Global Positioning System Satellite Transmissions

[carlcuper]

Global Positioning System, or GPS, navigation gets its transmission from GPS satellites. These systems act only as receivers; they cannot transmit signals. They require an unobstructed view of the sky to receive signals, so they are more functional outdoors. While on the road, motorists may be in areas where tall trees stand close to each other, creating a canopy that blocks the view of the sky, or you may travel to a city crowded with tall buildings. Under these conditions, the GPS navigation has trouble receiving transmissions. Each GPS satellite transmits data containing the time, precise orbital information, the general system health and rough orbits of every GPS satellites. The receive, in turn, interprets this data.

[jsmthjsmith83]

Nowadays the Gps system are more useful to track vehicles as well as exact location
of the person,with the help of the Gps we can find the right way due to forget the way
the system also use in communication field for finding better coverage as well as finding
information about weak coverage area or remote area,there are many vehicles with inbuilt
Gps system.

[smithdsouza]

Gps can also be used for mobile tracking. It can track the position by calculating it's distance from itself and three or more gps satellites. By measuring the time delay between the transmission and reception of the each gps radio signal it can give distance to each satellite. The signal also has information about the satellite position so one can track the position easily.

[jhonnymarsh]

The L5 signal is a key element of efforts to modernize the GPS constellation for civil users. It was designed in close coordination with civil aviation and other organizations worldwide and is transmitted in a frequency band protected for safety-of-life applications.

[Gurese]

A satellite transmission capturing method for the GPS receiver whereby PLL operation is stopped until the demodulation intensity of a demodulator reaches a predetermined level. The frequency of the reproduced carrier of the demodulator is consecutively changed in increments of a frequency range wider than the PLL capture range in search for satellite transmissions. This allows the demodulation intensity to reach the predetermined level in fewer frequency changing steps than ever before. Thus the time required to capture the desired satellite transmission is reduced. Where the integral time constant of a low pass filter in the demodulator is set to a value smaller than that in effect during PLL operation until the demodulation intensity of the demodulator reaches the predetermined level, a wide band demodulation intensity curve is used in search for satellite transmissions until that level is exceeded. This further widens the frequency range in which to search satellite transmissions, and the time required to capture the desired satellite transmission is further shortened accordingly.