NTRIP Client for USB Quick Guide

The NTRIP Client for USB is an Android application for high precision postioning that allows to provide GNSS corrections to your RTK receiver (Rover Station) from a public or private Base Station. The application gets GNSS message corrections typically via Internet (or via IP private network) and sends them out to the serial port of your Rover. The application includes the following features:
– Extract messages and collect statistics from a NTRIP caster (compatible with the RTCM3 protocol);
– Check the status and communicate with the RTK receiver through the Android OTG USB port (requires an OTG cable and a GNSS receiver connected);
– Push corrections to a USB port of the RTK receiver.

The application installation, configuration and its main operations are described hereafter:

Installation and permissions

The system installation typically uses public infrastructures but it can also work with private infrastructures, as depicted in the architecture figure below.

The NTRIP4USB application requires that the Android device is connected to the receiver throught a OTG cable. This cable will enable your Android device to act as a USB host and connect to the receiver peripherical.

The application does not require special usage permissions but only the USB permission that is explicitly requested to the user during the connection process.

Configurations and Settings

The application supports the following 3 modes of operations:
1. Full operation: normal mode connecting both the NTRIP Caster and GNSS receiver for enabling the RTK receiver to reach centimetre level positioning.
2. NTRIP Stats only: this mode aims to evaluate or test your regional NTRIP infrastructures by identifying the type of messages that are being received.
3. USB receiver only: this mode is used for testing the receiver and the USB connection with the mobile device.

The operation modes are setup in Settings where you may configure the NTRIP server, the USB device or both.

The NTRIP configuration options are presented in the figure.

The USB receiver configuration options are described in the figure.

Full operations with NTRIP and USB connection

The full feature is the normal mode of operations that acquires RTCM messages, forwards them to a USB port and checks the receiver’s status. The application flow is described in the figure.

The positioning monitoring is performed in two views. The USB data view allows to check the status of the receiver, while the NTRIP Stats view allows to identify the type of messages that are being received. The USB Data view logs the receiver’s messages and shows its status: unkown, invalid (no fix), GPS, DGPS, fRTK and RTK.

NTRIP Stats only

This mode aims to evaluate or test existing NTRIP infrastructures by identifying the type of messages that are being received.

You should use the NTRIP Stats view to check the messages received.

USB receiver data only

This mode aims to test the receiver and the USB connection to the Android device.

You should use the USB data view for check the status of the connection.