# Build array

## Visualization of Array Reponse

**build_array** ia a graphical interface for simple visualization
of the array response function for a specific array geometry.
The array reponse function is computed on a regular cartesian grid
in the wavenumber domain by evaluating:

Here, is the position vector of sensor i in
a cartesian coordinate system, the imaginary unit and
the *true* wavenumber vector of a single
plane wave.
As most seismological array applications are restricted to the
deployment of sensors on the earth's surface, the above equation
is evaluated in the horizontal plane, i.e.
and (horizontal wavenumber vector).

The evaluation of the array reponse function is simple, still the limits of the wavenumber range as well as the desired resolution for the grid computation needs to be specified. The resolution needs to be sufficient high in order to not miss small details of the peaked surface and the size of the grid should allow to determine the position of grating lobes or strong secondary side lobes in the 2D surface.

--Mao 20:25, 31 October 2008 (UTC)