{"id":1787230,"date":"2019-04-05T11:44:57","date_gmt":"2019-04-05T15:44:57","guid":{"rendered":"https:\/\/www.maproomblog.com\/?p=1787230"},"modified":"2019-04-05T11:44:57","modified_gmt":"2019-04-05T15:44:57","slug":"happy-gps-week-rollover","status":"publish","type":"post","link":"https:\/\/www.maproomblog.com\/2019\/04\/happy-gps-week-rollover\/","title":{"rendered":"Happy GPS Week Rollover!"},"content":{"rendered":"

It’s probably overstating things to compare the GPS week rollover to the Y2K bug (The Next Web<\/em><\/a>, The Verge<\/em><\/a>) but it’s hard not to see some parallels. In each case, it’s a function of too little memory assigned to timestamps.<\/p>\n

One of the things that GPS satellites do is transmit precise timing information. It does this in part by stating the week as a 10-bit integer, counting from week one. That means the date number rolls over every 1,024 weeks. Every 19.7 years, then, the GPS week “rolls over” and a new GPS epoch begins. It’s already happened once: the GPS era started on 6 January 1980, and the first rollover occured in August 1999. The next one takes place\u2014oh dear\u2014tomorrow. Cue the mass hysteria.<\/p>\n

How will our GPS receivers respond to that rollover? Because it’s happened before, and because consumer GPS tech doesn’t necessarily stay in use for long periods of time, it’s unlikely that your or my GPS receivers are affected. Anything released in the past two decades would have programmed after the last rollover. Also, receivers might have have had an offset<\/a> to the 1,024-week limit programmed into their firmware, starting the clock from the date of compilation rather than August 1999, so devices affected may not be affected all at once. U.S. government agencies note<\/a> that GPS receivers that conform to the IS-GPS-200 specification should not be affected: PC Mag<\/em> pins that on devices manufactured in 2010 or later<\/a>.<\/p>\n

My own legacy GPS receivers\u2014a Garmin eTrex Legend H and an Oregon 450t\u2014date from just before 2010, and while I haven’t used them in years (when your smartphone has built-in GPS, dedicated receivers are superfluous in the most common use cases), I’m half tempted to fire them up and see what happens. Both TomTom<\/a> and Garmin<\/a> claim that the vast majority of their devices are unaffected, but neither go so far as to give us a list of affected devices. Firmware updates are apparently being issued for some of those affected devices\u2014but again, a list would help.<\/p>\n

In any event, it appears that using GPS for location<\/em>, even on an affected device, will not be broken: at worst your tracklogs will have inaccurate timestamps. Receivers that use GPS for accurate timekeeping that have not been updated to handle the rollover might run into some trouble, though. And, like Y2K, any problems might be in industrial or embedded systems rather than consumer tech\u2014and from what I’ve seen online they’ve been getting warnings about this for years.<\/p>\n

In other words, as far as I can tell, the GPS world will not come crashing down tomorrow.<\/p>\n","protected":false},"excerpt":{"rendered":"

It’s probably overstating things to compare the GPS week rollover to the Y2K bug (The Next Web, The Verge) but it’s hard not to see some parallels. In each case, it’s a function of too… More<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"autoblue_enabled":true,"autoblue_custom_message":"","autoblue_shares":[],"autoblue_post_url":"","_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[254],"tags":[1332],"class_list":["post-1787230","post","type-post","status-publish","format-standard","hentry","category-gps","tag-gps-rollover"],"jetpack_featured_media_url":"","jetpack-related-posts":[{"id":1788176,"url":"https:\/\/www.maproomblog.com\/2020\/01\/gps-glitch-grounds-gopro-drones\/","url_meta":{"origin":1787230,"position":0},"title":"GPS Glitch Grounds GoPro Drones","author":"Jonathan Crowe","date":"6 January 2020","format":"link","excerpt":"GoPro\u2019s Karma drone, released in October 2016 and discontinued in January 2018 (when GoPro announced it was getting out of the drone business), has apparently fallen prey to the GPS rollover bug: they\u2019ve been grounded since the new year. See coverage at DP Review, Engadget and The Verge, as well\u2026","rel":"","context":"In "GPS"","block_context":{"text":"GPS","link":"https:\/\/www.maproomblog.com\/category\/gps\/"},"img":{"alt_text":"GoPro Karma","src":"https:\/\/i0.wp.com\/www.maproomblog.com\/xq\/wp-content\/uploads\/2020\/01\/gopro-karma-300x164.jpg?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]},{"id":1809347,"url":"https:\/\/www.maproomblog.com\/2022\/10\/new-apple-watch-features-include-dual-frequency-gps-virtual-breadcrumbs\/","url_meta":{"origin":1787230,"position":1},"title":"New Apple Watch Features Include Dual-Frequency GPS, Virtual Breadcrumbs","author":"Jonathan Crowe","date":"12 October 2022","format":"link","excerpt":"Apple is touting the Apple Watch Ultra\u2019s dual-frequency GPS support, viz., it uses the GPS L5 band in addition to L1 to improve accuracy. The new L5 signal is higher power and is supposed to provide more robust service, but with only 17 satellites broadcasting on it it\u2019s not yet\u2026","rel":"","context":"In "GPS"","block_context":{"text":"GPS","link":"https:\/\/www.maproomblog.com\/category\/gps\/"},"img":{"alt_text":"Apple Watch Ultra","src":"https:\/\/i0.wp.com\/www.maproomblog.com\/xq\/wp-content\/uploads\/2022\/10\/apple-watch-ultra-compass-188x300.jpg?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]},{"id":1819334,"url":"https:\/\/www.maproomblog.com\/2023\/10\/gpsjam-maps-gps-interference\/","url_meta":{"origin":1787230,"position":2},"title":"GPSJam Maps GPS Interference","author":"Jonathan Crowe","date":"18 October 2023","format":"link","excerpt":"GPS Jam, created by John Wiseman, is an online map of GPS interference, updated daily, based on GPS accuracy information reported by aircraft. It\u2019s not necessarily a map of where GPS is being deliberately jammed, but when you look and see that the hotspots are the eastern Mediterranean, western Russia\u2026","rel":"","context":"In "GPS"","block_context":{"text":"GPS","link":"https:\/\/www.maproomblog.com\/category\/gps\/"},"img":{"alt_text":"Screenshot of GPSJam website","src":"https:\/\/i0.wp.com\/www.maproomblog.com\/xq\/wp-content\/uploads\/2023\/10\/gpsjam-screenshot-1024x576.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.maproomblog.com\/xq\/wp-content\/uploads\/2023\/10\/gpsjam-screenshot-1024x576.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/www.maproomblog.com\/xq\/wp-content\/uploads\/2023\/10\/gpsjam-screenshot-1024x576.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/www.maproomblog.com\/xq\/wp-content\/uploads\/2023\/10\/gpsjam-screenshot-1024x576.jpg?resize=700%2C400&ssl=1 2x"},"classes":[]},{"id":1844922,"url":"https:\/\/www.maproomblog.com\/2025\/09\/suspected-russian-gps-interference-affects-european-commission-presidents-plane\/","url_meta":{"origin":1787230,"position":3},"title":"Suspected Russian GPS Interference Affects European Commission President’s Plane","author":"Jonathan Crowe","date":"2 September 2025","format":"link","excerpt":"Russia is suspected of engaging in GPS jamming that disrupted the navigation systems of a plane carrying European Commission president Ursula von der Leyen on a flight to Plovdiv, Bulgaria: BBC News, The Guardian, Reuters. It\u2019s the latest incident in which Russia has been accused of jamming or spoofing GPS\u2026","rel":"","context":"In "GPS"","block_context":{"text":"GPS","link":"https:\/\/www.maproomblog.com\/category\/gps\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":1787444,"url":"https:\/\/www.maproomblog.com\/2019\/06\/the-economic-impact-of-gps-and-gps-outages\/","url_meta":{"origin":1787230,"position":4},"title":"The Economic Impact of GPS\u2014and GPS Outages","author":"Jonathan Crowe","date":"20 June 2019","format":"link","excerpt":"A new study quantifies the economic benefits of GPS: in the U.S. alone, it estimates around $1.4 trillion in economic activity resulting from private-sector GPS use, about half of that coming from improvements in the telecommunications sector. (Roughly a quarter came from the telematics sector, and 15 percent from location-based\u2026","rel":"","context":"In "Aviation"","block_context":{"text":"Aviation","link":"https:\/\/www.maproomblog.com\/category\/aviation\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.maproomblog.com\/xq\/wp-content\/uploads\/2019\/06\/faa-gps-outage-300x148.jpg?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]},{"id":1788156,"url":"https:\/\/www.maproomblog.com\/2019\/12\/gps-is-easy-to-disrupt-and-the-consequences-of-disruption-are-serious\/","url_meta":{"origin":1787230,"position":5},"title":"GPS Is Easy to Disrupt, and the Consequences of Disruption Are Serious","author":"Jonathan Crowe","date":"20 December 2019","format":"link","excerpt":"In an article in the December 2019 issue of\u00a0Scientific American, now available online, Paul Tullis looks at the problem of GPS hacking, or spoofing\u2014how easy it is to do, how vulnerable GPS is to it, and the consequences we\u2019d face if GPS was disrupted on a broad level. It\u2019s essential\u2026","rel":"","context":"In "GPS"","block_context":{"text":"GPS","link":"https:\/\/www.maproomblog.com\/category\/gps\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]}],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.maproomblog.com\/wp-json\/wp\/v2\/posts\/1787230","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.maproomblog.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.maproomblog.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.maproomblog.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.maproomblog.com\/wp-json\/wp\/v2\/comments?post=1787230"}],"version-history":[{"count":3,"href":"https:\/\/www.maproomblog.com\/wp-json\/wp\/v2\/posts\/1787230\/revisions"}],"predecessor-version":[{"id":1787236,"href":"https:\/\/www.maproomblog.com\/wp-json\/wp\/v2\/posts\/1787230\/revisions\/1787236"}],"wp:attachment":[{"href":"https:\/\/www.maproomblog.com\/wp-json\/wp\/v2\/media?parent=1787230"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.maproomblog.com\/wp-json\/wp\/v2\/categories?post=1787230"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.maproomblog.com\/wp-json\/wp\/v2\/tags?post=1787230"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}