GNSS Corrections Map – Coverage and Accuracy
Estimated reading time: 5 minutes
A GNSS (Global Navigation Satellite System) corrections map shows where high-precision corrections are available and the accuracy you can expect. These maps matter to agriculture, construction, surveying, and autonomous systems. With the right feed, cm-level positioning becomes possible.
Table of contents
Summary
A GNSS corrections map shows where RTK, PPP/PPP-RTK, and SBAS are available and how accurate they are. Use it to align your accuracy targets with regional coverage and select the right service.
Start your 30-day free trial
Validate cm-level positioning on your routes and sites in the regions you care about.
Key takeaways
- A GNSS corrections map shows which correction types are available, where they work, and expected accuracy.
- Uncorrected GNSS is often 5–10 m off; with corrections, cm-level positioning is realistic.
- RTK delivers ~1–2 cm within ~10–30 km of a base; PPP-RTK approaches RTK-like accuracy over wider areas with quicker start than PPP.
- Coverage is strongest in North America, Europe, Oceania, and parts of Asia; gaps appear in mountains, forests, and sparsely networked regions.
- Plan jobs and uptime by checking coverage before you roll trucks, seed fields, or start a survey.
Fundamentals of GNSS corrections
Uncorrected signals are often 5–10 meters off—too inaccurate for precision work. GNSS corrections reduce errors from satellite clocks, orbits, the ionosphere, the troposphere, and multipath. With the right feed, cm-level GNSS positioning becomes possible for tight tolerances. A corrections map helps you anticipate coverage and expected performance before you roll trucks, seed fields, or start a survey.
Types and RTK coverage by region
- SBAS: 1–3 m accuracy; wide regional reach via satellites.
- DGNSS/Network RTK: about 1–2 cm; local/regional where networks exist.
- RTK (Real-Time Kinematic): 1–2 cm within roughly 10–30 km of a base—core to RTK coverage.
- PPP (Precise Point Positioning): about 3–10 cm; global, no local base; longer start; improves with steady tracking.
- PPP-RTK: about 2–8 cm; faster start than PPP; wider area than classic RTK.
A corrections map shows which options are available, their footprint, and where cm-level positioning is realistic across regions.
Open RTKdata Docs
Explore formats like RTCM and delivery via NTRIP to align correction types with your receivers and regions.
Accuracy and factors affecting accuracy
Accuracy is closeness to truth; precision is repeatability. Common terms: sub-meter/millimeter, CEP, RMS, 2DRMS, R95. Example: R95 of 2 cm means 95% of fixes fall within 2 cm. Results depend on:
- Receiver hardware: antennas and electronics steady the solution.
- Local environment: buildings, trees, and multipath degrade signals.
- Correction infrastructure: network density and update rates shape coverage.
- Atmosphere: changing ionosphere/troposphere shifts errors.
Regions with coverage & industry impact
- Surveying & Mapping: choose RTK or PPP-RTK to match project footprint.
- Agriculture: broad RTK coverage keeps machines accurate across large fields.
- Autonomous machines: plan routes where corrections are steady.
- Construction: verify site edges against coverage to avoid downtime.
Choosing the right service
Pick by needed accuracy, regional reach, available infrastructure, convergence time, and budget. Always consult a corrections map to align targets with real-world availability, PPP accuracy needs, and RTK coverage.
Plan your rollout with RTKdata
Discuss regional coverage, accuracy targets, and integrations—or try live corrections on your routes.
Frequently asked questions
What is a GNSS corrections map?
A GNSS corrections map shows where high-precision corrections (RTK, PPP/PPP-RTK, SBAS) are available and the accuracy you can expect.
How accurate can positioning get with corrections?
Uncorrected GNSS is often 5–10 m off. With corrections, RTK typically delivers ~1–2 cm within ~10–30 km of a base. PPP is about ~3–10 cm; PPP-RTK about ~2–8 cm.
What’s the difference between RTK, PPP, and PPP-RTK?
RTK uses local bases for real-time corrections. PPP is global but slower to converge. PPP-RTK blends both for wider reach and faster accuracy.
Where is coverage strongest today?
Generally in North America, Europe, Oceania, and parts of Asia, with gaps in mountains, forests, and sparsely networked regions.
How can I test coverage for my routes or sites?
1) Define accuracy targets. 2) Set up a trial. 3) Test routes and monitor fix status. 4) Compare logs to ground truth. Try Start Free Trial or Book a Meeting.