ONTARIO GRAIN FARMER TECHNOLOGY 15 Ensuring precision-agriculture software is up to date, however, should prevent problems. WHAT’S HAPPENING? The NGS is adopting NATRF2022 for latitude and longitude positioning, and NAPGD2022 for elevational positioning. Referred to as “datums,” these will replace NAD 83 and NAVD 88, correcting errors in accuracy relative to the true centre of the Earth. John Sulik, professor of precision agriculture with the University of Guelph, explains. “If I share my geographic coordinates with you, they are associated with a reference frame, often referred to as a datum. A datum defines the shape and size of the earth and serves as a reference for measuring coordinates… The GPS coordinates for any location depend on the datum used, and my location (the exact spot) would have different values if using the old or new datum you mentioned,” says Sulik, in mid-October 2025. “Farmers already have to deal with different datums and associated offsets, especially if using high accuracy corrections such as RTK, depending on the mode of correction delivery…The result of changing to the new datum is a ‘datum shift’ of one to four metres. The most common geographic data farmers use are field boundaries and guidance lines (i.e., AB lines). This data will likely need to be updated/redrawn unless their dealer tells them otherwise.” For Jordan Wallace, farmer and co-founder of GPS Ontario, the exact impact of updates to NGS reference systems are not entirely clear. Speaking October 23, 2025, Wallace has asked for clarity from the services GPS Ontario works with. However, he suspects businesses like theirs employing services which rely on a range of international guidance networks—what Wallace refers to as “multiconstellational”—will not be affected by changes made solely within the United States reference systems. UPDATING MAPS Writing for No-Till Farmer, Iowa State University extension staff Luke Fuhrer and Doug Houser confirm Wallace’s perspective. The pair report that those using systems with limited accuracy—only precise up to one or two metres—or those operating major commercial satellite RTK platforms, such as Trimble, John Deere, and others that already align to a global datum, will not notice the changes. Anyone relying on local RTK base stations set up with NAD 83 or NAD 88, or on maps and A-B lines made with older legacy systems, will need to update their maps. NGS resources recommend three courses of action for those affected: • Resurvey: Return to the field and collect new observations, relying on geodetic control that has coordinates in the new datum, • Readjust: Using existing observations, recompute new coordinates based on geodetic control that has been defined in the new datum, • Transform: Take finished products that have coordinates in the old datum and use transformation software to estimate coordinates in the new datum. The agency adds the following: “To inform your decision on which of these methods is appropriate, evaluate your accuracy requirements, any remaining original observations, and the metadata for your existing geospatial data and products. In many cases, if collecting new observations or reprocessing original observations is not feasible, transforming the data will be the only option.” “To prepare your data for transformation to the new system and to check whether you have the appropriate metadata to do so, run your data through the NGS Coordinate Conversion and Transformation Tool (NCAT) to transform to the current datums (NAVD 88, NAD 83 [2011]). When the modernized system is released, NCAT will be updated to transform your coordinates from current datums to coordinates in the modernized NSRS at its first reference epoch of 2020.00.” • TRUSTED GENETICS. PROVEN RESULTS.
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