Global Navigation Satellite Systems Engineering, Policy, and Design
The White House showed continuing support for the GPS program with a budget request that was, with one key exception, comparable to that of previous years. That exception though, a cut to GPS III procurement including the zeroing out of advance procurement monies, resulted in an overall program reductions of roughly $100 million.
By Inside GNSS
Galileo Sensor Stations (GSSs) pick up Galileo signals in space (SIS) to perform clock synchronisation and orbit measurements which are fed back to the twin Galileo Control Centres to serve as the basis of the navigation message incorporating clock and position corrections and associated integrity data. Uplink Stations (ULSs) then uplink this navigation message to the Galileo satellite navigation payloads for rebroadcast to users. Telemetry, Tracking and Command Stations (TT&Cs) provide the link between the Control Centres and the satellite platforms. ESA figureGalileo’s operation controllers will temporarily stop updating satellite orbital positions in the system’s navigation messages beginning near the end of this month in order to help implement upgrades in the ground mission segment, the European Space Agency (ESA) announced today (January 19, 2015).
Although the Galileo satellites will continue to transmit navigation signals, the generation and uplink of updated navigation messages will be interrupted during the last week of January for about five weeks.
By Inside GNSS
In a nod to the usefulness of international enhanced Loran (eLoran) systems the U.S. Department OF Defense (DoD) in January began a search for companies able to supply some 50,000 eLoran receivers. Meanwhile a multi-agency team continues sketching out the structure of a potential U.S. eLoran system for federal officials weighing a relaunch of the program as a backup to GPS.
By Inside GNSS
On Wednesday (December 17, 2014) Raytheon Company announced successful completion of the fourth of five planned launch and early orbit exercises being undertaken together with Lockheed Martin to demonstrate new automation capabilities, information assurance, and launch readiness of the U.S. Air Force’s next generation GPS III satellite and Operational Control System (OCX).
By Inside GNSS
With final passage of the Omnibus spending bill on December 13 Congress deepened by $17 million the fiscal ditch in which the new GPS ground system finds itself, possibly further delaying the completion of a modernized operational control segment (OCX) and increasing costs just as the Department of Defense’s top acquisition official steps in to take a closer look at budget overruns.
By Inside GNSS
Working Papers explore the technical and scientific themes that underpin GNSS programs and applications. This regular column is coordinated by Prof. Dr.-Ing. Günter Hein, head of Europe’s Galileo Operations and Evolution.
SIDEBAR: Locating a Distress Beacon Activated in Flight
By Inside GNSS
GPS III core structure at Lockheed Martin facility. Lockheed Martin photoThe launch of the first GPS III satellite could slip to as late as March 2017, further delaying a modernization program that already has been pushed back repeatedly by budget cuts and technical problems.
“The first GPS III launch is tentatively considered for the first half of FY17, based on booster availability and Air Force launch priorities,” a spokesman for the Space and Missile Systems Center told Inside GNSS.
By Inside GNSS
ISRO’s Polar Satellite Launch Vehicle, PSLV-C26, successfully launched IRNSS-1C, the third satellite in the Indian Regional Navigation Satellite System (IRNSS), from Satish Dhawan Space Center last Thursday (October 16, 2014 local time).
By Inside GNSS
IRNSS-1B satellite in clean room. ISRO photoA signal-in-space (SIS) interface control document (ICD) for the standard positioning service (SPS) of the Indian Regional Navigation Satellite System (IRNSS) is available for download from the Indian Space Research Organization (ISRO) website.
By Inside GNSS
Editor’s Note: An exclusive interview with Gen. Hyten is available here with more details.
Details are emerging about another restructuring of the contract for the new GPS ground system, a deal that pushes completion of the project back another two years and recasts the remaining work to fit within the Air Force’s strained financial profile.
By Dee Ann Divis
IFEN SX3IFEN introduced its new SX3 GNSS software receiver, a major upgrade of the company’s SX-NSR, last week at the ION GNSS+ conference in Tampa, Florida. Redesigned hardware frontends feature four wideband RF frequency bands that can be split into a maximum of eight sub-bands per unit. At the same time the bandwidth has been expanded to a full 55 megahertz, offering additional signal power especially in the Galileo E5 band.
By Inside GNSS
Working Papers explore the technical and scientific themes that underpin GNSS programs and applications. This regular column is coordinated by Prof. Dr.-Ing. Günter Hein, head of Europe’s Galileo Operations and Evolution.
By Inside GNSS
Orbits of the fifth and sixth Galileo satellites launched together on August 22, 2014, in red, compared to their intended position, in dashed green, and the position of the four IOV satellites launched in 2011 and 2012 in solid green. This view looks down over Earth’s South Pole, helping to illustrate how the two satellites’ orbital inclination relative to the equator is less than was intended ESA illustration.The European Space Agency (ESA) released dramatic illustrations today (September 16, 2014) of the orbital locations of the two errant Galileo spacecraft launched on August 22, the intended orbit, and the locations of four In-Orbit Validation (IOV) satellites.
By Inside GNSS
