# Dictionary:Fig F-11

FIG. F-11.
*f,k***plot**. (**a**) The region passed by array, frequency, and velocity filters is cross-hatched. Radial lines through the origin represent constant apparent velocity *V*_{a} (*V*_{a}=*f*/*k*=ω/κ). (**b**) Data beyond the Nyquist wavenumber *f*_{N} (determined by discrete spatial sampling) **wraps around** (**aliases**) and may get mixed up with the signal. In wraparound, data to the right of +*k*_{N} continues rightward from –*k*_{N}, where *K*_{N} is the Nyquist wavenumber.