RadioBanter - Visualizing radiation pattern

Dear Jim (KC7JFV):

I am surprised that Richard Clark's useful comment was not augmented.

A projection that is most helpful to the visualization of antenna
patterns is the Sanson-Flamsteed projection. It is an equal area type of
projection sometimes called the sinusoidal projection. I first saw this
projection being used in the classic antenna pattern book published by the
ITU in the 1950s. Its usefulness is awesome.

The idea of this projection is simple. The (new) y-axis is equal to the
elevation angle (above horizontal) of the antenna's pattern. This is often
expressed as y = latitude.
The (new) x-axis is equal to the azimuth either side of a particular azimuth
(usually selected as the azimuth containing the peak antenna radiation)
times the cosine of the elevation angle. This is often expressed as:
x = longitude times Cos(latitude).

Keep in mind that the latitude/elevation angle must be expressed in
terms of a type of angle (degrees, radians, grads, etc.) that is compatible
with the available Cosine calculator.

The projection is not a device, but it is a means for visualization that
I have found over some 50 years to be ideal.

73 Mac N8TT

--
J. Mc Laughlin; Michigan U.S.A.
Home:
"Richard Clark" wrote in message
...
On 5 Mar 2005 18:26:21 -0800, (Jim) wrote:
Is it only my dream or such device really exists?

Hi Jim,

Not a device, but rather from modelers and Mathcad:
http://home.comcast.net/~kb7qhc/ante...elds/index.htm

Select the antenna of choice to see the "xray" you speak of.

73's
Richard Clark, KB7QHC