PPP: Matching Performance to Application Requirements in the Field

PPP: Matching Performance to Application Requirements in the Field

Gofex, a small, family-owned contract farming company in Liptovské Vlachy, Slovakia, has reduced its planting time by employing PPP-based systems. This has allowed field equipment operators to keep an eye on planting, not on the row markers, increasing planting precision.

Gofex, which provides services such as corn planting, silage processing and harvesting, has found decimetre-level accuracy to be sufficient for their needs. This year, responding to customer demand for straight crop rows, Gofex began implementing precision agriculture for the first time. Jaroslav and Peter Urban had Ag Leader install its GPS 6500 receivers, based on NovAtel hardware and software, OnTrac3 Assisted Steering systems and Compass displays on the Claas Axion and New Holland T7.250 tractors. Gofex uses an eight-row Kinze 3500 and a six-row Kinze 3000 for planting.

PPP is a better option for Gofex than RTK, the Urbans believe. Slovakia is a small country, but its terrain varies widely, from lowlands near the border with Hungary to the south, to mountains in the north. Cellular reception also varies widely throughout the country. With TerraStar-C PPP, Gofex can obtain initial convergence—the length of time required to obtain a decimetre-level position solution from a “cold start” of the GNSS positioning—at times in less than 10 minutes. More importantly, if tracking lock on a minimum number of satellites is lost in the field, the system reinitializes within seconds to provide continued positioning. Field tests indicate that the NovAtel CORRECT system can regain sub-decimetre accuracy almost instantly following short outages. 

Having used the PPP system for a few months, the Urbans have high confidence in the system’s accuracy. At first, Peter Urban randomly checked the system’s performance with a measuring tape by simply measuring the distance between the rows. Later, he occasionally used field markers for visual checks. Because the PPP-guided performance met the tolerances of these methods, he no longer needs to check as often.

As a result of their experience with the Ag Leader GPS 6500 system, the Urbans believe that the higher customer satisfaction that results will equate to more work for the company in the future.