Global Navigation Satellite Systems Engineering, Policy, and Design
The GPS Directorate is requesting public comments on proposed changes to several interface specification (IS) and Interface Control documents (ICDs) for GPS signals in space. GPS receiver designers will be particularly interested in the changes as they affect how GPS signals should be processed in user equipment.
By Inside GNSS
In February 2011, Russia launched the first satellite of the GLONASS-K1 series, i.e., SVN (space vehicle number) 801 (R26), which in addition to the legacy frequency division multiple access (FDMA) signals, for the first time was enabled to transmit code division multiple access (CDMA) signals on the GLONASS L3 frequency (1202.025 MHz). Later in 2014, the GLONASS program added SVNs 802 (R17) of series K1 and 755 (R21) of series M, and in 2016, SVN 751 of series M, with the capability of transmitting CDMA L3 signals to the constellation.
By Inside GNSS
Secretary of the Air Force Deborah Lee James declared a critical Nunn-McCurdy breach on the GPS Next-Generation Operational Control System (OCX) today (June 30, 2016).
After a December 2015 Program “Deep Dive,” Undersecretary of Defense for Acquisition, Technology and Logistics Frank Kendall placed the OCX program under significant Department of Defense (DoD) oversight with quarterly reviews.
By Inside GNSS
Statue of Mazu, sea goddess, in Nantong, China, Museum. Wikimedia Commons photoA white paper published by the Chinese government earlier this month outlining the action plan for the BeiDou Navigation Satellite System (BDS) and a press conference featuring the director of the BDS management office provided new details on the progress for China’s GNSS program.
By Inside GNSS
The Senate approved defense authorization legislation last week before heading out for weekend campaigning. The measure contains a provision the White House said would further delay completion of the already overdue next-generation GPS control system (OCX) by 6 to 12 months.
Senators passed their version of the National Defense Authorization Act (NDAA) for Fiscal Year (FY) 2017 on June 16, defying the White House, which had said June 7 it would veto the bill.
By Inside GNSS
GPS program managers are looking for small firms with a fresh take on technologies ranging from handheld M-code receivers and cybersecurity solutions to ground infrastructure and satellite payloads.
By Dee Ann Divis
Lowri Evans, DG GROWTH. Photo by Peter GutierrezAs ranking European Union (EU) official, Commissioner for Internal Market, Industry, Entrepreneurship and SMEs, Elzbieta Bienkowska set the tone in a keynote speech that anticipated some major issues to be addressed in the upcoming “EU Space Strategy,” the EUropean Commission’s next big new European space policy document, expected to come out later this year.
By Inside GNSS
JRC Ispra settingA few places remain in the 2016 European Space Agency (ESA) International Summer School on Global Navigation Satellite Systems, which will take place at the Italian campus of European Commission’s joint scientific and research center (JRC – CCR ISRA) on Lake Maggiore in Ispra, near Varese.
By Inside GNSS
Senate lawmakers made clear their ire with the GPS program, recommending funding cuts for nearly every element and slashing development monies for the troubled new ground control system before taking off for the Memorial Day holiday.
By Inside GNSS
One of 12 magnetograms recorded at Greenwich Observatory during the Great Geomagnetic Storm of 1859
1996 soccer game in the Midwest, (Rick Dikeman image)
Nouméa ground station after the flood
A pencil and a coffee cup show the size of NASA’s teeny tiny PhoneSat
Bonus Hotspot: Naro Tartaruga AUV
Pacific lamprey spawning (photo by Jeremy Monroe, Fresh Waters Illustrated)
“Return of the Bucentaurn to the Molo on Ascension Day”, by (Giovanni Antonio Canal) Canaletto
The U.S. Naval Observatory Alternate Master Clock at 2nd Space Operations Squadron, Schriever AFB in Colorado. This photo was taken in January, 2006 during the addition of a leap second. The USNO master clocks control GPS timing. They are accurate to within one second every 20 million years (Satellites are so picky! Humans, on the other hand, just want to know if we’re too late for lunch) USAF photo by A1C Jason Ridder. 
Detail of Compass/ BeiDou2 system diagram
Hotspot 6: Beluga A300 600ST
Electronic Throwaways, Space X Wins, Drones at Sea and Shaking It Up
By Inside GNSSSo, if everything had gone as planned, we would have a new ground control segment (OCX) operating a new generation of satellites (GPS III) as they launch into an expanded constellation in support of modernized military GPS user equipment (MGUE).
But then the best-laid plans. . . .
By Inside GNSS
Advanced military receivers using the sort of modern multi-channel, multi-constellation capabilities already available commercially, could enable the Air Force to focus its anti-jam efforts on the ground, simplifying future GPS satellites and lowering their cost. Moreover, experts told Inside GNSS, the cutting-edge receivers could be deployed years before the anti-jam capability planned for the new GPS III satellites would be fully available.
By Dee Ann Divis
Symbols and AcronymsModernized GPS satellites give civil users the ability to achieve dual L1/L2 PY accuracy using dual L1CA/L2C ionosphere-free measurements and, with IIF satellites, dual L1/L5 signals. Because broadcast GPS ephemeris data is based on an ionosphere-free pseudorange calculated from dual L1PY/L2PY measurements and the civil signals are not all perfectly aligned to it, new broadcast parameters and a new modernized dual-frequency algorithm are needed in order to align new signals with the dual L1/L2 PY signal.
By Inside GNSS
