Land Surveyor · RTK

RTK Survey Setup Guide

Get a centimetre-accurate RTK Fixed solution with any GNSS receiver — from connecting the receiver to entering your NTRIP corrections, explained step by step.

What you need 1. Set up the receiver 2. Connect to the app 3. Enter NTRIP 4. Fix status Troubleshooting Before you buy

What you need

RTK works by correcting your receiver’s raw position using data from a reference base. Three pieces have to be in place:

A GNSS/RTK receiver

Any dual-frequency receiver that outputs NMEA-0183 and accepts RTCM 3.xcorrections. The phone’s built-in GPS is not accurate enough for RTK.

An NTRIP correction source

A caster that streams corrections over the internet — a national CORS network, a commercial service, or your own base station published online. You’ll get a host, port, mount point, username and password.

This app + internet on your phone

Land Surveyor reads the receiver’s position, pulls corrections from your NTRIP caster, and feeds them to the receiver. Your phone needs mobile data or Wi-Fi for the caster.

Step 1 — Set up the receiver (most important)

This is the step people miss. For safety, Land Surveyor never changes your receiver’s settings by itself — you set two things once, using the receiver’s ownsoftware or web page, and they stay saved on the receiver.

Set the datalink to “External”. A receiver can take corrections from its internal UHF radio, its own SIM, or from an external port (Bluetooth/USB). Land Surveyor feeds corrections over the external port— so the rover’s datalink must be set to External / “PDA network” / “Phone internet”. If it’s left on internal radio, the receiver ignores the app’s corrections and stays on Single.

Enable NMEA-0183 outputon the port you’ll connect over (Bluetooth, USB or Wi-Fi). If NMEA output is off, the app connects but receives 0 bytes.

Where these settings live depends on the brand — use its controller app or built-in web page:

Receiver brand	Its own software / config
Emlid (Reach)	ReachView / Emlid Flow
Topcon	MAGNET Field / Pocket-3D
CHC	LandStar
Hi-Target	Hi-Survey
South	SurvX / EGStar
Stonex	Cube
ComNav	SinoGNSS Compass / WebUI
Qianxun (Q-series)	Survey Mate / built-in WebUI
Many WiFi receivers	Built-in web page (connect to the receiver’s WiFi, open its IP in a browser)

Tip:if the receiver belongs to a surveyor, they already know how to set its datalink and NMEA output — just ask them to put the rover in “external / controller-NTRIP” mode with NMEA output on, then close their app before you connect.

Step 2 — Connect the receiver to Land Surveyor

Open RTK Survey → Connectand choose how the receiver is attached. Only one app can hold the receiver’s connection at a time, so fully close its own software first.

Bluetooth

Pair the receiver in Android’s Bluetooth settings first, then pick it in the app. The receiver must have NMEA output enabled on its Bluetooth port.

USB

USB (Type-C)

Connect the receiver with a USB-C cable and grant the permission prompt. Best choice when the receiver only outputs on USB — and your phone keeps its own internet for NTRIP.

WiFi

Wi-Fi (TCP)

Join the receiver’s Wi-Fi, then enter its IP and NMEA port in the app. Note: if the receiver’s Wi-Fi has no internet, your NTRIP caster won’t be reachable — prefer USB or Bluetooth when you need corrections.

A good sign: within a few seconds the Bytes received counter climbs and the app shows your position and satellite count. If it stays at 0 bytes, NMEA output is not enabled on that port (go back to Step 1).

Step 3 — Enter your NTRIP corrections

In the Connect tab, open the correction source and fill in the caster details from your provider:

Host / Address	The caster server, e.g. rtk.example.com or an IP address.
Port	Usually 2101 (sometimes 2100 or 8080).
Mount point	The stream to use. Tap the list button to pull the caster’s source table and pick the nearest one.
Username / Password	Your account with the provider.

VRS / network mounts need to know where you are before they send anything. Land Surveyor handles this automatically — it uploads your position (GGA) to the caster, so a network mount serves a base right next to you.

Distance matters.The closer the base, the faster and more reliable the Fix. Beyond roughly 30–40 km a single-base mount may only reach Float. The app shows the base it is actually being served (and the baseline distance) once corrections decode.

Step 4 — Understand the Fix status

The solution type tells you how accurate the current position is. Only Fixed is survey-grade.

Single

Raw GNSS, no corrections applied yet. Metres of error. Not for survey.

DGPS

Basic differential. Sub-metre, still not survey-grade.

Float

Corrections are working but the ambiguities aren’t resolved. ~10–50 cm. Wait — it usually climbs to Fixed.

Fixed

Full RTK. Centimetre accuracy. This is what you record points on.

Stuck on Single with corrections flowing?The receiver is getting NMEA out but not applying the RTCM in. Almost always the rover’s datalink isn’t set to External(Step 1), so it ignores the app’s corrections. A receiver “supporting RTCM3” is not the same as being set to take it from the external port.

Troubleshooting

Symptom	Likely cause & fix
Connected, but 0 bytes	NMEA output is off on that port, or the receiver streams on USB/Wi-Fi not Bluetooth. Enable NMEA-0183 on the connected port (Step 1), or switch to the port it does output on.
Position shows, but stays Single	Receiver isn’t applying corrections. Set the rover datalink to External (Step 1). Also confirm the app’s “Correction bytes written to receiver” is climbing and the base isn’t hundreds of km away.
Reaches Float but never Fixed	Baseline too long, poor sky view, or weak satellite geometry. Move to open sky, or use a closer mount point.
Keeps connecting / disconnecting	Bluetooth power-saving or a flaky link. Set the app to Battery → Unrestricted, keep the receiver charged, and stay in range.
No fix indoors	Normal — RTK needs a clear view of the sky. Test outdoors, away from buildings and trees.
Receiver needs an activation code	Some consumer receivers lock NMEA/output behind a paid satellite service (e.g. L-band). That code comes from the dealer; the app can’t bypass it.

The app tells you where it’s stuck.On the Connect tab it shows bytes received, whether valid NMEA was seen, correction bytes written, the decoded base and baseline, and an RTCM compatibility verdict — so you can tell “no sky” from “wrong port” from “receiver ignoring corrections” without guessing.

Before you buy a receiver

Land Surveyor works with any open receiver. Check these three things first — they decide whether a receiver will work with anythird-party app, not just its vendor’s:

✓ NMEA-0183 output over Bluetooth (or USB) — and not locked behind a paid service.
✓ RTCM 3.x correction input over the same Bluetooth/USB port.
✓ Not vendor-locked — able to take NTRIP from a third-party app, not only its own software.

Receivers that make this easy include Emlid Reach RS2/RS3, ComNav, CHC, Hi-Target, South and Stonex. Be careful with consumer / cloud-locked units that only work through their maker’s own app.