NTRIP Corrections

NTRIP (Networked Transport of RTCM via Internet Protocol) delivers real-time correction data from a base station network to your RTK receiver, enabling centimetre-level positioning accuracy. SiteView connects to NTRIP casters through the browser and forwards correction data to your receiver via Bluetooth.

Why You Need NTRIP

An RTK receiver on its own can determine position to about 2-5 metres accuracy using satellite signals alone (known as a "single" or "autonomous" fix). To achieve centimetre accuracy (10-20mm), the receiver needs correction data from a nearby base station.

NTRIP provides this correction data over the internet. A network of permanent base stations (called a CORS network — Continuously Operating Reference Stations) calculates corrections and broadcasts them through NTRIP casters. Your receiver applies these corrections to its satellite observations and computes a much more accurate position.

ℹ️ Did you know?

Without NTRIP corrections, your RTK receiver functions as a standard GNSS receiver with metre-level accuracy. With corrections, it achieves centimetre-level accuracy. The difference is significant for construction surveying work.

Configuring an NTRIP Caster

To connect to an NTRIP caster, you need five pieces of information. These are provided by the NTRIP service operator:

Entering NTRIP Settings

1. Click the RTK status chip in the SiteView header
2. Open the NTRIP section in the RTK panel
3. Enter the caster host, port, mountpoint, username, and password
4. Click Save

The settings are saved to your SiteView profile and persist across sessions.

QGPSnet Preset

SiteView includes a built-in preset for QGPSnet, the Queensland Government's free CORS network:

Click QGPSnet in the preset list to auto-fill all fields. QGPSnet is a free government service available to anyone working in Queensland, making it an excellent option for construction sites in that state.

💡 Tip

If you are working in another Australian state, check for your state's CORS network. Most Australian states provide free or low-cost NTRIP services. In New Zealand, PositioNZ is available through Land Information New Zealand (LINZ).

RTCM Correction Data

Once connected, the NTRIP caster sends RTCM 3.x correction messages to SiteView. SiteView forwards these messages to your RTK receiver via the Bluetooth connection. The receiver uses these corrections to refine its position calculation.

The flow is:

NTRIP Caster → Internet → SiteView (Browser) → Bluetooth → RTK Receiver

RTCM messages are binary data. SiteView handles the forwarding transparently — you do not need to configure anything beyond the NTRIP connection settings.

GGA Position Forwarding

Some NTRIP casters operate Virtual Reference Stations (VRS). A VRS caster needs to know your approximate position so it can calculate corrections specific to your location. This is done by sending GGA (position) sentences back to the caster.

SiteView automatically:

1. Reads the GGA sentence from your receiver's NMEA output
2. Forwards this GGA sentence to the NTRIP caster at regular intervals
3. The caster uses your position to generate locally-optimised corrections

ℹ️ Did you know?

GGA forwarding is automatic when connected to an NTRIP caster. For non-VRS casters (single base station streams), the GGA is accepted but not required. There is no downside to sending it in either case.

Test Connection

Before heading to site, test your NTRIP configuration:

1. Enter the caster settings
2. Click Test Connection
3. SiteView attempts to connect to the caster and retrieve the mountpoint table
4. A success or failure message is displayed

A successful test confirms that the hostname, port, and credentials are correct. The mountpoint is validated when you actually connect for correction data.

⚠️ Watch out!

NTRIP connections require an active internet connection. If you are on site with limited mobile coverage, ensure your device has sufficient signal to maintain the NTRIP data stream. Correction data uses very little bandwidth (approximately 1-5 KB/s), so even a slow connection is usually sufficient.

Auto-Connect

When enabled, SiteView automatically connects to the configured NTRIP caster whenever an RTK receiver is connected. This saves you from manually starting the NTRIP connection each time.

To enable auto-connect:

1. Open the NTRIP settings panel
2. Toggle Auto-connect on
3. The next time you connect a receiver, NTRIP will start automatically

What's Next?

• Capturing Points — use RTK-corrected positions to capture survey points
• RTK Status & Accuracy — understand fix quality and what the corrections achieve
• Connecting a Receiver — review the Bluetooth connection process
• Web Bluetooth Setup — check browser and hardware requirements