NTRIP

NTRIP stands for Networked Transport of RTCM via Internet Protocol. It is a protocol used to deliver real-time GNSS differential corrections over the Internet. NTRIP itself handles the transport and access control while the correction data can be in RTCM or other supported formats.

The architecture centers on three components: the NTRIP caster (server), the NTRIP client, and the data streams, often called mountpoints. The caster hosts one or more streams and provides a directory of available mounts. Clients connect to a caster to subscribe to a specific mountpoint, receiving the real-time correction data as it becomes available. A single caster can distribute the same stream to multiple clients, enabling scalable networks of rovers or receivers.

Operation typically uses HTTP or HTTPS as the transport protocol. The client authenticates with the caster, usually via a username and password or by IP-based access control, and requests a particular stream. The caster then transmits the selected correction data in real time over a TCP connection. While RTCM messages are the most common payload, other formats may also be carried by NTRIP streams.

Applications include GNSS surveying, precision agriculture, mapping, and autonomous navigation, where real-time differential corrections improve positioning accuracy. NTRIP is valued for enabling internet-based RTK networks without the need for dedicated radio links. Security considerations often lead operators to use TLS/HTTPS or VPNs to protect credentials and data, and performance depends on network conditions and caster configuration.