The Conjecture around GNSS Reliability Is Being Realized
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NEWS
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A Global Navigation Satellite Systems (GNSS) is a key piece of global infrastructure crucial for the operation of trade, logistics, transport, and timing services, or Position Navigation Timing (PNT) and even short outages can cause billions of dollars in economic damage. Infrequent occurrences of GNSS outages have happened in the past due to either technical issues, such as the 6-day interruption to Galileo in 2019, or astronomical events, including solar storms disrupting Starlink satellites in February 2022. Recent issues concerning Ukraine have renewed concerns and evidenced the impact of targeted GNSS disruptions, with European airlines reporting partial or total lack of GNSS signals around Ukraine.
What Technologies Are Available for Reliable PNT?
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IMPACT
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Multiple global organizations have begun and undergone investigations into resilient PNT solutions; in its 2022 Market Report, the European Space Agency (ESA) identifies the necessity for resilient PNT, especially for aviation and drone applications. There have been significant investigations from the U.S. Department of Transportation (DOT), published in 2021, and the European Union (EU), which presented its findings in May 2022, and efforts from the UK Space Agency and Ministry of Defense have led to £2 million in PNT grants. Further tests are ongoing and have branched out from space and transport investigation into the military domain, including activity from the U.S. Department of Defense, aiming to both detect and accommodate for GNSS disruptions, and the European Defense Agency kicking off a project in May 2022, citing the necessity of GNSS in military operation control.
The result is increasing awareness of the wider location ecosystem containing many technological solutions for supplementing GNSS functionality with wide-ranging coverage and competitive positioning performance. At its core, alongside supplementing GNSS, there are many applications for location, forcing location technology to evolve beyond where GNSS is viable, such as low-power, low-complexity Internet of Things (IoT), as GNSS can be too power hungry or be hindered in indoor locations where the high-frequency GNSS signals are unable to penetrate.
One of the leading ideas is the use of Low Earth Orbit (LEO) satellites versus GNSS constellations, as LEO satellites orbit the Earth much closer and much faster, and can be populated in much larger constellations. Although a novel technology, LEO satellites can broadcast signals at higher (1,000X) power compared to GNSS solutions with the added ability of compensating for line-of-sight issues and possibly Three-Dimensional (3D) location. This approach has attracted increased interest with companies like SpaceX, OneWeb, and Hanwha in the process of deploying constellations. Other investigated solutions include network-based PNT over wired telecommunication systems, such as that from OPNT, which focuses on precise time synchronization, older LEO solutions, such as those from Iridium and Globalstar, and short-range signal solutions, such as Humatics’ Ultra-Wideband (UWB) solution, and Wi-Fi positioning from Skyhook.
Both Industry Expectations and Government Mandates Will Lead to New Opportunities
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RECOMMENDATIONS
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While promising, LEO Internet solutions are in their infancy and both enterprises and governments will want to opt for more reliable and ready-to-deploy solutions when it comes to resilient PNT. The U.S. DOT highlights the use of the Globalstar LEO constellation designed for satellite and low data communication, which has been available since 1998. Echo Ridge offers positioning based on the Time-on-Arrival (ToA) of available Globalstar signals and Apple recently announced that the iPhone 14 will be able to leverage the Globalstar satellite for emergency response. Terrestrial solutions and established infrastructure are emphasizing the availability of the technology and reliability. The location capabilities provided by existing networks, such as cellular and 5G or IoT-focused Low Power Wide Area Networks (LP-WANs) like LoRa and Sigfox, offer wide coverage location independent of GNSS and at lower power levels.
The fractured location ecosystem has produced a number of unique solutions as well. NextNav’s terrestrial solution, for example, places transmitters around dense urban areas to supply GNSS-like location signals to nearby devices, which can also provide support for elevation and indoor location. Skyhook’s solution can provide consistent location through only Wi-Fi ranging and, even further still, cloud-based positioning solutions can provide location without many of the security risks associated with device-side location, such as GNSS.
ABI Research anticipates government mandates and legal requirements to create the need for location solutions and services previously not required. Precedence can be seen in the increased need for emergency response, lone worker safety, and even social distancing solutions pushing innovation. With the emergence of newer, more powerful location technologies, solution providers looking to branch into the resilient PNT space should focus on reliability and availability, while trying to address areas where they can supplement GNSS. Hybrid solutions are increasingly popular in consumer and enterprise use cases in order to compound availability and accuracy. Heavy multipath environments, such as urban canyons and indoors, are key areas where GNSS struggles, so resilient PNT solutions should aim to address these issues.