To perform an accurate RTK survey, you use a rover and a correction broadcast in real-time from a nearby base. The most common RTK correction sources are local base stations broadcasting the correction via radio (eg. UHF), or from a remote base, using technology called NTRIP.

NTRIP (Networked Transport of RTCM via Internet Protocol) allows your survey rover to accept corrections over the internet, removing the need for a local base station and extending your range between base and rover beyond what you could achieve with radio communications.

NTRIP includes the following components: a base, server, caster, and rover. Typically the base is a stationary Continuously Operating Reference Station (CORS). The data is then sent to the NTRIP caster, where it is retransmitted to the client’s rover. This requires an internet data connection and most commonly, a subscription with a commercial CORS network provider. Whilst convenient, the cost for this option can soon add up.

NTRIP Caster: Work with your own Base and Rover

Using existing technologies, such as mobile internet and existing protocols, Emlid Caster makes establishing your own RTCM corrections service really simple for any GNSS receiver that supports NTRIP.

Just set up your own RTK base station over a known or post-processed point, and configure it to send corrections to the Emlid Caster service.

If your base station is an Emlid Reach receiver, select the option for NTRIP in the Emlid ReachView3 App to broadcast your corrections to the Caster service via the internet.

Sign up for free and get started

Connect up to 10 rovers simultaneously, anywhere within a reasonable baseline (distance to your base). This only depends on your acceptable level of positional uncertainty – as with any kinematic positioning, longer baselines increase uncertainty.

Just sign up and your NTRIP credentials will be generated automatically. You can start using the caster immediately. Connectivity is limited to 5 bases and up to 10 rovers at the same time. If you need more connections, check Caster Pro.