Global Navigation Satellite Systems Engineering, Policy, and Design
Figure 1, 3, 4 & 5Q: What is Doppler collision and is it a problem in GNSS?
A: Doppler collision is a physical effect in code-division multiple access (CDMA) systems where code measurement errors are observed due to cross-correlation effects. Doppler collision may occur when the Doppler frequency between signals from two different transmitters is smaller than the code lock loop bandwidth.
By Inside GNSS
The GPS Aided Geo Augmented Navigation (GAGAN) system was developed by the Indian Space Research Organization (ISRO), together with Airports Authority of India (AAI), to deploy and certify an operational satellite-based augmentation system (SBAS). The system’s service area covers the Indian Flight Information Region (FIR), with the capability of expanding to neighboring FIRs.
By Inside GNSS
Figures and TablesIn satellite navigation, the user receiver finds its position by measuring its distance to satellites and knowledge of the satellite position. The distance is measured by ranging, i.e., finding the delay of the signal from the transmitter to the receiver. The delay will comprise of payload hardware delay and the geometric range delay. Hence, the payload delay of the signal from generation to radiation is very important and needs to be transmitted in navigation data.
By Inside GNSS
Small GPS jammers, particularly the “personal privacy devices” readily available on the Internet, pose one of the greatest risks to the nation’s critical infrastructure, according to a now-public Homeland Security assessment.
By Dee Ann Divis
Having settled its lawsuits against a trio of GPS receiver manufacturers, would-be broadband provider New LightSquared is now pointing to those settlements to support its assertion that it is fully addressing GPS interference issues.
By Inside GNSS
It will be a busy few weeks for GNSS satellite launches in January and February.
Up next is the Wednesday (January 20, 2016) is a launch of the fifth spacecraft for the Indian Regional Navigation Satellite System (IRNSS). The Indian Space Research Organization plans to complete the IRNSS constellation with two additional launches in February and March.
By Inside GNSS
NTSB Chairman Christopher HartOnce again, the National Transportation Safety Board (NTSB) has recommended GPS-aided positive train control (PTC) as one of its “most wanted” transportation safety improvements in 2016. But the agency, which has been advocating for PTC for more than 45 years, appears to be fighting an uphill battle against Congress and the railroad industry.
By Inside GNSS
Russia will host the eleventh meeting of the International Committee on GNSS (ICG) from November 6 to 11, 2016 in Sochi, on the Black Sea near Georgia. This meeting is organized by Roscosmos, the State Space Corporation. It will take place at the Pullman Sochi Center Hotel and Conference Center.
The ICG is a voluntary United Nations–backed association that brings together GNSS and augmentation providers, including the United States, Russia, European Union, China, India, and Japan.
By Inside GNSS
Preparing for a May 2016 event at the Hunan International Conference and Exhibition Center, Changsha.The 7th China Satellite Navigation Conference and exhibition will take place at the Hunan International Conference & Exhibition Center in Changsha (長沙), the 3,000 year old capital city of Hunan Province on May 18, 19 and 20, 2016.
Several thousand scientists, GNSS businesses and researchers from all over the world are expected to attend this high-level annual event. The conference language will be Mandarin, with simultaneous English translation.
Topics include:
By Inside GNSS
The Geospatial World Forum 2016 and industry exhibition will be held at the Beurs-World Trade Center in Rotterdam in Rotterdam, The Netherlands on May 23 – 26, 2015.
This year’s theme is "Where’s the Money? Disruptive Business Models." The annual event features plenary and technical sessions and workshops on policy, technology and user practices of the GIS industry. Plenary themes this year are:
By Inside GNSS
The sixth international conference on localization and GNSS will take place at the Universitat Autònoma de Barcelona (UAB) – Casa Convalescència, a UNESCO site, on June 28, 29 and 30 in Barcelona, Spain.
ICL-GNSS covers recent research on terrestrial and satellite-based positioning techniques to provide reliable, accurate and low latency position information with the goal of inspiring new design, implementation, test and evaluation methodologies for positioning platforms.
By Inside GNSS
The GPS Directorate at the Space and Missile Systems Center (SMC) released a request for proposals today (January 8, 2016) seeking proposals for the GPS III Space Vehicles 11+ Phase 1 Production Readiness Feasibility Assessment contract.
By Inside GNSS
Paul Flament, European CommissionApproval of a European Union (EU) petition to officially allow Galileo signals to be used in the United States may become an issue during upcoming negotiations over an American request for access to Galileo’s Public Regulated Service (PRS) signal, an EU advisor suggested.
By Inside GNSS
