MATLAB: Does the Azimuth pattern look wrong

Antenna Toolbox

My Azimuth plot is different depending on the elevation levels inputted. For example, if you execute the following lines, you see that the graph at elevation 0 is different for each.

d = dipole
patternAzimuth(d,70e6,[0 45])
patternAzimuth(d,70e6,0)

Why is one a circle, while the other is a figure 8 when they should both be the same graph?

Best Answer

Both graphs represent the same data. What changed between the graphs is the axes.

In the figure 8 formation graph, the axes are such that the outer ring is 2.11 and the inner ring is 2.1. If this data was plotted on a normal polar plot, the data would look circular. If you look at each individual data point on both graphs, the data is the same, even though the shape of the graphs has changed.

Related Solutions

MATLAB: Vectorize the code in azimuth calculation.

I don't have the mapping toolbox, so I'm just relying on the documentation to write my answer.

For a start, you can replace the inner loop with:

AzimuthPoints(ii,ii+1:end)=azimuth('rh',lat(ii),long(ii),lat(ii+1:end),long(ii+1:end));

I believe the following may work to replace both loops (and the AzimuthPoints declaration)

[lat1, lat2] = meshgrid(lat);
[long1, long2] = meshgrid(long);
AzimuthPoints = azimuth('rh', lat1, long1, lat2, long2);

The downside of this method is that it's going to calculate the whole AzimuthPoints matrix, not just the upper triangle, so it may actually be slower.

You could do:

lat1 = triu(lat1, 1);
%same with lat2, long1 and long2

to replace the lower triangle and main diagonal with zero, on the assumption that calculating

azimuth('rh', 0, 0, 0, 0)

is faster.

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Hi Philip,

When you pass in ang = [0 180], it is considered as two angles, az = 0 and az = 180. if you pass in ang = [0;180], then it is one angle pointing at az = 0 and el = 180.

HTH

Best Answer

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