GPS for farming: what a tractor actually needs
GPS on a farm is not one thing. It is four pieces that have to work together: a receiver on the roof that knows where the tractor is, a correction that makes that position accurate enough to farm by, a display in the cab that turns position into a line, and, if you want it, something that steers. Most of the confusion we hear on the phone comes from mixing those up. This page sorts them out and tells you what each job on the farm actually needs.
The four pieces
The receiver. An antenna and GNSS board, usually in one housing on the cab roof. On its own it can place the tractor within a few feet. Every FJD kit we sell, from the AG1 guidance system to the AT2 Ultra, uses an RTK-capable receiver, so there is no accuracy unlock to buy later.
The correction. This is what gets you from a few feet to an inch. WAAS is the free satellite correction and is on by default. RTK is a second receiver that knows exactly where it sits and tells yours how far off the satellites are right now, either a base station on your farm sending by radio or a network base like GEODNET sending over cellular. PPP is a middle option that comes straight from the satellites with no base, holds about two inches, and takes fifteen to twenty minutes to converge every time you start. The full comparison is in RTK vs WAAS for farming.
The display. The screen draws the guidance line, saves field boundaries and lines, and talks to your implement. On the AT2 and up that includes ISOBUS, so the display can run section control on a planter or sprayer and send GPS and ground speed to a rate controller over NMEA.
The steering. Either you steer to the light bar, or the system steers for you with a motor on the column, a factory valve through the steer-ready connector, or a hydraulic valve the kit controls directly. How auto steer works covers all three.
What each job needs
| Job | Correction | Steering | Why |
|---|---|---|---|
| Mowing, baling, broadcast spraying, tillage | WAAS is fine | Guidance or auto steer | A few inches of overlap does not cost you, and you are not coming back to the lines |
| Planting, strip till, banding fertilizer | RTK | Auto steer | You need to be on the same line in April, June and next year, within an inch |
| Spraying rows after planting | RTK | Auto steer | The sprayer has to follow the planter's line, not a new one |
| Section control on a planter or sprayer | RTK | Auto steer with ISOBUS display | Shutting sections off at the headland only pays if the position is good to an inch |
| Harvest | WAAS or RTK | Auto steer | Straight passes and full header width; RTK if you want to follow the planted rows |
Guidance or auto steer
Guidance means the display shows the line and how far off you are, and you turn the wheel. The AG1 guidance system is that: it runs WAAS out of the box and takes RTK for the same line the autosteer kits hold. It suits spraying, spreading and hay where a straight pass matters and you do not mind steering.
Auto steer adds a motor or valve so the tractor holds the line while you watch the implement. Once a farmer spends a season planting with it, we have not met one who went back. That is the AT2 family for any tractor with power steering, AS2 for steer-ready tractors with CAN, and AH2 for tractors with a hydraulic valve and no CAN.
It goes on the tractor you already own
None of this needs a new tractor. A 1970s or 80s tractor with power steering takes the same receiver, the same RTK, and a motor on the column, and holds the same line a new one does. The brand pages for John Deere, Case IH, Massey Ferguson, Kubota and New Holland list the models we have steered, and autosteer for older tractors goes through the common older models.
Where the correction comes from
If you have usable cell coverage in the field, GEODNET network RTK is the simplest: nothing to mount on a bin, the lines come back the same every season, and we set up the account and the NTRIP settings on the display. If coverage is thin, a radio base on the farm covers about eighteen miles reliably, or PPP keeps you within two inches with nothing but the receiver. Signal source is a menu setting on the FJD display, so you can run WAAS on the mower and RTK on the planter with the same kit.
- Tractor make, model and year
- What you pull with it and how wide
- Whether you plant or spray on last year's rows
- How good the cell signal is in your fields
Common questions
Do I need a base station?
Not if you have cell coverage; GEODNET's stations do that job. You need a base or PPP where cell is poor.
Will GPS go down?
Solar storms knock RTK and WAAS around for every brand; the big one in May 2024 cost a lot of farmers part of a day. A close base and patience are the fix.
Does the kit move between tractors?
The motor kits do, with a bracket for the second tractor. Lines and boundaries live on the display, so they move too.
What about yield maps and soil sampling?
Those need a yield monitor or a sampling rig that reads position from the same receiver. The AT2 display puts GPS out over NMEA for exactly that, but the monitor itself is a separate piece.
Is there an accuracy unlock to buy later?
No. Every FJD receiver we sell is RTK-capable out of the box. RTK needs a correction source, a base you own or a network subscription, not a different receiver.
More on auto steer
Auto steer for tractors · How auto steer works · Is my tractor steer-ready? · Autosteer for older tractors · Hydraulic auto steer (AH2) · AS2 steer-ready · All autosteer kits · RTK vs WAAS · FJD AT2 vs Wheelman · All buyer guides · Autosteer solutions across the United States
Published 11/6/2026 by the Deep Sand Technology support team. Written from our own installs and support calls on farms across the US, not from a brochure.
About Deep Sand Technology
Deep Sand Technology (Deep Sand Tech) is a farmer-owned, authorized FJDynamics dealer with over 30 years of experience. We sell, ship, install and support FJD autosteer kits and GEODNET network RTK for thousands of farmers across the US, in all 50 states. Everything on this page comes from our own installs and support calls, not from a brochure.
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