Carrier-Phase Differential
Double-differenced carrier-phase observables cancel satellite and receiver clock errors, ionospheric and tropospheric delays — pushing accuracy from meters to 8 mm + 1 ppm.
8mm
Horizontal accuracy (RMS)
<10s
Time to first fix
5GNSS
BDS · GPS · GLO · GAL · QZSS
1408ch
All-frequency tracking channels
Core Technology
The complete RTK capability stack
From signal acquisition to integer ambiguity resolution, from a single baseline to Network RTK — every layer serves one goal: a faster, more robust, more accurate fixed solution.
Multi-Constellation, Multi-Frequency
Simultaneous tracking of BDS, GPS, GLONASS, Galileo and QZSS across L1/L2/L5, B1C/B2a and E5 — more observables mean faster, more reliable ambiguity fixing.
Network RTK & NTRIP
Stream RTCM corrections over IP via NTRIP. VRS, FKP and MAC reference-station models extend single-baseline coverage to 70 km and beyond.
Sub-10s Ambiguity Fixing
LAMBDA integer least-squares search with partial ambiguity resolution fixes carrier-phase integers in under 10 seconds cold-start, with sub-second reacquisition after cycle slips.
Integrity Monitoring
Built-in RAIM fault detection and exclusion, real-time protection levels and solution quality indicators — engineered for safety-critical autonomy.
Deep Sensor Fusion
Tightly-coupled GNSS/INS with vision and wheel odometry sustains centimeter-level dead reckoning through urban canyons, tunnels and foliage.
How RTK Works
Four steps from satellite signals to centimeter coordinates
Simultaneous Tracking
Base station and rover track the same satellites, logging carrier-phase, pseudorange and Doppler observables in lockstep.
Differential Corrections
The base streams raw observations or correction terms to the rover in real time — over UHF radio or IP via NTRIP.
Ambiguity Resolution
Double differencing removes common-mode errors; the LAMBDA method searches and validates the integer carrier-phase ambiguities.
Fixed Solution Output
Once the ratio test passes, the engine declares FIX and outputs centimeter-level coordinates relative to the base — every epoch.
Applications
High-precision positioning is reshaping these industries
FAQ
High-precision positioning, answered
The questions GNSS engineers, surveyors and autonomy teams ask most — answered with the terminology of the field.
What is GNSS high-precision positioning?
High-precision positioning refers to GNSS techniques — primarily RTK and PPP-RTK — that use carrier-phase measurements plus real-time correction data to reach 1–3 cm accuracy, versus the 2–5 m of a standalone receiver. It is the foundation of surveying-grade mapping, machine control, lane-level autonomy and the low-altitude economy.
What is RTK and how does it achieve centimeter accuracy?
Real-Time Kinematic (RTK) is a carrier-phase differential technique: a base station at a known coordinate and a rover track the same satellites, double-differenced observables cancel common-mode errors, and the LAMBDA algorithm fixes the integer carrier ambiguities. Corrections stream over UHF radio or IP (NTRIP/RTCM), yielding 8 mm + 1 ppm horizontal accuracy in real time.
What are Network RTK and NTRIP?
Network RTK replaces a private base station with a regional CORS network: a rover connects over mobile IP via the NTRIP protocol and receives RTCM correction streams modeled by VRS, FKP or MAC techniques, fixing at centimeter level within seconds. Decentralized (DePIN) networks now crowdsource triple-band reference stations at global scale — high-precision positioning as a utility.
Why do robotics and physical AI need centimeter-level GNSS?
Physical AI — humanoid robots, mobile manipulators, autonomous vehicles and delivery drones — acts in the real world, so it needs absolute, drift-free ground truth. RTK provides the centimeter-level global frame that visual SLAM and IMU dead reckoning cannot sustain alone, anchoring perception, navigation and fleet coordination.
Should I choose RTK or PPP-RTK?
Choose Network RTK when you work inside CORS coverage and need instant, sub-3 cm fixes (surveying, auto-steer, robotics). Choose PPP-RTK when operating wide-area or offshore — SSR corrections broadcast via GEO satellite converge to 2–5 cm in under a minute with no terrestrial network. Modern engines support both and fail over seamlessly.
Which constellations and frequencies matter most?
Multi-constellation, multi-frequency is the single biggest lever on fix speed and robustness. Track BDS (B1C/B2a), GPS (L1/L2/L5), Galileo (E1/E5a/E5b), GLONASS (G1/G2) and QZSS together: 30+ satellites in view and triple-frequency combinations let the engine resolve ambiguities in seconds, even under partial occlusion.
Ready to enter the centimeter-level world?
Read the latest engineering insights on RTK trends, standards and field-proven best practices.
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