RTK systems also tend to be the most expensive, with systems typically starting at about $35,000.
GPS wins over lasers
Because his fields are contiguous and within a 6-mile radius, Hyatt says he can leave the RTK base station in one place. That’s a time savings compared with laser leveling, where the laser has to be moved from field to field along with the scraper buckets.
Hyatt says he found the system relatively simple to use, citing Trimble’s user-friendly display.
“It’s not a really difficult thing to set up,” he says.
Choose DGPS for citrus scouting
Growers who want the technology to scout citrus groves should use differentially corrected GPS, or DGPS, because of the higher accuracy, Ehsani says.
“If you were in the middle of a row collecting data with a low-cost GPS unit, you would have four or five trees and you couldn’t be sure which tree you were talking about,” he says. “If you’re using one with sub-meter accuracy, such as the [Trimble] AgGPS 132, you’ll definitely need to get close enough to the tree to be able to identify the tree later.”
Even if you’re using a DGPS unit, Ehsani says you have to pay attention to the signal strength to ensure optimum accuracy.
“Sometimes they’ll loose the WAAS, they’re not paying attention and they don’t know they’re not in the differential mode,” he says. “[The unit] will accept the location but it may not be accurate.”