How RTK, PPK and NTRIP work | Emlid Store

How RTK, PPK and NTRIP work

To achieve centimeter precision Reach RS uses the technology called RTK.

RTK, Real-Time Kinematics

Two Reach RS receivers work together. One is stationary, another moves freely. They’re usually called base and rover. Rover can’t calculate it’s precise position using only satellites signals, it needs a reference, and that’s what base is for. Rover connects to it and calculates relative position with centimeter precision.

They communicate over LoRa radio, which can work on distance up to 8 km. Multiple rovers can be connected to one base at the same time.

PPK, Post-Processed Kinematics

Along with RTK Reach supports PPK or Post-processed kinematic. This mode doesn’t require real-time connection between base and rover, making equipment setup simpler. In PPK all raw measurement data is recorded on receivers and is processed afterward to get centimeter precision.


You also don’t necessarily need a second unit for RTK. Usually there are local organizations that share their base stations over the Internet. This technology is called NTRIP. Basically, you just borrow base station from someone in your area. And you can also share your own.

NTRIP is a good option for occasional use and for areas with strong 3G/LTE coverage. In other cases using second Reach RS+ as a local base station has two advantages:
— Autonomy in the remote areas as there’s no need in the Internet connection;
— Independency from local providers, no additional fees by NTRIP service.

Choose your
Emlid device

RTK receivers

Emlid offers single-band receiver Reach RS+ and multi-band receiver Reach RS2. Both units are suitable for working in RTK and PPK modes, allow to perform PPP and use NTRIP for correction output. You can also purchase the survey kit: rover and base unit in a set, all ready for work immediately.


For working with UAV, order Emlid’s GNSS module Reach M+ or Reach M2 to connect to your drone. Suitable for both RTK and PPK, Reach M+/M2 are available in UAV mapping kits and UAV RTK kits.


Navio2 helps you turn your Raspberry Pi into a drone controller. Autopilot HAT 
for Raspberry Pi powered by ArduPilot and ROS, Navio2 tracks GPS, GLONASS, Beidou, Galileo and SBAS satellites and allows you 
to run missions and stream video from 
the drone.

Online Store and
Local Dealers

You can either buy Emlid products online in our online shop or order the Reach receiver from the official local dealer. We have local dealers in more than 20 countries: visit the list of dealers, find the desired product and see if somebody sells it in your country or nearby.

In Emlid online store you can find

  • Affordable and easy-to-use RTK receivers with up to a cm precision 
and high accuracy
  • Modules and adapters for autopilots
  • Various accessories for a comfortable 
and accurate survey

Payment and shipping

For online orders, we only accept PayPal transactions in USD. The final price doesn’t include import taxes and duties. For more details on payment and shipping specifics see the delivery and payment page.

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