UK Government’s 10 Point Resilient PNT framework is welcome news for the RIN PNT Advisory Group 

By Guy Buesnel and Andy Proctor 

 

UK Government announces a Resilient PNT Framework

The UK government has announced its long awaited Resilient PNT framework including a crisis plan, to support UK Critical National Infrastructure and essential services, which have all been identified as being critically dependent on the use of PNT data from GNSS. 
The plan includes the following points:
• Establishing a National PNT Office in the Department of Science, Innovation and Technology (DSIT) with responsibility for PNT policy, coordination, and delivery    
• Retain and update the Cross Government PNT Crisis Plan     
• Develop a proposal for a National Timing Centre
• Develop a proposal for ‘Ministry of Defence Time’ 
• Develop a proposal for a resilient, terrestrial, and sovereign eLORAN system to provide backup Position and Navigation  
• Rollout resilient GNSS receiver chips, develop holdover clocks, and consider options for legislation on CNI sectors to require minimum resilient PNT   
• Develop a proposal for a UK PPP Satellite-Based Augmentation System 
• Explore options for Centres for Doctoral Training PNT  and review PNT skills, education, and training 
• Develop a PNT growth policy, including R&D programmes, standards and testing, to drive innovation for PNT based productivity   
• Deploy existing R&D funding into a UK Quantum Navigator and investigate options for a UK sovereign regional satellite system   

 

10-Point plan broadly welcomed by PNT community

The UK government believes that “strengthening PNT capabilities will give direction to the PNT industry, whilst fostering innovation, growth, and cutting-edge technology development, positioning the UK as a global PNT leader.”

This is welcome news for the UK academia and industry experts who have been raising awareness of the overdependence on GNSS in critical infrastructure and other application areas.  
It also comes on the back of a updated London Economics study into the economic impact to the UK of a major disruption to GNSS, which noted that the impact of loss had risen from a conservative £1.1billion in 2017 to £1.4billion in 2021.

 

RIN PAG White paper addresses adoption of Resilient PNT

The announcement by the government was very timely, coming just a few weeks before the RIN holds its second “Leadership in PNT” event at the Royal Society and just after the publication of the updated UK National Risk Register, which included a risk of loss of PNT, and the publication of a RIN authored paper by the National Preparedness Commission noting the need to be more prepared for the loss of PNT services. In addition, the RIN PNT Advisory Group’s (PAG) published a white paper, “Recommendations to Promote the Adoption of Resilient Position, Navigation and Timing in the UK - With Growing Capabilities Come Growing Threats”

The white paper, the first major publication from the RIN PNT Advisory group asserts that Resilient PNT is an area in which the UK could provide leadership to improve PNT performance given the high level of expert knowledge and track record in innovation and excellence that the UK possesses.

The RIN PAG has been involved in activities to support decision makers, regulators, industry, academia, and all involved in developing the Resilient PNT framework for the UK. It is developing plans to carry its work forward during 2024 and beyond; setting out tasks to support the government and National PNT office in the delivery of its ten-point framework will be high on its agenda.  As well as developing and publishing its recommendations on the adoption of Resilient PNT in the UK, the Advisory Group since its formation has looked at the role of Low Earth Orbit (LEO) satellites for delivering PNT services,  is involved in work to assess the need for a dedicated UK PNT Innovation Institute and national test framework, and is assessing the impact of new PNT technologies such as Quantum and AI. The PAG also will continue working with the Ministry of Defence on the use of PNT in defence, and ways to improve, nurture and grow the UK skills base.  

“Multi-faceted Endeavour”

John Pottle, Director of the Royal Institute of Navigation, commented that the very welcome announcement by the government recognised that achieving greater PNT resilience was a multi-faceted endeavour. The ownership provided by the National PNT Office would provide policy and delivery oversight, and co-ordination across all stakeholders.    

As well as improving national preparedness, the PNT framework has potential to help further strengthen the UK’s thought leadership and innovation in robust and resilient PNT.   

Andy Proctor, Chair of the RIN PNT Advisory Group also welcomed the government’s announcement of the ten- point plan for a resilient PNT framework for the UK and said 
“The announcement of the measures and recommendations set out in the framework are a welcome step forward in addressing the vulnerabilities due to the UK’s dependency on satellite-based PNT, particularly GNSS. GNSS supports around £320 billion (15%)* of UK GDP, improving the UK’s PNT robustness, security and resilience will be key to mitigating vulnerabilities to the loss of satellite-based PNT, and to capture the significant growth opportunities that the framework could enable.”

 

Challenges ahead

Recent world events are reinforcing the need for improved PNT robustness, security, and resilience across critical applications and national infrastructure – but the road ahead to implement the framework will not be without bumps – the UK is rapidly approaching its next General Election and whilst the National PNT Office will be working very hard to develop more detailed costed plans for the framework, there are bound to be some uncertainties and delays in moving the plans forward. The RIN has a strong role to play in providing government with a source of knowledge, expertise, and support that it can rely on whilst it tackles more challenging task of making the framework a reality. 

As a learned society, the RIN brings a well-balanced voice to the task of raising awareness of PNT security and the need for responsible use of PNT more generally across society.

If you are interested in becoming a contributor to the RIN PAG work being planned for 2024, please contact either Andy Proctor (PAG Chair), Guy Buesnel (PAG Secretary) or Clare Stead (RIN Communications and Events Manager ) in the first instance.

* According to the 2022 UKSA Size and Health of the UK Space Industry Study

In our inaugural event on the 1st November we hosted around 100 senior Positioning, Navigation and Timing (PNT) leaders from across industry, academia and government at the Royal Society to discuss where PNT is in the UK, where the group thought it needed to be and how to get there. The meeting was held under Chatham House rules. 

A primary keynote was given keynote on the economic benefits of resilient PNT to the UK. This reflected a hypothesis that ‘the UK can generate value and sustainable leadership from investing in resilient PNT, benefiting government, academia, industry and, ultimately, individuals.’ The London Economics concept paper that this is based on, which can be downloaded HERE, notes that the UK has significant economic value at risk to even a temporary outage of GNSS, with the road transport, emergency, and justice services, and maritime found to be most precariously positioned. 

The London Economics paper continues to assess that major critical infrastructure sectors across the economy remain insufficiently prepared to face the consequences of outages or disruption to satellite-derived time and position, and that backup systems mitigate against the economic value risk. 

 

Some of the key messages and points made include: 
• the ability to monetise PNT services is a challenge when competing against “free”¹  with GPS. 
• The role, if any, for better use of legislation, regulation, and standards in resilient PNT – this requires systems thinking and a market focus, moving away from silos that sometimes we fall into.
• The afternoon panel discussed the important point of careers and heard from all panellists about the need to create skills and career pathways from academia [including further education, not just universities] into industry and then structure for CPD. 
• Overall, a strong call for co-ordinated action, led by government, on skills to have a greater focus that has been given thus far. It was recognised that individuals will invest their own careers in sectors with high growth and consistent investment. A strong strategy and programme for PNT in the UK would provide impetus and confidence for investment across the ecosystem, arguably reducing government’s own commitment required as well as reducing risks for all stakeholders. 
• There was a clear wish for collaboration, particularly on governance and skills. There was a recognition that a range of short, medium and longer term actions will be needed. There was a strong call for RIN to be more proactive, and support for RIN taking leading roles in these areas.  

 

What therefore is the role of the RIN in PNT going forward? 

 

The RIN is a learned society and as such is very well-placed addressing long term thinking, strategies and providing input to setting goals with Government. There was a call for the RIN to be the voice of PNT and Resilient PNT in the UK which means not only “helping Government walk backwards over the bridge” but in building the bridge in the first place! The call for RIN to take a proactive and leading role in this way received wide and universal support. 

The PNT Advisory Group (PNTAG), a special interest group under the Technical Committee, was warmly welcomed as the place to coalesce the UK’s PNT thoughts and directions but on the condition that it does something and not becomes a YATS (Yet Another Talking Shop). To that end I, in my summing up showed the PNTAG’s plan of action: 

 

The immediate task for the PNTAG is to update this workplan² to reflect the outcomes from the event and the community input. 

Next will be to act on the plan and show that the RIN can deliver on leadership, long term thinking, support our colleagues in Government and to provide advice/guidance to the sector. We agreed we will plan to hold a repeat event around the same time next year where we will track progress – holding ourselves to account! The enthusiasm in the room on the day certainly gave me confidence that the plan is achievable. 

To summarise and to channel one of the speakers’ comments a little, the takeaway for me is that for PNT in the UK, we have all the ingredients of success and growth, but need the recipe and hunger to cook the meal.  

Our job is to pull the recipe for resilient PNT together and create the hunger for its implementation.

I would like to end with a call offers to contribute to the various work streams – please do get in touch with me if you are able to support this work.

Andy Proctor, MA CEng, FRIN, FIET
Chair, RIN PNT Advisory Group

[1] I know implementing GNSS services is not strictly free, but GPS is free to access, which is what I mean.

[2] If any readers would like information on any of the workstreams, I would be pleased to receive questions. (andy.proctor@rethinkpnt.com)

 

On 10th June 2020, Dr Ramsey Faragher presented a webinar on a new method for processing GNSS radio signals called Supercorrelation. There were so many questions during the webinar that we couldn't get to everything in the time we had so Ramsey has kindly answered the remaining questions for us below. If you didn't catch the webinar at the time you can watch it back here and then read the Q&A below.

 

Does supercorrelation help with low signal situations? I mean help with getting a lock in low-signal situations (only reflections available) as opposed to getting a very precise position when line of sight signal is available.

There are two parts to answering this question:
1. Supercorrelation boosts sensitivity by around 7-20dB depending on the existing capabilities and performance of the receiver that the technology is going into. We are able to confidently track signals right down to 4dBHz with a 1-second-long Supercorrelation. The longest Supercorrelators we have tested with real data were 5 seconds long. The boost in sensitivity can often allow a weak and obstructed line of sight signal to be found, even if it was not apparently present according to a standard receiver.
2. Since the question specifically states “only reflections available” I will clarify that if all of the signals detected are reflected and no LOS are available then standard Supercorrelation will not see those reflected signals at all if they are coming into the antenna from a direction that does not correspond to the location of the satellite in the sky. However performing a Skyscan reveals where all the energy is coming from, and allows you to still make use of the measurements from those reflected paths if you have the means to do so. For example you could match them to buildings around you if you have a 3D building model, and then employ shadow matching or 3DMA. If low-accuracy positioning is acceptable for the use case (e.g. confirming location indoors to simply update a weather report on a smartphone) then weak non-line of sight signals can still be used, and the receiver would be able to warn that the positioning accuracy is being limited by the use of non-line-of-sight signals.



What are the input parameters to generate the skyscan energy maps?

Skyscans are created using a bank of Supercorrelators, each tuned to couple strongly to energy coming from different azimuths and elevations. So you are solving the same problems that are described in the talk for creating a Supercorrelator, but for a whole range of possible positions for the satellite across the sky.

When will we see this in nav Receivers on ships?

We are engaged with a number of GNSS hardware manufacturers and OEMs to bring the benefits of our technology to their customers as quickly as possible. Please ask your current GNSS receiver manufacturer to let you know their current level of progress in integrating our technology into their chipset.

 

When will we see in likes of iPhone?

FocalPoint are currently working with a number of major smartphone chipset providers and handset manufacturers. We are hoping to see smartphone deployments of S-GNSS within the next 2-3 years depending on the different chipset cycles between different manufacturers. Apple acquired the Intel GNSS chipset at the end of 2019 so they did very recently become a company that can directly deploy S-GNSS technology themselves directly.

 

Is there any limitation for the supercorrelation, especially in some very poor skywindow like the urban area in Hong kong

The key requirement for Supercorrelation to function is that the receiver’s antenna must be moving through space. The minimum speed requirement is a function of the desired length of the Supercorrelator, but for our usual settings, the minimum speed required is 5cm per second, which is roughly 20x slower than walking pace.

Thank you Dr. Ramsey for the presentation, very exciting. Question about latency : what is the net effect on latency compared to conventional GNSS of longer correlation period and improved accuracy of Supercorrelation?

The current latency is 0.5 seconds for our typical settings. However in our next generation of the Supercorrelator we expect to bring this down to a few milliseconds. Note also that the latency in the position estimate for existing smartphone receivers is typically about 1 second, because they typically average together about a second’s worth of GPS measurements before providing an output to the user in an attempt to reduce errors in the navigation solution. Such averaging is not required for Supercorrelation.

In a mobile phone the clock source will not be perfectly stable due to the thermal dynamics, how does this affect super correlation over 1sec

Yes we have seen great variations in the performance of smartphone oscillators. Not just from thermal dynamics but from other unpredictable factors. In some smartphones we have tested our technology on there can be regular discontinuous jumps of 100Hz or more. We had to develop specific clock modelling and signal processing techniques to account for these problems, including what we call the Ultracorrelator, which we did not have time to cover in the talk, but the patent is in the public domain if you would like to read how that works.

Hi Ramsey. Thanks for a very clear description. Do you have a rough estimate in MIPS (or similar) of the added processing needs. I am aware that we already use a huge amount in multipath mitigation, so I am looking for the difference between S-GPS and what we save from the conventional

Yes we have a variety of tools to answer this question for each chipset company, as they all have different existing capabilities before we add in our technology. In the best cases we can actually reduce the overall processing load because of the existing code and overhead that can be removed once Supercorrelation is added. For more thorough information about your chipset in particular please do get in touch.

Delighted that FPP have been given the DofE Award! My question is whether super correlation can be switched on/off by the user?

It is unlikely that this will be a user selectable option, but it is possible in principle.

Could the same method by applied to MMS GNSS receiver?

Supercorrelation can be applied to the ranging signals of all GNSSS, on all frequencies. It could also be applied to many terrestrial radio signals too.

How does the supercorrelation differ from autocorrelation?

Autocorrelation refers to when you correlate a signal with itself, in order to study particular properties of that signal. The supercorrelation process involves changing the correlator sequence stored locally to account for a set of error sources in order to provide a better estimate of the incoming radio signal from the satellite than you get by simply using the textbook description of what has been broadcast.

When do you expect this to become available in a product for the mass market?

FocalPoint are currently working with a number of major smartphone chipset providers and handset manufacturers. We are hoping to see smartphone deployments of S-GNSS within the next 2-3 years depending on the different chipset cycles between different manufacturers.