GPS Rollover is today. Here’s why devices might get wacky

GPS Rollover is today. Here’s why devices might get wacky

4:41pm, 6th April, 2019
The Global Positioning System time epoch is ending and another one is beginning, an event that could affect your devices or any equipment or legacy system that relies on GPS for time and location. Most clocks obtain their time from Coordinated Universal Time (UTC). But the atomic clocks on satellites are set to GPS time. The timing signals you can get from GPS satellites are very accurate and globally available. And so they’re often used by systems as the primary source of time and frequency accuracy. When Global Positioning System was first implemented, time and date function was defined by a 10-bit number. So unlike the Gregorian calendar, which uses year, month and date format, the GPS date is a “week number,” or WN. The WN is transmitted as a 10-bit field in navigation messages and rolls over or resets to zero every 1,024 weeks. Since that time, the count has been incremented by one each week, and broadcast as part of the GPS message. The GPS week started January 6, 1980 and it became zero for the first time midnight August 21, 1999. At midnight April 6, the GPS WN is scheduled to reset, which could be problematic for legacy systems and impact time and the time tags in location data. Utilities and cellular networks also use GPs receivers for timing and controlling certain functions. For instance, the uses timestamps embedded in GPS. The U.S. Department of Energy says that “GPS supports a wide variety of critical grid functions that allow separate components on the electric system to work in unison.” It should be noted that the WN restart date could be different in some devices, depending on when the firmware was created. The bug, which some has described as the Y2K of GPS, will cause problems in some GPS receivers such as resetting the time and corrupting location data. The GPS WN rollover event may hurt the reliability of the reported UTC, according to U.S. Department of Homeland Security. HDS said an GPS device that conforms to the latest IS-GPS-200 and provides UTC should not be adversely affected. The agency also provided a word of caution: However, tests of some GPS devices revealed that not all manufacturer implementations correctly handle the April 6, 2019 WN rollover. Additionally, some manufacturer implementations interpret the WN parameter relative to a date other than January 5, 1980. These devices should not be affected by the WN rollover on April 6, 2019 but may experience a similar rollover event at a future date. If you own a newer commercial device with updated software, it’s most likely fine. But double check and make sure the software is up-to-date. The U.S. Naval Observatory suggests contact the manufacturer of your GPS receiver if you have been effected by the GPS week number rollover. Some GPS receiver manufacturers can be found at the website. Work has been done to avoid this kind of rollover issue — or at least punt it down the line. The modernized GPS navigation message uses a 13-bit field that repeats every 8,192 weeks.
Watch OneWeb’s first six global internet satellites launch today

Watch OneWeb’s first six global internet satellites launch today

3:19pm, 27th February, 2019
After four years and more than $2 billion in funding, is ready to launch the first six satellites out of a planned constellation of 650 with which it plans to blanket the world in broadband. The Arianespace-operated Soyuz rocket will take off at 1:37 Pacific time from Guiana Space Center. . OneWeb is one of several companies that aims to connect the world with a few hundred or thousand satellites, and certainly the most well-funded — is the biggest investor, but Virgin Group, Coca Cola, Bharti Group, Qualcomm, and Airbus have all chipped in. The company’s plan is to launch a total of 900 (650 at first) satellites to about a 1,100-kilometer low Earth orbit, from which it says it will be able to provide broadband to practically anywhere on Earth — anywhere you can put a base station, anyway. Much cheaper and better than existing satellite connectivity, which is expensive and slow. Sound familiar? Of course SpaceX’s side project Starlink has similar ambitions, with an planned, and is aiming for a smaller constellation of smaller satellites for low-cost access. And Ubiquitilink just announced this week that its unique technology will remove the need for base stations and . And they’ve all launched satellites already! The launch vehicle fueling today at GSC. OneWeb has faced numerous delays; the whole constellation was originally planned to be in place by the end of 2019, which is impossible at this point. But delays are the name of the game in ambitious space-based businesses, and OneWeb hasn’t been just procrastinating; it’s been girding itself for mass production, raising funds to set up launch contracts, and improving the satellites themselves. Its updated schedule, as it states in the mission summary: “OneWeb will begin customer demos in 2020 and provide global, 24-hour coverage to customers in 2021.” At a reported cost of about a million dollars per satellite — twice the projected cost in 2015 — just building and testing the constellation will likely rub up against a billion dollars, and that’s not counting launch costs. But no one ever said it would be cheap. In fact, they probably said it would be unbelievably expensive. That’s why SoftBank and the other investors are “committing to a lot more capital,” as CEO Adrián Steckel last month. The company also announced its first big deal with a telecom; Talia, which provides connectivity in Africa and the Middle East, signed on to use OneWeb’s services starting in 2021. Soyuz launches could carry more than 30 of these satellites each, meaning it would take at least 20 to put the whole constellation in orbit. This first launch, however, only has six aboard; the other spots on board the mass launch system have dummy payloads to simulate how it should be going forward. A OneWeb representative told me that this launch is meant to “verify the satellite design and validate the end to end system,” which is probably a good idea before sending up 600 more. That means OneWeb will be testing and tracking these six birds for the next few months and making sure the connection with ground stations and other aspects of the whole system are functioning properly. Full payloads will start in the fall, after OneWeb opens its (much-delayed) production facility just outside Kennedy Space Center in Florida. .