RTK is the newest high-tech tool developed to allow satellite information from the Global Positioning System (GPS) network to guide field equipment (planters, fertilizer applicators, harvesters, etc.) with a very high degree of accuracy.
Almost everyone is familiar with GPS technology that helps us get from one address to another even in unfamiliar places. What many do not know is that the information from most GPS receivers, like the one on your car’s dashboard is, by design, accurate to only a few meters in any direction. Great if you are trying to find an office building or a house, but not so great if you are trying to precisely plant a row of corn or soybeans.
Growers, relying on the more commonly used Wide Area Augmentation Systems (WAAS) with their GPS receivers, experience pass-to-pass accuracy of plus or minus 8 to 10 inches and system errors (static accuracy) of up to 39 inches in any direction. With such a large gap, farmers risk running over plants or irrigation systems in the field, over/under applying products or missing valuable farm land altogether.
An RTK system employs a local base station that receives information from GPS satellites and re-broadcasts that information to ground-based farm equipment in the field while also correcting the positioning errors that it detects. The resulting information is transmitted to automatic steering equipment in the farm machines allowing it to plant or fertilize or harvest with an accuracy of one inch or less.
Until now, this type of accuracy correction has been available only through radio transmissions that had a limited range, and was restricted to line-of-sight reception. Hills, buildings and trees could interfere with the signal and disrupt reception by field equipment.
Southern States Cooperative, one of the largest farm supply retailers on the east coast, has announced their plans to offer Real-Time Kinematic (RTK) technology to its precision ag customers in the southeast.
The Southern States RTK service, provided by MyWay RTK systems, utilizes local cell-phone networks to broadcast corrected satellite information in a radius of up to 20 miles with no line of site restrictions. The only interface required for reception by field equipment is a MyWay receiver, a cell modem and a data plan available from most cell-phone carriers.
“Southern States’ RTK network allows a grower to maximize investments in fertilizer, crop protection products and tillage, with increased farming profits because the system of base stations is engineered to provide continual accuracy of one inch,” said Dave Swain, manager of precision ag technologies at Southern States.
“After a work stoppage, RTK also has the ability to position the equipment in the exact location it left off from, within an inch,” said Swain. “Farmers are able to save and re-use the same line without resetting it.”
Southern States currently operates base stations in Kentucky, with plans to expand to other heavy crop areas within its territory.