Position, Navigation & Timing
The benefits of Satellite Position, Navigation & Timing (PNT) to the UK economy
Timing signals from space are an essential component of systems that enable our everyday lives. Most people will identify the importance of satellite navigation, knowing our location on Earth, speed, and direction of travel, all through a small sensor that can be embedded in our personal technology, such as watches, mobile phones or even cars. Less people will recognise their reliance on satellite timing for their energy, banking, mobile networks and emergency services. GPS was a military technology, opened up to the world by the US, and remains essential for defence. Today low-cost single-chip GNSS1 receivers are pervading almost all of our technology, driven by very low size, power and cost, meaning it is often more a question of why you would not, rather than why you should, incorporate this capability. As a result, satellite technology is being widely and deeply embedded in almost all systems, to the point where we not only expect to know accurately the time and our position on demand, but that technology all around us is expected to know this also (see Internet of Things).
The US system, known as GPS, and the European system, named Galileo, cost billions to build and hundreds of millions per year to operate. However, a June 2019 NIST2 sponsored report estimated GPS to have generated $1.4 trillion in economic benefits since it was made available for civilian and commercial use in the 1980s, with the vast majority seen in the last 10 years. A 2017 London Economics report estimated the economic impact to the UK of a five-day disruption to GNSS at £5.2bn and the Size & Health of the UK Space Industry 2020 study estimated GNSS to support 14.7% of UK GDP.
Space-based PNT is part of a system of systems, including terrestrial networks and sensors, from which we derive accurate PNT information. Financial institutions and network operators often add cost-effective resilience (e.g. local oscillators) to maintain operations during a few days outage. However, the accuracy and ubiquity provided by signals from space at such low cost to the user often make it prime choice.
There are many applications of precision timing from space, and position and navigation using space-based signals. Precision timing is essential in much of our Critical National Infrastructure (CNI). Telecommunications networks rely on it for synchronising traffic, initialisation and handoff of calls, billing and more. Mobile network operators synchronise their networks using a mix of technologies, often with a reliance on space-based timing outside of the core network, where space-based PNT provides a ubiquitous low-cost time reference. Increasing timing precision can enable wireless networks to efficiently manage spectrum, increasing user numbers and connectivity speeds. Using these timing signals to pinpoint our precise position on Earth, along with our speed and direction of travel, all through a chip measuring mm’s across, which enable this vast number of applications in the modern world. When we combine navigation and telecom capability, devices are connected to communications networks, we can share and track locations of connected entities, as well as navigate using real-time information. This is essential for maintaining the global logistics and supply chain networks of today.
Did you know?
The US built the first GNSS, known as GPS. Systems have since been built by Russia (GLONASS), China (BeiDou) and the European Union (Galileo), with regional systems developed by US (WAAS), Europe (EGNOS), India (NavIC) and Japan (QZSS), to be added to by Korea and Australia. Most receivers are designed to use a combination of signals from different systems to improve accuracy, availability and resilience. This can provide accuracies down to cm and even mm in some cases. PNT in our devices, such as our mobile phones, is supported by many other systems than just satellite, which together can provide down to below cm accuracy.
A GPS receiver chip can cost less than £1 and provide within a few metres accuracy. A multi-GNSS multi-band receiver costing in the order of £200 can use signals from multiple constellations and different frequencies to provide within a few centimetres accuracy. More sophisticated receivers, with enhanced security, can be more than 5x this cost. The civilian GNSS service is provided free of charge. Free authentication services for civilian users of Galileo (OS-NMA) and GPS (Chimera) are being deployed, which will work to limit spoofing/deception and increase resilience to cyber-attack.
PNT services are provided through a system of systems, where satellites form one of those systems. Development of satellite and terrestrial systems will lead to greater precision, increased security and resilience, and ubiquity of PNT. More and more ‘things’ will use PNT, more and more services will rely on PNT infrastructure, and society will be significantly more dependent on PNT. Transport and logistics networks will be automated, with accurate 3D positioning and navigation enabling aircraft, drones, vessels, vehicles to manoeuvre safely and efficiently from place to place. Extreme precision timing will enable seamless management of energy and telecom networks, and close proximity operations. Every object on the planet will be instantly accessible through a precise digital twin.