Quick Answer
Emlid Reach RTK GNSS receivers provide professional centimetre-level positioning for surveying, drone mapping, and engineering applications. Using all-band RTK technology, they deliver sub-2cm accuracy in real-time at a fraction of traditional equipment costs.
What is RTK GNSS?
Real-Time Kinematic (RTK) enhances GPS precision from metres to centimetres. A "Base" station (fixed known point) sends corrections to a "Rover" (mobile unit) via radio or internet (NTRIP).
Accuracy comparison:
- Standard GPS: ~3m accuracy
- RTK GNSS: ~7mm + 1ppm horizontal, ~14mm + 1ppm vertical
RTK works by comparing satellite signals between base and rover. The base calculates atmospheric and orbital errors, then transmits corrections in real-time. This achieves centimetre-level precision without post-processing.
Emlid Reach Lineup (2026)
| Model | Use | Key Features |
|---|---|---|
| RS4 Pro | Advanced Survey | Dual cameras, AR stakeout, tilt compensation |
| RS4 | Base/Rover | All-band, tilt compensation, 16hr battery |
| RX2 | Network Rover | Ultra-portable, Bluetooth-only |
| RS2+ | Base/Rover | Multi-band, LTE, LoRa |
| M2 | Drone/OEM | Compact module for UAVs |
Browse our GPS Navigation Systems and GPS Modules.
Choosing the Right Model
- Visual stakeout: RS4 Pro (dual cameras, AR) - Essential for hazardous or inaccessible areas
- General surveying: RS4 (tilt compensation, faster work) - Work 30% faster without perfect pole levelling
- Quick site visits: RX2 (if you have mobile signal) - Lightweight, uses phone data for corrections
- Budget option: RS2+ (solid multi-band performance) - Still excellent for base/rover setups
- Drone mapping: M2 (UAV integration) - Precise timing for geotagging photos during flight
All current models support both RTK (real-time) and PPK (post-processing) workflows.
UK RTK Regulations
NTRIP (Internet): No licence needed. Uses OS Net or commercial providers (RTK FIX). Requires 4G signal. Ideal for urban areas with reliable mobile coverage.
LoRa (868MHz): Generally licence-exempt if compliant with Ofcom IR 2030. Power limits and duty cycle depend on specific sub-band configuration. Works base-to-rover up to 8km line-of-sight.
UHF: RS4/RS4 Pro receive UHF only. If your setup includes a separate UHF transmitter or base radio, that equipment needs Ofcom Business Radio licence (Simple Site Light, ~£75/5 years).
Which Should You Buy?
Network rovers: £500-900
Flagship kits with tilt/cameras: £2,000-3,500
Use network rover (RX2 or RS4) if you have consistent mobile signal - single unit, no base needed.
Use base + rover (two RS4 or RS2+) for remote areas without internet - no subscriptions, works anywhere.
For surveying teams, a common setup is one RS4 as permanent base + multiple RX2 rovers for field staff.
FAQ
Q: Do I need a UK licence?
A: NTRIP = no. LoRa = usually exempt (Ofcom IR 2030). UHF transmitter = may need licence.
Q: How accurate?
A: ~7mm + 1ppm horizontal, ~14mm + 1ppm vertical with solid "Fix".
Q: Base station or NTRIP?
A: NTRIP = less gear, needs signal, annual subscription (~£500-1,000/yr). Base = no subscriptions, works anywhere, but requires two units and setup time.
Q: RS4 vs RS4 Pro?
A: Pro adds dual cameras and AR stakeout. Same GNSS and tilt features otherwise.
Last updated: March 2026