Image: CHC Navigation
Precision agriculture — which enables growers to reduce inputs of water, fertilizers and pesticides by matching them to variations in soil conditions, thereby reducing environmental impacts, increasing yields and productivity, and reducing fuel consumption — is a prime use case for global navigation satellite systems (GNSS). While the typical open sky conditions in the fields minimize concerns about signal occultation and multipath, the accuracy requirements for this practice, particularly for certain crops and planting techniques, can be very high. Challenges for receivers often include severe roll and pitch due to bumpy terrain, the requirement to maintain exact heading at very low speeds, and the need to receive corrections over very large areas.
Precision agriculture began more than 30 years ago — GPS World published a few issues of a special supplement on the subject about 25 years ago — and now all tractors from major manufacturers come equipped with a GNSS-based guidance system. Adoption has increased hand-in-hand with improvements in enabling technologies. These include satellite-based and ground-based sensors, UAVs, geographic information systems (GIS), and a plethora of GNSS corrections services (see “Corrections Services Abound” in our January 2023 issue and “Understanding GNSS Correction Methods” on p. 28 of our January 2024 issue).