Articles in the GNSS Category

Oct 2006 | Comments Off on The ‘Namuru’ Open GNSS Research Receiver: An update

Development of a Field Programmable Gate Array (FPGA) based GNSS receiver platform has been underway at the University of New South Wales (UNSW) ‘SNAP’ lab since 2004. The receiver now has a name; ‘Namuru’ that means ‘to see the way’ in the language of the Eora people who inhabited an area around Sydney, including the UNSW campus, before the arrival of the British. The receiver was introduced in the Coordinates January 2006 edition and in this article we first provide a brief recap and then look at the latest developments and results from testing. But before launching into this, the question of why such a research and development platform is desirable must be answered.

Jul 2006 | Comments Off on FORMOSAT-3 GPS radio occultation mission

Six tiny FORMOSAT-3 satellites that were sped into space on April 15, 2006 are designed for systematic mass scale radio occultation (RO) studies of the Earth atmosphere and ionosphere at different altitudes by use of the GPS signals. Termed as the Formosa Satellite-3/ Constellation Observing System for Meteorology, Ionosphere, and Climate (FORMOSAT-3/COSMIC) mission, the new constellation’s primary science goal is to obtain in near real time the vertical profiles of temperature, pressure, refractivity, and water vapor in the neutral atmosphere, and the electron density in the ionosphere with global coverage. The measurements during five years of mission life will provide about 2,500 soundings per day, thus generating extensive information to support operational global weather prediction, climate change monitoring, ionospheric phenomena, and space weather research. The theory of RO measurements has been described previously (Gurvich and Krasilnikova, 1988; Yunck, 1988; Yakovlev, 2002; Hajj et al., 2002). During last four years, essential modernization in the RO technique has been introduced (e.g., Liou et al., 2002, 2006; Pavelyev et al., 2004 and references therein).

Jun 2006 | Comments Off on Space-based positioning system with no on-board atomic clocks

he Japanese Quasi-Zenith Satellite System (QZSS) represents an innovative multi-service satellite system able to provide positioning for mobile users over Eastern Asia and Australasia. The integration of the QZSS with the present GPS and the European GALILEO will improve accuracy, availability and capability over a wide area. Throughout a collaborative research program, the space technology group of AIST, Japan and the University of NSW…

May 2006 | Comments Off on A yen for regional navigation

In the 1970s, the US Department of Defense began GPS development as a military force enhancer. In 1983, President Reagan offered GPS civil services to the world, free of direct charges, as a result of the KAL007 disaster. This global offer sparked widespread civil use of GPS and significant investment in civil GPS technologies, to include GPS civil augmenting satellites (e.g. US Wide Area Augmentation System (WAAS), European…

Apr 2006 | Comments Off on Design methods for RF part of GNSS software receivers

Many researchers and R&D laboratories in the world deal with the design of the software-based or experimental GNSS receivers using digital signal processing for work and experiments with received navigational signals. These concepts have one in common: the necessity of use of some analogue RF part before conversion of the signal to the digital domain. The problem of the RF front end design of the experimental or special purpose navigation receivers has to be solved. It is not an easy task as can be seen from many papers and conference contributions. The aim of this paper is analysis of the possibility of such GNSS RF front end design. We will discuss the following three main approaches

Apr 2006 | Comments Off on Water vapour estimation at few GPS sites in Indian subcontinent

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…

Mar 2006 | Comments Off on National GPS programme for earthquake hazard assessment

The GPS technology is being used extensively all over the world to generate useful data for different purposes. The Department of Science
and Technology, Government of India has evolved a programme on GPS to study crustal deformation processes with the following objectives…

Mar 2006 | Comments Off on GAGAN update

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…

Feb 2006 | No Comment

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

Jan 2006 | Comments Off on An open GNSS receiver platform architecture

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.