EMLID Reach RS4 GNSS/RTK Receiver
Survey-Grade Ground Control. Professional survey services powered by EMLID technology.
About the EMLID Reach RS4
The EMLID Reach RS4 provides the ground control accuracy that transforms drone data from approximate to survey-grade. With ~5 s typical convergence, RTK accuracy of 7 mm + 1 ppm horizontal (5 mm + 0.5 ppm in PPK), and 16 hours as an RTK rover with tilt compensation, the RS4 ensures your engineer can rely on our deliverables.
Ground control points (GCPs) tied to real-world coordinates are what separate professional surveying from casual drone photography. We use the EMLID RS4 to establish GCPs that meet the most stringent accuracy requirements.
Key Benefits
- ~5 s typical convergence time
- RTK 7 mm + 1 ppm horizontal survey-grade accuracy
- 16 hours as an RTK rover with tilt compensation for full-day operations
- Tilt compensation lets you measure without levelling the pole
- 672 channels across six constellations for maximum reliability
Considerations
- Requires cellular or radio correction source for RTK
Technical Specifications
Official Emlid Reach RS4 Spec Sheets & Downloads
Official specifications are published by Emlid — emlid.com ↗
Free download — no email required. Documents are Emlid’s original files, served unmodified with credit to the manufacturer.
Where can I download the official Emlid Reach RS4 spec sheet?
Download Emlid’s original documents free from this page — Datasheet — 2026-03-23 (LoRa & UHF) (PDF, 0.2 MB). Each file is the manufacturer's unmodified publication, verified against the live official copy on 2026-08-22. Our full library is at thefuture3d.com/equipment/spec-sheets/.
Is the download free?
Yes. Every document in our equipment spec-sheet library is free to download with no email gate and no signup — one click, straight from the manufacturer’s original file.
Browse the full library: Equipment Spec Sheets & Downloads →
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Professional EMLID Reach RS4 surveying services available across 140+ locations in all 50 US states and international markets. avg 1-hour response time in major metros.
EMLID Reach RS4 Frequently Asked Questions
Why do you need ground control for drone surveys?
Ground control points (GCPs) tie aerial data to real-world coordinates with survey-grade accuracy. Without GCPs, drone data accuracy is limited by onboard GNSS alone. With GCPs measured on a survey-grade receiver, we deliver the positional accuracy engineers and surveyors require — the achievable figure depends on the site, and we state it per project.
What accuracy can I expect with EMLID RS4?
Emlid publishes RTK precision of 7 mm + 1 ppm horizontal and 14 mm + 1 ppm vertical for the RS4 (5 mm + 0.5 ppm horizontal in PPK, 4 mm + 0.5 ppm static). At a 1 km baseline the RTK figure works out to roughly 8 mm horizontally—meeting survey-grade requirements for engineering and construction applications.
How long does it take to set ground control points?
With the RS4's ~5 second typical convergence, establishing a GCP takes a couple of minutes including setup. On a typical site requiring five GCPs, ground control adds roughly half an hour to the field capture.
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