Global Navigation Satellite Systems Engineering, Policy, and Design
With just weeks to go before Congress disperses for a month-long break lawmakers have yet to finalize either a defense funding bill or legislation authorizing military spending for fiscal year 2016. The way forward looks particularly rocky as enacting both bills will require resolving a yearslong fight over spending caps.
By Inside GNSS
The U.S. stance on satellite navigation has long supported international cooperation and a degree of interoperability. In 2010 the Obama administration even adopted a space policy that said foreign satnav services could be used “to augment and strengthen the resiliency of GPS.”
That was easier in the abstract, however, when the only fully functional GNSS was GPS. Now, with other GNSS services coming online, American officials want to think things through again.
By Dee Ann Divis
The U.S. Air Force and its mission partners successfully launched the 10th Boeing-built GPS IIF satellite aboard a United Launch Alliance Atlas V from Cape Canaveral Air Force Stations today (July 15, 2015).
The spacecraft is destined for plane C/slot 3 of the GPS constellation
The launch almost coincided with Friday’s 20th anniversary of the declaration of full operational capability (FOC) for the GPS constellation, which occurred on July 17, 1995.
Just two GPS IIF satellites remain to be launched — Atlas V rockets will be used to launch both.
By Inside GNSS
Col. Steve Whitney now heads GPS DirectorateColonel Steve Whitney was sworn in Wednesday (July 8, 2015) as the director of the Global Positioning Systems (GPS) Directorate, Space and Missile Systems Center, Air Force Space Command, Los Angeles Air Force Base, California.
By Inside GNSS
Valérie Renaudin’s Compass Points
Geomatics engineer Valérie Renaudin now directs a major research laboratory in Nantes, France, working on the future of personal navigation and intelligent transportation systems (ITS).
By Inside GNSS
A few studies (by universities and industry) have shown the feasibility of simulation of real-time digital intermediate frequency (IF) signals based on a graphics processor unit (GPU). And a couple of articles have also demonstrated use of a universal software radio peripheral (USRP)–based software-defined radio (SDR) as a simulator (in playback mode) in real test environments.
By Inside GNSS
Figure 1The Indian Regional Navigation Satellite System (IRNSS) is an Indian Space Research Organisation (ISRO) initiative to build an independent satellite navigation system that provides precise position, velocity, and time (PVT) to users across the Indian region.
The primary objective of IRNSS is to achieve position accuracy of 20 meters (2σ) for dual-frequency users over India and the primary service area (a region extending to about 1,500 kilometers or 930 miles).
By Inside GNSS
Global navigation satellite systems provide position, velocity, and time (PVT) solutions to users whose receivers calculate position based on one-way ranging from satellites. As is well-understood, a key step in the positioning process involves a determination of the difference between the time of signal transmission identified in the satellite’s broadcast navigation message and the time of its reception by user equipment.
By Inside GNSS
The House Appropriations Committee voted May 13 to cut the White House request for civil GPS funding and a number of other GPS-related program at the Dept. of Transportation.
By Inside GNSS
GPS III satellites and their new ground system, both years behind schedule and hundreds of millions of dollars over budget, still may not be on track despite corrective actions, Air Force Secretary Deborah L. James told a U.S. Senate hearing recently.
By Inside GNSS
GPS Block IIF-5 on its way from Cape Canaveral on February 20, 2014. Photo by Ben Cooper, United Launch Alliance[Updated May 26, 2015] The U.S. Air Force released a draft request for proposal (RFP) yesterday (May 13, 2015) for GPS III Launch Services, including launch vehicle production, mission integration, and launch operations. The Space Exploration Technologies Corporation — better known as SpaceX and headed by Elon Musk — may well enter the competition.
By Inside GNSS
In April, Lockheed Martin fully integrated the U.S. Air Force’s first next-generation GPS III satellite at the company’s Denver, Colorado–area satellite manufacturing facility. The first in a design block of new, more powerful and accurate GPS satellites, GPS III Space Vehicle One is now preparing for system-level testing this summer. Lockheed Martin photoLockheed Martin has finally been able to announce victory in its effort to complete integration of the first GPS Block III satellite.
Integration took place last month at the company’s GPS III Processing Facility near Denver, Colorado, bringing together the system module — which includes the navigation payload that performs the primary positioning, navigation, and timing mission — the functional bus containing the electronics that manage all satellite operations, and the propulsion core that enables the satellite to maneuver for operations on orbit.
By Inside GNSS
The House Armed Services Committee (HASC) is considering legislation that would fully authorize the White House’s funding request for GPS and possibly add provisions aimed at evaluating the new, troubled GPS ground system and pushing the Pentagon to look at a global backup for GPS.
By Inside GNSS
