The rise of Satellite Based Positioning and Timing

Over the past twenty years, satellite navigation systems have been providing the world with accurate positioning and timing data.  The proliferation of devices that use the information from free of direct charge systems, such as GPS and Galileo has been astonishing – in those two decades, we have got to a point where there are said to be more GNSS receivers on the planet than human beings.

Accuracy and Convenience of GNSS

The very high accuracy of GNSS combined with the amazingly low cost of devices that can receive the signals has resulted in the use of PNT data becoming ubiquitous in many application areas where precise positioning or timing data are required. Some of those application areas are in use cases where safety or security are important considerations in addition to the convenience of a low-cost commercial solution.

Critical dependencies emerge

This has led to a growing and high dependence on Space based PNT data that is often not fully understood by the owners, operators and users of the dependent systems and services.  This is particularly true of timing data provided by GNSS, where often the use of satellite derived timing data in dependent systems is not even known about, let alone understood. The concern of many of these users remains accuracy and precision (i.e., repeatable accuracy), without regard to the other important PNT metrics of availability, integrity, and coverage.  This can and has led to unusual and sometimes alarming consequences when GNSS services have been disrupted.  The belief that by simply increasing the number of constellations and satellites this problem can be mitigated has led to significant investments in space-based PNT, while resilient ground-based PNT solutions have been ignored or, even worse, decommissioned. 

John Pottle, Director of the Royal Institute of Navigation (RIN) maintains that “used naïvely or in an “unprotected” way, there are risks to accuracy and trust of the information that comes from satellite navigation systems. Alongside the growing dependencies on PNT information, it can be argued that there is an uncomfortable over-reliance in many critical areas.”

RIN White paper identifies no standard set of test cases or approaches  to assessing resilience

In 2023 the RIN published a White Paper looking at existing standards for resilient PNT.  Titled “Recommendations to Promote the Adoption of Resilient Position, Navigation and Timing in the UK - With Growing Capabilities Come Growing Threats” it concluded that there is no current standard (or set of standards) that identifies the performance requirements needed to ensure resilient PNT to satisfy the needs of all UK Critical National Infrastructure (CNI) stakeholders. 

This finding is significant as it is not straightforward to assess the resilience of PNT systems - there is no standard set of test cases or test approaches; and that the concept of a simple “resilience score”, while compelling in theory, can be difficult to achieve in practice at application level, due to the divergence of specific requirements between stakeholder types.  However, there are obviously some general principles and guidelines that will have general applicability.

RIN to establish a “Best Practices”  Working Group

To help address this pressing need to improve guidance on Resilient PNT in the UK, the RIN intend to set up a Working Group to address the issues and work on developing a set of effective guidance and best practices, that can be used by regulators, operators, owners and users in critical application areas to improve the resilience of their systems and equipment.

The co-authors of the white paper,  Mitch Narins and Ramsey Farragher, have this to say on the need for general principles and guidelines that can improve PNT Resilience.

Ramsey Farragher said “Aside from the main actions out of the study, there were two really interesting findings for me from the stakeholder discussions and other background research for the paper. One was the realisation that people in different sectors and parts of the PNT value chain can mean quite different things when they use terms like resilient, robust and assured. Common language across the supply chain and among end users is critical and we will be able to help to establish that. The second realisation was that there will be so much benefit derived from a relatively simple and succinct set of best practice guidelines for each CNI that it will be a crucial “quick win” in advance of any major future undertaking involving legislation and standardisation.”

Mitch Narins highlighted that there is no current standard (or set of standards) that identifies the performance requirements needed to ensure resilient PNT to satisfy the needs of all UK Critical National Infrastructure (CNI) stakeholders (i.e., services providers, users, and use cases).  He also points out that over the past two decades many manufacturers and users throughout the world have migrated to using PNT services derived from GNSS without needing to determine their PNT requirements or having a thorough understanding of the impact that loss or degradation of the service would have to them.  Whilst creating a single universal standard to cover all sectors and use cases would be a huge and lengthy undertaking, the idea of the RIN working group is to develop a set of recommended best practices which will inform, influence, and motivate users to adopt resilient PNT services and solutions.

Andy Proctor, Chair of the RIN PNT Advisory Group said, “This key activity will take the initial steps forward to improve the PNT System resilience of our critical infrastructure. Forming the team and setting the short- and medium-term objectives and outputs will be crucial to ensuring adoption and success of the principles and practices identified.”

To learn more about the Royal Institute of Navigation's UK PNT Advisory Group or to sign up to its non-member mailing list, please click here.

An intriguing title to an excellent talk at the Little Ship Club by SCG Committee Member Darryl Hughes. This annual event organized by the Small Craft Group and hosted by the Little Ship Club was run both as an attended and an online evening. Those attending in person gave Darryl a full house, which he entertained, not only with tales of sailing but also his love of Irish poetry.

The course:      Start at Wicklow and sail clockwise round Ireland and all its islands (except Rockall, the ownership of which is uncertain). Finish at Wicklow. The tides are quite weak down the southern part of the course and fairly easy up the west and north coast until approaching Rathlin Head. One hopes to time one’s arrival here to catch the Rathlin Tidal Express round Rathlin Head and into the North Channel, between Ireland and Scotland. The winds will normally give a beat at the start, down to the South and along the South Coast of Ireland, and then they should be astern up the west and north coasts. After Rathlin Head, you take what comes.

The yacht:       Maybird is the oldest, and the only gaff-rigged, yacht to have completed this race. She was designed, as were many cruising yachts, by Fred Shepherd whose assistant Fred Parker signed many of the plans unearthed by Darryl during her restoration. She was built in Arklow at Jack Tyrell’s yard in 1937, where mostly work boats and a lifeboat were constructed. That she has survived for more than eighty years is down to the excellent quality of the materials from which she was built – pitch pine planking from Florida on Irish oak frames. Maybird was commissioned by Lt. Col. W C W Hawkes, the youngest of three career soldier brothers who all served at the Battle of the Somme, and were all awarded the DSO, all surviving the war.

From 2009 to 2011 Daryl managed the Maybird restoration project. The thirty-two Irish oak frames were still so strong that none needed replacing. To conform to modern RORC rules she needed to be fitted with a lot of electronic gear such as AIS and locator beacons on all lifejackets.

Racing:                        Taking part in the 1938 RORC race from Falmouth to Kingstown (now Dun Laoghaire) Maybird finished last in Class 2, some 14 hours behind the winner Maid of Malham, skippered by John Illingworth. This is a tradition that Darryl continues to uphold!

In 2011 Maybird completed the Fastnet in 6¹/2 days. Being a heavy displacement, long keel, gaff rigged yacht, she was never designed to be competitive to windward. From the start she was heading towards the Channel Islands, so never stood a chance of winning.

2011 Fastnet race. Credit: Peter Mumford of Beken of Cowes

Competing in the 2016 Round Ireland Race she was forced to retire by the time she reached the Fastnet Rock, as engine failure left her unable to charge her batteries and so unable to power the safety equipment she now needs to carry.

2018 Round Ireland Race:      To illustrate the race, Darryl chose to compare Maybird with another competitor, Jedi. Maybird has a displacement of 21 tonnes with a long keel, an overall length of 43 feet (13.1 metres) and was built for cruising. She isn’t good to windward. Jedi, by comparison, is a 10.75-metre racing yacht with a displacement of 4.9 tonnes. A deep fin keel with a heavy bulb gives her minimum wetted surface and so, less frictional drag.

Jedi has 80,000 miles of racing behind her, with several wins. Maybird has 8,000 racing miles, finishes last and, apart from Darryl, an all-Irish crew from the Arklow Sailing Club (I’m not sure how this could be seen as a handicap). With her displacement, it is difficult to get Maybird moving fast unless you hang up every sail including the mizzen staysail. Before the race Jedi was removing gear due to the light winds forecast, while Maybird was adding water, food and gear in anticipation of a slow passage. Maybird’s crew expected haute cuisine and loaded many prepared dishes while those aboard Jedi were content with freeze-dried meals.

Maybird used paper charts, compass and log, although she did carry a chart plotter, mainly to keep Ireland to starboard.

On Day 1 after the start of the race, the tide was south going for six hours. Jedi slipped away and got ahead. The Tusker Light was not working, which had not been disseminated in any navigation warnings, although a ferry did call Maybird to advise her. Jedi, way ahead and in the dark, managed to lose a man overboard; she put into practice the standard procedure with a visual watch being kept on the casualty, while sails were handed, and the MOB button pressed on the SatNav. After recovery, it was agreed that one most important aid was the flashing lifejacket light, in this case, a Spinlock Lume-On. By the time Maybird reached the Fastnet, the wind started dropping, but at least she had got farther than she did in the 2016 race.

Light winds then prevailed and by Day 4 the crew were fed up with the lack of progress. On Day 5 there seemed to be no isobars anywhere on the weather chart and the usual southwest wind had vanished leaving Maybird becalmed. Dolphin and gannet watching passed the time.

On Day 6 things started to change with the coming of a breeze. Maybird, now with the 12 or 13 knots of wind she needed to move, was passing Slyne Head, halfway around the course. Jedi had finished!

Day 7 and Maybird was heading northeast towards the top of Ireland. All the pre-prepared meals had been eaten and the crew were searching the stores on board for pasta and tins of Irish stew.

Day 8 brought quite good winds round Tory Island, but into stronger tides.

Passing Rathlin Island on Day 9 they hit fog.

Day 10 saw them off Strangford Lough after seven hours of south-going tide and some north in the wind. A good run down to Dublin Bay, under reduced canvas with 20 knots of wind, cheered all on board. By now the crew of Jedi had been back at work for two days. Then the wind dropped, leaving Maybird dodging the fishing fleet and ferries while heading for Wicklow and the finish.

Coming in to finish, assuming they were so late that no one would be around, the crew were astonished to be met by a RIB with an invitation to breakfast ashore. There they were met by the entire committee and many members of the Wicklow Sailing Club to welcome them home. Once alongside, the tracker carried to prove they had been round Ireland was collected, and the crew numbers were counted to ensure they hadn’t lost anyone during the race.

Result:             Maybird finished last. Even on handicap she was last!

She was the oldest yacht in the race and the only gaff rigger.

Footnote:       On completing the Fastnet Race in 2011 Maybird had been presented with the “Iolaire Trophy” for being the oldest yacht in the race. The Iolaire Trophy, a small section of boat timber, was donated to RORC by Don Street who sailed his famous engine-less gaff yawl, Iolaire, in the fiftieth edition of the Fastnet Race in 1975, to be awarded to the oldest boat to complete the course in future races.

Believing this was a good idea, (did he think he might also win it in the future?) Darryl decided to do the same with a section of Maybird’s original wooden main mast. This trophy, adorned with engraved brass plates, has been presented via the Old Gaffers’ Association to the Wicklow Sailing Club. This is to be presented to the oldest yacht participating in the bi-annual Round Ireland Race. Darryl is desirous of encouraging older yachts, and especially those gaff rigged, as he puts it, to give it a lash.

Maybird trophy. Credit: Darryl Hughes

John Hasselgren,

26/01/2024.

The next Royal Institute of Navigation (RIN) Conference, organised by their Small Craft Group (SCG), will address the highly important topic, of the Shifting Sands of Navigation and Pilotage for Small Vessels at Sea and the uncertainty which surrounds it. The Conference, to be held at CA House, in London and online on 24 February 2024, will feature talks on this topic by industry professionals, trainers and officials; it is of extreme relevance for leisure sailors, and the navigation equipment industry.

The momentum over the past few years to move away from paper charts to electronic charting has grown significantly.

Some countries’ Hydrographic Offices (HOs) had already announced, and set dates for, the withdrawal of their official paper charts, within a time-frame of what is now less than 3 years. However, over the last year or so a greater understanding of the implications and issues that still need to be addressed has been reached. These issues include back-up systems/software and, of course, training. The global nature of the electronic chart publishers and equipment manufacturers has also highlighted the requirement for any such standards to be agreed internationally.

Approved electronic charts and systems for leisure vessels are, however, just a small subset of the approval requirements for the so-called “sub-ECDIS” sector worldwide. Consequently, whilst the timescale for the withdrawal of paper charts by the UKHO has been extended from 2026 until at least 2030, there is still much to be accomplished in the intervening years, if this revised time-frame is to be met. The RIN’s Electronic Navigation Systems Guidance booklet - due to be updated in 2024 - and the RIN’s Electronic Navigation Conferences are designed to address these issues and inform leisure craft users, as we slide inevitably towards an all-encompassing digital navigation future. To find out more about this hybrid Conference and to register visit the RIN website event page https://rin.org.uk/events/EventDetails.aspx?id=1656297&group=

Above copied from an article originally published in Navigation News.

Confirmed speakers at the Conference include Anders Bergström from Raymarine, Jelte Liebrand from Savvy Navvy, Paul McKenzie & Luke Allen from Furuno, Hugh Agnew from A+T Instruments Ltd., Carlo Alberto Galli and Michele Graziani from Garmin/Navonics, Lucy Wilson from Imray, Richard Falk from the RYA, Jane Russell from the RIN, C-Map and UKHO.