Author: Graeme Buchannan – Sales Manager

At the end of a product demo day, when there is still a boat available on hire, drinks in the eskie (a fridge, to those not from these parts) and customers onboard, there’s only one sensible option, especially when you’re in Perth, Australia – take off on a river cruise. Oh, and while we’re there, let’s put one of our latest instruments to the test and see if anyone on board can correctly guess how accurate it would be.

That’s just what we did and the results impressed even us.

We had half a day’s vessel charter left at the end of our Fusion 2 demo week in Freo (or Freemantle to the non-locals), so we jumped at the chance to put one of our SPRINT-Navs to the test using DVL-aiding alone and comparing the position against our RTK GPS position.

With some of the 50 clients on-board that had been part of the week’s Fusion 2 demos , we sailed out of Success Harbour for a three-hour trip up the Swan River on Inception II, which was fitted with a SPRINT-Nav 500. For fun, it was declared that bragging rights would go to the person who could correctly guess how many metres the position output from this state-of-the-art INS (Inertial Navigation System) would drift during the cruise. 

High performance in a compact form factor

SPRINT-Nav on the benchFor those not familiar with SPRINT-Nav, it’s our all-in-one navigational instrument which combines INS, DVL (Doppler velocity log), AHRS (Attitude and Heading Reference System) and depth sensor in one single unit. It’s proving to be very popular because of its performance and compact form factor. I recently heard that, for one US-based client, the opex savings generated by their SPRINT-Nav topped more than a US$1 million.

The SPRINT-Nav was being used to help show off the capabilities of our new INS and LBL software, Fusion 2, which we launched in Singapore in late November. Fusion 2 makes Sparse LBL and LBL set-up and operation even easier than ever, using less equipment and fewer interfaces. And both of these systems are helping companies to meet the region’s stringent contracting specifications for subsea positioning. 

Fusion 2 river cruise

Anyway, back to our impromptu demo. Setting off from Success Harbour with the region’s finest surveyors on-board, the entries for the guestimates of how much the INS unit would drift while running on DVL-aiding alone were gathered. As INS systems are normally quoted as a percentage of distance travelled, those with their phone calculator to hand and knowing that the SPRINT-Nav datasheet says 0.06%, and estimating we might get to travel around 8 kilometres in the time available, were putting the smart money on an error of around 5 metres.

With an RTK position to be used as truth, off we went. For a start, the 8 kilometre estimate was a little under. Before we knew it, we’d ended running 20 kilometres! Good conversation, perfect temperatures and the natural beauty of the river had clearly been a distraction.

Who guessed correctly? So, with our 0.06% of distance travelled, we should have, in theory, been looking at an error of 12 metres. But, what did we get? More? Less? Well it turns out, a lot less. Just 3.2 metres. That’s right, 3.2 metres drift after running for 20 kilometres. That’s less than 0.02% of distance travelled!

Fusion 2 river cruiseWell, obviously we were all amazed – cue the opening of a few (more) tinnies (as is customary in those parts) and photos of us pointing at the screen. In front of expert witnesses, it was the best possible end, albeit completely unplanned, to an amazing week in Australia, showing off Fusion 2 and SPRINT-Nav.

If you’d like to learn more, about either Fusion 2 or SPRINT-Nav, get in touch. We’d be happy share some data and to do a demo for you too.