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Types of accuracy in GIS
How to achieve centimeter-level accuracy
Recommended receiver
GIS · Accuracy Guide
GIS Data: Achieving Centimeter-Level Accuracy
Why accuracy matters in GIS
Municipalities and utility companies rely on GIS systems to build and maintain reliable maps of their assets — fire hydrants, water and gas lines, sewer lids, and more. Technicians use these systems to accurately record the location of newer assets, update existing ones, and find assets that need maintenance or repair.
Accurate GIS mapping saves time by allowing workers to find assets and get to work without searching based on vague coordinates. This becomes especially valuable in challenging conditions:
- Underground lines. With accurate GIS data, workers only have to dig once.
- Heavy snowfall. Accurate coordinates minimize the hassle of digging in the wrong spot.
- Urban congestion. Work crews can plan ahead and park as close to an asset as possible.
And while emergencies are rare in this context, accurate coordinates can also save precious time when it matters most.
Types of accuracy in GIS
Baseline
Sub-meter accuracy
Achieved using SBAS data. Generally accurate within roughly two meters with no guarantee of precision. Sufficient for many applications. Learn GIS terminology →
Advanced
Centimeter-level accuracy
Requires RTK corrections of GNSS data via an NTRIP service or your own base station. The standard for utility mapping, survey, and construction.
How to achieve centimeter-level accuracy
1
Pair your receiver with an NTRIP service
NTRIP services provide RTK corrections over the internet. Many US states operate free NTRIP networks. Paid services with wider coverage are also available.
Find NTRIP services in your state
2
Pair your receiver with your own base station
Placing a base station such as the Emlid Reach RS2+ on the roof of a building lets you perform your own RTK corrections without engaging a state agency or private contractor.
Need an NTRIP network provider?
Check out RTK PremiumRecommended receiver
Emlid · GNSS Rover
Emlid Reach RX2
Compact RTK rover with IMU tilt compensation and centimeter precision. Pocket-sized and lightweight — compatible with ArcGIS Field Maps, QField, and other GIS apps. Works on iOS and Android. No training required.
Whether you're purchasing your first GNSS receiver or updating an existing fleet, the Reach RX2 offers the advanced capabilities and user-friendly interface favored by new and experienced users alike.