By Fred Nwaozor
A
satellite is a celestial object or spacecraft that orbits another object while
serving for a particular purpose. It could be natural or artificial (manmade).
The Moon is a good example of a natural satellite
that orbits the Earth. The world’s first ever artificial satellite – the
Sputnik 1 – was launched by the Soviet Union in 1957. Since then, countless
satellites have been launched into the Earth’s orbit.
So
far, about 6,600 satellites have been launched by different countries around
the globe. Survey shows that, by 2013, 3600 of them remained in orbit. Among
these, only about 1,000 were operational, whilst the rest have lived out their
useful lives and thus become mere space debris.
Research
further indicates that approximately 500 operational satellites are in
low-Earth orbit (at about 2000km altitude), 50 are in medium-Earth orbit or
intermediate circular orbit (at about 20000km altitude), and the rest are in geostationary
orbit (at about 36000km altitude).
It’s worth noting that satellites are used for
many purposes. Common types include the weather satellites, navigation
satellites, military cum civilian earth observation satellites, communications
satellites, and space telescopes.
Moreover, space stations and human
spacecrafts in orbit are equally known as satellites. This discussion, as long
as it lasts, would border on communications satellites, particularly ‘television
satellite’ as the topic implies.
A communications satellite, which is purposely
deploys for telecommunications, is an artificial satellite that relays and
amplifies radio telecom signals via a transponder. It creates a communication
channel between a source transmitter and a receiver at different locations on
the Earth.
It is used for television, radio,
internet, telephone, or military applications, as might be the case. There are,
at the moment, over 2,000 communications satellites in the Earth’s orbit, used
by both private and government organizations.
Wireless communication via television, for
instance, uses electromagnetic (EM) waves to carry signals. These waves require
line-of-sight, and are thus obstructed by the curvature of the Earth. The prime
purpose of communications satellite is to relay the signal around the curve of
the Earth allowing communication between widely separated points.
A communications satellite uses a wide
range of radio and microwave frequencies. To avoid signal interference, international
bodies have regulations for which frequency range, or band, any firm is allowed
to use.
Specifically, Television (TV) satellite
delivers TV programming using signals relayed from space radio stations. The
signals are received via an outdoor parabolic reflector antenna often referred
to as a satellite dish, and a low-noise block (LNB) down-converter.
A satellite receiver then decodes the
desired TV programme for viewing on a TV set. The receiving device can be in
form of an external set-top box known as ‘decoder’, or a built-in TV tuner. On
TV satellite, some transmissions and channels are unencrypted, hence are
free-to-air or free-to-view, whilst many other channels are transmitted with
encryption requiring a subscription.
Most
homes these days are set up for Cable TV, though there’s a growing number who
have opted for the more advanced Direct Broadcast Satellite (DBS) TV commonly
called ‘Satellite TV’. With newer technologies in satellite broadcast being
developed, it has apparently overtaken cable pattern of broadcast. Meanwhile,
there are two sides to satellite TV that you should consider before cutting
your ties with cable provider.
Satellite TV has access to a wide range of
channels and services, especially in geographic areas without terrestrial/cable
TV. The ability to receive and send broadcast signals using satellite tech
increases the possibilities of gaining access to channels from other countries
that utilize similar tech for broadcasting. Hence, you are not restricted to
only the channels on cable networks. DBS TV has high-quality audio and picture
display compared to cable TV.
DBS TV
possesses parental lock-out options. It takes the worry out of parents who are
concerned at what their kids are watching while they are away. Most DBS TV
receivers are now able to block certain channels from a TV set.
It equally has WebTV option, contrary
to cable TV that does not. Internet data can be transmitted wirelessly, thus
DBS TV can receive internet service from your TV set. In addition, it has
digital video recorders. With some satellite TV receivers, one can record
shows/programmes directly to a hard-disk drive for playback later.
However, for initial investment, the receiver
and satellite dish could be exorbitant. Similarly, multiple TV sets would
require multiple receivers unlike in the case of cable TV, thereby making both
installation and sustenance very expensive if one has more than one TV set at
home.
Its installation techniques, which
involved many technologies, might attract additional charges. Above all, DBS
can malfunction in bad weather. Since the satellite dish is usually located
outdoors, it becomes susceptible to malfunction owing to atmospheric conditions
like rainfall, strong winds, snow, or lightning, or what have you. For instace,
thunderstorm could pose a threat to, or even completely damage, the receiver.
However, it’s noteworthy that
obtaining high quality products could help to curtail or prevent any of these
anomalies. Hence, we are advised to invariably opt for products manufactured by
reliable firms whenever we intend to upgrade our viewing pleasure. This
precaution can best be adhered to by involving an expert when need be.
Whatever the case might be, the fact is: TV
satellite remains the best mode of radio cum micro waves transmission. But it’s
pertinent to note that its installation and day-to-day maintenance require
sound and adequate professional attention. Think about it!
frednwaozor@gmail.com
Twitter: @mediambassador
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