Communications satellites are nothing but radio transmitter/receivers ('transceivers').
Whether it's a direct-to-home TV satellite, an orbiting satellite carrying amateur radio (OSCAR),
or a Hubble Space Telescope, people on the ground transmit radio to it, and the satellite either
repeats the same information back down to other people, or performs some operations of its own
and then reports its results by radio to the people down below waiting for the report.
What signal does GPS use
There are currently 27 global positions system (GPS) satellites in orbit around the earth. Of these, 24 are active and the other three act as backups. Each satellite transmits a regular GPS signal that is carried by radio waves in the microwave part of the electromagnetic spectrum.
Each GPS satellite continuously broadcasts a navigation message at 50 bits per second on the microwave carrier frequency of approx 1600 MHz. FM radio, for comparison, is broadcast at between 87.5 and 108.0 MHz and wi-fi networks operate at around 5000 MHz and 2400 MHz. More precisely, all satellites broadcast at 1575.42 MHz (this is the L1 signal) and 1227.6 MHz (the L2 signal).
The GPS signal gives the precise "time-of-week" according to the satellite's onboard atomic clock, the GPS week number and a health report for the satellite so that it can be discounted if it is faulty. Each transmission lasts 30 seconds and carries 1500 bits of encrypted data. This small amount of data is encoded with a high-rate pseudo-random (PRN) sequence that is different for each satellite. GPS receivers know the PRN codes for each satellite and so can not only decode the signal but distinguish between different satellites.
The transmissions are timed to begin precisely on the minute and the half minute as indicated by the satellite's atomic clock. The first part of the GPS signal tells the receiver the relationship between the satellite's clock and GPS time. The next chunk of data gives the receiver the satellite's precise orbit information.
Electromagnetic radiation in the form of radio waves allows the ground unit to 'communicate' with the satellites of the GPS system - to ascertain its position on earth relative to their positions in space.
The Applied Electromagnetics Laboratory crew has been working on having minimal lateral radiation waves. Not much radiation is being emitted from a Global Positioning System (GPS). Check here for more information: http://www.egr.uh.edu/ece/research/?e=ael
Gu-libble waves are used to transmit GPS wave signals, the approximate wave length of a gps signals are upto 7Km.
Radio waves at two frequencies, near 1.23 GHz and 1.58 GHz.
Microwaves or radiowaves
GPS uses an electromagnetic radio wave.
Meteroligical satellite
overshooting top
satellite
landsat satellite
Geostation is similar to satellite but it forecasts the weather. You better ask a meteorologist about that. It is even one of the 'unknown word', try to type Geostation. That's all I know.
Gamma rays
parabolic
Electromagnetic energy
Radio waves.
Gamma rays.
Microwaves. These poke through the ionosphere to reach the satellite
It is communication with a satellite orbiting the planet using microwaves, a type of electromagnetic wave of lower frequency than light but higher frequency than radio waves. Microwaves are often used in this way as they can penetrate the earth's atmosphere, but can travel a long enough distance to reach the satellites, unlike x ray waves.
There are several uses of satellites which depends on the particular type. In most cases, they are used for space exploration, communication of signals, navigation and astronomical ventures among others.
radio waves (part of the electromagnetic spectrum)
radiation
Communication Satellite, launch and used by Philiipines
introduction of satellite based communication