Global Navigation Satellite Systems Engineering, Policy, and Design
Q: 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
In 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
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
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
NavtechGPS Spring GPS/GNSS Technical Training 2016 will take place March 14-18, at Crowne Plaza Redondo Beach Marina & Hotel in Redondo Beach, California, USA.
Registration information can be found here.
By Inside GNSS
The topic of the International Federation of Surveyors (FIG) working week 2016 is "Recovery from Disaster." It will take place at the Horncastle arena and Addington Events Centre in Christchurch, New Zealand from May 2 through May 6. Appropriately enough, Christchurch has deep familiarity with recovery from disaster after the 2010-11 earthquake sequence that took place there.
Abstract submissions are now closed.
By Inside GNSS
The 2016 InterGEO Trade Fair and Conference for Geodesy, Geoinformation and Land Management will take place at the fairgrounds —Hamburg Messe und Congress (HMC)—in Hamburg, Germany on October 11, 12 and 13.
Now 22 years old, the fair attracts 16,000 visitors from 92 countries who process, use or analyze geodata online or in the field.
The conference will cover the latest developments in surveying, geoinformation, remote sensing and photogrammetry and allied technologies. Proceedings are conducted in German and English.
By Inside GNSS
The Southern California Section of the Institute of Navigation’s December meeting will take place at the John Deere facility in Torrance, CA on December 15, 2015.
Dr. Chun Yang will speak at the meeting. The title of the talk is Sharpening Peak Performance of GPS Signals. In this talk, the variable IF tracking architecture that improves the
peak performance will be presented together with possible implementation
schemes. Simulation results will be used for illustration and analysis.
The founders of Chronos and UrsaNav announced a new collaboration yesterday (December 3, 2015) intended enhance the resilience and reliability of space-based positioning, navigation, and timing (PNT) services.
By Inside GNSS
1. DÉJÀ VU
Annapolis, Maryland and Kings Point, New York USA
