In the realm of RTK architecture, the precision positioning calculations depend on RTCM correction data stream. Within this framework, transmitting correction data to the RTK rover is an indispensable aspect. Presently, there are two predominant methods for correction data transmission. They are: radio-based and internet-based (NTRIP) solutions.
Establishing a radio connection requires radio module hardware for both the base and rover. However, radio connections can be complex to configure. Moreover, regulatory restrict on radio frequencies in most countries, often mandating permits. Some frequencies might even be banned in certain regions. Additionally, radio transmission distances are constrained.
In contrast, transmitting correction data over the internet(NTRIP) has gained widespread popularity. Internet-connected devices exist everywhere, such as smartphones, tablets, computers, Raspberry Pi, Arduino, and various internet-enabled modules. The internet connectivity, via cable, fiber, cellular, and satellite are widely accessible. Internet transmission holds a distinct advantage over radio-based methods. It transcends distance limitations, proving more dependable and user-friendly.
This article delves into the NTRIP caster services available at the moment in 2024:
NTRIP Caster Services
Setting up and managing an NTRIP Caster can be complex, requiring extensive knowledge of RTK and computer systems, as well as maintaining a server operating 24/7. For most users, utilizing an existing NTRIP Caster service is likely the most practical solution.
GeoAstra, a subsidiary of CanadaGPS, has recently launched its NTRIP Caster service, providing production-grade NTRIP services to the public. It offers free, pro, and enterprise subscription plans to suit different usage scenarios. Check it out at www.geoastra.com.
In addition to our GeoAstra NTRIP Caster service, there are several other NTRIP services provided by third parties, such as rtk2go and Emlid. You can find the latest information on their official websites.
Compared to these third-party NTRIP services, even the free plan of GeoAstra offers a fully-featured, commercial-grade NTRIP service without any reduction in functionality or connection time limitations. This is one of the significant advantages of using GeoAstra NTRIP Caster.
Setting Up and Operating Your Own NTRIP Caster
SNIP Software:
I would like to mention SNIP software.
SNIP is Windows-based NTRIP caster software available in Lite, Basic, and Pro editions. While Lite is free, it lacks NTRIP caster functionality. Should you opt to run your NTRIP caster, acquiring a Basic or Pro edition license is necessary. Further details can be found on their website.
Personally, I do not particularly like the concept of utilizing a Windows console application to operate the NTRIP service. If SNIP could function as a Windows or Linux service, it could potentially enhance the reliability. However, the options for NTRIP caster software are somewhat limited in the current market landscape of 2023. Consequently, choices are relatively constrained for those seeking to operate their NTRIP service.
Other options:
An official NTRIP Caster by BKG is available at https://igs.bkg.bund.de/ntrip/bkgcaster. This software is priced at 1000€, inclusive of the source code. It serves as a valuable resource for reference if you contemplate developing or running your NTRIP Caster service. While I haven’t personally tested it, your experiences and insights with this tool are welcome.
Additionally, I found several NTRIP caster projects on GitHub that had shared source code. I conducted tests on them, but unfortunately, none of them have demonstrated functionality at this point. Should any of you come across a functional NTRIP solution with source code, please don’t hesitate to share your findings below. This collaborative approach ensures that a wider audience can reap the benefits of your knowledge and information.
I will try to keep the NTRIP caster information on this article current. Stay tuned for updates.
Thank you and best regards,
Jack Wu
Director,
GPSWebShop
RTK GNSS products can be purchased from:
https://gpswebshop.com (US & WorldWide)
https://canadagps.ca (Canada)