Global Navigation Satellite Systems Engineering, Policy, and Design
746th Test Squadron commander Lt. Col. Amy McCain dedicates an exhibit with Director Randall Hayes of the New Mexico Museum of Space History in Alamogordo. A tradition of testing of navigation systems and missile components began for the 746th Test Squadron (746 TS) in 1959 and continued as it reached its golden anniversary in May 2009.
By Inside GNSS
The GPS Wing has announced that the Raytheon Modernized User Equipment (MUE) team has achieved live satellite M-code tracking with an MUE receiver.
The team has developed modernized versions of the Avionics GPS Receiver Application Module and Ground Based GPS Receiver Applications Module (GB-GRAM) receivers under MUE receiver development contracts awarded to three companies in June of 2006. M-code signals from Block IIR GPS satellites were acquired using a Raytheon GB-GRAM-M.
By Inside GNSS
CSR plc and SiRF Technology Holdings Inc., have completed the merger between SiRF and a wholly owned subsidiary of CSR.
By Inside GNSS
GPS satellite L-band antenna elementsThe GPS Wing is reaching out to receiver manufacturers and the user community to gather comments on the SVN49 signal anomaly and the Air Force’s provisional solution to the problem.
Despite earlier news reports suggesting that the problem, which has kept the latest GPS satellite from being declared operational, was on its way to being solved, a GPS Wing spokesperson characterized the remedy of altering the satellite’s broadcast orbital position (ephemeris) and time as only a “partial fix.” Indeed, high-precision dual-frequency users, such as those in the International GNSS Service, may continue to encounter difficulties in handling the SVN49 signal.
By Inside GNSS
FAA graphicGNSS manufacturer NovAtel Inc., of Calgary, Alberta, Canada, has received a new contract from the Federal Aviation Administration (FAA) to develop the next-generation GPS Wide Area Augmentation System (WAAS) reference receiver (the “GIII” receiver). The three-year contract is worth up to US$9.7million.
By Inside GNSS
When GPS reference receivers at the European Space Operations Center (ESOC) detected a 150-meter error in the broadcast ephemerides (orbital position) for the latest GPS satellite — Space Vehicle Number 49 or SVN49 — scientists there assumed that a problem had arisen with the spacecraft’s navigation payload.
After all, coupled with an apparent 500-nanosecond clock error, the ephemerides could produce many kilometers of errors for navigation receivers.
By Inside GNSS before launch.jpg)
Members of the 45th Launch Support Squadron, along with the 45th Range Management Squadron’s GPS team, pause in front of the GPS IIR-20 satellite atop its Detla II booster prior to its launch March 24. (Lockheed Martin photo/Bruce Johnson) U.S. Air Force officials have confirmed that signal anomalies on the latest GPS satellite — IIR-20(M), also identified as SVN49/PRN01 — are related to the interface to the new L5 payload also on board.
But the problem appears fixable.
The spacecraft has remained is still in early orbit checkout since its launch on March 24 and has not been introduced into the operational constellation.
A dedicated response team of Air Force and contractor experts are wrapping up their investigation of the cause of the L1 signal anomalies, which were detected on April 9. The signal distortion was initially observed as an elevation-dependent bias in ranging measurements from GPS monitor stations.
By Inside GNSS
Loran tower – Starkey Loran research photos 2001To say that enhanced Loran (eLoran) has been an on-again off-again program would give short shrift to multiple generations of official ambivalence about the proposed backup for GPS.
The latest chapter began on June 4 when Senator Maria Cantwell (D-Washington) introduced S. 1194, the Coast Guard Authorization Act for Fiscal Years 2010 and 2011 (FY2010/11).
Among other details, the measure directs the Secretary of Transportation to continue the Loran system until a plan has been drawn up and implemented to transition the program to eLoran.
By Inside GNSS
Applanix
has introduced the POSTrack 410 flight management and direct
georeferencing system designed for use with the latest generation of
medium-format airborne digital photogrammetric camera.
The POSTrack 410 incorporates Applanix’s POS AV GNSS-inertial navigation
system (INS) and POSPac Mobile Mapping Suite (MMS) office software,
featuring the IN-Fusion technology and SmartBase module. This system
can process both GPS and GLONASS signals as well as those from
satellite-based augmentation systems.
DAGR 2008. Rockwell Collins imageDevelopment and acquisition of military GPS user equipment (MGUE) are taking on new dimensions across the board — institutionally, procedurally, and technologically.
Along the way, the changes could redefine relationships within the Department of Defense (DoD) and between the agency and industry.
At the agency level, a proposal is forthcoming to “stand up” a positioning, navigation, and timing (PNT) user equipment joint program office (JPO) that would incorporate UE responsibilities (and budgets) now exercised by the GPS Wing (GPSW).
By Inside GNSS
Two weeks after a Government Accountability Office (GAO) report warned of potential gaps in the GPS satellite constellation, reassurances from Department of Defense (DoD), U.S. Air Force, GPS program officials, and industry are slowly restoring calm to an anxious public.
Coupled with a May 7 congressional hearing (and subsequent media coverage) that fanned the flames, the report described scenarios — for instance a two-year setback in launching the first GPS III spacecraft — that could lead to deterioration in the quality of GPS service due to delays in building new generations of satellites and past program management problems. The news coverage drew primarily on the GAO report and prepared statements presented at the hearing and not on the much more interesting dialog with subcommittee members captured on video or on the assumptions and methodology underlying the constellation analysis.
By Inside GNSS
(Updated May 22, 2009) Leading researchers from Ohio University, Stanford, and the University of Colorado have released their initial observations of the GPS L5 signal broadcast, including an anomaly in SVN49’s L1 signal reported by the GPS Wing’s chief engineer on May 4.
The U.S. Air Force switched on the eagerly awaited, modernized L5 signal on April 10 after the successful launch of the newest GPS Block IIR-M satellite – SVN49 – in March. This was the first broadcast of a GPS signal in a frequency band dedicated solely for civilian use.
By Inside GNSS
Mike Shaw, NCO Executive DirectorA June 18 meeting of the National Space-Based Positioning, Navigation, and Timing (PNT) Executive Committee (ExCom) will bring together leaders of the Obama administration in the key interagency setting for GPS issues.
Established under a 2004 National Presidential Security Directive, the ExCom advises and coordinates federal departments and agencies on matters concerning the Global Positioning System and related systems. The deputy secretaries of defense and transportation and co-chair the committee, which includes equivalent-level members from seven other federal agencies.
By Inside GNSS
