Global-navigation Satellite Systems (GNSS) provide navigational data to airborne transportations and various other applications. Mainly two satellite constellations are in use today for navigational purposes. They are global positioning system (GPS) which is provided by the United States and global navigation satellite systems (GLONASS) which is provided by the Russian federation [1]. GPS and GLONASS satellites fly in medium Earth orbit (MEO) at an altitude of approximately 20,200 km and 19,100 km respectively. These satellites primarily transmit the timing and a data message consisting of its orbital parameters which are received by the GNSS receivers to calculate the range from the satellite which will further provide a relative three dimensional position and time from the satellites. Many other states are coming up with their own regional navigation satellite systems. Europe is coming up with European Geostationary Navigation Overlay Service (EGNOS), Japan is moving forward with Multifunctional Transport Satellite (MTSAT) and India is targeting to have its own regional navigation satellite systems christened as GPS Aided Geo Augmented Navigation (GAGAN) by the end of the year 2014. This will aid in providing more precise and advanced navigation. Thus the global nature of GNSS makes it necessary to have a close coordination between all of the states.
The data from the satellite based navigation systems can also be used for trains, buses and other locomotives. Further the navigation data are also important for military in warfare and in battlefield. Thus the high speed and precise satellite based navigation systems are becoming a necessity of the future. However there are many challenges to overcome to make fast and accur...
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...ng, Peng Chen, Wei Hong, T. Djerafi and Ke Wu, “Substrate Integrated Waveguide Beamforming Networks and Multibeam Antenna Arrays for Low-Cost Satellite and Mobile Systems,” Antennas and Propagation Magazine, IEEE, vol. 53, no. 6, pp. 18-30, 2011.
[7] S. Sugawara, Y. Maita, K. Adachi and K. mizuno, “Characteristics of a mm-wave tapered slot antenna with corrugated edges,” in Proceedings IEEE MTT-S Microwave Symposium Digest, 1998, pp. 533-536.
[8] T. Djerafi and K. Wu, “Corrugated Substrate Integrated Waveguide Antipodal Linearly Tapered Slot Antenna Array Fed by Quasi-Triangular Power Divider,” PIER C, Vol. 26, pp. 139-151, 2012.
[9] P. Shrivastava, D. Chandra, N. Tiwari, and T. Rama Rao, “Investigations on corrugation issues in SIW based antipodal linear tapered slot antenna for wireless networks at 60 GHz,” ACES Journal, vol. 28, no. 10, pp. 960-067, 2013.
At higher frequencies, the dielectric constants are almost independent of frequency. This is because, at higher frequencies periodic reversal of the field takes place so rapidly that the charge carriers will hardly be able to orient
Reading, Gwem. "Radar Operator in WW2." Letter. 8 Nov. 2003. N.p.: n.p., n.d. N. pag. BBC WW2 People's War. Web. 23 Apr. 2014.
NSSS states a few current trends in space as being “congested and contested” (NSSS, 8), which is shaping our space strategic environment as well as fueling debates for space weapons. “Congested” trend refers to the current “60 nations and government consortia that own and operate satellites and the expectation to have 9000 satellite communication transponders in orbit by 2015.
The invention of the GPS started with Dr. Ivan Getting leaving his position at Raytheon Company, and armed with the knowledge of what was at the time the most advanced navigational technology in the world, they began developing the Global Positioning System. He, Roger L. Easton, and Bradford Parkison began in the 60’s with a constellation of 24 satellites (placed in six orbital planes) orbiting the earth at a very high altitude (about
Around 1886, Heinrich Hertz demonstrated experimentally the existence of radio waves. It is said that Hertz only smiled incredulously when anyone predicted that his waves would one day be sent round the earth. Hertz died in 18...
MTC ONLINE, " Reports of Current Experimentation with Microwave and EM Weapons," <http://www.heart7.net/mcf/1.html> (10 August 2003)
Wire time (or panghantar such as an antenna) conducts alternating current, electromagnetic radiation is propagated at the same frequency as the electric current. Depending on the situation, electromagnetic waves can be waves or like particles. As a wave, characterized by speed (speed of light), wavelength, and frequency. When considered as particles, they are known as photons, and each has an energy associated with the frequency of the waveform shown by the Planck relationship E = Hν, where E is the photon energy, h is the Planck constant - 6.626 × 10 -34 J · s - and ν is the frequency of the
This chapter describes an experimental of using Iterative Least Square (ILS) with the application of GPS navigation base on Matlab programming software. The psuedorange and satellite position of a GPS receiver at fix location for a period of 812 seconds is provided.
The GPS is sensing knowledge to help with navigation with the car and destinations. Autonomous cars are not yet available on a large scale of the world such as out of the United States of America, but have been programmed and developed to travel along the roads of America. Most autonomous cars are programmed only for American roads, we have made a big step towards the future with autonomous cars, with them being only available mainly in America, they are a luxury. They are making their way to larger scale autopilot features, and will eventually be available on a larger scale.(Ali
‘ICAO Performance Based Navigation (PBN) Programme’, 2011, ICAO [Online] Available , Accessed 15 June 2011.
TVS and telephones are using satellites, and I thought it would be a good idea
There was a time a person would use a roadmap to get from one location to another. Some also would stop and ask for directions. Today, you seldom see paper maps and people stopping at a local gas station for directions. Many vehicles come with a navigation system that provides a real-time map of the vehicle’s current location as well as systematic directions to requested destination.
If a radiowave of constant amplitude is incident on the irregularity slab of thickness L (Fig 2.2) where the layer is assumed to be a phase changing screen, the wave changes its phase when propagates through it. The emergent wave is represented as,
GPS is a navigational aid that is satellite based. It is made up of a network of 24 satellites in orbit around the world. The first satellite was launched in 1978 and the last was put into orbit in 1994. Every 10 years another satellite is put into orbit because each satellite is made to last that amount of time. The system began as a military application but in the 1980’s the government decided to make it available to everyone, anywhere, anytime. The system finds your position by measuring the time it takes to receive the signal back to the satellite. It then does that with other satellites to triangulate your position in relation to the earth. To calculate a position in 2D the system has to be locked on to at least three satellites, but for a 3D representation you need to be locked on to at least 4 satellites. Once the position is found the GPS can calculate much more info like speed, bearing, track, distance, etc… The GPS system is very accurate; Garmin (a leader in GPS technology) states that their newest receiver is accurate up to an average of 15 meters.