# GNSS Published articles for GNSS. This is one page of public article previews, not the complete archive. Follow Next page to continue. Summaries are not the original full articles. ## The invisible heartbeat of our networks DevFeed: [The invisible heartbeat of our networks]() Original publisher: [Read original article]() Author: Luca Cicchelli Published: 2026-08-31T23:03:47Z Content type: article Language: en Sources: [APNIC Blog]() Topics: [Networks](), [distributed-systems](), [Critical Infrastructure](), [Security](), [5G](), [Cybersecurity](), [cloud-infrastructure](), [AI Infrastructure]() Tags: [5g](), [ai](), [ai-infrastructure](), [critical-infrastructure](), [cybersecurity](), [data](), [distributed-systems](), [engineering](), [gnss](), [gps](), [guest-post](), [hardware](), [network](), [networking](), [networks](), [outage](), [outages](), [post](), [servers](), [systems](), [tech-matters](), [time](), [transactions]() ### AI overview The article examines how accurate time synchronization underpins modern networks and distributed systems. It uses the Telstra outage to show how misaligned time servers can disrupt communications and rail services, and discusses resilient time sources, terrestrial backups, local atomic clocks, and synchronization requirements for finance, 5G, cloud, and AI infrastructure. ### Source excerpt Guest Post: The recent Telstra outage highlighted a critical but often overlooked dependency in modern networks: Accurate time synchronization. ## Time: The cornerstone of digital sovereignty and independence DevFeed: [Time: The cornerstone of digital sovereignty and independence]() Original publisher: [Read original article]() Author: Luca Cicchelli Published: 2026-08-18T01:45:10Z Content type: article Language: en Sources: [APNIC Blog]() Topics: [digital sovereignty](), [systems](), [1.1.1.1](), [spoofing](), [Cybersecurity](), [5G](), [Cloud](), [Artificial Intelligence]() Tags: [5g](), [ai](), [cloud](), [cybersecurity](), [digital-sovereignty](), [energy](), [gnss](), [guest-post](), [ixps](), [operational](), [spoofing](), [systems](), [tech-matters](), [time]() ### AI overview Time is presented as a foundational requirement for digital sovereignty and independent operation. The article explains how synchronized time supports telecommunications, finance, energy, cloud and AI systems, and transport, while dependence on GNSS introduces risks from interference, jamming, and spoofing. ### Source excerpt Guest Post: Though often overlooked, time underpins telecommunications, finance, energy, cloud, AI, and transport systems. As dependence on GNSS increases, organizations need resilient, traceable time sources to strengthen cybersecurity, improve operational continuity, and support digital sovereignty. ## Galileo Testing Exposed Communication and Reliability Concerns DevFeed: [Galileo Testing Exposed Communication and Reliability Concerns]() Original publisher: [Read original article]() Published: 2025-05-28T11:50:00Z Content type: opinion Language: en Sources: [Bert Hubert's writings]() Topics: [reliability](), [communications](), [navigation](), [digital]() Tags: [communication](), [digital-autonomy](), [gnss](), [infrastructure](), [navigation](), [partner](), [reliability]() ### AI overview The article argues that Galileo is important independent European navigation infrastructure but criticizes the EU and EUSPA for poor communication about service testing and disruptions. It describes outdated data being transmitted during a test and says the lack of explanation confused professional users. ### Source excerpt When Galileo (the European satellite navigation system) was proposed there was a lot of criticism. "We already have the US GPS", and we'd always be able to rely on our historical partner to take care of us. The US very much also said this. Yet, the EU persevered and now we have an independent worldwide navigation capability. And given recent developments, I think we can be well pleased that we don't have to rely on the US, China or Russia for this vital need! ## Improved Galileo Time to First Fix DevFeed: [Improved Galileo Time to First Fix]() Original publisher: [Read original article]() Published: 2022-09-07T10:47:39Z Content type: article Language: en Sources: [Bert Hubert's writings]() Topics: [navigation](), [realtime](), [Resilience](), [communications]() Tags: [cloud](), [communications](), [devices](), [gnss](), [gps](), [navigation](), [realtime](), [resilience]() ### AI overview This article explains how new Galileo features can help supported devices obtain a position and time fix faster and more robustly. The features are especially useful for unconnected devices, can improve resilience during communication disruptions, and may speed time synchronization on connected devices. ### Source excerpt In the world of Global Navigation Satellite Systems (GNSS), change tends to happen very slowly and cautiously. It is therefore quite exciting how many new features Galileo, the "European GPS" has been rolling out lately. Earlier I wrote a little bit about the High Accuracy Service (HAS), whereby the Galileo satellites themselves provide properly equipped receivers (not your phone) with near-realtime updates that can be used to achieve very good accuracy. ## MCH2022: DNA and GPS/Galileo/GNSS Talks DevFeed: [MCH2022: DNA and GPS/Galileo/GNSS Talks]() Original publisher: [Read original article]() Published: 2022-07-27T11:41:11Z Content type: article Language: en Sources: [Bert Hubert's writings]() Topics: [navigation](), [Hacking]() Tags: [biology](), [dna](), [event](), [gnss](), [gps](), [talks](), [video]() ### AI overview A personal recap of MCH2022, a large Dutch hacker community campsite event, featuring two talks: one introducing DNA and genome editing, and another explaining GPS, Galileo, BeiDou, GLONASS, and the galmon.eu satellite-monitoring project. ### Source excerpt (scroll down for my two talks if you are in a hurry) As I write this I'm suffering from severe post-camp blues. Every four years the Dutch hacker community organizes a stupendously large multi-day campsite event, with ample international help. To a large extent, "everyone" is there. And this time, like every time, people who originally decided they could not make it.. show up by day two. Because the pull is just too strong. ## Leap Seconds and GNSS Time Offsets DevFeed: [Leap Seconds and GNSS Time Offsets]() Original publisher: [Read original article]() Published: 2021-08-03T08:03:10Z Content type: article Language: en Sources: [Bert Hubert's writings]() Topics: [systems](), [navigation]() Tags: [gnss](), [timing](), [utc]() ### AI overview The article explains how GNSS systems handle leap seconds. GPS, Galileo, and BeiDou use continuous monotonic timescales and broadcast their offsets from UTC so receivers can derive UTC accurately. ### Source excerpt Leap seconds are controversial things. Since the Earth does not rotate at a steady rate, over time the Earth could get ahead or behind "atomic time". Whatever solution you propose for this, someone is going to be unhappy. I take no position on what the best thing to do is here, except that one day I would like to do the math on the "great leap second gyroscopes" that we could mount near the poles to steady the Earth's rotation, so we can stop talking about this. ## GNSS Jamming and Spoofing, aka Galileo's Authentication Algorithm Part 3 DevFeed: [GNSS Jamming and Spoofing, aka Galileo's Authentication Algorithm Part 3]() Original publisher: [Read original article]() Published: 2020-09-13T09:49:53Z Content type: tutorial Language: en Sources: [Bert Hubert's writings]() Topics: [spoofing](), [Authentication](), [Protocol (disambiguation)](), [navigation](), [Resilience]() Tags: [aviation](), [gnss](), [gps](), [navigation](), [protocol](), [resilience](), [spoofing]() ### AI overview Part 3 of a series on OSNMA, the proposed Galileo Navigation Message Authentication protocol, explaining GNSS jamming and spoofing, the threat model, and related detection and mitigation concerns. ### Source excerpt Welcome to part 3 of my series on OSNMA, the proposed Galileo Navigation Message Authentication protocol. This part can be read independently from part 1 and part 2, but it might be useful to read the introduction to part 1. This post attempts to explain GPS (GNSS) jamming and spoofing, so it might be a useful read even if you don't care about Galileo or its authentication. As usual, I've been helped tremendously by Daniel Estévez & many other researchers and Galileo professionals, and again I am very greatful for all the links, corrections, suggestions and knowledge you provided. ## Galileo's Proposed Authentication Algorithm: Part 2 DevFeed: [Galileo's Proposed Authentication Algorithm: Part 2]() Original publisher: [Read original article]() Published: 2020-08-26T08:43:09Z Content type: article Language: en Sources: [Bert Hubert's writings]() Topics: [Cryptography](), [Authentication](), [Encryption](), [public key](), [Protocol (disambiguation)](), [navigation]() Tags: [authentication](), [cryptographic](), [cryptography](), [encryption](), [gnss](), [navigation](), [protocol](), [public-key]() ### AI overview This second part explains how Galileo OSNMA uses delayed disclosure of symmetric cryptographic keys to let receivers verify earlier navigation-message signatures. It also discusses how the protocol fits authentication data into Galileo page and subframe structures. ### Source excerpt Recapping from part 1: Galileo will soon add cryptographic signatures to the navigation messages. These cryptographic signatures are made with symmetric cryptography, which means clever techniques are required to prevent receivers from impersonating the network. The key to the technique is first signing messages, and only later disclosing the key used for the signatures, thus invalidating it for further use. Receivers can however verify that earlier signatures were indeed made with that key. ## Galileo's Proposed Authentication Algorithm: Part 1 DevFeed: [Galileo's Proposed Authentication Algorithm: Part 1]() Original publisher: [Read original article]() Published: 2020-08-13T18:50:09Z Content type: article Language: en Sources: [Bert Hubert's writings]() Topics: [Cryptography](), [Security, Privacy and Abuse Prevention](), [integrity](), [Provable security](), [Network]() Tags: [cryptography](), [gnss](), [receiver](), [rf](), [series](), [spoofing]() ### AI overview This first part of a series explains Galileo's proposed Open Service Navigation Message Authentication (OSNMA), focusing on the TESLA cryptographic scheme and its role in improving trust in GNSS messages. It notes that message authentication cannot by itself prevent sophisticated RF spoofing, but is an important step toward detecting unauthenticated or altered data. ### Source excerpt Position, velocity and time (PVT) information can be a 'nice to have', but in other circumstances knowing place and time has legal or military importance as well. Heavy vehicles for example are typically outfitted with tachographs that track driver speed and/or location. This has importance for rest regulations, but also to check if loads are actually from where they say they are. Our Global Navigation Satellite Systems so far are broadcasting unauthenticated data, at least to civilian users. ## Multi-Signal GNSS & the Curious Case of Galileo E24: Part 1 DevFeed: [Multi-Signal GNSS & the Curious Case of Galileo E24: Part 1]() Original publisher: [Read original article]() Published: 2020-07-18T07:07:23Z Content type: article Language: en Sources: [Bert Hubert's writings]() Topics: [systems]() Tags: [engineering](), [equipment](), [gnss](), [phones](), [signal](), [standard]() ### AI overview This article investigates why Galileo satellite E24 was reported as being 1.5 meters off while phones and other positioning equipment showed no problems. It introduces multi-frequency GNSS and explains how ionospheric delays affect satellite-distance measurements. ### Source excerpt GPS, GLONASS, Galileo, BeiDou (Global Navigational Satellite Systems, GNSS) are miracles of engineering. And within any complex system hide surprises and unsuspected complications. In this post I go over how we resolved an odd observation: that everyone (including major institutions) reported that one of the Galileo satellites (E24) appeared to be off by 1.5 meters, while actual positioning equipment (like phones) showed no problems at all. Through the explanation, we'll casually learn a thing or two about the cool concept of multi-frequency GNSS. ## Review of the Uputronics GPS/RTC Raspberry Pi Expansion Board DevFeed: [Review of the Uputronics GPS/RTC Raspberry Pi Expansion Board]() Original publisher: [Read original article]() Published: 2020-07-09T11:38:00Z Content type: comparison Language: en Sources: [Bert Hubert's writings]() Topics: [Raspberry Pi](), [Hardware](), [Monitoring]() Tags: [configuration](), [gnss](), [measurements](), [pi-4](), [raspberry-pi](), [receiver](), [review](), [timing]() ### AI overview A review of Uputronics' GPS/RTC Raspberry Pi Expansion Board, tested with the galmon.eu GNSS monitoring project. The board uses a u-blox M8 timing receiver, provides raw GNSS and correlator data, and offers a stable clock signal. The review also covers antenna performance, Raspberry Pi 4 configuration, UART communication, and baud-rate considerations. ### Source excerpt Hi everyone, Disclaimer: this is a review of a free sample I got sent by Uputronics. I recently spotted on Twitter that Uputronics had launched a GPS/RTS Raspberry Pi Expansion Board, and that they were looking for worthy projects to test it. I thought our Galileo/GPS/BeiDou/GLONASS monitoring project galmon.eu might be worthy and Uputronics agreed. Relevant for our purposes, this is an actual 'timing receiver'. Any GNSS chip will get you a location, but some of them go the extra mile to also deliver a very stable clock signal. ## The new Galmon.eu Weekly Galileo Report DevFeed: [The new Galmon.eu Weekly Galileo Report]() Original publisher: [Read original article]() Published: 2020-07-07T09:54:59Z Content type: article Language: en Sources: [Bert Hubert's writings]() Topics: [Monitoring](), [data](), [Open Data](), [realtime]() Tags: [blog-post](), [data](), [gnss](), [gps](), [performance](), [realtime](), [report](), [thread](), [weekly]() ### AI overview The post announces the Galmon.eu unofficial Weekly Galileo Report, a public account of Galileo's performance. It explains that the report uses a worldwide GNSS monitoring platform and open data sources to provide near-real-time visibility into the European navigation system. ### Source excerpt I have a longer story brewing, but in this post I want to briefly announce the "Galmon.eu unofficial Weekly Performance Report". This is a blog post version of an earlier Twitter thread. I'm very proud to present the first full Galmon.eu Weekly Galileo Report! And the good news is: it was a good week with very little to report. The email has just gone out, but you can also find it here. ## The Galmon GNSS Monitoring Project DevFeed: [The Galmon GNSS Monitoring Project]() Original publisher: [Read original article]() Published: 2020-01-08T12:53:08Z Content type: article Language: en Sources: [Bert Hubert's writings]() Topics: [Monitoring](), [Open Data](), [Open Source]() Tags: [data](), [gnss](), [irc](), [monitoring](), [open-source](), [orbit](), [outages](), [space](), [web]() ### AI overview The Galmon project is an open source and open data monitoring network for major Global Navigation Satellite Systems and space-based augmentation systems. It collects satellite transmissions through a global network of stations and provides coverage maps, raw GNSS data, and automated updates about outages, satellite health, clock changes, and orbit discontinuities. ### Source excerpt Welcome to the Galmon project! Our goals are to monitor the major Global Navigation Satellite Systems, including GPS, GLONASS, Galileo and BeiDou, but also Space Base Augmentation Systems like WAAS, EGNOS and GAGAN. Galmon is an open source & open data project with a community of over 30 station operators running more than 50 receivers. Some history of the project may be found in the second part of this blog post, and on this page on the big Galileo 2019 outage. ## A 2019 update on PowerDNS, Galileo, DoH and other things DevFeed: [A 2019 update on PowerDNS, Galileo, DoH and other things]() Original publisher: [Read original article]() Published: 2020-01-01T14:37:52Z Content type: article Language: en Sources: [Bert Hubert's writings]() Topics: [powerdns](), [Internet](), [Programming]() Tags: [diary](), [dns](), [gnss](), [lua](), [powerdns](), [privacy](), [programming]() ### AI overview A 2019 professional update covering the author's work on PowerDNS, DNS over HTTPS, Galileo, and related community and advisory activities. The article also explains that the PowerDNS team had taken full responsibility for day-to-day management and technical decisions. ### Source excerpt Last year I wrote a post listing what I had been doing in 2018, because it turned out it was a lot, so much that it was useful to summarise it somewhat. This year there is less to report, but people have wondered what I've been up to. And I've learned that if you leave room for speculation about your intentions, wrong answers tend to come up. This (professional) year for me mostly consisted of two things: DNS over HTTPS and Galileo. ## The July Galileo Outage: What happened and why DevFeed: [The July Galileo Outage: What happened and why]() Original publisher: [Read original article]() Published: 2019-11-07T08:48:53Z Content type: article Language: en Sources: [Bert Hubert's writings]() Topics: [navigation](), [systems]() Tags: [atomic](), [clocks](), [gnss](), [orbit](), [outage](), [performance](), [precision](), [systems](), [technical-article](), [timing]() ### AI overview An excerpt examines the July Galileo outage, explaining how GNSS operation depends on accurately modeling satellite orbits and atomic clocks and distinguishing errors in satellite, clock, and ground timing data. ### Source excerpt By bert hubert / bert@hubertnet.nl This post is an excerpt of a far longer post on Galileo, its structures and the cause of the outage. Here we'll only focus on the outage - the potential underlying reasons behind it are described in the full article. Since the week-long outage in July I've been fascinated by Galileo and, together with a wonderful crew of developers, experts and receiver operators, have learned so much about what I now know are called 'Global Navigation Satellite Systems' or GNSS. ## Galileo Satellite Navigation Network: Status, Monitoring, and Observations from an Outsider DevFeed: [Galileo Satellite Navigation Network: Status, Monitoring, and Observations from an Outsider]() Original publisher: [Read original article]() Published: 2019-11-07T08:47:53Z Content type: opinion Language: en Sources: [Bert Hubert's writings]() Topics: [navigation](), [Network](), [Monitoring](), [Open Source]() Tags: [article](), [gnss](), [monitoring](), [navigation](), [network](), [open-source](), [opinion](), [receiver]() ### AI overview An outsider's personal assessment of the EU's Galileo Satellite Navigation Network, covering its operation, the July outage, and efforts to improve public understanding. The article also describes the galmon.eu open source monitoring project, which provides 24/7 coverage of Galileo and other global navigation satellite systems through dashboards and reports. ### Source excerpt By bert hubert / bert@hubertnet.nl In this post I want to document some mostly non-technical aspects of the EU's Galileo Satellite Navigation Network. I will also share some observations on how things are going, and perhaps how they could be improved. NOTE: A shorter version of this article, focusing only on the July outage, can be found here. Since the week-long outage in July I've been fascinated by Galileo and, together with a wonderful crew of developers, experts and receiver operators, have learned so much about what I now know are called 'Global Navigation Satellite Systems' or GNSS. ## GPS Lesson for 10-11 year olds DevFeed: [GPS Lesson for 10-11 year olds]() Original publisher: [Read original article]() Published: 2019-10-14T18:09:53Z Content type: tutorial Language: en Sources: [Bert Hubert's writings]() Topics: [navigation](), [context]() Tags: [education](), [gnss](), [gps](), [navigation](), [technical]() ### AI overview A practical write-up of a lesson for 10-11-year-old children explaining how GPS and satellite-based navigation work. It uses everyday phone location sharing and travel examples, along with sound, light, distance, maps, rulers, and compasses, to introduce positioning and encourage interest in technology. ### Source excerpt The Netherlands is struggling with a shortage of primary school teachers, which as a nice side effect means that I get ample opportunities to do technical propaganda in the name of education. This is a quick writeup of a lesson on how GPS (or in general, satellite based navigation) works. I'd like to thank Jasper Vos and Michel Dingen of OBS De Notenkraker for the opportunity & the very useful feedback on the lessons! ## GPS, Galileo & More: How do they work & what happened during the big outage? DevFeed: [GPS, Galileo & More: How do they work & what happened during the big outage?]() Original publisher: [Read original article]() Published: 2019-09-30T18:05:33Z Content type: article Language: en Sources: [Bert Hubert's writings]() Topics: [navigation](), [Monitoring](), [Open Source](), [GitHub](), [JSON]() Tags: [github](), [gnss](), [json](), [monitoring](), [navigation](), [open-source]() ### AI overview An explanatory article about how GPS, Galileo, GLONASS, and BeiDou navigation satellites determine position. It also documents the Galmon monitoring project, which publicly publishes satellite monitoring results and discusses the 2019 Galileo outage, while noting that the outage section includes the author's speculation. ### Source excerpt By bert hubert bert@hubertnet.nl / @bert_hu_bert / https://galmon.eu/ Late July 2019, Galileo, "the European GPS" suffered from a week long outage. I'm a proud European, and I think we should have our own well-functioning navigation system, so I tried to figure out what was going on. Surely someone was monitoring this stuff in public? I come from the internet where we monitor all the things, if someone asked for it or not. ## Beidou Satellites Misclassification DevFeed: [Beidou Satellites Misclassification]() Original publisher: [Read original article]() Published: 2019-09-02T06:37:13Z Content type: article Language: en Sources: [Bert Hubert's writings]() Topics: [Monitoring](), [Database]() Tags: [automated](), [gnss](), [gps](), [location](), [monitoring](), [orbit](), [space](), [speed]() ### AI overview The article describes GNSS monitoring with galmon and an automated process that matches satellite orbits to published TLE data. It reports that BeiDou satellite pairs C21/C22 and C25/C26 appear to be swapped, and that M11 and M12 may also be reversed pending verification. ### Source excerpt Hi everyone, As noted previously I've gone all in on GNSS monitoring. GNSS is the generic term for GPS, Galileo, GLONASS and BeiDou satellites. Eventually a big blog post will come out, but meanwhile you can see the results on galmon.eu. A few days ago, an unknown GLONASS satellite started transmitting signals on slot R26 and I tried to figure out which one it was. By definition, GNSS satellites broadcast their own very precise location & speed, which makes it possible to match up their orbit to published "TLEs", which document where objects in space are. ## Galileo Notes: Ephemeris, Anomalies, I/NAV, SFRBX DevFeed: [Galileo Notes: Ephemeris, Anomalies, I/NAV, SFRBX]() Original publisher: [Read original article]() Published: 2019-07-30T13:35:10Z Content type: article Language: en Sources: [Bert Hubert's writings]() Topics: [navigation](), [data](), [Protocol (disambiguation)](), [payload](), [interface]() Tags: [gnss](), [gps](), [payload](), [protocol](), [receiver](), [signal](), [usb](), [windows](), [wine]() ### AI overview This article presents working notes on receiving and interpreting data from the EU's Galileo Navigation Satellite System. It covers configuring a u-blox 8 receiver, enabling Galileo and relevant message formats, extracting raw I/NAV data from UBX-RXM-SFRBX messages, and understanding Galileo ephemeris parameters. ### Source excerpt I've recently been spending quite some time on the EU's Galileo Navigation Satellite System. In this post you'll find some rough notes on things I've found out, both about how to receive data & how to understand the Galileo ephemeris parameters. Feedback is very welcome on bert@hubertnet.nl or @bert_hu_bert! I'm no Galileo specialist, so I am sure this page could be better. Please also let me know if this page has been useful to you.