Learn RTK
Beginner how-tos for drone pilots and surveyors. Written in plain words and based on NOAANational Oceanic and Atmospheric Administration. The US agency that includes NGS and runs the CORS network.Full definition NGSNational Geodetic Survey. The part of NOAA that runs the official US coordinate system, CORS and OPUS.Full definition and manufacturer documents. Dotted words show a quick definition when you hover or tap.
New? Start here: the 5-step beginner path →RTK glossary: every term in plain words →
What is RTK and do I need it?
What RTK is, in plain words, and when a drone or rover job really needs it.
Read →RTK vs PPK
Fixing positions live versus fixing them after the job, and when to pick each.
Read →NTRIP explained: caster, mount point, port and login
The five boxes every RTK app asks you to fill in, and what each one means.
Read →Fix vs float, and why you lose a fix
What the status on your controller means, and what knocks it down.
Read →Baseline length and accuracy
Why your distance from the base matters, and how to read ppm on a spec sheet.
Read →Datums and geoid basics for drone mapping
NAD 83(2011), NAVD 88, GEOID18 and ITRF in plain words, and how to keep your maps lined up.
Read →Free state network vs paid service
How to choose between a state network, a private network and a nationwide service.
Read →Your first NTRIP connection on a DJI controller
Set up Custom Network RTK in DJI Pilot 2, one step at a time.
Read →Troubleshooting no-fix
A checklist for the field when you're stuck on SINGLE or FLOAT.
Read →PPK with free NOAA CORS data
Download free base station files from NOAA and use them to correct your drone or rover data.
Read →OPUS: get a precise position for your base
Use NGS's free OPUS service to pin down your own base's position for PPK or RTK.
Read →Start here: the beginner path to your first RTK fix
Five steps, in order: learn what RTK is, pick a service, set it up, get your first fix, and keep PPK as a backup.
Read →Fix: stuck in FLOAT
Corrections are coming in, but your rover never gets to FIX. Here's what to check, in order.
Read →Fix: no NTRIP connection or 401 Unauthorized
Your app says it can't connect, or shows 401 or 'bad password'. Here's what each message means.
Read →Fix: wrong mount point
You connect, but get a list of mount points or no corrections. Here's how to pick the right one.
Read →Fix: VRS sends nothing (GGA not turned on)
You're logged in to a VRS or 'nearest' mount point, but no corrections arrive. Turn on GGA.
Read →Fix: FIX, but your points are in the wrong place
Your status says FIX, but points land off from known marks or old surveys. Usually it's a datum or geoid mismatch.
Read →Fix: age of corrections keeps climbing
The 'age' number keeps going up and your fix drops. That's your data link, not your sky.
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