Grumman-581 wrote:
"Antoņio" wrote in message ...
I'm not sure of what that remark means.
The earth is round... Radio travels line of sight, which means a straight
line...Draw a large circle with a protractor... Choose a point on the
circumference at the top of the circle... Draw a line tangent to the circle
through this point... The line is horizontal... If an object is above this
line, it will be able to 'see' the original point, if it is below the line,
but above the circumference, it will not be able to 'see' the original point
since the body of the circle (i.e. the earth) is getting in the way of the
signal... The greater the distance the object is above the circumference of
the circle, the more of the circle it is able to 'see'...
Now, extend this concept into three dimensions...
That argument would be acceptable if the service volumes were increased
at regular rates as one increased in altitude. However, according to the
AIM, they do not. In fact the configuration presented is non-linear.
Once again I say take a look at the drawings in the AIM of the service
volumes. The distances that VOR's of varying service offerings are
depicted to offer is schematically represented as sort of like stacked
tires of differing sizes! Your linear geometric model explanation just
does not hold up to what is pictured there in the AIM.
Antonio
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