MyWay RTK (www.mywayrtk.com) will provide correction signals covering every tillable acre in Illinois. Although MyWay hasn’t divulged its list of owners, participants include about 50 agricultural retailers. Their goal is to improve the efficiency of custom applications by reducing confusion that occurs when farmers ask applicators to follow guidance lines generated by a hodgepodge of RTK systems.

“If we all used the same correction source, we would eliminate a lot of the concern about AB data not matching up,” says Don Bierman, MyWay RTK manager. “This would allow us to exactly follow their tracks so we don’t have to bump RTK lines or make up for systems that had problems during the day.”

The long-term goal is to build a system that encourages navigation equipment manufacturers to develop hardware that works together and enables data to flow to and from various systems, Bierman says. “Today the concern is that technology manufacturers will continue to innovate in isolation,” he says. “In the end, you have a product that stands alone and can’t interact.”

MyWay RTK subscription prices have not been set, but are likely to be in the $1,250/unit/yr. range. A subscription would provide access to correction signals throughout the system.

The Slingshot system from Raven Industries (www.ravenslingshot.com), which the company 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 can receive RTK correction data from many Internet-connected sources, including MyWay RTK, Trimble’s VRS Now and state DOT CORS networks. Slingshot partners also are building RTK correction base stations to supplement, and sometimes compete with, existing cellular RTK networks, says Paul Welbig, Slingshot operations manager.

By the 2011 planting, new systems in the Midwest using Slingshot RTK base stations will be available (or are available now) across Ohio, Indiana and parts of Illinois (owned by Equipment Technologies, www.etsprayers.com), as well as eastern South Dakota and southeastern North Dakota. More robust networks supplemented by new Slingshot base stations also will be available in eastern Nebraska and Kansas and western Missouri.

“We are network agnostic,” Welbig says. “We want to leverage what is already there. The end user at the end of the day doesn’t care where he gets his RTK correction signal as long as it works.”

Annual subscription fees are $1,500/unit for Slingshot dealer-provided RTK corrections and $750/unit for outside correction signals. A three-year subscription for outside correction signals is $1,000. All subscriptions include support for GPS, GLONASS and other Global Navigation Satellite Systems (GNSS) sources. A Slingshot Field Hub retails for $2,000.

Since it was introduced in 2009, Trimble’s VRS Now (www.trimble.com/vrsnow) cellular system has expanded from its Illinois base to include northern and western Indiana, most of Iowa, south-central and southwestern Minnesota, the southeastern corner of South Dakota, all of Nebraska except the Sandhills and peripheral areas, as well as other states.

While MyWay RTK, Slingshot dealers and some CORS systems provide corrections from individual base stations, VRS Now uses proprietary software to generate RTK corrections based on location information across its network of base stations. “Unlike simple single-base systems, a networked solution will not lose accuracy as the distance from any individual base increases,” Pfitzer says.

For ag subscribers using Trimble navigation technology, Trimble VRS Now subscriptions are $1,200/yr. for GPS corrections and $1,500/yr. for full GNSS corrections, including GPS and GLONASS.

For non-Trimble users of the VRS Now network, prices vary by region. In northern and southern Illinois, for example, the subscription is $1,200/yr. for GPS and $1,650/yr. for GNSS correction data. Access is limited to a specific region.