TABLE OF CONTENTS Within this text, far-field vector-pattern functions are tabulated almost exclusively using a regular azimuth over elevation spherical coordinate system. Although a regular direction cosine grid is a more natural partner for use with spectral techniques, this equatorial spherical system is adopted as it is commonly employed within other antenna measurement facilities. The choice is unimportant provided that the definitions and implications are understood. The schematic representation contained in Figure 5.16 contains a comparison of the spherical angles azimuth, elevation and ?, ?. Here, the line OR lies within the xy-plane whilst the line OQ lies within the xz-plane, RP is parallel with the z-axis and QP is parallel with the y-axis.
An alternative arrangement is illustrated in Figure 5.17. Here, OS is the projection of P onto the yz-plane, Az (termed ? to avoid confusion in the mathematics) is the angle between OS and OP and El (termed ? to avoid confusion in the mathematics) is the angle between the z-axis and OS. In both of these cases, the observer is assumed to be standing behind the antenna looking in the positive z-axis, of the antenna coordinates thus as the y-axis is vertical and is directed up, this means that to have a right-handed set, the x-axis must...
