Articles in the GNSS Category
Atmospheric water vapour estimation from the GPS data, surface total pressure and the mean tropospheric temperature is the most cost effective method which gives all weather good spatio-temporal coverage. Precipitable Water Vapor (PWV) in the atmosphere can be estimated from GPS data by determining the travel time delay of GPS radio signals through the troposphere. Water vapour is already identified as…
GAGAN is an Indian Space Based Augmentation System (SBAS). Airports Authority of India (AAI) and Indian Space Research Organization (ISRO) to provide the seamless navigation service for all the phases of fl ight over Indian airspace jointly undertake this project. The AAI’s efforts towards implementation of operational SBAS can be viewed as the first step towards introduction of modern CNS/ATM system over Indian airspace…
JAESat is an Australian joint micro-satellite project between Queensland University of Technology, Australian Space Research Institute and other national and international partners, i.e. Australian Cooperative Research Centre for Satellite Systems, Kayser-Threde GmbH, Aerospace Concepts, Auspace to name some of them
In early 2004 a plan was hatched to develop a Global Navigation Satellite System (GNSS) receiver based around Field Programmable Gate Array (FPGA) technology as a platform to support research in this fi eld. A joint project was set up between the School of Surveying and Spatial Information Systems (SISS) at the University of New South Wales and the National ICT Australia (NICTA), and soon after a small team was established. The team consisted of Kevin Parkinson, a post-graduate student at SISS with experience in FPGA and circuit board design, Frank Engel, a researcher with NICTA with software, Real Time Operating Systems (RTOS) and VHDL design knowledge and me, Peter Mumford from the SISS GNSS research group. At the end of the project we hoped to have an L1 GPS receiver running on a custom circuit board with the baseband processor and navigation solution processor running on an FPGA chip. The project is coming to an end now, and in this article, I will describe our design path, what has been achieved to date and then some potential research areas, but fi rst a little background.
GNSS is a global navigation satellite system comprising of network of satellites that transmit ranging signals used for positioning and navigation anywhere around the globe; on land, in the air or at sea. The US Global Positioning System (GPS/Navstar GPS), the Russian Global Navigation Satellite System (GLONASS) and the upcoming European GALILEO system, Data communications satellites with navigation payloads and Augmentation systems are all part of GNSS.
The 746th Test Squadron (746 TS) has conducted complex GPS jamming experiments since the early 1990s and played a key role “behind the scenes” creating multiple high-profile jamming environments for programs such as the Joint GPS Combat Effectiveness (JGPSCE) exercises and Quick Reaction Tests. These programs, conducted to support real-world operations, enhanced the 746th TS’s ability to recreate realistic jamming environments and resulted in the 746 TS earning the reputation as the recognized experts for open-air GPS vulnerability testing.
As the designers and builders of infrastructure; surveyors, engineers and construction contractors know well the benefits gained from a strong infrastructure. Whether transportation, utilities or communication systems, infrastructure constitutes a society’s basic structure, the foundation upon which the growth of a community, state or entire nation depends.
In order to provide seamless navigation to the world aviation community by airport service providers, the International Civil Aviation Organization (ICAO) has adopted a new strategy on the implementation of Future Air Navigation System (FANS) and use of non-visual aids for approach, and landing. The solution for the above requirements is Global Navigation Satellite System (GNSS). A stand alone GPS fails to provide the required navigation accuracy for all phases of the flight. Therefore, to achieve the required navigation accuracy, the core constellation i.e. GPS, GLONASS, and Galileo (under planning stage) needs augmentations to fulfill the GNSS, particularly in satellite-based augmentations such as WAAS (USA), EGNOS (Europe), MSAS (Japan), GRAS (Australia) and GAGAN (India). It also includes ICAO’s acceptance of an offer to make the Global Orbiting Navigation Satellites System (GLONASS) available for use by civil aviation. The ICAO Council had earlier accepted a similar offer concerning the GPS. These three satellite constellations (GPS / GLONASS / Galileo) are the key components of the GNSS. This article describes briefly, the different systems including GAGAN (India) and the status of GNSS.
Since Japan is an earthquake prone country with a lot of volcanoes and active faults, Geographic Survey Institute (GSI), the Government of Japan has constructed about 1,200 GPS Fixed Stations called “electronic control points” all over Japan. Since 2003, GSI released GPS data to public through web site. The authors have already checked and confirmed the evidence of early warning for the past big earthquakes such as Tokachi Earthquake (M8.0: 2003.9.26) and Nigata Chu-etsu Earthquake (M6.8: 2004.10.23) which occurred in Hokkaido, north of Japan and middle of Japan respectively. International GPS Service (IGS) provides world wide GPS data at GPS stations located at 10 stations near Indonesia and other Asian regions.