Can You Do RTK Without Internet? (Offline RTK Workflows Explained)
One of the most common questions for new GNSS users is: Can I still use RTK if there’s no internet?
Yes — and in fact, offline RTK is the original method used long before NTRIP and mobile apps became popular. This post explains how to achieve centimeter-level RTK accuracy without any internet connection.
🌐 RTK with Internet vs. RTK without Internet
| Method | Internet Needed? | Typical Range | Pros | Cons |
|---|---|---|---|---|
| NTRIP (Online RTK) | ✔️ Yes | Up to 50 km | Easy to set up, wide coverage | Needs mobile data, less reliable in rural areas |
| UHF Radio (Offline RTK) | ❌ No | 0–5 km | Fully offline, stable FIX | Shorter range, needs radio config |
📶 Offline RTK with UHF Radio — How It Works
In this setup, your base station broadcasts RTCM correction data using its built-in or external UHF radio. The rover GNSS receiver receives the signal directly and applies it in real time.
No SIM cards. No mobile hotspot. Just direct base-to-rover connection.
🧰 Equipment You’ll Need
- 📡 Base GNSS Receiver with UHF Radio (e.g. Trimble R8, Topcon Hiper, South Galaxy G1)
- 🔵 Rover GNSS Receiver with UHF support
- 📟 Antenna or internal radio modem
- ⚙️ Radio Configuration Software (if external radio used)
🔧 Setup Steps (Offline RTK via UHF)
- Mount Base Station on a known point
- Enable Base Mode and select correction format (e.g. RTCM 3.2)
- Configure UHF Radio settings:
- Frequency/channel (e.g. 450 MHz)
- Baud rate (e.g. 9600/19200 bps)
- Protocol: Transparent, Satel, Trimtalk, etc.
- Set Matching Settings on the Rover
- Connect and Test — Rover should achieve FIX in 15–60 seconds
Tip: Make sure both base and rover use the same antenna height and clear sky visibility.
📌 Use Cases for Offline RTK
- 🌲 Forest or jungle environments
- 🛤️ Remote construction sites or mining areas
- 🚜 Agricultural fields without mobile coverage
- 🛶 River mapping or marine surveys far from towers
Offline RTK is especially useful for operations where internet reliability is poor or where mobility and independence are key.
💡 Final Thoughts
RTK without internet is 100% possible and still widely used around the world. UHF radios offer stable, low-latency correction for short-range precision work. The key is having a compatible base/rover setup and properly configured radios.
🔧 Need Help Setting Up Offline RTK?
We offer tested, used GNSS kits that include UHF functionality — and we’re happy to guide you through your first setup.
Next article: What Is NTRIP and How to Use It with Android Devices