and can be used to access non-Slingshot cellular RTK corrections, including those from state DOT, MyWay RTK and CenterPoint VRS networks.

Since 2010, new Slingshot RTK correction signal networks have been built covering most of Ohio, Indiana and central Illinois, and along the I-29 corridor in Iowa, Nebraska, South Dakota, and parts of North Dakota. Networks are continuing to expand, with a new network expected in Kansas in 2012, says Colin Pollock, a Slingshot sales specialist.

The cost equation

Commercial RTK network annual subscriptions typically cost $1,250 to $1,500, plus cellular costs where applicable. To date, corrections from DOT systems have been free, though cellular data costs still apply. Pricing details are available from network providers.