NTRIP (Networked Transport of RTCM via Internet Protocol) is a protocol for distributing GNSS correction data over the internet. It enables high-accuracy positioning (typically centimetre-level, sometimes better) by feeding real-time correction streams from reference stations to mobile GNSS receivers.

In short: NTRIP delivers RTCM-format corrections from a network of fixed reference stations to GNSS receivers via the internet. The receiver applies the corrections to its own satellite measurements to remove the major sources of GNSS error (satellite clock errors, atmospheric delays, orbit inaccuracies). The result is centimetre-level positioning rather than the 3 to 5 metres typical of uncorrected consumer GPS. NTRIP is delivered over standard HTTP or HTTPS, with the receiver acting as a client to an NTRIP caster (the distribution server).

Typical applications for NTRIP-corrected GNSS include precision agriculture (autonomous tractor guidance, variable-rate fertiliser application), surveying and construction (machine control, as-built records, site setting-out), autonomous mobile equipment (ground robots, off-highway vehicles, automated guided vehicles), and UAV operations where centimetre accuracy is needed for mapping or inspection.

For IoT, NTRIP's relevance is in the connectivity link. The mobile receiver needs a reliable cellular connection to pull correction data from the NTRIP caster, ideally with low latency. NB-IoT and LTE-M are usually not suitable because of latency and bandwidth constraints; 4G LTE Cat 4 or above is the typical choice. Some industrial cellular routers support NTRIP client functionality directly, allowing the router itself to pull corrections and forward them to a connected GNSS receiver via serial or Ethernet, simplifying the integration on the device side.