The first messages sent by telegraphs or telephones were more about making sure these inventions worked than actually relaying information. As they were improved, people quickly learned many different ways to use these communication tools.

The same thing is true with farming using auto-guidance technology today.

The precision farming community has been focused on getting an accurate signal to the rover - the tractor or unit working out in the field. Now, many tools are becoming available to allow a tractor to steer with sub-inch accuracy.

Consequently, farmers, ag businesses and others are thinking of ways to use auto-guidance to improve the bottom line and quality of life.

David Ohm, a precision farming specialist for Titan Machinery, said CNH recognized the need to get accurate auto-guidance in order to develop new precision farming applications.

Titan Machinery offers Case IH and New Holland agricultural and construction equipment at 72 stores located in seven states.

“Application controls - end-of-row functions for planters, and turning on and off the sprayer controls - has become as big as auto-guidance,” Ohm said. “This has all evolved from everyone making straight rows to the next level.”

That includes harvesting corn with auto-guidance.

“This is a proven return on investment,” he said. “That's the whole concept of advanced farming systems. We use less seed to get more crops. We use less spray to obtain the same end results for weed control and to properly place a prescription rate of fertilizer.

“This is a financially beneficial way to reduce your input costs.”

Ohm spoke at the Fargodome in early December at the Northern Ag Expo.

Here are some of the partnerships and tools that CNH has explored to provide farmers with guidance accuracy.

GLONASS - An abbreviation for the Russian Federation Government Global Navigation Satellite System, GLONASS satellites can complement the United States' Global Positioning Systems (GPS) satellites and other radio-based satellite navigation systems.

The satellite system includes 21 satellites in three orbital planes. The positioning satellites transmit their locations constantly as they circle the earth.

“With GLONASS coming into our solution, instead of having six to eight satellites, we now have 14, 15 or 16 satellites on various displays,” said Ohm. “More satellites will mean you have a greater opportunity to keep your dilution of precision low, which means higher accuracy.”

Satellite visibility that could have caused a poor quality signal will almost be nullified, he said. The opportunities for seeing a better satellite constellation have dramatically improved.

CNH has partnered with Trimble-based GPS systems, offering advanced receivers capable of receiving and using the free transmission from the GLONASS satellite system.

Rural Tower Network (RTN) - The Rural Tower Network is a dedicated signal provider of Real Time Kinematic (RTK) GPS.

Each RTK station uses a single base station receiver that broadcasts to mobile units. The stations provide a dedicated system and highly accurate guidance correction.

Its only purpose is to send a satellite-based correction radio transmission to rovers working in fields.

Titan Machinery, RDO Equipment and Butler Machinery have installed and erected over 60 RTK towers running from just south of the Canadian border to Wheaton, Minn. The towers run from west of Aberdeen, S.D. to Fergus Falls, Minn.

The RTK is considered the most accurate and repeatable form of GPS correction available.

For tractor auto-guidance operations, RTK provides sub-inch accuracy repeatable year after year. The system allows farmers to practice auto-guidance strip tillage, precision fertilizer placement, field drainage management, planting and harvesting.

The RTN is expanding service in North Dakota, South Dakota and Minnesota.

Continuously Operating Reference Stations and Virtual Reference Stations  - Continuously Operating Reference Stations (CORS) are generally owned by the states in which they are located.

The system is set up for use by the Department of Transportation.

“The Department of Transportation uses the Virtual Reference Stations (VRS) and CORS networks mainly for their surveying work, which saves tax dollar money because surveyors now use GPS for a lot of their corrections, rather than sending survey teams to the field,” Ohm said. “The DOT can do most of their work with GPS. We're just using the same correction source on the ag side.”

Using CORS, a VRS extends the use of RTK to areas that are not in an existing RTK network. The system allows auto-guidance accuracy, usually within an inch, and can be very helpful in rolling terrain with trees.

Ohm said a cell modem in the tractor communicates with a central server that knows the rovers latitude and longitude. The server picks up the data from the CORS station, figures the best correction, takes the data, puts it into the server and sends it back to the rover.

“What makes this successful, is the availability of cellular reception,” said Ohm. “It's not, at this time, as reliable as an RTK network. Even though the VRS and CORS signal is considered ‘free,' you still have to play for the cellular service and you have to pay for a data package to get uninterrupted data transmission from a cellular system.”

OmniSTAR - CNH works in conjunction with OmniSTAR to provide GPS enhancement data via satellite.

OmniSTAR uses geostationary satellites that move at the same speed as the earth to transmit dual band corrections to rover units in the field.

Customers subscribe to OmniSTAR services.

OmniSTAR HP offers accuracy of 2 to 4 inches. It operates in real time without the need for local RTK base stations. OmniSTAR XP offers accuracy of 3 to 5 inches.

“GPS and auto-guidance started out in the high value row crop situation, but now we've gone far beyond that,” Ohm said. “In the major farming areas, we're using GPS for end-of-row shutoffs and eliminating overlaps, and input costs go down drastically with the use of advanced farming systems.”

Source: Farm and Ranch Guide