GNSS RTK
What is GNSS RTK?
GNSS RTK, or Real-Time Kinematics, is a method used to make GPS positioning much more accurate — from a few meters down to a few centimeters.
Normally, GPS alone can tell you where you are, but small errors (from the atmosphere, satellites, or timing) make your position “wiggle” a bit. RTK fixes that by using a known reference point on the ground to correct those errors in real time.
How RTK Works (Step by Step)
Satellites send signals Several GNSS satellites (like GPS, Galileo, or GLONASS) are orbiting Earth and constantly sending timing signals down to receivers on the ground.
A base station listens carefully A base station is placed at a spot where its exact position is already known very precisely. It receives the same satellite signals as your GPS but can tell exactly how much each signal is “off” compared to where it should be.
The base sends corrections The base station calculates these tiny errors and sends correction data to another GPS receiver — called the rover — through a radio, Bluetooth, or internet link.
The rover fixes its position The rover (on a drone, survey pole, robot, etc.) uses the same satellite signals plus the correction data from the base. This allows it to adjust its own position and know exactly where it is — often within 1–2 centimeters.
Why It’s Useful
Very accurate: Positions are precise to a few centimeters.
Fast: You get corrected positions in real time.
Reliable: Works as long as the rover stays close to the base (usually within 10–30 km).
Real-Life Examples
Surveying: Measuring land or construction sites.
Agriculture: Guiding tractors along perfect straight lines.
Drones: Flying precise paths for mapping or inspection.
Robotics & autonomous vehicles: Staying exactly on track.
In Short
RTK is like giving your GPS a local helper that already knows exactly where it is. By comparing notes, that helper tells your GPS how to fix its errors — letting you know exactly where you are, down to a few centimeters.
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