In the wake of the arrival of our next-generation RT products, this article focuses on one particular new feature designed to simplify configuration and enhance the ease of use of the new RT3000 v3: its built-in NTRIP client.
What is NTRIP
To recap, Networked Transport of RTCM via Internet Protocol – NTRIP – is a form of RTK differential correction transmitted over the internet, as opposed to sending corrections from base station to rover via a radio modem. It allows the user to obtain highly accurate positioning data in real time, so is particularly valuable for autonomous vehicle testing or ADAS testing on the open road.
Over the past few years, NTRIP has become a well-established, cost-effective and relatively simple to use method of achieving real-time RTK integer accuracy. Even when operating in challenging environments during open-road testing, the DGPS corrections received via NTRIP help to provide centimetre-level position accuracy. This is particularly useful when carrying out tests over extended distances.
How it works – an overview
In order to make use of NTRIP corrections, the test vehicle’s location is sent over mobile internet to an NTRIP server to find the closest base station in the user’s network. Corrections are transmitted via the base station’s NTRIP caster and received through a SIM card-equipped data collection device running the NTRIP client software. This then passes them on to the rover unit. NTRIP corrections can be received anywhere there is internet coverage. More advanced NTRIP services can even extrapolate from multiple base stations to create a virtual base station at the precise location of the user and transmit corrections from this point.
Prior to the arrival of our next-generation range of inertial navigation systems, RT users needed additional hardware to receive NTRIP corrections. First, you needed a separate router, either a smartphone or internet-enable laptop running proprietary NTRIP client software. For optimum performance, a bespoke NTRIP router such as the dual-SIM Ercogener GenPro 325e. In each case, the NTRIP client software would be configured to receive the desired corrections and output them to the RT so it could operate in RTK mode.
That set-up obviously required the additional data collection hardware, plus the associated serial cable connection to the RT and, at least in the case of the router, a power supply. And, of course, space had to be found for the extra hardware in the test vehicle. For as long as the configuration worked, then all was well and good and the RT could operate with RTK integer accuracy. However, if there was any problem with the set-up, the RT would be unable to determine exactly where the issue was.
NTRIP Client makes it simple
Thanks to the RT3000 v3 built in NTRIP client, things are now much simpler. During the RT’s regular configuration procedure, details of the desired NTRIP service are entered in the ‘Interface’ section of NAVconfig. No extra cabling is required, in turn reducing a potential point of failure. Thanks to the next-gen RT’s built in Wi-Fi, all that’s required is a mobile device to make an internet connection, so once again, there’s no need for extra cabling.
More importantly, because the NTRIP client is running within the RT’s firmware, we now know the status of the stream of correction data at all times. If there’s a problem with the NTRIP service, for example if the base station is down, then the system is now able to report what the issue is.
This time-saving simplification of the RT’s set-up and functionality has been made possible by the next-generation product’s more powerful processor. The upgraded CPU now has sufficient processing capacity to run the NTRIP client software in the background while carrying out its primary functions. But the bottom line is that the RT is now simpler to set up and easier to use than ever.