Industry experts share GNSS trends in the ag industry

January 23, 2019  - By

Industry experts share how GNSS can be used for precision agriculture.

Headshot: Vazquez


Juan Vazquez
Team Leader, EDAS Service Provision

Pass-to-pass accuracy is the key performance indicator to assess the precision of guidance systems, characterizing the short-term dynamic performance determined from off-track errors along the straight segment passes (error with respect to the desired path in the direction perpendicular to the tractor trajectory).

The results of the tests reported in this article, jointly performed by Topcon Agriculture and ESSP, confirm that EDAS DGPS corrections can support a wide range of precision agriculture applications and represent a real alternative for cereal farms, when located in the vicinity (at least up to 260 km away) of an EGNOS reference station, complementing the benefits that the EGNOS signal-in-space is already providing to a large number of agriculture users in Europe.

More info on EDAS is available at

Headshot: Keable-Vézina


Nicos Keable-Vézina
Director of Precision Agriculture

Thanks to artificial intelligence, variable-rate application of nitrogen has made great strides in recent years. Science has demonstrated that effective nitrogen management requires an array of technologies, including massive databases. Data is geospatial (positioning signal and satellite imagery enabling the identification of changes in nitrogen requirements), agronomic (mainly soil texture and seasonal weather), and economic (grain and nitrogen price).

To automate extraction and analysis of such data, combining very low-cost positioning technologies, satellite imagery and artificial intelligence is paramount. A democratized access to technology has led to the development of scientifically proven nitrogen prescribing platforms, among them FieldApex, that calculate the most profitable nitrogen rates and generate prescriptions in seconds without soil sampling. Further technological and platform integrations are likely to bolster such innovation.

Headshot: Rioja


Julian Rioja
Channel Development and Business Intelligence Manager

All tests were performed using Topcon receivers, vehicles and auto-steering systems. Two different Topcon guidance systems on board tractors ran simultaneously to assess the EDAS DGPS positioning performance with respect to the reference provided by a real-time kinematic (RTK) system. Hence, two independent positioning outputs were continuously available (the receivers were placed along the same longitudinal axis on the roof of the tractor):

  • RTK position: provided by the AGI-4 receiver fed by Topcon’s Hiper V RTK base.
  • DGPS position: provided by the AGI-4 receiver fed by the EDAS Ntrip service.

On board the tractor, two Topcon X35 consoles were each connected to one of the receivers. A Topcon AES-25 electric steering system was installed on the tractor so that the selected navigation input (RTK or EDAS DGPS) could be used to automatically guide the tractor along the defined reference pattern.

Headshot: McClure


John McClure
Engineering Manager, Precision Agriculture

Precision agriculture is expanding the use of ISOBUS for CAN communication between a common terminal and implements, to reduce clutter in the cab. These virtual terminals now act as display and user entry for multiple applications including GNSS receivers and factory or after-market steering systems.

INS-aided GNSS solutions, typically using RTK or satellite-based correctors such as Atlas, provide time/position data for rate and section control and auto-steering. CAN-based NMEA 2000 is the commonly used receiver protocol for position data, replacing serial NMEA 0183.
All major tractor, agricultural equipment, and GNSS manufacturers attend regular “Plugfest” meetings, organized by the Agriculture Industry Electronics Foundation, to test interoperability of products and set common standards.

Smart CAN dongles are being developed to read sensors and control systems, supplying positioned data via telematics as the Big Data for real-time and post analysis.

More: Precision agriculture aided by internet, SBAS