RTK GPS turns meter-level GNSS into centimeter positioning using a correction stream. What it is, how accurate it is, and when it's worth the effort.
GNSS Handbook
GNSS Handbook
The Kalmix GNSS Handbook explains how satellite positioning actually works, from first principles to the protocol layer. It covers the GNSS pseudorange equation and receiver clock bias, signal bands and constellations, the RTCM correction protocol that RTK depends on, and the coordinate-system pitfalls that can put a perfect fix off the map. Written for engineers integrating GNSS into robotics, AGV, agriculture, and field-automation hardware.
9 articles
Engineering series
GNSS / RTK resources
Overview
Kalmix GNSS Handbook is a free engineering series covering GNSS fundamentals, satellite ranging, pseudorange, satellite geometry, L1/L2/L5 signal bands, constellations, RTCM correction protocols, and geographic coordinate systems including WGS84 datum issues for developers building RTK-based machines.
Your GNSS fix drifts because six errors enter along the signal's 20,000 km path. This guide maps where each error comes from and how large it can be.
GNSS works by measuring satellite signal travel time, converting it into pseudoranges, and solving position plus receiver clock bias with at least four satellites.
Understand why a GNSS receiver does not use every satellite in the sky. This guide explains GPS, GLONASS, Galileo, BeiDou, L1/L2/L5 bands, antenna matching, and signal-leve...
RTCM is the binary correction-data layer behind RTK positioning. Learn how RTCM streams work, which MSM messages matter, and how to debug rover Fix issues.
A perfect GNSS or RTK fix can still appear shifted when your receiver, correction service, map layer, and software use different coordinate frames.
A practical guide to NTRIP for RTK GNSS integration: how correction streams move from base stations to rovers, how NtripCaster/client workflows work, why GGA feedback matte...
A practical engineering guide to NMEA 0183 for GNSS integration: sentence structure, checksum validation, Python parsing, serial-stream edge cases, and RTK status decoding ...
GNSS accuracy is not a fixed error number. This guide explains CEP, RMS, R95, accuracy vs precision, DOP, and why satellite positioning should be read as a probability dist...