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These images have been chosen for their uniqueness. Subject matter ranges from
historic events, to really cool phenomena in science and engineering, to relevant
place, to ingenious contraptions, to interesting products (which now has its own
dedicated Featured Product
category).
When a structure is measured for an official
height, it includes every part of the structure - including the antenna(s) and support
mast(s) that is(are) almost always included at the very top. Take the current height
record holder, the Burj Khalifa, in Dubai, for instance. The overall height of the
structure including the antenna is 828 meters; however, the antenna is 207 meters
tall, so the building itself is only 621 meters. As can be seen from the chart below,
only two pure antennas (including support mast) are included in the world's tallest
structures. Antennas are used for television, radio, data, and even optical transmission.
If you read
Arthur C. Clarke's article in the October 1954 edition of Wireless
World where he conceived of a geosynchronous satellite system to broadcast television
signals rather than using a series of terrestrial towers, it is apparent why even
using antennas at heights like the one on the Burj Khalifa would not even come close
to providing coverage needed for the entire earth. The following table gives the
line-of-sight*, including earth curvature, range for each antenna (assuming maximum
specified height). With an earth circumference of 40,000 km, you would need nearly
700 towers just to provide continuous coverage along the equator. A few thousand
would be required for global coverage. The logistics for construction, maintenance,
and operation of such a network would be daunting... if not impossible. Imagine
the aerial navigation that such an array would pose!
*
Line-of-Sight Calculator** "...we wanted
to create a 'female' tower being complex, transparent, curvy and gracious."
![Graph of World's Tallest Structures - Including Antennas - RF Cafe](images/worlds-tallest-structures-antennas.jpg) Graph of World's Tallest Structures - Including Antennas
Well, this started out being about pictures of high antennas (i.e., Cool Pic),
but it kind of evolved into a little more.
Posted July 11, 2011
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