Standard linear array

A standard linear array (SLA) is a linear array of interconnected transducer, e.g. microphone or antenna, elements where the individual elements are arranged in a straight line spaced at one half of the wavelength of the intended signal to be received and/or transmitted. The reason for this spacing is that it prevents grating lobes in the visible region of the array. Intuitively one can think of a linear array of elements as spatial sampling of a signal in the same sense as time sampling of a signal. Per Shannon's sampling theorem, the sampling rate must be at least twice the highest frequency of the desired signal. The analog of radian frequency in the time ___domain is wavenumber in the spatial ___domain. Wavenumber, ${\displaystyle k={\frac {2\pi }{\lambda }}}$ radians per meter. Therefore the spatial sampling rate, in samples per meter, must be ${\displaystyle \geq 2\times {\frac {k}{2\pi }}}$. Therefore the sampling interval, in meters per sample, must be ${\displaystyle \leq {\frac {\lambda }{2}}}$.