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GPS : May - June 1999
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L2 Signals for Civil Purposes
Locating Yourself with Mobile Phone
They are going to street level databases for cars…
…And we also join the race
L2 Signals for Civil Purposes
GPS will be more accurate and reliable
The Interagency GPS Executive Board (IGEB) has selected the 1227.6 MHz band (currently known as the L2 signal) as an addition to only one signal received by civilian GPS currently. The second civil frequency will allow receivers to measure the time of arrival for two signals that have passed through the Earth’s atmosphere and correct for the distortion introduced by passage from space to earth. NAVSTAR Global Positioning System (GPS) is a constellation of 24 satellites developed, launched, and maintained by the U.S. Air Force. The new signals are intended to be added to the GPS Block II satellites. These signals will be available to all civil users worldwide. Internationally, interest has been expressed via the International Civil Aviation Organization (ICAO) in the use of a second GPS civil signal in conjunction with the Japanese MSAS and the European EGNOS augmentation programs. The addition of a second frequency will enhance the accuracy, reliability and robustness of civilian GPS receivers by enabling them to make corrections for the distorting effects of the Earth’s atmosphere on the signals from space. GPS has always provided signals on two frequencies for military users for this purpose.This will mean significant improvements in navigation, positioning and timing services to millions of users worldwide — from backpackers and fishermen to farmers, airline pilots, and scientists. An improved location calculation will allow safety-critical users requiring dynamic, reliable capability to be more reliant on the GPS signal. It will allow the high-accuracy users (surveying, geodesy, weather forecasters, etc.) to determine their data in a faster, more reliable manner. In addition, the second civil signal will allow the safety-critical users to have a backup signal in the event of inadvertent disruption of the current civil signal.
Locating Yourself with Mobile Phone
The new technology claimed to be cheaper than GPS
Mobile phones are now becomingmulti-purpose. Using the technology developed by Cambridge Positioning System the mobile phones will help to find out the nearest cash point, restaurant, pub or any other such joint. In the beginning a trial involving 250 business users will begin in Cambridge using handsets that can be linked to the databases of the AA motoring organisation.
The user has just to call AA Monitoring Organisation, and the operator sitting on the other side will automatically get the caller’s phone number and his present location flashed on his/her map. By feeding the requirements in his computer, he will let the user know desired destination as per the database keyed in the computer. Directions can also be sent as text using the Short Message Service (SMS) facility of the digital phones. A 160-character pager-style message can be easily sent to a mobile phone. The mobile phones are connected to a network called Vodafone GSM Network.
The device is capable of operating up to 100 meters range from the handset. According to the Chief Exec. of Cambridge Positioning System, Mr. Chris Wade, this technology is cheaper than Global Positioning System (GPS) as their system comprises only one hardware that is a box that is to be strapped to the antenna.
They are going to street level databases for cars…
Accuracy is the striking feature
The navigation system made by AlpineElectronics for Acura in US puts out a version for installation in existing cars at a suggested retail price of around $2,100. This is combined with a map database from Navigation Technologies. While driving, the five-inch LCD display offers a choice between a map view, which can zoom from block level detail to city overview, and a diagram of driving instructions. NavTech’s database divides US into nine regions. The most striking thing about the Acura system is its accuracy. Major metropolitan areas have block-by-block details for all the streets. Rural areas and smaller cities offer only major roads.
…And we also join the race
Bangalore and Delhi set the trend
Bangalore will be the first to deploy a Vehicle Tracking and Monitoring System for off-line monitoring of the buses operated by the Bangalore Metropolitan Transport Corporation (BMTC) and private operators. Bharat Electronic Ltd. is executing a project on a pilot basis. The first prototype will be ready by May end. BMTC has placed an order for 200 units at Rs. 20 lakhs. It has taken a sample of 200 buses plying in different routes of the metropolis.
A compact GPS based receiver unit mounted on the bus gets minute-to-minute information on its position. Recorded data can be stored for three days, before it is downloaded into the Central Control System (CCS). The CCS contains a GIS based map of Bangalore with roads, bus routes, stops, shelters, etc. as fixed information. The dynamic information collected through the bus mounted GPS is then juxtaposed on the GIS data and several useful interpretations are generated for the use of the BMTC.
If Delhi government has its way, the 7,000 odd yellow-black taxis will be replaced by 5,000 yellow-striped cabs connected by wireless — an air-conditioned taxi will be a phone call away. These taxis will be either Marutis or other high-end cars equipped with GPS. The Delhi Government has also decided to give a face-lift to Delhi’s bus stops. In a Rs.4-crore project starting next month, 100 bus stops in all nine districts of Delhi will be given electronic boards that, connected to the GPS on buses will provide the position of a bus on a particular route.
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