Spherical basis vectors in 3-by-3 matrix form

`A = azelaxes(az,el)`

returns
a 3-by-3 matrix containing the components of the basis$$({\widehat{e}}_{R},{\widehat{e}}_{az},{\widehat{e}}_{el})$$ at
each point on the unit sphere specified by azimuth, `A`

= azelaxes(`az`

,`el`

)`az`

,
and elevation, `el`

. The columns of `A`

contain
the components of basis vectors in the order of radial, azimuthal
and elevation directions.

MATLAB^{®} computes the matrix `A`

from
the equations

A = [cosd(el)*cosd(az), -sind(az), -sind(el)*cosd(az); ... cosd(el)*sind(az), cosd(az), -sind(el)*sind(az); ... sind(el), 0, cosd(el)];