RTK on a robot lawn mower is a satellite positioning method that corrects the mower’s GPS fix with reference data, sent from a fixed station in your yard or from a network service, which narrows the position error to a few centimeters. That precision lets a wire-free mower follow a saved map instead of a buried wire.
Every May the canopy over my orchard alleys closes in, so my first question about any satellite map is how much sky it gets. Below I explain how RTK works, what it needs from your yard, and what it cannot do.
What Is RTK on a Robot Lawn Mower? The Short Answer
RTK stands for real-time kinematic, a way of correcting satellite positions while the receiver moves. An ordinary receiver listens to navigation satellites and works out where it is. An RTK system adds a second receiver, the base station, that stays at one fixed spot and sends corrections to the mower over a wireless link. Some models take the same corrections from a network service instead, and most of this guide covers the local-station kind. My guide to local and network RTK mowers compares the two correction methods and the coverage each one needs.
According to NOAA, an RTK system has a base unit and a rover unit joined by a wireless data link, and it reaches accuracy on the order of a centimeter relative to the base. On a robot mower the rover is the mower and the base is the antenna or pole you set up in the yard. Mammotion’s manual for the LUBA 2 AWD 3000HX gives approximately 5 cm (2 in) for its own system. I cover the station setup and the real mowing on that model in my LUBA 2 3000HX review.
The Short Version
RTK is GPS with a correction from a fixed reference, either a station in your yard or a network service. It tells the mower where it is to within a few centimeters. It does not tell the mower what is standing in front of it.
One study shows what canopy does to a fix. In a static test with post-processing, a smartphone receiver’s error stayed under 0.5 m in open sky and grew to about 1.5 m under tree canopy (1). It was not a moving mower and not a comparison with RTK, so it is only a picture of how trees degrade a satellite fix.
On the farm I think of the base station as a survey stake that the mower measures every position against. I read the 5 cm figure as the best case on a clear day, the same way I read any spec sheet.
How RTK Works Step by Step
RTK works because two receivers see the same satellites at the same time. NOAA says the processing rests on the satellites both units have in common, and that the rover’s position comes out as a vector measured from the base station. That is why the base has to stay where it is.
The Base Station
The base station is the fixed half of the system. NOAA says its antenna needs a clear view of the sky, and that a completely open site beats a well-known spot with a half-blocked view.
Makers package it in different ways. The Mammotion LUBA 2 AWD 3000HX has a separate reference station that you mount on a pole or a wall. The Segway Navimow i105N feeds a GNSS antenna into its charging station through a cable. The Sunseeker X3 Plus has a powered antenna that stands in the yard. I compare the antenna and station setup of those two in my guide to the i105N versus Sunseeker X3 Plus.
The Receiver on the Mower
The mower carries its own satellite receiver. The Lymow One Plus manual calls it an integrated RTK-GNSS receiver and says the mower will not map until RTK is bound and accurate. On camera models the receiver is one input among several. Mammotion’s manual says the LUBA 2 AWD can switch to vision positioning when eaves or trees block the satellites, for up to 300 m (984 ft) of travel, and that the mower stops if it does not get back to RTK coverage before that limit. My guide to RTK versus vision robot mowers explains when the camera is enough and when the satellites are needed.
The Link Between Them
The corrections have to reach the mower. The LUBA 2 AWD manual lists two link modes: a radio link with a stated range of 120 m (390 ft), and an internet mode that needs stable Wi-Fi or 4G. The Sunseeker X3 Plus station sits within home Wi-Fi coverage and talks to the mower over its own wireless link. A network service can replace the yard station on some models, and Segway says its Network RTK models need no local antenna and that owners check coverage by postcode.
Reading the Fix Status
The app shows how good the fix is, and each maker decides what counts as good enough. The manuals give a plain rule for each model, and the rule matters because a mower that mows on a weak fix drifts.
| Model | What you see | What the manual says |
|---|---|---|
| Mammotion LUBA 2 AWD 3000HX | Good, Float, Single or None | Only Good enables automatic mowing; Good means under 10 cm |
| Lymow One Plus | RTK accuracy in the status bar | Within 0.05 m before mapping, ideally 0.01 to 0.05 m |
| Segway Navimow i105N | Satellite Signal Analyzer; a yellow light on the station | At least 5 satellites in common view; yellow means poor GPS signal |
| Mammotion YUKA 1500 | Float or Single | Signal is poor; the robot should wait or be moved |
What a Centimeter Fix Buys You on the Lawn
A tight fix lets the mower hold a line. Because an RTK lawn mower knows its position to a few centimeters, it can follow a drawn boundary, repeat a path and stay out of zones you excluded, with no wire in the ground. I explain what the cable adds and what a saved map replaces in my guide to boundary wire and wire-free mowers.
Error Against Cutting Width
I do this arithmetic before I trust any accuracy claim, because a number only means something next to the width of the blade. The Lymow One Plus has a 16 in (400 mm) cutting path, and its manual asks for RTK accuracy within 0.05 m, about 2 in, before mapping. Next to the cutting path, that error is one eighth of a pass. My Lymow One Plus mower review shows how that RTK requirement plays out in daily use.
As a hypothetical illustration only, give the same mower a drift of 1.5 m, the smartphone result under trees. That is 150 cm against a 40 cm cutting path, or about 3.75 passes. A mower that wanders by almost four cutting paths cannot hug a flower bed or a drip line.
| Fix | Error | Share of one cutting path |
|---|---|---|
| RTK within the Lymow manual limit | 0.05 m (2 in) | About one eighth |
| Hypothetical drift of 1.5 m (smartphone result under canopy) | About 1.5 m (5 ft) | About 3.75 passes |
A Saved Map Instead of a Wire
The second gain is the map. You drive the mower around the edge once with the app, and it stores the boundary, the no-go zones and the channels between lawns. The Lymow manual allows up to 80 zones, and the LUBA 2 AWD 3000HX handles up to 30. My guide explains how a robot mower knows where to mow, from the boundary map to the path it follows.
On my land the first no-go zones are obvious: the drip lines on the soil and the young trunks planted in 2016. For the orchard alleys I do not plan a robot at all, because they are mown every two to three weeks and the canopy shades them.
What RTK Needs From Your Yard
RTK needs open sky at the station and across the mowing area. That includes the paths between lawns. The correction only helps when both receivers see enough of the same satellites, so anything that blocks the sky weakens the fix. Every local-station RTK mower manual asks for the same thing: a station or antenna with a clear view. Network RTK models depend on the maker’s coverage instead.
Trees and Canopy
Studies back the makers. A forest harvester carrying a survey-grade RTK receiver under mature spruce reached 8 mm precision for 86 percent of its readings, but more canopy meant fewer satellites and larger errors (2). A second study, in forests with 40 to 90 percent canopy, found that adding satellite systems beyond GPS and GLONASS improved RTK positioning, and the authors note that under canopy RTK can take time to lock or fail (3).
My house lawn has two or three shade trees, so I judge it by the sky over the station spot and over the whole lawn, not by its size. If shade is your problem, my guide to RTK against LiDAR robot mowers lays out the trade-off.
Walls and Metal
Tall walls and metal roofs reflect satellite signals. NOAA lists these reflections, called multipath, as a source of positioning error, and it says a rover blocked by trees or buildings loses its signals and has to start its fix again. The machinery shed beside my yard is a tall wall, and it is the first place I rule out for a station.
What the Makers Ask For
Each maker sets its own clearances. These figures come from the manuals for the exact models.
| Model | Clearance rule for the station or antenna | Link to the mower |
|---|---|---|
| Mammotion LUBA 2 AWD 3000HX | At least 3 m (10 ft) from any wall or tree; no obstruction within 5 m (16 ft) when the signal is weak | Radio, stated range 120 m, or the internet |
| Segway Navimow i105N | More than 2 m (6.6 ft) from houses, trees and walls; open sky; not on a slope | Antenna cable to the charging station, which sends positioning data to the mower wirelessly |
| Sunseeker X3 Plus | More than 1.5 m (5 ft) from walls and trees; sky angle of at least 100 degrees; upright, not on a slope | Wireless link; station within home Wi-Fi coverage |
| Lymow One Plus | At least 2 m (7 ft) from walls or metal surfaces; not under a tree or at the corner of an L-shaped building | Radio antenna; coverage radius up to 1 km (3,200 ft) |
When a Camera Steps In
Several models add a camera that keeps the mower going when the sky closes. The LUBA 2 AWD 3000HX has vision positioning as a limited fallback, and the Mammotion YUKA 1500 manual says its 3D vision takes over when eaves or trees block the satellites. I treat a camera backup as a bridge across a shaded corner and never as a reason to put the station under a tree. My guide to vision navigation on mowers covers what the cameras can and cannot do.
What RTK Does Not Do
RTK answers one question, which is where the mower is. It does not see a hedgehog, a dropped toy or a garden hose, and it does not trim the edge, as the sections below show. My guide on how a robot mower works puts the position fix next to cutting, obstacle sensing and charging.
It Does Not See Obstacles
Obstacle detection comes from bumpers, cameras and other sensors, never from the satellites. In a test of 18 robotic mower models with hedgehog cadavers, none detected juvenile hedgehogs under 200 g, and every model had to touch the hedgehog to detect it (4). The authors suggest that running mowers by day might largely avoid the problem. I schedule runs for daytime and walk the lawn first, picking up sticks, fallen fruit and anything left on the grass.
Safety Before Every Run
Keep children, pets and bystanders off the lawn while the mower runs, as the manuals say, and never lift it while it runs. Before you lift, tip, clean or move the mower, press stop, switch it off with your model’s own procedure, wait for the blades to stop and put on protective gloves. That procedure can include removing the security key, locking the mower with its PIN or disconnecting the battery, so read it in your manual first. A satellite fix does not replace watching the lawn.
It Does Not Finish the Edge
In a study of seven sites managed by autonomous mowers, all seven needed manual finishing along curbs and walls (5). A mower can sit exactly on its line and still leave a strip. Some makers add edge settings, such as the Offset Edge option in the Lymow One Plus manual, but I still plan a trimmer pass where the lawn meets the gravel yard.
It Does Not Work Without Its Corrections
On local-station models the station is another device with its own power cable. The Lymow One Plus manual says that without RTK the mower can mow only 100 to 150 m2 (0.025 to 0.037 acre) for up to 10 minutes. The LUBA 2 AWD manual says only Good status enables automatic mowing. When the corrections drop, the result depends on the model: the LUBA 2 AWD can bridge a short gap with its camera, the Lymow One Plus falls back to the short mowing limit above, and a network model needs its cellular link in the same way.
How to Place the Station and Protect the Map
Place the station once and leave it there. The saved map is measured from that spot, so on most models moving the station breaks the map. The Mammotion manual says not to move the RTK station after mapping, or the map diverges, and the Lymow manual says moving it means deleting the map and mapping again. The Sunseeker X3 Plus manual warns that moving the antenna can leave the mower out of its work area (error E1).
The Segway Navimow i105N manual says the same for its antenna and adds a winter rule: after storage the antenna and station must go back to the same spot within 5 cm (2 in), or the mower needs a new map. Follow the order in your own manual. This is the general sequence.
- Stand where the station would go and look at the whole sky. Note every tree, roof and wall that cuts it.
- Measure the distance to the nearest wall and tree and compare it with the maker’s figure for your model.
- Mount the station upright on open, flat ground or on the supplied pole. For a lawn shaped like an O or a U, or for several separate lawns, the YUKA 1500 and Sunseeker manuals recommend a wall or roof mount.
- Power it with the supplied power supply, and keep the cable off the lawn. A cable lying on the grass is something a mower can catch.
- Wait for the good-fix signal in the app before you map: Good on a Mammotion, accuracy within 0.05 m on the Lymow.
- Map the lawn, then mark the station spot with a peg and leave the station where it is.
Pro Tip
Before I lift a station for winter I put a peg in the ground where it stood. The Navimow manual includes pegs for marking the station spot, and a peg is cheaper than a new map.
Who Should Choose RTK and Who Should Skip It
An RTK robot lawn mower suits an open lawn with a good spot for the station. Shade over most of the lawn is the reason to look at something else. On a quarter-acre lawn with open sky at the station spot and over the whole lawn I recommend RTK, and where shade covers most of the lawn I recommend a wire or LiDAR model. My guide to LiDAR on a robot mower explains how the laser scanner replaces the satellites.
Choose RTK If
- The sky is open: the whole lawn, the paths between lawns and the station spot are clear of canopy and tall walls.
- You want no wire in the ground: a saved map replaces a loop wire that can break.
- You can power a local station: an outlet is within reach of a pole or wall mount.
- Your network covers the station: the LUBA 2 AWD internet mode needs stable Wi-Fi or 4G, and the Sunseeker X3 Plus station needs home Wi-Fi coverage.
Skip RTK If
- Shade covers most of the lawn: the fix drops where the canopy is thickest.
- Tall walls or metal roofs flank the lawn: reflections and blocked sky weaken the fix.
- You do not want a second device outside: a local station needs power, a pole and a fixed place for the life of the map. A network RTK model avoids the station but depends on the maker’s coverage.
A robot lawn mower without RTK has other ways to find its place. According to Dreame, the A3 AWD Pro 3500 takes its position from LiDAR and cameras and has no RTK base station, and the GARDENA SILENO life follows a boundary wire. Each of those has its own limits and its own comparison. I describe how that mower handles rough ground without a base station in my A3 AWD Pro mower review.
What to Remember About Satellite Mowing
Three things matter. RTK is GPS corrected by a fixed reference, and that correction is what brings the error down to centimeters. It needs open sky at the station and over the lawn. A local station must stay where it was when you made the map.
Before any purchase I stand where the station would go and look straight up, then walk the lawn the same way. If I cannot see sky, I look at a wire or LiDAR model instead. Read the clearance figure for your exact model, then check your lawn against it. A satellite map is only as good as the sky above the RTK station, so check that sky before you decide how your robot lawn mower finds its way. My ranking of the best LiDAR robot mowers is where I would start.
Frequently Asked Questions
Do robotic lawn mowers use GPS?
Many robotic lawn mowers use GPS, and RTK models add a station in the yard to correct the satellite fix to a few centimeters. Wire-guided models such as the GARDENA SILENO life follow a boundary wire instead. Even a LiDAR model can carry a satellite receiver, as the Dreame A3 AWD Pro 3500 manual describes for location tracking and anti-theft.
What is RTK GPS?
RTK GPS is satellite positioning that uses a fixed base station to correct the position of a moving receiver. NOAA describes the result as accuracy on the order of a centimeter relative to the base. A robot mower uses it to steer along a saved map.
What is an RTK base station?
An RTK base station is the fixed antenna that stays in one place and gives the mower a reference for its position. NOAA says it needs a clear view of the sky, and each maker’s manual sets the clearance from walls and trees. Moving it after the map is saved forces a new map on models such as the Mammotion LUBA 2 AWD 3000HX.
What is RTK correction?
RTK correction is the data that a base station or a network service sends to the mower so it can remove satellite errors from its own fix. It travels by radio, Wi-Fi or a cellular link, depending on the model. The Mammotion LUBA 2 AWD manual lists a radio link with a stated range of 120 m and an internet mode that needs stable Wi-Fi or 4G.
What is an RTK module?
An RTK module is the receiver that reads the satellite signals and applies the correction, and on a mower it sits inside the machine. The Lymow One Plus manual calls it an integrated RTK-GNSS receiver and says the mower will not map until RTK is bound and accurate. The station you place in the yard is the other half of the system.
References
- Tomaštík J, Everett T. Static Positioning under Tree Canopy Using Low-Cost GNSS Receivers and Adapted RTKLIB Software. Sensors. 2023;23(6):3136. doi:10.3390/s23063136
- Lopatin E, Väätäinen K, Kukko A, et al. Unlocking Digitalization in Forest Operations with Viewshed Analysis to Improve GNSS Positioning Accuracy. Forests. 2023;14(4):689. doi:10.3390/f14040689
- Andreas H, Zainal Abidin H, Anggreni Sarsito D, Pradipta D. Study the capabilities of RTK Multi GNSS under forest canopy in regions of Indonesia. E3S Web of Conferences. 2019;94:01021. doi:10.1051/e3sconf/20199401021
- Rasmussen SL, Schrøder A, Mathiesen R, Nielsen JL, Pertoldi C, Macdonald DW. Wildlife Conservation at a Garden Level: The Effect of Robotic Lawn Mowers on European Hedgehogs (Erinaceus europaeus). Animals. 2021;11(5):1191. doi:10.3390/ani11051191
- Sportelli M, Martelloni L, Orlandi A, et al. Autonomous Mower Management Systems Efficiency Improvement: Analysis of Greenspace Features and Planning Suggestions. Agriculture. 2019;9(6):115. doi:10.3390/agriculture9060115
Safety Note: A robot mower has sharp blades. Keep hands and feet away from them. Do not run it with children, other people or animals on the lawn; stop it and park it or switch it off if they come onto the lawn. Never ride on it or let children play with it. Clear toys, hoses, sticks, stones and fallen fruit before a run, and do not mow while sprinklers run. Never lift or tip it while it runs or while it sits in its charging station. Before you lift it, clean it or touch the blades, press STOP, switch it off exactly as your manual says, wait until every blade has stopped, and wear protective gloves. Daytime schedules reduce encounters with animals that come out at night, though animals can be on the lawn by day too. Plug the power supply into a covered outdoor GFCI outlet, keep its cable out of the mowing area, and follow your manual for installation, slopes, charging and storage.