solar fade
(n.) Also referred to as sun fade, sun outage or solar outage, a signal degradation phenomenon that affects the transmission of radio signals in satellite communications.
GEO satellites orbit the earth above the equator and rely on microwave signals in the radio frequency spectrum for communications with an earth-bound antenna. The sun also emits large amounts of electromagnetic energy in the microwave portion of the spectrum. Through the majority of the year, the radio frequency energy from the sun does not affect satellite communications. However, during the spring and fall equinoxes the sun is positioned above the earth’s equator (in the equatorial plane) and therefore will align itself behind the GEO satellites as they move with the earth’s rotation. When the sun is directly behind a satellite the radio signals of the satellite communications are overpowered by the sun’s radio frequency energy, creating noise, and the communications are therefore disrupted.
Signal interference only occurs once a day for any satellite and usually lasts less than eight minutes, though many factors, including antenna size and downlink frequency, effect the duration and intensity of the solar fade. The exact date and time of solar fade is different for each satellite. Many satellite operators have solar fade calculators accessible on the Internet.
Read Also:
- solid ink-jet printer
A type of color printer that works by melting wax-based inks and then spraying them on paper. Solid ink-jet printers produce very vivid colors and can print on nearly any surface. Early models of solid ink-jet printers were quite slow and expensive. Today however you can purchase color office solid ink-jet printers in and around […]
- Solid State Disk
Abbreviated SSD, a solid state disk is a high-performance plug-and-play storage device that contains no moving parts. SSD components include either DRAM or EEPROM memory boards, a memory bus board, a CPU, and a battery card. Because they contain their own CPUs to manage data storage, they are a lot faster (18MBps for SCSI-II and […]
- Solus Email Marketing
Solus email is a term used in the email marketing industry. A solus email is a third-party advertisement that is sent to an opt-in subscription email list that is comprised of demographics of target consumers that the third party wants to advertise to. An example of a solus email marketing would be for the owner […]
- sound card
An expansion board that enables a computer to manipulate and output sounds. Sound cards are necessary for nearly all CD-ROMs and have become commonplace on modern personal computers. Sound cards enable the computer to output sound through speakers connected to the board, to record sound input from a microphone connected to the computer, and manipulate […]
- source
(1) A place from which data is taken. Many computer commands involve moving data. The place from which the data is moved is called the source, whereas the place it is moved to is called the destination or target. If you copy a file from one directory to another, for example, you copy it from […]