RTK installation tips for optimal GPS signal strength

I supply cheap RTK kits with my farming GPS guidance systems. They are included in packages such as the Ultimate RTK and the Ultimate+ RTK. I often get a request for RTK installation tips, and how to optimize GPS signal strength. Unlike regular GPS, RTK requires an excellent signal both at the rover, and at the base station. It’s especially important at the base station, so that it can get a very strong fix and start providing corrections. Read on below to find out how to avoid RTK signal lost issues. If you’re looking to buy an RTK kit, or a full agriculture GPS guidance system with RTK, please contact me!

RTK installation tips: ground plane for optimal signal

The GPS antenna (the 2×2 inch black waterproof box on a 15 ft coax cable, if you got my kit) can be mounted onto a ground plane for signal optimization. This can be especially handy for RTK, which are quite picky about signal strength beyond regular GPS lock. Optimal ground plane size to cover all GNSS types (GPS, Beuidu, GLONASS, EGNOS) is 3.75 x 3.75 inches (9.5 x 9.5 cm). Example materials for ground plane include: copper or aluminum foil, or any other RF reflective material. Ideally, the plane should be grounded. The GPS antenna is placed in the center of the ground plane. Examples of GPS antenna ground planes can be viewed here. A ready made product is offered for sale here at a very reasonable price, and is pictured below!
RTK installation tips - ground plane example RTK installation tips - ground plane example with GPS antenna in the middle, on a tripod

Troubleshooting RTK lost / no RTK fix issues

  1. The base station antenna needs to be outside with clear view of the sky and no obstructions. Signal that’s good enough for a GPS fix may not be strong enough to enter “TIME” mode which is required by the base station to operate.
  2. Before and after powering on the base station, make sure the antenna is fixed and is not moved
  3. Power on the base station and wait for 5 minutes. You can power on the rover at any time.
  4. On my RTK kits, when the rover is receiving data, you can see the XBEE>GPS LED on the rover board blinking. This confirms that the radio link between the rover and the base station is active. 
  5. On my units, the rover (receiver which goes in the tractor) is typically connected to the Toughbook. You can open u-Center and open View > Messages View. Open UBX, and find UBX-RXM-RTCM. These are the RTK corrections messages. You should see the list of RTCM messages being received.
  6. You can also connect the base station to the Toughbook or any other computer and connect to it by u-Center. The u-Center, the “Fix Mode” should be “TIME”, not any other fix type. If it doesn’t go into TIME mode, you need to improve GPS signal strength at the base station.

Radio link considerations – RTK installation tips

Let’s take the kits I supply as an example, but this will apply to any RTK kit. The 10 km (6 mi) and the 50 km (31 mi) are the ranges that they offer. Keep in mind, that these are maximum ranges with no obstructions such as hills and trees. They can only be achieved when the base station antenna is mounted high up, and with no interference. The frequencies they use are in the 902-928 MHz range, and the radio antenna connects via a standard SMA connector. Don’t even think about using a regular SMA extender cable for this. It needs a be low-loss RF cable!

I do not recommend using generic 4G/LTE or other cheap antennas from Amazon or other places, as they are not tuned for the narrow range the radio link operates in. Therefore, the range with those huge impressive looking antennas may be quite poor in practice. Yes if you go through 10 different antennas, you may find one that works well, but don’t you have better things to do? I have excellent external IP67 antennas on a 2m (6.5 ft) low-loss RF cable which can be added to my kits to increase the range and simply installation.

Being a line of sight technology, it’s always better to mount the radio link antenna as high as possible and with as little RF obstructions such as other antennas, metal or concrete elements in the way. This will help increase the range and signal strength a lot!

It’s good to remember that radio link strength degrades as a square of distance. Therefore, if you’ve got some challenging terrain it’s good to remember that at half the max distance, the signal will be four times stronger etc. If there’s any doubt, I recommend getting the higher range since it’s not a significant expense! While a radio link may reach out to 50 km, at that distance the RTK corrections are no longer as accurate since atmospheric conditions can vary this far out. Therefore, I recommend operating within 20 km (12 mi) of the base station for optimal sub-inch RTK accuracy.

Take care with metal roofs – RTK installation tips

A special note on metal roofs and base station placement on them. Please place the GPS antenna in the center of a metal roof (if possible), at least 5 cm away from any roof bars or radio antennas. Do not mount the antenna close to the edge of the roof, as reflections from the ground may interfere with the signal. Avoid the edges, as reflections from the A-pillars will cause problems!

You can always contact me if you’d like to order something, or discuss!

Why are my agriculture GPS systems a good choice?

All of the units below can’t beat the value I offer. They can’t beat the fact that there’s no subscription. Their functionality is similar. It’s a clear win, from a value perspective! Topcon X14 | Agricision onTrak | Patchwork BlackBox Air | Sixty-5 Grass-Guide | Ag Leader InCommand Teejet Matrix 430 | Raven Cruizer | Trimble GFX-750 EZ-Guide 250 GFX-350 | CenterLine 220 | John Deere | FieldBee. My systems are compatible with with all tractor brands such as: John Deere, Case IH, Massey Ferguson, New Holland, Fendt, Mahindra, Deutz-Fahr, Kubota, Valtra, Claas, International. I also supply systems for marine navigation, and the same unit can work for both. Dealers still charge tens of thousands of dollars for farming GPS systems in 2022! This is not technologically justifiable. RTK and other technologies have developed to the point where they should be affordable to anyone, not just big farmers with a budget in the tens of thousands. Get in touch with me to see how little you can spend.