GPS On The Move

When it comes to precision farming, global positioning is the heart and soul of any strategy.

And as the GPS revolution rolls into its second decade since it truly became a widely available public access technology, much has changed for the better. Satellite signal availability and accuracy options have increased significantly. And over the course of the last seven years, the availability and accessibility of real-time kinematic (RTK) correction has moved rapidly from the new technology on the block to an investment that more and more end-users are able to afford.

We’re certainly closer to a vision that Mike Gomes, agriculture product manager for receiver manufacturer Topcon, discussed in a 2006 article in sister publication PrecisionAg Special Reports. “The idea is that global positioning becomes like a utility,” he said. “For instance, when you turn on a light, electricity makes it work; or when you turn on the water, it is clean and usable. Imagine there being no time of day issues, no issues with compatibility or satellites or your position on Earth. It’s just there, always on and ready to use.”

Inside agriculture, receiver technology has evolved to the point where it is built into most equipment, notes Paul Welbig, marketing manager at Raven Industries. “The reliability, cost, and usability of GPS technology has really reached a point where customers trust it and use it in more and more applications,” he says.

More Satellites, More Signals

Real-time kinematic (RTK) gets most of the press these days, but satellite-based GPS continues to evolve. Here’s a glance at what’s happening in the sky:

1. Upgrades to the North American GPS system will include the addition of two new civilian signal types, L2C and L5. Both are dual frequency signals that will provide more reliability and accuracy than L2. These offerings are at least five years off, but on the way.

2. From Russia comes GLONASS, a project started by the Soviet Union in the 1970s that is now moving forward with some gusto. The North American-GPS compatible system is not operational as a stand-alone unit. But receivers that feature GLONASS compatibility can utilize the satellites to potentially add accuracy.

3. Galileo is Europe’s answer to GPS and GLONASS, but has been very slow to get up and running. Because Galileo is compatible with the current constellation, any satellites that go up will add to the total available to growers, but it could be a decade before Galileo is operational as a stand-alone system.

Evolution Of The Revolution

GPS has gone through an evolution almost simultaneously with, and arguably no less remarkable than, the Internet. Like the Internet, GPS was in its infancy back in 1995, and product developers were working on a receiver that provided accuracy good enough for agriculture applications. Initial products were only providing accuracy measured in meters, which didn’t fit the bill, says Sid Siefken, product manager for Trimble.

“The data farmers got from recording the yield monitor was jumping around 2 to 5 meters,” he explains. “So a farmer would get his data back and say, “I didn’t drive like that — this isn’t accurate enough for my application.”

A little more than a decade later, an end-user interested in georeferencing field operations using a GPS system has a wide range of options in receiver technology, from the very basic sub-meter system all the way down to the sub-inch accuracy level. These developments have come both in signal technology and at the receiver level.

There are essentially four sources of GPS signals available today. The Wide Area Augmentation System, built originally to replace the current system for coordinating commercial air traffic, is available at no cost from the federal government. The signal  provides accuracy averaging around 6 inches — a bit more or a bit less depending on the receiver used.

OmniSTAR provides a subscription-based signal with three options depending on accuracy needs — VBS at the basic level, followed by XP and HP, providing accuracy as good as 3 inches at the top end. The Coast Guard beacon system also continues to be accessible to users within range of a beacon.
Finally, there’s real-time kinematic systems, which require a static ground receiver and “rover” receiver that provides true sub-inch accuracy. The other potential benefit with RTK is repeatability — if the static receiver is returned to the precise same location each time it is used, or is permanently installed in one location, it will provide guidance that is repeatable. That is, you’ll be able to return to the same spot in the field, year over year.

The big news with RTK systems is price point reduction and accessibility. A few years ago, you could expect to invest $30,000 at the low end to add RTK. Individual systems today come in at under $20,000, and where there are tower networks available to pick up a broadcast signal (for a subscription fee), potentially much less than that.

“Cost-effective and easy-to-use base stations have put the power of repeatability through use of RTK within the reach of more (users),” says Deane Malott, director of product marketing for AutoFarm.

Satellite Signal Improvements

While RTK systems have gotten the lion’s share of the  press, satellite-based GPS — and the receivers that use the signal — also have been steadily improving over the years. One of the most significant improvements is the availability of a “dual-frequency” signal.

Dual-frequency receivers use two of the GPS frequencies, L1 and L2, explains John Pointon, marketing manager at OmniSTAR. “Up until a few years ago those were exclusively used by surveyors who wanted high accuracy, and because of cost the ag market used only single frequency L1. With L1, you really cannot get better than submeter accuracy.

“People who are serious about automatic steering and planting and strip-till need to be within an inch or two, and thus need a dual-frequency receiver,” he continues. “Dual frequency permits better compensation for atmospheric errors and helps with the complex calculations required for high accuracy positioning. This is really where the growth is in the market today.”

Of course, not everyone needs or wants that kind of accuracy. So manufacturers are offering a wide range of accuracy options that balance price and value expectations.

What should you consider when weighing up receiver options? Pay attention to the antenna design of the receiver. Antennas today are designed for specific purposes, and knowing their abilities and limitations will ensure you are getting what you expect. It’s also important to note that newer technology is better. A newer, higher quality antenna will deliver a cleaner signal that minimizes interference that is generated by reflected signals and obstacles in the path of a signal.

Leave a Reply

Featured Stories

CropLife 100Wilbur-Ellis To Relocate Agribusiness Division To Denver
July 16, 2014
The move Eastward will allow Wilbur-Ellis’ Agribusiness Division to be more accessible to relevant geographies and is expected to enhance communication and collaboration among the division’s nearly 3,000 employees. Read More
Soybean field
FungicidesValent Launches New Seed Protection Fungicide For Soybeans
July 16, 2014
The INTEGO SUITE System contains the first new, novel seed protection fungicide chemistry registered in 30 years by the EPA for protection against Pythium and Phytophthora. Read More
LegislationUSDA: Quick Implementation Of Disaster Assistance Programs A ‘Top Priority’
July 9, 2014
USDA has processed 106,000 payments to farmers in 40 states across the country who suffered livestock and grazing losses between Oct. 2011 and passage of the 2014 Farm Bill. Read More
Eric SfiligojDoes Biotech Crop Labeling Really Matter?
July 7, 2014
Initiatives to label products made with biotech crops are intensifying. But should the industry continue to fight them? Read More

Trending Articles

EquipmentSummer Show Preview 2014: Superior Sprayers Take The Field
July 3, 2014
In this final installment of our coverage of the major categories of Big IRON that retailers can expect to test-drive at this summer’s events, here is a look at 19 sprayers. Read More
Scouting a soybean patch at Green Valley Ag.
EmployeesCropLife Compensation Survey: Battling Talent Drain
July 2, 2014
Retailers too often lose employees to companies outside of agriculture, while recruiting efforts are most often limited to competitors and other ag-focused organizations. Read More
HerbicidesDow AgroSciences Introduces SureStart II Herbicide
June 16, 2014
The enhanced formulation has improved viscosity and increased stability under heat and controls more than 60 high-anxiety grasses and broadleaf weeds found in corn fields. Read More
HerbicidesBASF Investing $270 Million To Expand U.S. Herbicide Production
June 11, 2014
BASF has invested more than $270 million to expand herbicide production capacities in the U.S., including more than 20 new products to be launched over next two years. Read More
EquipmentGPS: 25 Years And Still Growing
June 2, 2014
The evolution of global positioning systems applications in agriculture remains ongoing as the technology hits a notable milestone. Read More
CropLife 10013 Key Acquisitions Pinnacle Has Made In The First Half Of 2014
May 29, 2014
The only thing that has reached a more frenzied pace than #plant14 might be the multiple acquisitions that Pinnacle Agriculture Holdings has made in the first half of the year. Read More

Latest News

EquipmentPrecisionAg.com Relaunches With Responsive Design For M…
July 22, 2014
PrecisionAg, the worldwide leader in precision agriculture information and analysis, announces the launch of its completely redesigned website, PrecisionAg.com. Read More
FungicidesEPA OKs Two Willowood Fungicides
July 21, 2014
The EPA has approved Willowood Azoxy 2SC and Willowood AzoxyProp Xtra. two widely used broad spectrum, preventative fungicides with systemic and curative properties. Read More
Precision AgFarmers Learning Fast As UAVs Take Off
July 17, 2014
Farmers and others interested in how UAVs can be used in agricultural applications were able to learn more about the technology during the recent Precision Aerial Ag Show. Read More
CropLife 100Bobby Knight, Richard Petty To Highlight Ag PhD Field D…
July 17, 2014
Attendees at the July 24 Ag PhD Field Day at Hefty Farms will learn about the latest agricultural technologies, and get a chance to meet legendary sports figures Bobby Knight and Richard Petty. Read More
WebinarsUpcoming Webinars
July 17, 2014
Register for one of our upcoming Webinars or access our archive of past Webinars to view recordings of presentations that may be of interest to you. Read More
A finished Willmar 16-ton side-shooting tender.
TendersNew Production Facility Helps Willmar
July 17, 2014
In 1963, a group of businessmen started Willmar. Today, a half-century later, the company is one of the ag industry’s longest-running brands. Read More
FertilizerCF Industries Sells Carbon Credits To Chevrolet, Donate…
July 17, 2014
CF Industries has completed the sale of a large block of carbon reduction credits to Chevrolet, and will donate the net proceeds of $600,000 to the National FFA Foundation. Read More
CropLife 100Grainland Cooperative, Minier Cooperative Grain To Merg…
July 17, 2014
The shareholders of Grainland Cooperative and Minier Cooperative Grain Co. approved a merger of company operations effective August 1, 2014. Read More
ManagementStudy: Drought Costing California Billions
July 17, 2014
A new study has found the drought has cost the state $2.2 billion, primarily in lost farm revenue and wages. Read More
FertilizerCF Industries Resumes Production At Oklahoma Nitrogen C…
July 17, 2014
The company had shut down production at the Woodward, OK, facility in April to address an issue in one of the site’s boilers. Read More
CropLife 100Wilbur-Ellis To Relocate Agribusiness Division To Denve…
July 16, 2014
The move Eastward will allow Wilbur-Ellis’ Agribusiness Division to be more accessible to relevant geographies and is expected to enhance communication and collaboration among the division’s nearly 3,000 employees. Read More
Soybean field
FungicidesValent Launches New Seed Protection Fungicide For Soybe…
July 16, 2014
The INTEGO SUITE System contains the first new, novel seed protection fungicide chemistry registered in 30 years by the EPA for protection against Pythium and Phytophthora. Read More
Crop InputsSyngenta Drive To Thrive 10 Finalists Announced
July 15, 2014
Finalists are chosen based on the quality of their essays and photos depicting what makes them thrive. Read More
FertilizerHow To Minimize Phosphorus Losses In Runoff
July 15, 2014
Phosphorus losses from agricultural fields can be divided into three categories: flash losses of soluble phosphorus, slow leak losses and erosion events. Here's how to minimize losses in each instance. Read More
ManagementCalifornia Drought Threatens To Dry Up Farm Wells
July 15, 2014
Farmers hit hardest by California's drought could begin to see wells run dry next year, according to a new study by The Center for Watershed Sciences at the University of California, Davis. Read More
Precision AgPoll: Do you plan to attend this year’s InfoAg Co…
July 14, 2014
This year’s InfoAg Conference is just two weeks away. The premier event in precision agriculture takes place July 29-31 at Read More
LegislationFarm Bill Implementation Continues
July 14, 2014
The bill provides $28 billion over the next five years for conservation on private lands while streamlining several old programs and creating new ones like the Regional Conservation Partnership Program. Read More
MicronutrientsH.J. Baker Continues Expansion Of Atmore Facility
July 14, 2014
The company has improved its molten sulphur unloading system to help meet increased sulphur demand at Tiger-Sul’s Atmore, AL, facility. Read More